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-   -   BA056 JNB-LHR Incident. (https://www.pprune.org/rumours-news/373713-ba056-jnb-lhr-incident.html)

whattimedoweland 12th May 2009 18:44

BA056 JNB-LHR Incident.
 
I have heard different rumours (thats what this forum is about) that the
BA056 11.5.2009 returned to Jo'burg shortly after take off due to 'multiple' engine failure.

Can anyone in the know with any real facts give a more accurate account to confirm or deny this incident.

WTDWL.

beamender99 12th May 2009 19:35

The latest report
 
Incident: British Airways B744 at Johannesburg on May 11th 2009, two thrust reversers indicated open in flight

By Simon Hradecky, created Tuesday, May 12th 2009 19:05Z, last updated Tuesday, May 12th 2009 19:07Z
The crew of a British Airways Boeing 747-400, registration G-BYGA performing flight BA-56 from Johannesburg (South Africa) to London Heathrow,EN (UK), decided to dump fuel and return to Johannesburg after two thrust reversers were indicated unlocked after takeoff. The airplane landed safely about 90 minutes after takeoff.

Engineers determined that the indication was false, the thrust reversers had been properly locked in closed position.

The flight was initially postponed by 23 hours and later cancelled.


Zulu01 13th May 2009 14:23

It's bigger than that - they nearly bought the farm:

From Av Com

by Romeo E.T. » Wed May 13, 2009 6:31 pm I have just heard some further info..........SCARY STUFF

from some of our technical "boffins" in the office today....results of the DFDR, crew interviews etc.

1)The B747 was very heavy and on rotate one of the engines flamed out, and another "rolled" back to idle RPM.....now on 2 engines only.
2)the thrust reverser light for 2 engines came on, and as per the design features of the B747-436, the leading edge devices retracted.....this is an auto response to prevent F.O.D. to the leading edge devices during reverse thrust operations..... thus even more loss of lift at a very critical phase of flight.
3)thru fast actions the captain was able to restore thrust to the engine that had "rolled back to idle".....but only after leveling off...or even descending doen to 35ft...35ft http://www.avcom.co.za/phpBB3/images...s/icon_eek.gif http://www.avcom.co.za/phpBB3/images...s/icon_eek.gif http://www.avcom.co.za/phpBB3/images...s/icon_eek.gif http://www.avcom.co.za/phpBB3/images...s/icon_eek.gif
4)the aircraft slowly accelerated to climb speed with the partially extended leading edge devices and only on 3 engines.
5)fuel dumping took 2hours
6)after landing the crew refused to take the same aircraft out again...and they "paxed" back last night
7)SACAA has impounded the aircraft at ORTIA where the DFDR has been downloaded to annalize the incident

Juan Tugoh 13th May 2009 18:04

Very scary stuff, sounds like an appalling situation handled with some excellent awareness and fast smart thinking. :D

Hotel Mode 13th May 2009 18:13

I'm not sure about the thrust loss, that certainly hasnt been mentioned in BAs release of DFDR data.

suninmyeyes 13th May 2009 18:29

Those facts don't quite add up. I think you'll find a heavily laden 747 cannot get airborne out of JNB with a loss of 2 engines and also leading edge slats at VR.

LH once tried to takeoff from NBO on a 747 classic without leading edge slats on 4 engines and still didn't make it.

ray cosmic 13th May 2009 18:39

fly around on 2 engines to dump fuel for 2 hours?
Sounds both insane and untrue. The rate of Jettison in the -400 with all pumps operating is 105000 kg/hr, so explain me how much fuel they exactly carried.

wobble2plank 13th May 2009 18:47

Engines 2 + 3 gave spurious thrust reverser unlocked indications at rotate leading to an automatic slat retraction with associated loss of lift.

Crew handled the amber thrust reverse warning with full thrust and gear retraction with onset of stick shaker.

Aircraft flown away and returned to JNB after dumping fuel.

Excellent handling of the situation by the crew who contained an extremely serious incident.

As has been mentioned before a Lufthansa aircraft which tried to get airborne from NBO didn't make it when the LE Slats weren't deployed so it shows the quick thinking of those involved.

M.Mouse 13th May 2009 18:52

The quoted piece above comes from AvCom topic - emergency in JHB now?

The 'authoritative' postings from people who are clearly clueless would suggest it is somebody trying to impress that he has inside knowledge when in reality he hasn't. Gems such as 'Thrust reverser warning light' (no such thing on a B744) with another idiot explaining that a B744 can only dump fuel from the centre tank (it can dump fuel from all tanks).

I do also know the pilots didn't 'refuse to fly it back'.

TURIN 13th May 2009 18:56

I am confused, surely the LE devices would extend again as soon as the craft got airborne.

From another thread...

Automatic Leading Edge Flap Retraction
Group A leading edge flaps are automatically retracted during ground
reverse thrust operation in order to improve structural life of the flap
panels. The function is armed when the airplane is on the ground and
the flaps are operating in the pneumatic mode.

