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-   -   BA038 (B777) Thread (https://www.pprune.org/rumours-news/340666-ba038-b777-thread.html)

infrequentflyer789 5th March 2008 22:38


Originally Posted by Green-dot (Post 3954269)
After digging into some background information i ran into an article in a "Code One Magazine" which may be of interest.

Interesting. This passage caught my eye:

"then you will start to hear strange noises as the combustion becomes unstable in the engine. You will hear a low rumble as parts of the ejector nozzles become too lean to burn."

Various news reports have eye witnesses reporting odd engine noises ("roaring" and "rumbling")...

Chris Scott 5th March 2008 22:50

Oldlae,

Yeah - Guess that's the point grebllaw123d was making. So, I suppose we can assume that the 200ER has not been fitted with the fuel scavenge system design changes that the Service Bulletin is addressing.

Smilin_Ed 6th March 2008 01:05

Compressor Inlet Guide Vanes
 
The AAIB report says that the compressor inlet guide vanes responded properly to the demand for more power.

SeldomFixit 6th March 2008 03:45

....which loaded the compressors more, without the required F/F increase....

spannersatKL 6th March 2008 05:20

Wilyflyer
See the AAIB report that shows that whilst the fire handles were pulled the LP valves did not close....the crew shut down procedures has now been modified...

wilyflier 6th March 2008 09:08

SpannersatKL
..Yes,but the engines should have been unable to run if the HP cocks were closed by the fire drill , thus still a little niggle about not much fuel should have been leaking if the engines really continued to run on the ground ,(which I doubt)
..But a bigger niggle as to was there evidence was to show the CWTs were really as dry as they should have been by then; in order to disprove any ice block misbehaviour of the CWT scavenge systems?

lomapaseo 6th March 2008 13:11

SeldomFixit


....which loaded the compressors more, without the required F/F increase....
:confused:

even I can't read between the lines when there are no lines posted as a reference to your post:(

airfoilmod 6th March 2008 16:04

Post #160
 
With all due respect, "what's Old is New again." Noises on approach, human factors, stall avoidance, etc. 108 knots with an AOA at that value, is Scary. That Aircraft is not to be stalled, period. (Notwithstanding nonsense replies from bug smasher pilots.) Fuel exhaustion is still on the table, but so is information starvation. This thread is on life support.

FAStoat 12th March 2008 12:29

Oh by the way,am I correct in thinking David Learmont said in one of the initial reports that the Crew experienced a slight Power Surge problem when they came off the Lam hold????This has not been mentioned in any of the threads I have read,or is a figment of my imagination?

F14 12th March 2008 16:34

err, wasn't GB flying a BA777 too??

Think u'll find it was good old Vmca on approach, long flight tired crew. Engine No2 failed (check the pics) Crew went heads in, didn't spot speed decay till below Vmca, ie, cannot go around!! must trade height for speed.
The lads did a good job because every body walked away, however couldn't be a great landing because unable to use the aircraft again.

Basically there are no "new" aircraft accidents, just a swiss cheese that when the holes in training, hardware, automatics and Humans line up we get an incident...

Smilin_Ed 12th March 2008 19:18

Electromagnet Interference
 
Everyone keeps forgetting that the original report by the AAIB says that the fuel metering valves opened in response to the Autothrottle and the crew's movement of the power levers. This means that the engines should have accelerated but instead, they hung up at just above idle. This clearly indicates a lack of sufficient fuel at the fuel metering valves. The real question is why?
[/COLOR]

SilsoeSid 12th March 2008 21:29

DingerX

Feel free to look at the maps and tell me where you would expect the motorcade to be "under the approach path.

How about anywhere between Hounslow and the crash site!

http://i52.photobucket.com/albums/g1...d/Hounslow.jpg

Or
Within 2 miles of the crash site....anywhere in this picture!

http://i52.photobucket.com/albums/g1...esid/27L-1.jpg

Or
Anywhere east of 27L threshold with the aircraft below 10,560'!

http://i52.photobucket.com/albums/g1...oesid/east.jpg

Or if you want a road map, how about an autoroute route from Downing Street to Heathrow.
Notice, if you will, how the A4 dips nicely south towards the approach path!

http://i52.photobucket.com/albums/g1.../autoroute.jpg

X-37 13th March 2008 15:12

Why are so many posts hostile to the idea of electronic interference?
The AAIB have not ruled this out in fact they don't seem to know what caused the accident.
It could be electronic, it could be that contaminated fuel got to both engines within 7 seconds ( or rather fuel didn't get to..).
Incidentally Both lifts in the Control Tower failed at exactly the moment of the incident. This may not be relevant, on the other hand it may well be. Was the accident caused by fuel,was it a burst of RF, was it Gordon Brown, was it onboard cellphones/laptops????
None of us here know the cause.
The AAIB are not saying, so all bets are on until they tell us what happened.

grumpyoldgeek 13th March 2008 15:19


Why are so many posts hostile to the idea of electronic interference?
Because many of us have worked in electronics for years. We intuitively understand antenna theory, the inverse square law and the incredible difficulty of transmitting significant amounts of electrical energy through air.

tubby linton 13th March 2008 17:34

This tool is interesting.The last time I looked I think the day of the accident had been sanitised.
http://lhr.webtrak-lochard.com/template/index.html

airsound 13th March 2008 18:36


This tool is interesting
It certainly is, tubby. Thanks for the heads up. Shame about 17 Jan though.

airsound

Green-dot 13th March 2008 20:42


Because many of us have worked in electronics for years. We intuitively understand antenna theory, the inverse square law and the incredible difficulty of transmitting significant amounts of electrical energy through air.
With respect to all with a profession in aviation, regardless of background, intuition does not always win it from the facts.

I personally had to replace main fuel shutoff valves in engine feed systems (back in the 1980s) because intuition and inverse square laws did not prevent them from closing in an unscheduled manner then. The valves were redesigned and the wiring was provided with an improved electrical connector. And guess what, EMI filter modules were added between the connector and fuel shutoff valve.

I won't go into specific details here, not about what i wrote above nor specific T7 details, not that it matters much because i have noticed that a thread posted by me regarding a GENERAL explanation of the EMI phenomenon yesterday has been removed without the decency of the "puppet-masters" on this forum to explain to me as to why!!! And it has not been the first time with regards to BA038. That makes me wonder.


Regards,
Green-dot :oh:

Del Prado 13th March 2008 21:15


Incidentally Both lifts in the Control Tower failed at exactly the moment of the incident
I believe that was an on going problem throughout the day and NOT coincident with the accident.

grumpyoldgeek 13th March 2008 21:48


I personally had to replace main fuel shutoff valves in engine feed systems (back in the 1980s) because intuition and inverse square laws did not prevent them from closing in an unscheduled manner then. The valves were redesigned and the wiring was provided with an improved electrical connector. And guess what, EMI filter modules were added between the connector and fuel shutoff valve.
Means nothing unless you know that the fault was caused by *radiated* EMI rather than conducted.

Oldlae 13th March 2008 22:30

The AAIB bulletin stated that the fuel control system was working, the open spar valves were blamed on a faulty shut-down procedure, so it is unlikely that all the RF and the PM's ECM affected the elecrics. So it is obvious innit, all the RF and ECM made the fuel boil thus sending fuel vapour to the engines, causing cavitation and lack of thrust.:)


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