Nowadays, Virgin Atlantic is among life and death. They’ve just announced its Gatwick base closure and a plan to cut up to more than 3.000 jobs. How this emblematic airline was started up?
Virgin Atlantic is on the verge of disappearance if there is no investment from its owners. It’s a very well-known because of his founder, Richard Branson, a charismatic businessman who allowed his trademark “Virgin” was globally known, creating a relationship between a successful trademark and a successful man.
It’s ironic Virgin leaves Gatwick, the airport where it took off for the first Virgin commercial flight in June 22 of 1.984 to New York Newark. On that maiden flight, the B747-200 registered G-VIRG, “The Maiden Voyager”, took off with Richard Branson himself, other famous people and media on board. They installed a screen in the cabin, so passengers were able to watch take off from their seats. In the image they could see both pilots and the flight engineer having a relaxing chat, meanwhile the airplane was speeding the runway. As soon as the nose of the airplane lifted up, both pilots turned to the camera and people realised they were two famous cricketers, and the flight engineer was Richard Branson himself. They recorded the video during previous day in a simulator. The airline was profitable in the first year of operation.
The beginnings were never easy.
The first contact Richard Branson had with aviation, took place during holidays with his family. That day, Richard and his wife, Joan, were heading to Puerto Rico after spending some days in Virgin Islands to connect with other flight. However, when they arrived at the airport, their flight had been cancelled. He soon realised there were other stranded passengers around with the same problem and called an air charter company. Their flight to Puerto Rico would cost $2.000. Richard borrowed a little blackboard and wrote: “Virgin Airways, $39 single flight to Puerto Rico”. After walking around the terminal could filled in the plane. 6 years later, Virgin Atlantic would see its maiden flight. However, was not as easy as that.
Randolph Fields, an american lawyer, had founded British Atlantic Airways with an ex-pilot from Laker Airways. In 1.983, the Virign Group was looking for investments to diversify their Business and Fields got in touch with Branson as a potential investor in his airline. After a year, in February 1.983, Virgin and Fields were equally partners of Virign Atlantic Airways. Nevertheless, Virgin Banks requested Virgin to have most of stakes to control the airline. Fields then reduced his ownership percentage to a 25%, and Virgin would have the 75% of the airline.
British Caledonian, lodged an objection to Virgin Atlantic license application and, soon Fields would be involved in a hearing with CAA (Civil Aviation Authority), questioned about emergency drills, maintenance and financing. The project was still an idea on paper. Richard Branson showed up himself in front of CAA to demonstrate the financial viability of the airline. CAA showed sceptical about Field’s ability to manage the airline and imposed a minimum of £3 million working capital. Virgin had to deal with some tripping, known as “Dirty Tricks Campaign”, orchestrated by British Airways.
The troubled flight test.
After long and difficult negotiations with Boeing, they finally got an agreement to lease a B747-200 for one year. The airplane, which came from Aerolíneas Argentinas, should do a flight test, a non-commercial flight with a CAA official on board to obtain its awaited operator license.
For this flight, carried the new flight attendants, one hundred of Virgin staff and Richard Branson who was seated on last row with CAA official. Everything was normal involved in a happy atmosphere… until a loud bang with a bright flash coming from one engine leaving a track of black smoke, silenced the cabin. The airplane had ingested a flock of birds. Amid a stunned silence, the CAA officer put his arm around Branson’s shoulder and said: “Never mind, Richard, these things happen”.
Inaugural flight was three days after this incident, and they have no license yet. Roy Gardner, Virgin’s chief of engineering installed the new engine and was ready for the next day for the flight test in a record time. However, there was a cost for Virgin of £600,00 because insurance only covered for an engine damage under an operator license.
Virgin, as every passenger airline in the world is a victim of current context, and it’s facing a very difficult situation, again. Virgin Will leave Gatwick, whose volume of operation will be affected. British Airways, Norwegian, Thomas Cook and Virgin all have a share of almost 33%. At least Wizzair will increase its presence in the airport.
At the same time, Virgin Atlantic will ground all 7 B747-400 left, airplane which grew with the airline after B747 classic were retired. Besides this, Virgin will ground 4 A330 before 2.022. Virgin currently operates a mixed fleet of 42 airplanes, A330, A350, B747 and B787. Amongst its 33 destinations, fly mainly to caribe, United States and Asia.
Maybe Virgin will overcome its destiny and will be able to come trough thanks to a new investment. With disappearance of Virgin Australia, Virgin America’s acquisition by Alaska airlines, is the only Virgin airline which remains in the sky.
Prototype will advance Boeing’s global Airpower Teaming System.
A Boeing – led Australian industry team has presented the first unmanned Loyal Wingman aircraft to the Royal Australian Air Force, a historic milestone for the company and the Commonwealth.
The aircraft, which uses artificial intelligence to extend the capabilities of manned and unmanned platforms, is the first to be designed, engineered and manufactured in Australia in more than 50 years. It is Boeing’s largest investment in an unmanned aircraft outside of the United States.
As the first of three prototypes for Australia’s Loyal Wingman Advanced Development Program, the aircraft also serves as the foundation for the Boeing Airpower Teaming System (ATS) being developed for the global defense market.
“This is a truly historic moment for our country and for Australian defence innovation,” said the Hon. Scott Morrison MP, Prime Minister of Australia. “The Loyal Wingman will be pivotal to exploring the critical capabilities our Air Force needs to protect our nation and its allies into the future.”
Air Marshal Mel Hupfeld, Chief of the Royal Australian Air Force, said the rollout of the first aircraft was a significant milestone in the Boeing Loyal Wingman project.
“This project is an excellent example of innovation through collaboration and what can be achieved working together with defence industry,” said Air Marshal Hupfeld. “This demonstrates the importance of the relationship Air Force has with Boeing Australia and defence industry more broadly. I look forward to exploring the capabilities this aircraft may bring to our existing fleet in the future.”
More than 35 members of Australian industry are supporting prototype work across four Australian states. With a global market demand for highly capable but extremely affordable unmanned aircraft, Boeing applied company-wide innovation to achieve those goals. The aircraft was engineered using a digital twin to model its structures, systems, capabilities and full life-cycle requirements; manufactured with Boeing’s largest-ever resin-infused single composite piece; and assembled using proven advanced manufacturing processes.
“We are proud to take this significant step forward with the Royal Australian Air Force and show the potential for smart unmanned teaming to serve as a force multiplier,” said Kristin Robertson, vice president and general manager of Autonomous Systems for Boeing Defense, Space & Security. “We look forward to getting the aircraft into flight testing and proving out the unmanned teaming concept. We see global allies with those same mission needs, which is why this program is so important to advancing the development of the Boeing Airpower Teaming System.”
The Loyal Wingman prototype now moves into ground testing, followed by taxi and first flight later this year.
Airlines with almost their whole fleet grounded, are struggling to survive. It’s about time to ponder and to create new strategies. However, customers may have changed their product demand.
Airlines: Their cash, their survival.
Obviously, airline’s business is to transport passengers and/or cargo from one place to another. However, situation forced airlines to keep almost their entire fleet on ground. In some cases, all of them. Then, Airlines are burning money everyday. Lufthansa, for example is losing $1 million a day! Thei first task is to keep their savings as longer as possible. It’s is as difficult as to try to stop time.