Group A leading edge flaps retract when armed and engines 1 and 4
are placed in reverse thrust or engines 2 and 3 are placed in reverse
thrust. The flaps re-extended when the reverse thrust signals are
removed.


NOTE:
Thrust reverser operation is defined as reverse thrust
selected or airmotor brake released or gearbox unlocked
on a symmetrical pair of engines.

Not questioning the integrity of the reports, just asking the question that's all. :ok:

wobble2plank 13th May 2009 19:00

M Mouse,

Sorry but my post was written entirely by me. Not by the source you claim. I have the full details of the incident. There was no un-commanded thrust reduction or engine shut down but the loss of the inboard and mid LE slats was enough to cause the stick shaker at 12 feet and a level off at about 40 feet.

Extremely scary stuff in a heavy 744 out of JNB.

Still, very well handled by the crew involved.

TURIN 13th May 2009 19:16

Don't think he means you Wobble.

Zulu01? :suspect:

spannersatKL 13th May 2009 19:24

Zulu01 I have nerer read such rubbish........clearly you have no idea of the interlocks in place to prevent leading edge devices retracting when not selected to so do!! !!! I assume on the take off roll the reverse thrust levers were not pulled, flapes not in landing range etc!!! Pure speculation and fantacy on your behalf!!!

Hotel Mode 13th May 2009 19:33


clearly you have no idea of the interlocks in place to prevent leading edge devices retracting when not selected to so do!!
Thats the bit thats correct. The reverse amber did appear and the inboard and midspan LE slats did retract. Looks like another interlock is needed!

What didnt appear to happen was thrust loss.

M.Mouse 13th May 2009 19:36

No I was not referring to you Wobble but the post by Zulu01 lifted from the AVcom website.

I have since learned that the statement ....."rolled back to idle".....but only after leveling off...or even descending doen(sic) to 35ft...35f'' is complete nonsense.

The leading edge slats DID retract at the same time as the reverser unlocked EICAS warning occurred.

It was a very unpleasant incident but was not as dramatic as the factually inaccurate posting from AVcom implies and was well handled by the crew.

TopBunk 13th May 2009 19:57

Typically BA B747-400's take off from JNB at about 354 tonnes (ZFW about 232t + about 122tonnes fuel) for the 10:30 flight to LHR. This at about 15-20 deg C OAT and calm wind will require about 1.68-1.70 EPR from the engines, which is not short of full thrust.

Max EPR with packs off at that density altitude is about 1.74, ie the take off is pretty limiting, and frequently the EGT's will be about 740deg C (vs 785 max).

In those conditions, there is NO WAY that a Flap 20 take off will result in a successful conclusion with 2 engines not delivering thrust (with or without leading edge devices as expected).

There is a lot of bullsh1t here. As I understand it, there were spurious reverser EICAS messages, at the same time there were leading edge flap anomalies; but the engines still produced commanded thrust. What little excess thrust remained was applied, the gear retracted, and after at about 160'agl the leading edge devices re-deployed to the correct position.

Prior to that, stick shake activations had occurred at about 12'agl.

gas path 13th May 2009 20:30

Well seeing as its now in the public domain!
Wobble2plank has it on the money!
It was not a reverser unlock! and on the subsequent landing it all did 'what it says on the tin'!
Engines 2 and 3 REV Amber (cowl position) within approx 15 secs of each other during the roll. As the aircraft was still on the ground this resulted in a command to the FCU's to retract the L/E flaps Group A. The reverser commands to the FCU's operate in pairs 1&4 2&3
The L/E flaps probably extended again as the a/c became airborne.:8

Joetom 13th May 2009 21:11

Sounds like Wobble and Gas have many facts.

From memory, the LH at NBO had all L/E stowed, sad day for them.

Would like to know if subject aircraft had any/much history of REV ind problems with its engines ???
.
ASN Aircraft accident Boeing 747-130 D-ABYB Nairobi-Jomo Kenyatta International Airport (NBO)
.

Romeo E.T. 13th May 2009 21:30

Wobble2plank and gas path...you 2 must be closer to the source than what I am.

as I mentioned on the Avcom website, I was on technical refresher today...course presenters are ex SAA B742/3 flight engineers, and being a BA franchise airline, we do get a lot of info handed down within the company....although "second-hand".

When our technical staff and our FSO relayed the sequence of events including the loss of thrust on initally 2 then restored to only one eng out, I believed their version of the story....

seems I may be wrong on those accusations, but it does still sound like the "reverser-unlock" and subsequent retraction of LE's close to or during rotate and the stick shaker activation still makes it a very scary event, and total "hats off/respect" to the crew for getting it safely out of that situation and to an uneventfull return to land.

wobble2plank 13th May 2009 21:45

M Mouse,

Sorry about that then, I must read more carefully!

:}


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