Tag Archives: birdstrike

Birdstrike on a windshield

The following interesting pictures show the effects of a birdstrike on a windshield of an Airbus 321. Fortunately, the aircraft involved was able to land safely but as we have discussed much on this site, the injection of a bird in the engines can be devastating.

Turkish Airlines B737-800 crashes in Amsterdam

On Feb. 25, a Turkish Airlines B737-800, “TC-JGE”, flying as TK1951 from Istanbul to Amsterdam with 127 passengers and 7 crew members, crashed shortly before landing on RWY 18R at Amsterdam’s Schiphol International airport right around 10.35LT. As a result of the impact, the airframe broke into three main parts: 9 people (comprising Captain and First Officer) died and 50 were injured.

Obviously, there are lot of possible reasons why the airplane crash landed where it did (fortunately, in an isolated area). Basing on the details which have surfaced so far it is possible to try to theorize the root causes of the accident and to explain why media is reporting many different scenarios:

1) from the picture released so far, there’s no evidence of fire, just like the aircraft ran out of fuel before crashing (it would be coherent with the fact that someone saw the aircraft “gliding”). However it was reported that the B738 was fully loaded with fuel at the departure

2) a few witnesses standing or driving on the nearby highway said the airplane was flying slow at low altitude when, suddenly, the tail went down and the nose up. After pilot correction, the airplane flew horizontally again before it pitched down into the field. Many reported as the aircraft fell like a brick from the sky (it most probably stalled).

3) wind shear could be a possible cause, even if no other aircraft reported it. The METAR at the time of the crash was: EHAM 251025Z 22011KT 3500 -DZ BR OVC007 05/04 Q1027 TEMPO 2500 that is to say wind from 220 at 11 knots, 3500 meters of visibility, overcast at 700 feet, drizzle, mist, temperature 5° C, dew point 4° C, pressure 1027 millibars. Nothing special for Schiphol. Experiencing wind shear crew members would select TOGA (Take Off / GO Around) thruust to avoid falling into the ground while witnesses saw the aircraft touching the ground with low energy and pictures of at least one of the engine show the compressor’s blades in good shape, meaning that the engine was windmilling / low regime.

4) right engine separated from the wing and rested some hundred meters apart from crash location (slightly ahead of the B737). Someone speculated one engine separated from the aircraft during landing but in this case it would have fallen somewhere behind the wreckage location. If one engine separated at AMS it would be the second time an in-flight engine separation takes place in the same location. In 1992 a LY B747-200 crashed into the houses during night approach at Schipol. Aviation disasters some times have the habit of coming up with strange coincidences.

5) double flame out caused by multiple birdstrike will be investigated (but it seems unlikely to me, since it would be the third occurrence in a few months). But I don’t think the pilot would have reacted to such an emergency by

6) the aircraft declared an emergency for engine(s) problem. This is somehow strange: if the aircraft had a catastrophic failure that brought to a rapid stall, there would (probably) be no time to radio a Mayday or to declare an emergency. The famous rule “Aviate, Navigate, Communicate” always applies. In this case, looks like the pilots were not able to fly the aircraft, so they would not even think to communicate.

This accident and what has been reported so far by the media reminded me of the British Airways 038 crash landing in London Heathrow. In that case as I explained here) as I watched an amateur video of the B777 I explained: “Looking at this video, it appears that the B777 is trying to keep the glideslope while speed is decreasing.

The aircraft has, in fact, an unusual pitch attitude, probably induced by the autopilot that is raising the AOA (Angle Of Attack) to maintain the ILS to compensate insufficient thrust, under deteriorating speed conditions. Very dangerous attitude (especially) at 600ft that made the aircraft get less horizontal distance, thus touching short of the runway 27L”. What if the Turkish Boeing 737 ran out of fuel (or experiencing insufficient thrust because of a birdstrike, autopilot problem, bad data input, or for any other reason, separation comprised) while performing the approach? The autopilot would have raised the nose to keep the ILS and the aircraft would near stall conditions very quickly. It is to avoid such a dangerous situation that as soon as a failure of one or two engine is detected the crew has to shut off autopilot and autothrottle and to apply TOGA to prevent stall.