Some measures will allow airlines to alleviate, just a little, their costs. Some airport managing companies such as Aéroports de Paris, London Heathrow managed by Spanish company Ferrovial, or Amsterdam’s airport, have suspended airport taxes. With exception for Spain in all airports managed by AENA. Besides, to allow airlines to keep their SLOTS given to fly between airports, European Comission has suspended the rule which results mandatory to use at least 80% of them. This will prevent Airlines of flying empty trying to keep their SLOTS. However, almost all mitigating measures will be done by airlines.
As mentioned before, any port in a storm for airlines will be keeping their cash savings. Depending on how “fat” before the crisis they were, will allow the airline to keep their cash for a little longer. In other words, structural costs, debt in short to medium term, and excess of staff. The amount of cash has to be translated into time, so Lufthansa’s group, one of the most solid in cash terms before crisis commenced, around $4.7 billion, requested state aid to Germany.
Government intervention has been considered of crucial importance for some airlines. Air Europa which drags a great debt before storm, secured a credit from the Spanish state to hold their heads above water level while they’re looking forward their acquisition by IAG as a rescue boat. Acquisition which is still pending from European authorities to be cleared. On the other hand, Air France and KLM has secured €7 billion aid from their respective governments. Alitalia, is the most remarkable cases after being nationalised.
State aids look like panacea initially, but they are a double-edge sword. Aids have many dealt conditions implicitly attached. Firstly, there is no doubt they are big credits, in high risk conditions and must be given back. In other words, they are a financial cost which will affect to airline’s operating margin. Even more in a not favourable context. Secondly, but not least important, state’s intervention. This could come up with many options such as to impose decision more political than technical, or to give a seat in the council of the airline. In any case, it could be “uncomfortable” to allow an outsider interferes in airline’s decisions.
With this concerns CEO of IAG, Willy Walsh, has seriously considered other option before asking for certain state aid. Lufthansa, on his side is considering to choose between insolvency and state aid.
Post COVID-19 scenario.
The economy’s predictive signs for this year were not very promising from the beginning of the year. A downturn was also expected in some countries though. Some airlines reported profit warnings for this year. The Chinese virus increased the economic downturn, and airlines were caught by surprise.
Some airlines are not expected to survive to this crisis. And for those who do it, will have to deal with a very weak demand. There will be less airlines to fight for a little cake. In many interviews and webinars, the airline CEOs concurred in the fact that we are facing to an unprecedented crisis in the whole civil aviation history. There is a certain level of confusion in how to act to an unknown scenario.
According to some analysts, air traffic will commence to raise in June. However, other scenarios were taken into account with different tendencies. The most favourable one would end this year a 15% below corresponding 2.019 result. How the airlines are going to face their sales strategy? How’s the customer going to behave when this crisis has passed? There are some questions what commercial departments wondered nowadays. The passengers are afraid of being infected instead of feeling fear to fly, so new necessities have to be taken into consideration by commercials in the airlines.
The new passengers.
From an economical point of view, there will be many jobs cuts thus travel expectation for many people will be reduced and airlines will lose possible customers. Putting this matter aside, let’s focus on some other matters which airlines never have taken into account before.
People, during confinement, have been working with telematic tools. They had to get used to it and maybe from now on they’ve found the way to avoid flying. A very important matter is how they will fly. Maybe passengers who need or want to fly, demand a more aseptic service, and their decision to choose the airline will be based in either the airline is “COVID-FREE” or not. Maybe passengers would not look for an airline with access to internet but to avoid being infected. Airlines will make great investments in to adapt to this new environment to their customers. The Low cost high density cabins could be affected.
We all payed attention to some recommendations such as leaving the middle seat free. In other words, airlines would leave 33% with no chance to put it in the market. To be able to be profitable, airlines would need to pass on to the ticket price. Then we should wonder how many passengers would be willing to pay the extra charge. The distance would never be the recommended one of 1.5 – 2 m between passengers… Michael O’Leary, president of Ryanair Group, rushed to make a statement about this measure, saying it would not be feasible for Ryanair to fly with middle seat blocked.
New cabin seat configurations have been disclosed to media. Some seats appeared alternatively looking to the front and to the rear and with screens as a divider. However, this screen could slow a possible evacuation, and then, to reduce the maximum certified number of passengers an airplane can carry. Its installation must be taken into account. Besides, it looks like a good solution, but its installation also needs more room than the conventional seats, so we would back to the previous paragraph… wasted space implies higher costs per seat. It needs to remind to install new cabin configurations requires great investments by airlines. It’s not like empty your living room and put new sofas instead the older ones. It needs technical documentation from the aircraft manufacturer, to install new wiring and collectors to organise toilets, galleys and In Flight Entertainment (IFE). If passengers are not demanding this kind of services, or if this demand is temporary, it would open a hole in airline’s financing. One more.
To avoid personal contact is the most effective measure. Using Individual Protection Equipment (IPE), such as masks and gloves, is generalised. Airlines have protection kits for passengers before boarding the airplane. However, it’s very common to find boarding cards from one hand to another or security screenings which not really avoid personal contact or need people very close to each other.
On board, in flight service have been drastically reduced to a minimum. In order to reduce airplane’s weight and to help with environment, many airlines moved their paper press to electronic one before Covid-19. Now, the appearance of brochures or magazines is even more reduced. Regarding meals and drinks, is also been reduced to a bare minimum, and they are given in closed boxes to avoid direct contact.
Emirates, made a procedure to do quick test before boarding to all passengers. This was tested on a flight from Dubai to Tunisia last April. Other airlines, for example, has improved some other measures like Iberia which has been successfully tested biometric boarding. However, airports have a lot to say about it. Airlines cannot make all the investment by themselves. Installation of infrared detection equipment to watch body temperature, screens between staff and passengers or airport health controls need to come from the airports side. It is a coordinated effort by all players involved.
Passengers got used to uncomfortable measure along history depending on the threat of the moment. Since 2.001, security measures have evolved and changing to prevent terrorist attacks. Now, health measures must to be taken to protect passengers from an invisible threat. It’s not only for their safety but because they demand this to feel safe to fly. Security measures are mandatory and on the other hand, health measures are most of them recommendations, and still not being regulated. This allows to airlines a certain free decision on how to apply these recommendations and to improve their own in order to differentiate from other airlines to bring customers to their “COVID-FREE” airline. Ironically, for low cost airlines is their cost based philosophy. Until now, low cost airlines follow the statement: “if it’s not mandatory is expendable”. Maybe, from now on Low cost airlines need to reconsider their service. A passenger may not see very favourable seeing flight attendants trying to sell masks or gloves on board, for example. However, if ticket price is low enough, fear we mentioned before could be appeased…
Airlines have adapted to customer’s necessities along years after turbulent periods of time. If not, they joined to big airline cemetery.
According to IATA statistics, passengers as time passes, expressed an increasing desire to fly again. This gives a hope to a moribund business. Maybe to offer extraordinary services are no longer needed, or these new services need to be removed sooner or later and everything go back to normality once passengers have forgotten their fears.
In my experience as a flight instructor and as a flight examiner, I’ve observed some PPL and ULM pilots reluctant to go-around. This misgivings about going around are more an attitude rather than aptitude. I’d like the reader, a pilot, could think about it.
