2002 report on Garuda 737 double flameout in 62,000 ft CB
 

Just found this 2002 accident report on the Garuda B737-300 that had a double flame-out on penetrating a super-cell of 62,000 feet. Adding to the crew woes the aircraft battery was defective resulting in the inability to start the APU. Total electrical failure followed and the 737 belly landed flaps up into a shallow river. One of the most interesting reports I have read. In particular where the engines flamed-out under heavy rain and hail conditions beyond the ability of the engines to recover. The stuff of nightmares.

http://www.dephub.go.id/knkt/ntsc_av...0GA%20Solo.pdf

Check out Southern Airways Flight 242 for similar bad experiences in thunderstorms.

"It also suggested from CVR read-out analysis that the intensity of attenuation was heard as a GPWS warning “terrain – terrain”

That is some heavy weather indeed....

Call-out was "the rain, the rain". Very sophisticated device, well ahead of the competition.

poorjohn, very witty :)
Recommendations didn't seem to mention anything about maintenance - of the battery - or did I miss something?
Recollect being in Thailand with knackered APU battery which a certain Australian scrap merchant wouldn't pay to have replaced :*

That would be one hell of an updraught...

- oh I don't know.:)

The one I thought showed a crew on top of their game was TACA Flight 110. A 737 lost both engines descending through 16,500 feet as a result of encountering a level 4 TS. Dead sticked onto a levee bank, undamaged save for one cooked engine, which was changed, and the aircraft flown out from an adjacent road.

FTW88IA109

Air Europe had a double flame out on a B737-300, back in the mid eighties, in heavy rain somewhere south of Thessaloníki. Don Wright was the captain and he and his FO got them both going again, thank God!

Checking proves you correct IGh. A stretch of grass some 6000X120 feet as indicated by the red dots.

http://i101.photobucket.com/albums/m...am227/TA-1.jpg

Reading through the Garuda report it seems that the crew kept the engine power set at flight idle in the descent.

After the TACA incident guidelines were issued to increase power in heavy rain to avoid a flame-out. Maybe Garuda did not get the telex.

I was working in Solo when this occured. You should have seen the crowds and "street sellers" in the areas around the aircraft. A sight to see !!

Wached many a Garuda depart in the the most horrific rainstorms. Always scared the what's it's out of me !

A couple of interesting things to read in the report about hail.

"Another method to quantify the density of hail encountered is using the GPWS phenomena. It is recognized from the CVR and DFDR that the radio altimeter picks up high density precipitation as false terrain closure and triggers the GPWS to give terrain warning. It is known that GPWS could give false terrain warning when its radio altimeter signal is reflected by heavy precipitation. However, this method could only be used as an indication of the density of the rain/hail."

"It is known that the fuel flow is affected by the amount of hail/water ingested into the engine."

" The presence of water in the core engines will increase the fuel required to keep engine N1 (fan rotation) at certain throttle setting."

"At entering the turbulence, the recording indicates water ingestion by the engines as the fuel flow increased from 600 lbs/h to as high as 770 lbs/h, before it went down to 510 lbs/h at the end of the recording."

"The engine model showed that the estimated 150 lbs/h fuel hike indicates that a 3.5% water/air ratio existed in the core of the engine, which is equivalent to over 5 g/m3 hail content in the atmosphere. The standard for the highest rain could not result in a 3.5% of water/air ratio. Therefore, hail must have been present in the air at the time."

I don't know why fuel flow is affected by water/hail ingestion. Anybody?

Is fuel flow related to the mass of 'air' flowing past? Like the MAF sensor on a car. Surely wet air has more mass than dry air. Engine suddenly thinks it is 10,000 feet lower.

Re. the fuel flow increasing.
IIRC the early CFM 56s have a hydro-mechanical MEC that is basically an N2 governor that is trying to maintain the selected N2 rpm. If the HP compressor is deluged with water or ice that tends to slow it down, the MEC will increase fuel to try and maintain the rpm.

That reminds me …
after the levee landing ; in heavy rain we had to use 55% N1 or so on 737-300s . That was basically approach power ; and to fit in the LHR approach sequence became challenging . So …when one or the other of us started singing Don Mclean’s American Pie …
‘‘’ Bye, bye Miss American Pie
Drove my Chevy to the levee but the levee was dry
And them good ole boys were drinking whiskey and rye
Singin' this'll be the day that I die
This'll be the day that I die ‘’’

You knew it was time for gear and full speedbrake , fully close one throttle , [ ' risk it for a biscuit '] the other at 55% N1 and sideslip her down .
A long descent like this , we might bring idle one to 55% and idle the 55%er , sideslipping in the opposite direction


Took a redesign of the engine nose cowl / spinner shape , and other bits to cure the rain prob , and the CFM56 lost it’s ‘’C**ppy French Motor ‘’ sobriquet . Excellent engine since .

Rgds condor

Aircraft was 2 weeks old when this happened. Still flying in 2016 as N697SW with Southwest. Seems to have ranged as far apart as San Jose CA and Orlando, via many places along the way, only today.

62,000 feet !!
It's a wonder the donks didn't die of hypoxia at that level.
Be lucky
David

The control system seems to be accommodating a shift in efficiency (N1/FF) of about -20%, I suggest that the engine model water content of 3.5% is too far off. I think this change is probably due to openning the VBV [report section 1.18.2 - last sub-paragraph].