The following pictures released to the media show the wreckage of the aircraft:

US Air 1549 vs Tuninter 1153: two differing ending ditchings

Analysing the recent US1549 ditching in the Hudson River (http://cencio4.wordpress.com/tag/awe1549/), I explained that the success in the difficult splash down was the result of a perfect maneuver and luck. Even if I still believe that luck is important to increase survivability in case of emergency, when talking about aviation safety, I believe that it sometimes doesn’t come alone and it is strictly tied to the crew’s airmanship. Capt. Sullenberger perfomed a difficult maneuver he had never attempted before. He was lucky, as the rest of the crew and the passengers were, but the “happy ending” could have been tragic and luck would most probably be enough if “Sully” had not made the right decisions and had not followed the correct procedure. Pilot’s experience, skill and cold blood, are paramount to increase the possibilities of achieving a succesfull crash landing. In order to emphasise this point I will remind you another crash landing, the one of the Tuninter 1153. On Aug 6, 2005, TUI 1153 flight, an ATR-72-200 with registration TS-LBB, enroute from Bari-Palese airport, Italy, to Djerba-Zarzis Airport in Djerba, Tunisia, ran out of fuel and ditched in the Tyrrenhian sea 26 chilometers to the North East of Palermo, Sicily. 16 POB (2 crew members and 14 passengers) died in the accident while 23 survived the crash. The root cause of the crash was an ATR-42 fuel gauge erroneously installed on the ATR-72. Both gauges have the same form factor but they are different as the Fuel Quantity is calculated by processing the signals coming from capacitance probes in the tanks with a specific algortithm that differs from aircraft to aircraft, depending on the shape and size of the tanks. When TUI 1153 departed from Bari, the FQI indicated 2.700 kilograms, while the actual amount of fuel was only 570 kgs. At 15.17′47″LT, 4 minutes before the first engine failed, the crew did not notice the low pressure indication. At 23.000 feet, at 15.21, the aircraft lost the first engine, to be followed by the second at 15.23. The pilot declared an emergency at 15.24 informing Rome Radar that they were diverting to Palermo Punta Raisi airport. The aircraft did not make to Palermo, glided for 14 minutes before ditching at around 15.40. Six Tuninter employee at the time of the disaster were found guilty by the court of Palermo. Among them, Captain and Fist Officer who survived the crash (the only 2 crew member to escape the aircraft of the 4 on board).
Even if the problem was with the gauge, according to the investigation the pilot made a series of mistakes that for sure contributed to the crash and did not help to solve the emergency:

before experiencing the emergency:
– he did not check that the installed FQI was correct (both him and the FO had requested a replacement the day before for a failure, replacement that was performed in Tunis) and working properly

– he ignored the acoustic warning 4 minutes before the first engine quit
– after losing the first and later both engines he started a steep descend instead of gliding smoothly
– there was too much confusion in the cockpit and 10 minutes after the aircraft had lost both engines, the crew had not started the appropriate check list yet
– ditching was not performed as foreseen: the aircraft has an angle of attack comprised between -0,1° and 0,8 even if AOA, according to the manual, had to be of 9°. The Vertical Speed is too high: 13 feet per second instead of the foreseen 5 fps. The approach to the surface of the water was performed with tail wind and not parallel to the waves. In particular, the uncorrect aircraft attitude was the root cause of the violent impact with the water and the subsequent quick deceleration and disintegration of the airframe.

Nobody can say if a ditching performed “as prescribed” would have changed the destiny of TUI 1153. For sure, despite the gauge mistakenly installed on the aircraft, the investigation focused to a large amount of cockpit crew’s errors, which, most probably, cost some human lives. In your opinion, did this ditching fail because of bad luck? In my opinion, it was not a matter of luck (only). Most probably the particular high-wing of the ATR72 (the same of the ATR42) did not help since the floating line was above the cabin (as the following picture of an Alitalia ATR42 shows)

but the captain had some luck (he was flying at high altitude, he could point the ATR72 towards some boats, he had plenty of time to perform the check list and appropriate procedures, he ditched in the warm water of the Tyrrhenian Sea in August) and he simply wasted it.