The go around procedure is a relatively easy manoeuvre. Pilot needs to internalise the actions sequence in order to make it safely. Because when needs to be done, in most of cases is unexpected.
When a pilot makes the go around must to have clear in his mind the speed. Approach speed is a relatively low speed. At the same time, flap deflection is high, so it is the aerodynamic drag; and, when applying power on a single engine aircraft, the P factor must be counteracted to avoid a yaw at low speed, low altitude and high aerodynamic drag. This means, actions to be done are summarised in just three:
Apply power counteracting with rudder (P factor);
Raise flap to our desired position;
Nose up to fly the correct speed.
Even though the exact order of pilot actions may vary depending of aircraft’s procedures, as you can see, they’re only three simple actions. So, why do we make mistakes when we go around? What do we have to avoid making mistakes during its execution?
Despite having our manoeuvre very clear in our mind, there are some factors which divert our attention of what we’re doing.
Surprise is one of them. There is a technical term, “Startle factor”. If you watched “sully’s movie”, you’d probably would know what I’m talking about. When a pilot finds himself on a final approach and final checks completed, in his mind there is only one thing going through: To land. If in that moment, the tower instructs to go around, lasts an average of almost two seconds to realise what’s the tower’s instructions. This lapse of time is what his brain needs to assimilate an instruction “he was not mentally prepared for”.
In other scenario, very often too, just after receiving the go around instruction, controllers give you later instructions to follow after going around. i.e.: “RIS089G, after passing the tower, turn left and join left downwind…” Meanwhile, pilot is still doing first actions of the procedure. This could make pilot not to focus enough in what he’s doing or not to paying attention to controller’s instructions either.
It’s hard to some controllers to have a picture of what is the pilot’s workload after giving the go around instruction. But, pilot far from being distracted, must focus on making the manoeuvre and not to listen controller’s instructions until the procedure is completed. A distraction at this time could be fatal. To achieve this, there’s one thing pilot must do: TO FLY THE AIRPLANE. Nothing else. You can get a lot from just 3 seconds which lasts to execute the manoeuvre.
A typical error I observed, is to readback the go around instruction on the radio while you’re in the middle of the manoeuvre… There’s time enough to communicate, so first: FLY THE AIRPLANE. Pilot needs to prioritise his actions in an order to preserve safety:
Fly the airplane (focus on doing the manoeuvre);
Navigate (fly straight to overfly runway);
Communicate (“RIS089G, going around”).
We mentioned some of them previously. To keep yourself in good shape, pilots needs training. This helps to execute the manoeuvre without losing time thinking in how to do it, we interiorise our actions, and we reduce our mental energy, giving more capacity to other tasks.
How many of you remind yourselves how to perform a go around before commencing the approach, or when reading final checklist before landing? This is a good way to think about the go around, to remind ourselves how to do it, and what direction to proceed during this phase. To include it in our approach briefing keeps the procedure clear in our mind. It eases the surprise factor, but it remains though.
Distractions affect us. That’s with is recommended to follow our mentioned priorities: fly the airplane, navigate and communicate. In this way we’ll be able to avoid put the airplane in a risky attitude, going where we should go, and communicate to ATC what we’re doing is what we’ve been instructed to. In case a controller gets anxious, we might be tempted and paying too much attention to him instead of our airplane. We could put the airplane into an undesired situation… We’ll have time to kindly use the “SAY AGAIN” later.
When an airplane is coming to land, in pilot’s mind, the more the closer to ground the airplane is, the idea of landing is higher and higher. This desire rules out the not to land idea, closing a door to plan B: GO AROUND.
“Landing is a failed go around”.
We should reconsider the go around concept and put it in the other way around. At all times we have to perform a go around, but if the approach is flown inside a stablished profile, you continue until ground. Recently, a friend of mine, Miguel told me: “Landing is a failed go around”.
Pilots should deprive of the idea of going around is a shame. Landing when you should not, even when nothing happened, is a big mistake. Fatal in many cases. There are events of runway excursions because speed during approach was too high and after landing, brakes were not able to absorb the excessive energy and broke up. However, after a smooth landing… A go around was always able during approach.
I remember very well during a PPL exam, the student, during first attempted approach, the airplane was diverted from its trajectory due to a gust, when he tried to correct the airplane speed was too high. He felt so “uncomfortable” that initiated a goa round immediately. After landing I could read his concern on his face. He wrongly concluded his exam was failed do to his first approach. Far from that, I did congratulate him and even more, I encouraged to continue that way. “If you’d haven’t done it, I’d had to do it myself”, I told him. In that case we would have a different tone conversation.
Instructors have to make students, at the final stage of training, to be able to take their own decisions in order to keep safety of the flight. Is one of the signs which shows a student is ready to obtain his license. Is a process where we should let them to make mistakes and giving them tools to be able to decide. It’s curious, flying with some experienced pilots, when they are instructed to go around, tend to turn their heads to flight instructor in order to receive an approval sight. Go around instruction is an irreversible decision. So, it’s something that you do it first and discuss the reason later. It must be done with certain celerity and without hesitation.
It’s common in air clubs to find two similar experienced pilots in the same aircraft. It may happen, meanwhile one of them is at controls, the companion may feel a little uncomfortable during an approach… Do not hesitate. Cowards allways win here. If one of them see something the other did not, it’s better to go around instead of landing. The safest solution is: GO AROUND.
Remember, the best landing is not to do it. Have always in mind and don`t close the safest door, going around. It’s recommended to train its execution in the correct sequence and, one decision is made, it’s irreversible and we must complete it.
Finally, I’ve put a link of a very interesting video about an accident which happened in United States during a go around of a Cirrus aircraft.
In the afternoon
of April 13 of 1.918, Luis Cenobio Candelaria, an Argentinian pilot achieved
the milestone of flying over the Andes for the very first time. With his wooden
made monoplane Morane Saulnier Parasol, mounting an 80 HP piston engine, had to
face strong winds. At that time, the results of these winds could cause on an
aircraft flying over the Andes were unknown. Mountain wave is the result of
2.019. Flight Madrid – Santiago de Chile.
We are in
the briefing area in order to prepare our flight from Madrid to Santiago de
Chile. Our airplane is an A340-600X and we have an expected take of weight
close to 373 tonnes. Quite different to Candelaria’s Morane. During briefing,
Captain makes a special question which is not made in other flights: “How is
it over the Andes?”
is very large mountain range which extends along South American continent. On
the occidental side of the continent besides Pacific Ocean. It’s 8.500 km long
with an average altitude between 3.000 and 4.000 metres above sea level. The
Aconcagua is the highest peak with nearly 7.000 metres. This big natural wall
causes very often turbulences, severe in certain occasions due to a phenomenon
called Mountain wave. Specially in the area between Chile and Argentina. Let’s
see what’s the mountain wave is and how to prevent it.
quite smooth. Wind, temperature, pressure difference… But, let’s go back the
beginning. Why is this data necessary? What is the mountain wave? Why should we
wave are great air oscillations on the leeward side of a high elevation as a
result of horizontal air mass movement disturbance over the high terrain
elevation. To make a picture of the size of this phenomenon, these disturbances
can reach hundreds of kilometres horizontally and to reach tropopause
vertically. Mountain wave is associated with turbulence, from light to severe.
