BA 777 crash at heathrow

Damage to the fan blades suggest engines on low power setting or just windmilling on impact.

i6.tinypic.com...

i17.tinypic.com...

Down-right on this picture:

i19.tinypic.com...

The RAT is clearly deployed and sweapt under the fuselage on impact.

On the triple seven the RAT deployes when both engine driven generators drop off line, or all hydraulic systems indicates low pressure.

The APU door was also open, the APU on the triple seven autostart when
both AC-transfer buses is no longer supplied by the engine driven generators.

So, at this point it seems like they lost power on both engines at final approach.

Turns out it was the co pilot that landed the aircraft and not the captain

BBC

Although i assume he must have assisted in some way?

reply to post by solidshot


Probably calling out hight speed etc for the co-pilot. a little unusal considering the number of accidents where the pilot take control and is in control for but if this was the sudden failure that it seems like the smart thing to do in order to not mess up cockpit management would be to keep the co-pilot who it seems was flying the landing in control.

reply to post by Freaky_Animal


Just to be clear where actually people are looking at with the one picture the RAT on a 777 is located here as seen in this picture of another 777 on landing.



The location in the other image posted by Animal (and corrected for shadows by myself so people don't claim fake) is here and in comparision to my other image it seems to be on the other side? so are we talking differences in versions or something? or has one of the images been flipped with out my knowledge and lack of res to be able to determine.

Originally posted by solidshot
but what would explain both the loss of power and the electronics failure both at the same time?

American workmanship?

reply to post by RichardPrice


RIchard good answer..I did automatic test of GE FADEC 1+2(Airbus 320/Airbus 340, 747) engine controls for 13 years..I know some 777s had GE GE90 Engines/controls. I am somewhat familiar with those as well I suspect the 777 has either what GE calls FADEC 3 or if older GE90.
Yes they have dual redundant controls for each engine. Usually power is supplied by Alternator but there is also DC backup. Software compares reality with existing profiles and picks what is closest to fly by. What I mean is if one channel of control has a parameter out of whack the SW will switch to the other but either case it compares to profiles that actually check a certain pressure which is a function of altitude..it doesn't in any case turn off engines.
This is a strange one I doubt it could be controls.

The initial AAIB report says that both engines failed to respond to an autothrottle commanded thrust increase, and then also failed to respond to a manually commanded thrust increase (via throttle movement). The investigation into why commanded thrust increases failed to be acted on by either the engines or the engine management system is currently ongoing.

This has a a few implications for both BA, Rolls Royce and Boeing - is it a maintenance issue that caused the engines to become unresponsive, is it an engine issue (unlikely since it occurred in both at the same time) or is it an engine management software issue and thus a design fault? This could have wider implications in the currently flying 777 fleets.

Could an EMP (Electromagnetic pulse) weapon cause something like this to happen? I know that Air Force One has systems that shield the aircraft from an EMP attack, but I doubt a civilian airliner would have the same thing. And being fly by wire, I would think that an EMP attack would be especially dangerous. With the information on the accident so far, I think that the root of the failure is electronic in nature. There was a crash of an Airbus 320 that was doing a low pass during a demonstration. When the pilot applied power for the climb-out, the engines did not respond and remained idle. Some think this was caused by a programming error in the fly by wire software.

Hey John Lear, what are your thoughts on the fly by wire systems?

Originally posted by Rotoplooker
There was a crash of an Airbus 320 that was doing a low pass during a demonstration. When the pilot applied power for the climb-out, the engines did not respond and remained idle. Some think this was caused by a programming error in the fly by wire software.

The engines responded - they just dont spool up that quick from idle. That pilot was an idiot, flying below the height of obstacles surrounding the air field, and changed his plan at the last minute (changed direction of the demo). That was an accident waiting to happen.

There are a couple of compounding issues - Airbus had released an advisory note a few weeks prior relating to the altimeter, but regardless the pilot was below the height of surrounding obstacles.

Oh, and an EMP 'weapon' would have much more widespread effects that just the aircraft.

[edit on 18/1/2008 by RichardPrice]

Just comming on and have not read the entire thread.,

Was this an ETOPS a/c?

Twin engine failures IMHO points to either a fuel issue or some kind of software code error. A dual birdstrike is highly unlikely as is an EMP type device. As Richard noted and EMP device even small would still have area effects and would have taken out alot of the avionics as well. Plus it would have been detectable in and of itself.

The engines on the 777's have been fairly reliable to this point and you can bet that Boeing is going to fight tooth and nail if there is any suggestion of software or engine reliablity as they do not want to out the 180-240 minute ETOPS at risk

[edit on 1/18/08 by FredT]

reply to post by Rotoplooker


No EMP IMHO..
First controls are all encased in aluminum chassis.
Second now other effects reported in that area.