The following pictures were taken by the Italian Coast Guard a few minutes after the crash landing. According to the autopsies the majority of the dead passenger didn’t survive the crash, but some drowned).

US Air 1549 update

During the last few days many new details surfaced about the last 6 minutes (more or less) of US Air 1549 flight that ended with a successful textbook ditching of an Airbus 320 in the cold water of the Hudson river, New York City.

First of all, many videos have been released, some of which clearly show the aircraft touching softly the surface of water and stopping a few meters later. I would have expected it to “sail” a few more, but it seems that it came immediately to a stop.

For sure, it seems like the A320 has some unexpected amphibious capabilities, especially if you think the pilots had not pushed the Ditching button that closes all the “holes” of the airframe to enhance floating  ability of the aircraft at sea (because it was later on the ckecklist they were following and had not time to read it). This is one of the most interesting things that was explained in the last NTSB press conferences on the mishap. The other details deals with the following points:

  • The aircraft touched down in the Hudson, where the water depth is around 50 feet. The weight of the plane, filled with water after sinking was about 1 million pounds and for this reason the aircraft had to be lifted by a crane very slowly in order to let the water drain.
  • While the right engine is still in its original place, the left one was found some 50 feet below the surface.
  • The crew members were the last to evacuate the aircraft and as it was recalled by the survivors, Capt. Sullenberger twice checked the cabin for missing passengers before escaping from the front door that was around 2 or 3 feet above the water level. Among the passengers there was also one lap child and a small one. The crew members were flying the forth leg of a 4 day shift (KPIT-KCLT-KLGA-KCLT).
  • Capt. has 3.800 hours on the A320 while the First Officer, that was the initial Pilot Flying just 35. According to what they have recalled, the FO saw birds and shortly later the windscreen was filled by big dark (brown) birds. After experiencing the loss of thrust, the Capt. took the command saying “My aircraft!” then he lowered the nose in order to gain speed (that had reduced for the loss of both engines) while the FO began the Dual Engine flame out check list (and attempting to relight the engines). Turning back to La Guardia was discarded since the Airbus was too low and too slow; Teterboro was too far so the pilot called for Flap 2 and headed for the river trying to land as near to a boat as possible.

Noteworthy, Teterboro was considered too far. I initially thought that the Capt. had not opted for that airport because the runway was too short: actually, the airport has a runway (01/19) that is 2.134 mt long, equipped with ILS and PAPI that could be used by an Airbus 320. But, the runway orientation would have required the US1549 to perform at least a couple of turns to aligh, meaning that the distance for Teterboro could not be covered by the N106US flying without both engines. An Airbus 320 should have a gliding ratio of 17:1. This means that, with no thrust but in the correct configuration, starting from an altitude of 1.000 meters, it could fly for 17 chilometers before reaching the ground. Let’s say that that value is just theoretical and that, in that conditions, the N106US had a gliding ratio of 13:1. Since it was around 1.000 meters it should have been able to cover a distance of 13 chilometers (in straight line, without considering buildings in the overflown area). Using Google Earth I calculated that the distance from the birdstrike position to the airport (without considering any turn) exceeds 15 chilometers. So, Teterboro was indeed too far.