In other words, when winds blow over an elevation creates oscillations on the
other side of the elevation. When oscillations are larger, break off and create
areas of turbulence. That’s is the reason why we should know how to prevent it.
factors are necessary for a mountain wave to exists. Already mentioned before,
it’s the most contributor factor of all, the existence of perpendicular wind to
the mountain range. Depending on size of the elevation, from 15 to 25 knots is sufficient.
necessary a certain atmospheric stability. Stability forces the air to climb on
the windward side of the mountain and it’s also forced to descend on the
leeward side. Because of its stability, when it’s “pushed” downward creates a wave
on its way. If this air reaches a certain speed, it can break away from the up
and down air waves having as result the “rotors”.
Rotors are kind
of circular air movement which are the main cause of severe and extreme
turbulence. A very famous case was when a B52 of U.S. Air Force was caught
close to the Rocky Mountains, in the area of Kansas and lost its vertical
stabiliser. Miraculously, they achieved an emergency landing with no further consequences.
wave is not always visible. If humidity is enough, clear signs of mountain wave
like clouds, makes this possible. When there isn’t, there are diagram to
prevent it like Graphic of Harrison in the Andes, so the turbulence could be foreseen.
case, when analysing wind chart in different levels, it’s easy to see if there
is a perpendicular wind to a mountain range and its intensity, so we can expect
some turbulence. If the wind speed it’s moderate and there is enough atmosphere
stability, the clouds shape “stylizes”, turning into the well known as lenticular
clouds. It’s very usual to find temperature inversion in this area. In fact, we
can see sometimes some stationary clouds on top of the others due to different
wind layers. These are a very representative type of clouds, and they’re located
on the crest of waves. They can reach 9 kilometres high easily.
In some occasions,
on the windward side the air is forced to climb the slope of the mountains
which condenses, creating cloudiness up to the crest. Nimbostratus and
cumulonimbus are the most typical type of clouds, covering totally or partially
the lenticular clouds in the lower layers. It’s likely to find icing accretion
at these levels before reaching to leeside.
Once on the
leeside, the air is forced downward the slope and clouds dispel, creating the
Föehn wall or cloud-cascade. However, in the upside of the air wave, a little
further away from the mountain, air condenses again creating little cumulus or
cirrus type clouds. As mentioned before, if wind is strong enough wave brakes
away from the rest of waves and creates rotors clouds. This rotor cloud looks
like a twisting movement cloud, causing sensation of circular movement by appearing
and disappearing. This type of cloud is Cirrus and, you’d better keep away from
them, sinking air prevails over lifts.
documented accidents due to this phenomenon, took place in Spain in 1.953. A
Bristol 170 Freighter Mk21 (EC-AEG) of Spanish airline Aviaco was flying from
Bilbao and Madrid when they encountered mountain wave and crashed. In an aviation
meteorology book, authors Manuel Ledesma and Gabriel Baleriola, published a
letter fragment written by Captain Cañete about weather conditions found flying
before, and during accident. Captain describes in great details all weather
phenomenon found, relating to mountain wave concepts clearly with no doubts at
Andes mountain range.
Andes have the highest peaks in the world. To fly over them is a daily
To fly over
Andes to/from Santiago de Chile from the Argentinian side is the most difficult
one because all mentioned factors affecting are more significant, specially
between Mendoza and Santiago. In fact, Aconcagua, the highest peak is in this
area. Prevailing winds, coming from west blow on Andes perpendicularly and increases
probability of turbulence.
Due to these
local peculiarities, some studies helped to develop procedures to anticipate and
to avoid mountain wave. Graphic of Harrison is one of them.
This is a
graphic used to obtain a reference of turbulence intensity comparing the
pressure difference (abscissa axis) between two sides of mountain range, Santiago
de Chile and Mendoza, and wind at 18.000 feet (ordinate axis) in Juan Fernández
archipelago located 450 NM west of Santiago de Chile. This is, the greater
pressure exists on the leeward side, and the lower in windward side, it’s
likely to find mountain wave. Besides this, the stronger wind will increase
turbulence factor. The result, obtained combining two previous factors in the
graphic, gives three different colours areas. Each colour means an
expected different turbulence intensity.
quicker but less accurate, to determine turbulence, is to compare temperatures
and QNH (barometric pressure) between Santiago de Chile and Mendoza. If there was
a difference of 5º C or more, higher in Mendoza than in Santiago, or if
barometric pressure would be higher in between 8 to 12 hPa in Santiago than in
Mendoza, we would have a higher probability to find turbulence. It’s more
simple and quicker.
summary, studies which gave birth the Graphic of Harrison, there are some factor
which when concur at the same time raise probability of turbulence in Andes:
direction at FL180 in between 280º and 320º;
higher in Mendoza than in Santiago;
occlusion in Juan Fernández archipelago. Specially in austral winter;
temperature in Santiago than in Mendoza.
There is no
doubt a pilot reports are necessary and, in this case is part of the procedure
when overflying certain waypoints. When overflying from east to west, a full
report to Chilean ATC is given with next information: Flight level, sport wind,
temperature and level of turbulence found. This data is gathered to make predictive
reports of mountain wave. Airplanes are, sometimes, mobile meteorology stations
capable of giving very useful atmospheric data.
four main routes to fly over the Andes. The highest probability to find severe
turbulence is in the area of waypoint UMKAL, south of Aconcagua. In this case,
the better option is to divert south, where the terrain is lower, overflying waypoint
ANKON. Other waypoints are MIBAS and ASIMO, north of UMKAL, where conditions
are likely to be more favourable.
If the route
comes from north, it’s more convenient to overfly the Andes a little more up
north instead to fly south to ANKON. Flying parallel to Andes on the “bad”
sector would expose your aircraft to turbulence associated with mountain wave.
How to avoid turbulence?
In the previous
point, we mentioned mountain wave created in Andes between Mendoza and Santiago
de Chile. However, there are plenty of mountain waves around the world in bigger
or lesser scale.
would have been reported moderate to severe turbulence, or just some of the
previous mentioned visual signs would have been sighted, to scape is a very
healthy procedure. Turn 180º or choose an alternate route are the best
contrary, if you’re surprised by turbulence, or after a risk analysis you have
decided to continue, speed will be your best friend. To keep turbulence speed
according to your airplane flight manual, is the best safeguard to keep the structural
integrity to high loads caused by turbulence.
your ally. Is mandatory to keep at altitudes above the highest peak of mountains.
