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Bob Adams
02-27-2009, 11:12 AM
Was just reading a survivor account. He said he heard full power being applied as the plane fell from the sky. Is there any way the thrust reversers can be deployed in flight? I thought it was not possible.

carioca1232001
02-27-2009, 11:30 AM
Is there any way the thrust reversers can be deployed in flight? I thought it was not possible.

There was a tragic accident in Brasil on a shuttle SP-to-Rio flight around 10 years ago with a FOKKER F-28 twin-jet airplane.

Thrust reverser on one engine got activated - on its own, it seems - just as the airplane got airborne.

The airplane veered to one side and the pilot applied more power to the faulty engine assembly hoping to correct attitude but this just compounded the situation.

How was he to know that the thrust reverser got activated on it own ?

Gary E
02-27-2009, 11:31 AM
From what I heard it was to low, to slow, and it stalled before the power could push it back up above stall speed.. then it hit the ground...Pilot error... isnt it almost always pilot error?

Bob Adams
02-27-2009, 11:44 AM
From what I heard it was to low, to slow, and it stalled before the power could push it back up above stall speed.. then it hit the ground...Pilot error... isnt it almost always pilot error?
That's what I thought until I read the survivor account. Let me go find the link.
About halfway down the page.
http://news.yahoo.com/s/ap/20090227/ap_on_re_eu/eu_netherlands_plane_crash

norseman
02-27-2009, 12:01 PM
..Pilot error... isnt it almost always pilot error?


"human errors are symptoms of deeper trouble" ;) Article here (http://www.tc.gc.ca/CivilAviation/publications/tp185/2-07/Pre-flight.htm#Thoughts).

That's my guess anyway,deeper trouble.

pila
02-27-2009, 12:15 PM
The reports sound like it settled into the ground in a landing attitude, likely in a stall configuration. Any other attitude would likely have really busted the airplane up a lot more. Reversers have been known to deploy from electrical problems in their circuitry. Maybe so....maybe pilot error. The recorders should give most of the answers. Luckily it didn't burn.

Gary E
02-27-2009, 12:32 PM
That's what I thought until I read the survivor account. Let me go find the link.
About halfway down the page.
http://news.yahoo.com/s/ap/20090227/ap_on_re_eu/eu_netherlands_plane_crash

You mean this


"We were coming in at an odd angle, and I felt the pilot give the plane more gas," he said. He thought the pilot might have been trying to abort the landing, because the nose came up.


That fits zactly what I said... I been on to many of them almost just like that.
And that means Pilot error... to low, to slow, and to late with the gas

John of Phoenix
02-27-2009, 03:53 PM
Wake turbulence sounds reasonable.
ISTANBUL, Feb 27 (Reuters) - Turbulence created by a large plane landing at Amsterdam just ahead of a Turkish Airlines passenger jet may be the most likely reason it crashed, a Turkish pilots' association said on Friday.

This picture indicates a very low forward speed at impact - as in a stall and fall type crash.
http://www.google.com/hostednews/ap/media/ALeqM5jFDOKCqeiGqd3X7D74VZZDcyMj9A?size=m

John of Phoenix
03-05-2009, 12:02 PM
Stall and fall it was, but caused by a bad altimeter.

Paris, 3/4/09
A faulty altimeter contributed to the fatal crash last week of a Turkish Airlines jet that plunged into a field on its approach to Schipol Airport in Amsterdam, Dutch officials said Wednesday.

They added that they had asked Boeing to alert users of the aircraft about possible risks.

The Dutch Safety Board, which is investigating the Feb. 25 accident, said one of the aircraft's two radio altimeters, an instrument that gauges a plane's altitude, sent a wrong reading to the automatic pilot system, resulting in an abrupt loss of airspeed.

Witnesses said the Boeing 737-800 aircraft, carrying 135 people, appeared to drop like a stone. It landed first on its tail, then slammed into the ground, skidded on its belly and broke into three parts just short of the runway. Nine people on flight TK1951 from Istanbul, including the three pilots, were killed.

During its descent, when the aircraft was at 1,950 feet, or 594 meters, the left altimeter suddenly indicated a change in altitude to minus 8 feet, and sent that reading to the autopilot system, according to a report released Wednesday.

"The aircraft reacted as if it were two meters above the ground," said Fred Sanders, a spokesman for the Dutch Safety Board.

Sanders said the flight recordings showed that the plane had experienced problems with its left radio altimeter twice before, in similar pre-landing situations. "We have asked Boeing to warn users of this system and this type of plane," he said.

Boeing said Wednesday that it was reminding its 737 operators to "carefully monitor primary flight instruments during critical phases of flight."

Gideon Ewers, a spokesman for the International Federation of Airline Pilots Associations in London, said it was not unusual that the plane was landing on autopilot.

Another report from the BBC
http://news.bbc.co.uk/2/hi/europe/7923782.stm

Paul Pless
03-05-2009, 12:17 PM
"carefully monitor primary flight instruments during critical phases of flight."
Is there such a thing as a noncritical phase?

Tom Wilkinson
03-06-2009, 02:26 PM
737 throttle don't just retard to idle without the crew knowing about it, and can the autothrottle can be overridden at anytime by crew input. The autothrottle system physically moves the throttle levers so the crew should have noticed the throttle movement and the should have noticed that their airspeed was dopping below minimums.

Airspeed cannot always be 100% controlled by the autopilot/autothrottle, infact no autoland can occur without pilot input. Since airspeed is a function of thrust vs drag, the pilot always has the ultimate authority. The autopilot cannot deploy flaps or landing gear, both of which will hve great effect on airspeed. It is entirely possible that the autothrottle system cannot maintain the required speed (usually too fast than too slow) so the crew should always be monitoring throttle setting and airspeed for a give configuration.

I am always leery of news reports regarding such incidents as they greatly generalize about the systems in play.

(the above statements don't apply just to the 737-800, but nearly every commercial airliner that I am familiar with)

CK 17
03-06-2009, 05:21 PM
Would a bad RA cause it to enter a flare manuver to soon? This alone shouldn't cause a crash.

Tom Wilkinson
03-06-2009, 05:46 PM
Without looking at the wiring prints and a good system d&o I wouldn't want to say for sure but in an autoland confuguration these systems generally need to have at least two systems in agreement to make a control input. If both RA don't agree then it should not enter a flare maneuver. I don't know what other system inputs are required but am sure it is more than just RA.

If I have time to look into it deeper this weekend I will.

I beleive there is a whole lot more to the story than a failed RA system.

The Bigfella
03-06-2009, 05:57 PM
There was a claim at the time that they ran out of fuel. No more on that?

John of Phoenix
03-06-2009, 06:24 PM
I suspect that closer to the ground in the final stages of landing that the crew would be on the controls and would have noticed the throttles backing off. At 2000 feet they'd likely be going through checklists and not expecting anything other than the autopilot to continue the approach when out of nowhere it looks and sounds like a power failure. At that point it was grab the controls and try to figure out what's happening just in time to stall.

At least one survivor said power was applied just before impact so that casts doubt on the fuel exhaustion scenario.