Furthermore, some journalists discovered that the same aircraft, whose registration is N106US, flew the same route as flight US1549 (AWE1549) on Jan 12 and that on Jan 13 it suffered a compressor stall. As it was reported by the CNN, about 20 minutes after departure from La Guardia, the plane “had a series of compressor stalls on the right engine. There were several very loud bangs and fire coming out of the engine. The pilot at first told us that we were going to make an emergency landing, but after about five minutes, continued the flight to Charlotte.” Since I have already reported the highlights of the press conference, the fact that the aircraft had a compressor stall on the same route 2 days prior to the dual engine failure is just pure coincidence (even if it is better to wait for the NTSB final report…).
Roland Posnett sent me the link to the full article about US1549 flight of Jan 13, 2009:

Passengers report scare on earlier US Airways Flight 1549

* Story Highlights
* Three say US Airways Flight 1549 nearly made emergency landing earlier last week
* Two days before last week’s crash-landing, passengers report loud bang on flight
* One passenger says he sent a text message to his wife: “I love you”

By Abbie Boudreau and Scott Zamost
CNN Special Investigations Unit

(CNN) — Two days before US Airways Flight 1549 crashed into the Hudson River, passengers on the same route and same aircraft say they heard a series of loud bangs and the flight crew told them they could have to make an emergency landing, CNN has learned.

Steve Jeffrey of Charlotte, North Carolina, told CNN he was flying in first class Tuesday when, about 20 minutes into the flight, “it sounded like the wing was just snapping off.”

“The red lights started going on. A little pandemonium was going on,” Jeffrey recalled.

He said the incident occurred over Newark, New Jersey, soon after the plane — also flying as Flight 1549 — had taken off from LaGuardia Airport in New York.

“It seemed so loud, like luggage was hitting the side but times a thousand. It startled everyone on the plane,” Jeffrey said. “We started looking at each other. The stewardesses started running around. They made an announcement that ‘everyone heard the noise, we’re going to turn around and head back to LaGuardia and check out what happened.’

“I fly about 50 to 60 times per year, and I’ve never heard a noise so loud,” he said. “It wasn’t turbulence, it wasn’t luggage bouncing around. It was just completely like the engine was thrown against the side of the plane. It just — it didn’t shake the plane but it shook you out of the seat when you’re drifting off, it really woke you up. And when it happened again, everyone just started looking at each other and there was a quiet murmuring around the plane, and you could feel the tension rising just in looking.

“I remember turning to my [business] partner and saying, ‘I hope you got everything in order back home, life insurance and everything, because that didn’t sound good.’ ”

Jeffrey said he sent a text message to his wife about a “scary, scary noise on the plane. Doesn’t sound right. They’re flying back to LaGuardia to check it out. I’ll call you when we land. I love you.”

He added, “About 10 minutes later when we never made the turn, we kept going, that’s when the pilot came on and explained — I wish I could remember the words — I remember him using air, compression and lock — I’m not sure the right order, but he made it sound like the air didn’t get to the engine and it stalled the engine out, which he said doesn’t happen all the time but it’s not abnormal.”

Expert Aviation Consulting, an Indianapolis, Indiana, private consulting firm that includes commercial airline pilots on its staff, said the plane that landed in the Hudson was the same one as Flight 1549 from LaGuardia two days earlier. PhotoSee images from the rescue in last week’s crash »

“EAC confirms that US Airways ship number N106US flew on January 13, 2009, and January 15, 2009, with the same flight number of AWE 1549 from New York’s LaGuardia Airport to Charlotte Douglas [International] Airport in North Carolina,” Expert Aviation said in a statement to CNN.

The company said it checked with contacts in the aviation industry to confirm that it was the same plane.

The National Transportation Safety Board released the tail number of the downed Airbus A-320, which is N106US.

NTSB spokesman Peter Knudsen said as part of its investigation into the Hudson River crash, it will be looking at all maintenance activities, but has no indications of any anomalies or any malfunctions in the aircraft, so far in the investigation.

The Federal Aviation Administration referred CNN to US Airways.

US Airways would not confirm that the Flight 1549 that took off January 13 was the same plane that splashed into the Hudson two days later.

Valerie Wunder, a US Airways spokeswoman, said: “US Air is working with the National Transportation Safety Board in this investigation.” She would not comment on any other details, including Tuesday’s flight, though she did confirm US Airways is looking into it.