As we mentioned before, rotor clouds are the most dangerous and found at a
lower altitude than crests. However, if altitude is too high, the aircraft
could encounter high altitude waves with very dangerous lifts and sinks. It is then
recommended to fly at altitudes around 25.000 feet which is the safest zone. Even
though, lifts and sinks you’d be flying through, suggest keeping thrust power
above flight idle to use it in case was necessary. Some flight manuals recommend
to disconnect Autothrust/Autotrottle because in certain circumstances system
time reaction is longer than required.
general aviation, besides precautions that have to be taken when flying in high
terrain, in the mountain wave case, there is a rule of thumb which helps to determine
the safest distance from the mountain to fly away from mountain wave when flying
on the leeward side. This is, the elevation of mountain in feet multiplied by
wind speed in knots. For example, if the mountain is 1.000 ft high, and wind
speed is 20 kt., 20.000 ft (around 6 km) will be the minimum safest horizontal
passengers means a special briefing to cabin crew is needed when turbulence
from mountain wave is expected. The cabin must be secured in advance to avoid unexpected
movement of objects which may cause personal injuries. Explaining to passengers
the reason of “fasten seatbelts” sign is crucial. We know, some passengers consider
excessive our indications of seatbelts use, but we also know that consequences are
report ATC is not only necessary but MANDATORY, by the way.
we were flying between cities of Bucharest (Romania) and Sofia (Bulgaria) on a
Bae146-200QT. In spite it was a cargo flight, typically flown night, we were flying
just after sunrise and we could observe some lenticular clouds scattered over
the Balkan Mountains, north of Sofia. During descent we’re having some tailwind
and winds at Sofia were westerly. We were just passing 25.000 feet and we complicit
gazed each other when we realised flight would be a little bumpy over the
mountain range. Automatically we ask ATC to stop descending and to reduce speed
to our turbulence’s one… Some moderate jerks later on, gave us the impression
we took the correct measures. Manolo and I, after more than a decade later, we still
remember what happened. With no further consequences we normally landed minutes
later in Sofia, by the way.
It was not
all bad, after all.
mountains or high terrain is the target of some air sports such as hang-gliders
The wind which helps to create the mountain waves on the leeward side, is the same wind which creates the right conditions to practice this kind of air sports. Near Santiago de Chile there’s an aerodrome where the gliders take the advantage of the westerly winds when blowing towards the mountain range. In Spain, in Piedrahita, Ages or Fuentemilanos; Larange or Lachens in France; Monte Cucco in Italy, are clear examples where to find this addictive air sports.
ever wondered what does the channel numbers on the SBAS approach charts stand
When you select
a PBN approach, we find WAAS approach type in United States, or EGNOS in Europe,
amongst others. Below the approach procedure designator, i.e. RNAV (GPS) Y 04L
in KJFK, a WAAS with CH 77519 appears underneath. Just below channel numbers
there is a combination of letters and numbers.
remember, WAAS is system which augments GPS signal in other to improve GPS
position. To do that, a geostationary satellite system broadcast a correction
signal to aircraft. In U.S.A is WAAS. Then, it’s not necessary to place any
ground station at airports to broadcast this correction signal to correct
aircraft GPS position like in GBAS system. But why there is a channel on the
approach chart though?
system was designed, the channel number was considered as an optional equipment
capability which allowed to pilot to use a 5-digit number to select a specific
approach instead of using the menu method as we usually do to choose from our navigation
database. These numbers correspond to only one type of approach and they’re
channel numbers, there is a combination of 4 letters and numbers. This is the
approach identifier. In conventional radionavaids, when an ILS or VOR is
selected, there is Morse code to aurally ident it. In this case, is visually
identified to verify the selection and extraction of the correct approach chart
from the navigation database. The first letter corresponds to augmentation system
used: W for WAAS or E or EGNOS. The next two numbers are used for runway
designator. When there are parallel runways, lest say LEFT, CENTER or RIGHT,
letter A, B or C are added at the end. So, in KJFK, for the approach RNAV (GPS)
Y 04L, our approach ident will be W04A.
Have you ever wondered why is it faster to fly from America to Europe than the other way around? The answer is the Jet stream. This ‘river’ of air flowing through the Earth plays a big role in aviation. Airlines have learned how to take advantage of it and plan their flights accordingly.
DISCOVERY OF JET STREAM
The discovery of the Jet Stream is often attributed to Wasaburo
Ooishi, a Japanese meteorologist. Back in 1923, he observed
that strong winds aloft would deviate atmospheric balloons as
they gained altitude. By tracking their position, he was able to
determine the wind speed. Although it was only a prediction, he
was able to record a trend over the years and determined that
these winds followed a pattern. His observations remained mostly
unnoticed as he published them in Esperanto.
During World War II, Ooishi’s observations allowed Japan to launch “Operation Fu-go”. Using his prediction on winds aloft, the Japanese launched nearly 10,000 hydrogen balloons carrying bombs over the Pacific Ocean to America. Predictions of 190 knots (350 km/h) in wind speed (between 30,000 and 38,000 feet) would carry the balloons to the United States west coast in 3 days. His predictions turned out to be inaccurate and only some balloons arrived and didn’t cause the intended effect.
American aviator Wiley Post is also attributed the discovery of the Jet Stream. Post achieved the first around-the-world solo flight in 1931, developed the pressure suit and explored the limits of high- altitude flying. In 1935, while flying at 30,000 feet in his supercharged Lockheed 5C Vega “Winnie Mae”, he experienced speeds up to 340 miles per hour. Flying in the Jet Stream he was able to cover 2,035 miles between Burbank, California and Cleveland, Ohio in 7 hours and 19 minutes, proving the benefits of high-altitude flights. The same distance, at sea level, would have taken 12 hours and 42 minutes.
A WORLDWIDE EFFECT
The air acts like a fluid, just like water. And so, it flows and it is
affected by external forces, modifying its behavior and shaping its
On earth, due to the differential heating along its latitude, the vertical development of the atmosphere changes. Close to the Equator the air is warmer, so it ascends creating an area of low pressure near the surface. The surrounding air tends to fill in this ‘gap’, so it flows from the higher pressure area to the lower. The ‘gap’ created by the air moving to the low pressure area at surface, creates a sinking motion for the air that is up at the Tropopause. Thus, creating a circulation.
There are three circulation cells per hemisphere. The Hadley, the Ferrel and the Polar cells. These cells find their top at the Tropopause, the layer at which the air stops rising. Close to the equator, the air is warmer and ascends much higher, elongating the Tropopause further up. The average (it varies during the year) altitude of the tropopause at the equator is 56,000 feet, and 30,000 feet at the poles.
The Jet Stream originates at the boundary of these cells. Due to Earth’s rotation, the air traveling to this boundary is forced sideways. This is called the Coriolis effect. In the Northern hemisphere, the air traveling North will be forced to flow East. This is why the Jet Stream flows primarily in that direction. The greater the air velocity, the greater the deviation. If the difference in temperature is high between cells, the Jet Stream speed increases, up to 200 Knots (370 Km/h).
The Jet Stream is like a continuous ‘river’ of air, meandering. This is due to the difference in Coriolis effect at different latitudes. These are called Rossby waves, and it’s the reason why we often see Jet Streams that are not directly heading East.
THE JET STREAM IN AVIATION
With all this knowledge, aviation can take advantage of a given
atmospheric condition at any time. By using meteorologic and
satellite information, we can predict future weather phenomena,
winds aloft and more. Airlines use hourly updated information to
plan their flight avoiding dangerous weather worldwide.
When dealing with Jet Streams, flight planning departments take into account the position, height, extension and speed of the wind on their planned route. Therefore, anticipating themselves and being able to modify the route to, for example, avoid a strong headwind o a turbulence area associated with it.
Pilots also receive weather information in form of SIGWX (Significant Weather Chart) and wind charts. Then, they can also judge the situation, discuss and decide the better course of action. On long haul flights, a route deviation implies a great deal of considerations: Fuel planning can be affected, ETOPS operation may restrict certain deviations, en-route alternate airports may have to be adjusted, the airline may have to consider schedule affectations on connecting flights, etc.
