Faulty Radio Altimeter may have triggered Turkish crash - inquiry
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Faulty Radio Altimeter may have triggered Turkish crash - inquiry
Wed Mar 4, 2009 11:04am EST
By Catherine Hornby
THE HAGUE, March 4 (Reuters) - A malfunctioning altimeter contributed to the crash of a Turkish Airlines flight last week at Amsterdam airport, said Dutch authorities, who issued a warning to the plane's maker Boeing.
When flying at about 1,950 feet (594 metres) the plane's left radio altitude meter indicated the Boeing 737-800 was flying at minus 8 feet, prompting the automatic pilot to shut down the engines, the Dutch Safety Board said on Wednesday.
"The crew initially did not react to these events," Dutch Safety Board head Pieter van Vollenhoven told reporters.
When an alarm went off that the plane's speed would drop below the minimum, the pilots reacted and reignited the engines.
"But the plane was too low at 150 metres. As a consequence the plane crashed 1 kilometre before the runway," said Van Vollenhoven.
Five Turks and four Americans were killed when the Boeing plane plunged into a field short of a runway while trying to land last week at Schiphol, Europe's fifth-largest airport by passenger numbers and third largest by freight volume.
Among the dead were three pilots and a flight attendant. The plane carried 127 passengers and 7 crew, of whom 28 are still in hospital.
"We are focussing the investigation on the malfunctioning radio altimeter and its consequences. Whether there could have been a different reaction will take more time to find out," Van Vollenhoven said.
"The reason to go public now already is to warn Boeing and all users of this plane type that vigilance is required with regards to the altimeter," he said.
Boeing said in an statement it was "issuing a reminder to all 737 operators to carefully monitor primary flight instruments during critical phases of flight".
The plane initially hit the ground in a boggy field with its tail followed by its undercarriage, with a forward speed of 175 km per hour on impact. An aircraft should normally have a speed of 260 km per hour for landing, the safety board said.
Braking caused by the ground meant that the aircraft broke into two pieces. Most of the fatally wounded were near the rupture, in business class, and the three crew members in the cockpit died as a result of the enormous braking forces.
- - - -
*Additional reporting by Gilbert Kreijger in Amsterdam, and Bill Rigby in Seattle; Editing by Louise Ireland
I do not fly a 737 but maybe somebody who does could please explain how a faulty rad alt will cause the engines to shut down? Seems crazy to me!
By Catherine Hornby
THE HAGUE, March 4 (Reuters) - A malfunctioning altimeter contributed to the crash of a Turkish Airlines flight last week at Amsterdam airport, said Dutch authorities, who issued a warning to the plane's maker Boeing.
When flying at about 1,950 feet (594 metres) the plane's left radio altitude meter indicated the Boeing 737-800 was flying at minus 8 feet, prompting the automatic pilot to shut down the engines, the Dutch Safety Board said on Wednesday.
"The crew initially did not react to these events," Dutch Safety Board head Pieter van Vollenhoven told reporters.
When an alarm went off that the plane's speed would drop below the minimum, the pilots reacted and reignited the engines.
"But the plane was too low at 150 metres. As a consequence the plane crashed 1 kilometre before the runway," said Van Vollenhoven.
Five Turks and four Americans were killed when the Boeing plane plunged into a field short of a runway while trying to land last week at Schiphol, Europe's fifth-largest airport by passenger numbers and third largest by freight volume.
Among the dead were three pilots and a flight attendant. The plane carried 127 passengers and 7 crew, of whom 28 are still in hospital.
"We are focussing the investigation on the malfunctioning radio altimeter and its consequences. Whether there could have been a different reaction will take more time to find out," Van Vollenhoven said.
"The reason to go public now already is to warn Boeing and all users of this plane type that vigilance is required with regards to the altimeter," he said.
Boeing said in an statement it was "issuing a reminder to all 737 operators to carefully monitor primary flight instruments during critical phases of flight".
The plane initially hit the ground in a boggy field with its tail followed by its undercarriage, with a forward speed of 175 km per hour on impact. An aircraft should normally have a speed of 260 km per hour for landing, the safety board said.
Braking caused by the ground meant that the aircraft broke into two pieces. Most of the fatally wounded were near the rupture, in business class, and the three crew members in the cockpit died as a result of the enormous braking forces.
- - - -
*Additional reporting by Gilbert Kreijger in Amsterdam, and Bill Rigby in Seattle; Editing by Louise Ireland
I do not fly a 737 but maybe somebody who does could please explain how a faulty rad alt will cause the engines to shut down? Seems crazy to me!
I don't either, but there is a lot of info (mixed with the dross) on the thread over at rumours and news.
This probably answers the question fairly adequately.
This probably answers the question fairly adequately.
Last edited by Tarq57; 5th Mar 2009 at 02:30.
please explain how a faulty rad alt will cause the engines to shut down?
Why the aircraft then crashed slow and short is another matter.
Interesting that the Firies couldn't get into the cockpit through the door. They then concentrated first on the pax, only retrieving the pilot's bodies through a hole they cut in the roof, so Flight reports.
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I don't fly them either, however my understanding is that the autothrottle is connected to the radalt (in this case, the left, faulty one), which prompted the autothrottle to go into flare mode, and retard the trottles to idle.
Unfortunately it would seem this was not caught, and resulted in the aircraft not making the runway.
'Shutdown' would be typical journalistic accuracy.
Unfortunately it would seem this was not caught, and resulted in the aircraft not making the runway.
'Shutdown' would be typical journalistic accuracy.
Capn Bloggs
As mentioned in other threads previously, in a crash where there are survivors recovering dead bodies is NOT a priority. Especially when the dead are in the cockpit. It is important to preserve everything in the cockpit so investigators can determine cause by location of switches, throttles, flight controls, radios etc. All these can be easily knocked about by attemted removal of the dead before investigators arrive.
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Thanks for the info folks.
Thread running here for anyone interested: http://www.pprune.org/rumours-news/3...-schiphol.html
TID
Thread running here for anyone interested: http://www.pprune.org/rumours-news/3...-schiphol.html
TID