An emp would surely have knocked out the electronics around the airport? also don't aircraft have their electronics encased within some kind of faraday cage to protect them from lightening strikes ect? and wouldnt this have rendered an emp useless?

[edit on 18-1-2008 by solidshot]

Originally posted by FredT
Just comming on and have not read the entire thread.,

Was this an ETOPS a/c?

Yes, all BA 777s are maintained to ETOPS 207 standards, and the 777 has manufacturer level ETOPS certification.

Twin engine failures IMHO points to either a fuel issue or some kind of software code error. A dual birdstrike is highly unlikely as is an EMP type device.

Theres no evidence on any of the photos released of any bird strike heavy enough to take down both Trent 800's (feathers, blood etc), and the fact that both engines failed to respond at the same time indicates a possible failure in the FADEC (Full Authority Digital Engine Control) or EMC (Engine Management Computer).

[edit on 18/1/2008 by RichardPrice]

Originally posted by solidshot
An emp would surely have knocked out the electronics around the airport? also don't aircraft have their electronics encased within some kind of faraday cage to protect them from lightening strikes ect? and wouldnt this have rendered an emp useless?

[edit on 18-1-2008 by solidshot]

You have to specifically harden against EMP if you want to survive an EMP, and yes one would knock out a considerable area around the approach path. This was not caused by an EMP, end of.

reply to post by solidshot

Another method of protection is to keep all essential electronics within an electrically conductive enclosure, called a Faraday cage. This prevents the damaging electromagentic field from interacting with vital equipment. The problem with Faraday cages is that most vital equipment needs to be in contact with the outside world. This contact point can allow the electromagentic field to enter the cage, which ultimately renders the enclosure useless.
www.globalsecurity.org...

The images that where located above that Animal claimed the RAT hatch was showen and my question about its location due to finding a photo that showed what I thought made sense that it was located on the other side was never commented on and has been over looked by the following posts.

However in the report release they show the image and comfirm its locations to be on the other side. However they are unsure if it had been deployed or riped out.

Here is the photo from the correct side.



just some further statements as well.

The aircraft came to rest at the edge of the pre-threshold tarmac of runway 27L having made a very short ground run of about 350m. Witness reports of the aircraft attitude as it crossed the boundary fence suggest the aircraft was at or close to its stalling speed.

Sources at Heathrow say the crew had declared an emergency early on final approach but did not have time to be specific about the problem.

Almost all the passengers who have commented since the accident say the approach felt normal and the crew did not provide any warnings, but many did not realise they had "crashed" until the cabin crew ordered the evacuation. There was no fire

www.flightglobal.com...

Also Guys and Gals this thread should be flagged! its a great informed discussion that will go un-noticed otherwise. Lets help get people the good info.

[edit on 18-1-2008 by Canada_EH]

The theory pilots propose is that although fuel was plentiful, a heavier-than-fuel contaminant, such as water, represented a minute proportion of the fuel in the tanks on the approach, so problems did not arise.During the flight, the fuel was cold-soaked and any contaminant could have frozen to crystalline or solid form. Then, in the bumpy approach at lower levels, as the fuel warmed, the melting contaminant began to circulate in the relatively small amount of fuel remaining, forming a slush that could impede the fuel flow to the engines

www.flightglobal.com...

Seems like a very plausible reason seeing as a birdstrike has all but been ruled out. I wonder if any checks are being performed at the Airport in China to ascertain any issues with the quality of fuel used ?

reply to post by juggle


That make much more sence. There are two things both engines share. Fuel and Software. Other than that they have thier own redundant back up systems

Kudos really need to go to the flight crew on this one. The plane is no doubt a total, but they got the a/c down and everybody surrvived. If this is not worthy of a Queens medal (or whatever she gives out) then Im not sure what is.

Originally posted by juggle
Seems like a very plausible reason seeing as a birdstrike has all but been ruled out. I wonder if any checks are being performed at the Airport in China to ascertain any issues with the quality of fuel used ?

Its plausible but it does not explain why it affected both engines at basically the same moment - both engines feed from the wing tank they are hung off, so both engines fuel supplies are isolated, no two engines run at the same efficiency, so there will be differences in the amount of fuel in the two tanks, and yet the issue hit both engines at essentially the same time.

In a scenario like this, even fuel contamination in both tanks would not affect both engines at the same time - there would be a delay between the two engines being affected for the reasons given above.

This is looking more and more likely to be a FADEC or EMC issue I think.

Originally posted by Rotoplooker

Hey John Lear, what are your thoughts on the fly by wire systems?

I thank the good Lord Above daily, that I was able to retire before I ever had to fly an airplane that used fly by wire technology.

I often think of the pilots of Swissair 111 who spent the last few minutes of their lives back in First Class not only because of the fire in the cockpit but because every means of controlling the aircraft had been disabled by the fire.