TURBULENCE ASSOCIATED, CAT AREAS
As we have seen the Jet Stream is a fast-flowing stream of air. The air surrounding it is, by comparison, slower or even still. When an aircraft is approaching a Jet Stream area and the wind suddenly increases, it suffers from what is called Windshear. This is a sudden change in relative speed between two adjacent air masses. A change in wind speed causes instability within the air mass. As it flies through it, the aircraft is subject to those disturbances, suffering from turbulence. Also, as the Jet Stream flows right next to the border of the Cell, we find a transition between air temperatures, thus changing the density of the air and creating instability as well.
This type of turbulence is not associated with clouds, that’s why it’s called CAT, Clear Air Turbulence. Usually the turbulence is reduced to a mere bumpy road-like feeling. With short and repetitive shaking, this kind of turbulence is unpleasant for passengers rather than dangerous for flight safety. Nevertheless, there have been situations in which moderate and severe turbulence has been encountered as a result of CAT.
From the flight planning stage, with help of the aforementioned
maps & charts, pilots do their best to avoid such areas. CAT
areas are marked and their vertical extent also advised. As we
can see in the map, the blue dotted line over Sardinia (Italy)
represents an area of potential clear air turbulence. In the legend
we can see it ranges from FL210 to FL410. We can also see how
it is associated with a Jet Stream that is flowing from North to
South (Red line) at 120 knots (Every triangle represents 50kt and
every line 10kt).
When an aircraft is subject to moderate and severe turbulence,
the pilots shall report it to the ATC —Air Traffic Control— to help
other traffic in the surrounding area and raise awareness of
potential hazardous areas. A simple change of Flight Level
(Altitude) shall suffice to get out of the turbulent area. Often
times, pilots ask the ATC for an altitude change to avoid the
As a little example of the big influence the Jet Stream can have
on a given flight, we are going to take a look at a flight from Los
Angeles to Tokyo-Haneda, and how we can take advantage of
We can see that the Jet Stream, the same that instigated the
Japanese balloon project, flows along the Pacific Ocean. If we
were to follow the standard routing, we would find ourselves right
in the middle of the Jet Stream. Let’s take a look at the effect of it.
When flying through the Jet Stream, we are experiencing a sustained headwind of up to 120kt along he whole route. This would result in a flight time of 12 hours and 45 minutes to cover 4835 Nautical Miles, and an estimated fuel burn of 94,800 Kg of fuel. Allowing for contingency, final reserve and alternate fuel we would need roughly 108,000 Kg of fuel on departure.
Conversely, if we decide to deviate further North, even though we will fly a longer route (123 Nautical Miles longer) we will avoid the Jet Stream and the effects are very noticeable. Let’s see:
Flying the Northern route we would fly a distance of 4958 Nautical Miles, it would take only 11 hours and 25 minutes. 1 hour and 20 minutes and nearly 10 tones of fuel less. This represents a massive time and fuel cut, even when flying a longer route. Of course, this is a perfect example, some days the difference would be less. But, all in all, it means millions of dollars in savings when thousands of flights are scheduled on a yearly basis. This is how important is to have an effective operations & flight planning team supporting the flight operation.
is a complex, ever-changing business. Crew schedules, route network, customer
service or staff management. Every aspect of it is subject to sudden changes
and continuous adjustment. Airlines sometimes find it difficult to strive in
this ultra-competitive world. Mergers, acquisitions and bankruptcies are no
strangers to many airlines. We, the people behind this circus, are sometimes
caught in the middle of it all.
This is a tale of a pilot’s last flight for an airline.
It hasn’t been an easy summer. Rumours in the office, cockpit talks, hints on the news… We all know something is cooking. Some colleagues are already searching for a way out, others keep the faith and will stay. During this week my schedule has changed several times. The airline is adjusting and re-adjusting the flights, some aircrafts have been impounded by their owner, the lessor. Others are still on maintenance. It looks bad, but we’ll keep on fighting until the end.
I check my roster and my flight has been changed. I will fly to Tirana, stay the night and come back in the morning. As I drive to the airport, I can’t help but think it can be the last time. I’m going to enjoy this flight like it’s the last. I will try to remember every little detail and make the best out of it. When I make it to the office, the captain is nowhere to be seen. Our aircraft is late by more than an hour and he will probably show up right before it lands. I take the flight briefing folder and start to prepare the flight. The office is quiet, nobody dares to speak more than the necessary, everyone suspects we won’t be around much longer. Finally, the captain arrives and, we brief the flight together. It’s looks like a smooth ride over the Balkans on our way to Albania. We check the technical status of the aircraft and decide how much fuel we will take. It looks like the flight is further delayed, so the captain decides we won’t have time to go to the hotel in Tirana. We will stay in the aircraft, as we will have a little longer than two hours until we will have to come back to Ljubljana.
We make our way to the terminal, pass the security control and walk to the aircraft. The apron is quiet, we can see three of our airplanes grounded, sealed. It’s sad we won’t see them flying anymore. We agree he will fly the first leg and I will fly the way back tomorrow morning. Finally, we arrive to our Bombardier CRJ-900. S5-AFA has only been with us for 2 years. It came from Air Nostrum, where it was registered as EC-JNB. We open the doors and I start with the initial checks.
One hour later, we are cruising at FL350. A moonless night brings us wonderful views of the milky way. The purser brings the dinner to the flight deck. I’m not hungry, thoughts race through my mind, I feel uneasy. Nevertheless, this might be the last dinner onboard, so I decide to eat. The flight progresses as usual. We land in Tirana and passengers disembark the plane. It’s 1:30 AM and the captain is powering down the aircraft. Meanwhile, I close the door and set the alarm.
Wake up call. The screen of my phone illuminates the passenger cabin, pitch-black, it’s 4 AM. Swollen face, red eyes, better make some coffee. I pick up the ATIS, prepare the route and calculate the performances, as the passengers start boarding the plane. They probably have no idea of what’s going to happen with the airline and some of them might not be able to come back home after their holidays. Captain asks for the checklist and we start up the engines. “ADRIA727, wind is 020 at 2 knots, runway 35 cleared for take-off”. AFA starts rolling, illuminating the runway as speed increases. “V1, rotate” and I gently pull the yoke to lift up the nose. The aircraft leaves the asphalt slowly and starts climbing into the dark of the night.
It’s 5:30 and the stars are disappearing in favour of a dark blue twilight. The weather is perfect in Ljubljana and we will be the first inbound flight this morning. One of the cabin crew brings coffee. You can’t say no to a cup of coffee with the best views in the world.
As we start our descent, the sun rises
over the Balkan skies, calm as ever. We can’t talk to each other, gutted.
“Gear down”, we feel this could
be our last landing in Ljubljana.
“Adria 727, Cleared to land runway
30, wind calm”.
“50, 40, 30 – Thrust idle – 20, 10 –
Flare…” And we kiss the runway for the last time.
A smooth approach and landing put an end to it. As always, we bring our passengers home, safely, but this time, it feels different. As I step out of the cockpit, I look back and take a last glance at it. Here is where it all started. This airline gave me my first chance, my first job as an airline pilot. I learned how to fly a masterpiece of an aircraft.
Two days after Adria Airways ceased operations temporarily. A week later, on September 30th, the airline filed for bankruptcy. This article is dedicated to the people of Adria Airways (1961-2019).