Jeffrey told CNN that US Airways earlier Monday confirmed to him that the Tuesday incident occurred aboard the plane that crashed.

John Hodock, another passenger on the Tuesday flight, said in an e-mail to CNN: “About 20 minutes after take-off, the plane had a series of compressor stalls on the right engine. There were several very loud bangs and fire coming out of the engine. The pilot at first told us that we were going to make an emergency landing, but after about five minutes, continued the flight to Charlotte.”

In an interview, Hodock said the pilot “got on the intercom and said they were going to have to make an emergency landing at the nearest airport. But then, only five to 10 minutes later, the pilot came back on and said it was a stalled compressor and they were going to continue to Charlotte.”

A third passenger, who did not want her named used, also said she heard a “loud banging sound” on the right side of the plane. She said she heard the pilot say the “compressor for the engine was stalled” and they needed “to turn around and go back.” However, she said, the problem was fixed and the flight continued without incident.

Pilots and aviation officials said that a compressor stall results from insufficient air getting into the engine and that multiple stalls could result in engine damage. However, the officials said, a momentary compressor stall may be less serious and could be corrected in flight by simply restarting the engine.

A bird strike could lead to a compressor stall, the officials said.

All AboutUS Airways Group Inc. • Air Travel

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Top image credit: Associated Press

Some lessons learned from US Air A320 ditching in NYC’s Hudson River

The recent episode of the US Air Flight 1549 down in the New York City’s Hudson River 5 minutes after departure from La Guardia airport underlined a few things about Aviation Safety and, more generally speaking, about Aviation, that should be taken into consideration.
So far, the happy ending of flight AWE1549 highlighted the following “Lessons Learned”:
1) Birdstrikes can be catastrophic: the A320 suffered a dual flame out after impacting flocks of Canadian geese shortly after departure. A few weeks ago, something similar had happened to a Ryanair B737-800 landing in Ciampino. In both cases, the pilot managed the emergency but something more must be done to protect the engines from birds.

2) Ditching is not always the last chance: according to an interesting post on http://www.huffingtonpost.com/ when Capt. Sullenberger informed the New York TRACON (Terminal Radar Approach Control Center) controller about its emergency, the controller gave the AWE1549 a heading to head back to RWY 13 in La Guardia but the pilot replied: “unable.” As Sullenberger saw the small airport in NJ, asked what it was and if he could head towards it. The controller explained that it was Teterboro, a small airstrip used by commuters and private plane and cleared AWE1549 to perform an emergency landing there. But Sullenberger replied again: “unable.” Maybe that loosing both engines, even with the power provided by the RAT (Ram Air Turbine) he could not apply the thrust reversers and he could not stop the aircraft safely on the Teterboro runway. Immediately after, the pilot advised the TRACON that he was attempting ditching in the Hudson River. So, under unbelievable pressure, Capt. Sullenberger was able to opt for the ditching even if there was a landing field within gliding range. Pilots have always to take the environment they find themselves in and exploit it at the best. In this case the only part of the environment that had not any obstacle was the river.

3) When you are going to travel with an airplane you have to think to your footwear: an interesting article published by the Washington Post has an interview with some of the survivors. One of them, Schugel, regretted the choice he had made of three-inch heels: ““They were very cute,” she said, but they offered little purchase atop a wing slick with jet fuel and water. “We had to go out to the very narrow part to let more people out on the wing. I was trying to take them off, holding onto the lady next to me, and then I’m barefoot on the wing. I don’t know if it was a wave or what, but I slid right off the wing into the water.”

4) Always read the safety card: most of the survivors did not know what to do when the pilot announced they were going to perform an emergency landing. This should never happen. If they want to improve their possibilities of surviving an in-flight emergency (by escaping, helping the flight attendands and the other passengers), they have to listen carefully to the F/A and they have to read the aircraft’s safety card.

5) Life vests are required also for flights taking place above the ground: some airlines had recently hypothesized the removal of flight vests for flights not going to overfly the sea, to save weight and fuel. The AWE1549 demonstrated that they are always needed.