Edgar Domenech Llinares is an airline pilot rated on Bombardier CRJ700 and 900 series. He has been based in Slovenia flying for Adria until vert recently.
He started his career as a cabin crew. He worked for 6 years based in Palma de Mallorca where he managed to get his pilot licenses and ratings.
His passion for aviation drove him to make his dream to come true, learning a lot in the process, and looking forward to learn more in the future.
2.018, ASL Ireland took a strategic decision of closing freighter company Pan Air.
Pan Air which started operations in 1.988, had a highly demanded speciality in
their portfolio thanks to their professionality and aircraft used: To transport
and summer months, is very characteristic to see in United Kingdom and France
racehorses in the weekends. It is a billionaire event thanks to bets and draws
many people. Horses are product of best breeds and stables, descendants of
champions. It’s value ranges from 5 to 10 million pounds.
Most of Pan
Air flights were done from Shannon, in the west Irish coast. Very close is where
the most important stables of Europe are located. Due to the highest value of
horses and distance from Farnborough, Deauville, Cambridge or Edinburgh,
transport by plane worth it.
BAe 146 has
been the most accepted model amongst the customers for this specific purpose. It’s
a regional four jet engine aircraft manufactured by British Aerospace in the beginning
of last decade of twentieth century.
was designed to land in short runways and, for that purpose has a very
characteristic airbrake in its tail cone, a very strong landing gear and very efficient
It’s also relatively
quiet, and its cockpit is wide and very comfortable.
a freighter airplane, there are no seats in the cabin. Instead, there are some
rails and metal locks to move and fix pallets and freight containers to the floor.
loaded into the plane through a big hydraulically operated door on the rear
left side of the fuselage. It’s the way horses use to get on the plane as well.
the cabin for livestock, up to seven single stables are installed alongside the
cabin to make horses as if they were at home.
A pallet of
seats is installed in the area between de freight door and the rear part of the
airplane. These seats will be designated to all people who travel besides
horses: veterinary, loadmaster, and engineer, and grooms.
seats are in the rear part of the airplane, horses are facing backwards in
order to have visual contact with their grooms.
Very sensitive guests.
Special considerations have to be taken when carrying racehorses onboard of
an airplane. The goal is to take them to a race and that is the reason why they
are given no substance to make their flight more comfortable. Otherwise, their
capabilities could be diminished during the race.
Unknown people are not permitted to get closer in order to avoid they get
nervous. Only their personal grooms, veterinaries or, even another animal who
travels besides as a companion such as her colt if her/his mother races. Usually,
two or three horses are carried and maybe only one or two will race.
to avoid the get nervous, airplane noises are reduced to a minimum. The APU Will
be started once the freight door is closed and engines are about to be started
into the cabin yelling or making noise is absolutely prohibited. For this reason,
unless in case of an emergency, the used of PA (Passenger Addressing) through
speakers is restricted. All messages take place through interphone with
Loadmaster who plays the role as a purser in fact.
flight, only grooms are authorised to stand-up and stay beside the horses to
keep them calmed if necessary.
Given customers are more sensitive than usual, flight operation has to be
move horses are more like luxury caravans rather than typical animal transports.
Trailers are parked just in front of the airplane’s freight door and their
grooms take them into the airplane thanks to a special ramp designed for animals.
When this operation is taken place nobody else is allowed to get closer to animals
as they could be afraid of a stranger.
One they settle
in their respective stable, doors are closed, ramp is disassembled and put into
the belly holds of the airplane, and airplane’s freight door is closed.
mentioned before, noise could disturb animals. So, APU is started once all doors
are closed and just before engine start.
BAe 146 has
four jet engine but, its start procedure is quite fast, and there is no need to
wait for so long to start taxi.
is not a long airplane, is able to turn very close. Because of this, to leave
the parking area have to be done with special care and very slowly to avoid
high speed turns that could disturb horses. Furthermore, taxi speed is slower
than usual and air traffic controllers, who are familiar with this type of
operations, advice other airplanes we are carrying “livestock on board”. Basically,
to ask for understanding.
is about to take place, power is applied progressively and slowly, adjusting
take-off power just before a certain speed. To avoid a high speed rotation and
a very steep climb, flap position is selected in a very high deflection (30º).
take-off, climb gradients do not exceed 1.000 feet per minute in order to avoid
steep climbs. This allows animals not to make too much effort with their legs. Flight
levels chosen are around 20.000 feet in order to keep the pressurisation system
working with a relatively low cabin altitude. Then horses will not suffer any
adverse symptoms during race. Besides, in the unlikely event of loss cabin
pressure, breathable atmosphere would be reached very soon and there would be no
risk for the animals.
and approach is initiated, air traffic control coordination, again is very
helpful an essential. Even is contained in our flight plan and controllers are
familiar with this kind of flights, we give this information on the radio when we
have the first contact on their frequency. Descent is initiated to with time
enough to plan it slight.
flown very smooth. When reducing speed, airplane tends to raise it nose, increasing
it angle of attack. To avoid it, we select flaps earlier than usual trying to ease
nose up momentum. Moreover, turns to final approach are done with lower angle and
at a distance of 15 NM, which is longer than usual.
landing is about to come, autopilot is disconnected and, as my friend Rafa
says, is “when technology ends and art begins”. Overflying runway threshold, tailcone
airbrake is deployed smoothly and firmly. Touchdown must be done flat, almost allowing
to land with main landing gear and nose landing gear at the same time. Captain’s
gold hands are necessary at this time. The Bae 146 is very appreciated after a
smooth touchdown and commences to decelerate easily with wing mounted spoilers
and its full deployed tailcone airbrake.
done manually and progressively, using the full length to stop the airplane.
on stand, a convoy is waiting to take horse to their destination: the race. Before
opening freight door and assemble the ramp, engines and APU must be switched off.
are being taken to their new ground transport, number of inquisitive ramp
workers are attracted to the plane asking about the animals… Bets move a
lot of money.
End of service.
When this first sector is
finished, the whole crew goes to hotel until daily races are over. Then, we’ll
start again to take them back to Shannon.
ususally infected with groom’s joy after winning races. Meanwhile, jockey is
back on his A319ACJ with horse’s owner.
After a series
of flights a bond between crews and people who works with horses is created. There
is an empathy with horses and grooms which has been translated into a relationship
of more than 25 years. A lot of gratitude has been received thanks to the very
good crew’s attitude, high experience and professionality.
For many years Pan Air pilots has shown their value. Even up to their last day. Their commitment has always been showed when situation was very far from being favourable.
I’d like to dedicate this short article to whom they were may colleagues in Pan Air Líneas aéreas for almost a decade. Therefore, serves as a tribute to all staff in the company: administration, maintenance, flight operations, ground operations and, my beloved friends and cockpit colleagues, the pilots. Many names are coming up to my mind, some of them retired some years ago.
All of them in a new professional stage in other airlines but, we’re always will be “Paneros”.
increase in density of air traffic in Europe, United States, and remote areas
such as the North Atlantic Ocean, made the necessity to implement Single
European Sky programs (SESAR) and NEXTGEN. To achieve this goal, technology
plays a vital role. The ADS-B is one of them.
to stablished critera by every civil aviation administration, as of 2.020,
aircrafts must be equipped with ADS-B system. In Australia, pioneers in remote
airspace management is already implemented since December 2.009 above FL300.
Thanks to this technology they were able to reduce aircraft separations from 30
NM to only 5 NM, increasing airspace capacity significantly. But, What is it?
And How does it work?
(Automatic Dependent Surveillance – Broadcast), is a surveillance system which
will replace information already obtained from radars.
system allows navigation systems onboard of an aircraft to obtain its position
from GPS signals. Signals are joint together with other flight data gathered
from other aircraft’s systems and broadcasted. Signal broadcasted is received
by ground stations, inflight stations or satellite’s receivers and represented
on a screen.
to be able to supply air traffic control with radar, air traffic controllers
have one o more radar stations on ground to provide aircraft’s position. This
information is obtained from radar echoes PSR (Primary Surveillance Radar), or exchanging
information between aircraft and ground station, thanks to the transponder. This
is known as SSR (Secondary Surveillance Radar). Between the two systems, SSR is
the most accurate with MODE S transponder.
System and capacity.
has two basic capacities known as “OUT” and “IN”.
ADS – B
“OUT” defines its capacity to broadcast ADS – B information. As an example of
what kind of information broadcasts, the A330 with “OUT” capacity sends out the
next information automatically and in a continuously manner:
and longitude, Horizontal Integrity Limit (HIL), the difference between
barometric altitude and geometric altitude and ground speed (GS). All obtained
from GPS signal;
altitude is obtained from ADIRS;
and vertical speed given by IR’s;
ATC flight number introduced in the preflight check is given by FMS;
altitude and heading, and barometric pressure (QNH/QNE) from the FCU.
function allows ATC, if they are equipped with proper system, to see on their
screens their clearance and what pilot selected on the same radar tag. Very
similar to what it happens with MODE S “enhanced” which uses “Down – link of
Airborne Parameters” (DAP). This is what happens in airports such as London
Heathrow. But this is another story…
other hand, ADS – B “IN”, defines its capacity to receive information from
other ADS – B “OUT” stations which broadcast information.
obvious that an aircraft equipped with both functions will be able to broadcast
and to receive ADS – B information, to and from other ADS – B stations.
aircraft to able to be equipped with ADS – B technology, is necessary to have datalink
equipment in VHF band. To do that, aircrafts use mainly two different
equipments: 1.090ES and UAT978.
(Universal ADS Transceiver) is an equipment only used in United States below
18.000 feet. Created for general aviation, if it’s equipped with “IN” capacity,
will be able to receive weather information free of charge. However, the rest
of the world Will be using 1.090ES complying with ICAO requirements, what in
fact has higher data transmission capacity.
is 1.090ES all about? Basically, is a mode S transponder modification,
currently on board of aircrafts. As the mode S transponder does, transmits on
1.090 Mhz., broadcasting information instead of waiting for the interrogation
from a SSR station. This transponder has a group of extra capacities added to
mode S, that the reason for its name: “Extended Squitter”.
it’s working on the same frequency, it’s able to comply with airspaces where
SSR radar service is provided and with ADS at the same time.
all conventional radar information which air traffic controller receives, ADS –
B is more reliable. All data is sent directly from the aircraft’s navigation
other factor which affects service which is the transmission speed. Nowadays,
secondary surveillance radars use interrogation/response of onboard
transponders to obtain data information from aircrafts. Let’s say for a moment
and aircraft flying under radar coverage equipped with transponder. The SSR
antenna begins with an interrogation on 1.030 Mhz. and aircraft through its
transponder will response on 1.090 Mhz. with information asked. Once this
information is received on ground, is presented to air traffic controller’s
screen. To the contrary, ADS – B broadcast twice per second automatically
without the necessity to be interrogated by any other equipment. An ADS – B
“IN” antenna receiver is only needed.
With ADS –
B, all radar antennas could be easily replaced by ADS – B receivers, simpler to
install, easy to maintain, more energy efficient, and in the end, cheaper.
explained it correctly until now, maybe you were able to guess other advantages
or capacities this technology has.
If we add an
ADS – B receiver antenna to an aircraft, we would give it ADS – B “IN”
capacity. We only would need a way to represent this information in the
cockpit: CDTI (Cockpit Display of Traffic Information).
will be translated into being represented on places we’re all familiar with,
such as TCAS screen, on a MFDU (Multifunction Display Unit), or on a ND
(Navigation Display). We would be able to see on one of these screens onboard
of our aircraft the same information as the air traffic controllers on their
radar screens. There is no doubt how this increases pilot’s situational
awareness in highly congested airspaces.
mentioned before, he appearance of ADS – B has brought about some new
applications: TIS – B (Traffic Information Service) and FIS – B (Flight
TIS – B
allows information regarding aircrafts with transponder but not ADS – B
equipped, flying under radar coverage, to be broadcasted by ADS – B “OUT”
stations. This information is received by ADS – B “IN” equipped aircrafts being
able to see on their screens onboard other aircrafts around them which are not
equipped with ADS – B.
FIS – B
allows aircrafts equipped with ADS – B “IN” to receive weather information,
ATIS, or NOTAM from ADS – B “OUT” ground stations. This type of service is well
known as FIS – B.
Procedures stablished on NAT – HLA oceanic airspace.
ADS – B is a very substantial improvement in air traffic control. The ITP (In
Trail Procedure), allows aircraft to choose optimum flight levels without being
“blocked” by other aircraft flying at a distance with no radar further than
This is, if
an airplane wish to climb or descend crossing other airplane’s flight level,
and both are ADS – B (“IN” & “OUT”) equipped, sending the request via CPDLC
to ATC, it will show distance from other
aircraft, their flight level and callsigns before being sent to ATC on CPDLC’s
ADS – B, ATC will receive more accurate information and will have a total
picture of airplanes instantly with no ADS – B equipped and ADS – B airplanes.
So, it will be easier for ATC to see if they have separation enough to give the
clearance for level change request.
other hand, over remote areas and over oceans, receiver antennas on ground is
not possible or feasible. Because of that, for some time companies have been
working on a low altitude satellite constellation able to receive ADS – B
signals from aircrafts.
constellation called Iridium is made of 66 active nanosatellites and 9 as
spare. They are in an orbit just at 785 km from earth’s surface, being able to
receive ADS – B signal and send it to ATS centres. It’s expected to be fully
operational in the end of 2.018.
and to mention flight MH370 disappearance, the company FlightAware has signed
an agreement with Aireon (Owner of Iridium Constellation) to supply airlines
with a fleet management and tracking capabilities based on this system. This is
the solution to ICAO’s system called GADS (Global Aeronautical Safety System)
to continuously monitor aircraft’s position.
comparing to United States, there are no immediate plans of integrating ADS – B
position to ATC’s system in all regions, and to provide ATC service. That’s the
reason why Iridium is fastest solution. In Italy, for example, will be
of ADS – B is, as you have read, a very remarkable change in what we already
knew about surveillance. There is no doubt the reduction on aircraft’s
separation in remote areas will be very valuable, especially in HLA airspace in
the North Atlantic Ocean, as it happened before in Australia with no effect on
safety at all.
able to handle information rapidly and accurately, crews and air traffic
controllers will be able to increase their situational awareness which will
lead to take decisions easily.
implementing ADS – B procedures like ITP, will allow an optimization of
airspace. Aircrafts will be able to fly closer to their optimum flight level,
reducing fuel burn and CO2 emissions.
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