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WASPERNATOR
15th Apr 2012, 09:51
Apparently 'forced to return to SFO' after lightning strike.

Why?

beerdrinker
15th Apr 2012, 09:57
Pax oxygen masks were deployed (not by crew).

See Incident: United B772 at San Francisco on Apr 12th 2012, lightning strike (http://avherald.com/h?article=44df03ce&opt=0)

WASPERNATOR
15th Apr 2012, 10:08
Thank you. All we need to know now is why they deployed?

Huck
15th Apr 2012, 12:59
Queertrons....

DC-ATE
15th Apr 2012, 13:28
Fuel Dumping -

I never had to dump fuel in my whole career [except in the Sim of course !! ], but even though it supposedly vaporizes, I can't believe that SOME fuel doesn't reach the ground. I always thought that if I ever had to dump, I'd sure try and be over water or far from civiliztion.

Thoughts...

lomapaseo
15th Apr 2012, 13:57
I can't believe that SOME fuel doesn't reach the ground

it does as road grime on your car windshield. Pretty much indistinguishable from every day dirt on shinny surfaces.

The ppm makes it low enough that very few know.

I was aboard a B747 where the pilot announced dumping fuel while over New Jersey. Some of us laughed about if the folks on the gorung would know.

I was never quite sure if his announcement was a pre event or during. I never did forget his announcement right after the first one "please do not smoke"

I spoke to him afterwards and we both stated it was our first air-turn-back and fuel dump.

Sampan Angkasa
15th Apr 2012, 14:11
A question for the experts; during fuel jettison will the fuel become atomized and be susceptible to fire hazard from lightning? Likewise in a small fuel leak, will the atomized fuel ignite due to St Elmo's fire type electrical static charge?

I surmised that they must have dumped fuel away from the area where they first had the lightning strike.

Machinbird
15th Apr 2012, 15:02
As a Naval aviator, we routinely dumped fuel. In my type aircraft, we usually left a couple of thousand pounds in the wing where it was dumpable, and transferred the rest in. Landing gross weight limitations were absolute and had to be met. You were always saving fuel to better handle contingencies, and then dumping down to landing weight at the last minute, often on downwind and even into the groove. We often observed our wingmen's dump and our own. Depending on the rate of dump and airspeed, the fuel plume would break up into fine droplets and be invisible within a couple of plane lengths.

I've always been amazed at the amount of agonizing airline folks do over dumping fuel.

Swissair Flight 111 comes to mind. Instead of fiddling around with the dump, they would have been far better off to have turned on the dumps, point the nose toward Halifax, and come on down as quickly as possible (only under control this time).

DC-ATE
15th Apr 2012, 16:29
Machinbird -
I've always been amazed at the amount of agonizing airline folks do over dumping fuel.

Uh.....don't get me wrong; I would've dumped in a minute IF I ever had to. But, fortunately, I never had to. Pan Am was "The World's Most Experienced Airline" and we let THEM have all the experiences !! :O

ion_berkley
15th Apr 2012, 18:29
April 12 was quite the day to go flying around SFO...10 miles further North...
http://blu.stb.s-msn.com/i/60/DFF9BA5BA42389B56C9B8E64A4113F.jpg

69flight
15th Apr 2012, 18:30
@Machinbird:
Quote:
"Swissair Flight 111 comes to mind. Instead of fiddling around with the dump, they would have been far better off to have turned on the dumps, point the nose toward Halifax, and come on down as quickly as possible (only under control this time)."

Before making such statements take the time to read the final report about the SR111´s accident.

Emoclew
15th Apr 2012, 19:18
Agree, there but for the grace of God......

jet_737ng
15th Apr 2012, 19:58
Before, you are wise; after, you are wise. In between you are otherwise”
― David Zindell (http://www.goodreads.com/author/show/399921.David_Zindell), The Broken God (http://www.goodreads.com/work/quotes/1133015)

Machinbird
15th Apr 2012, 21:22
Before making such statements take the time to read the final report about the SR111´s accident.
I believe I've read it several times through over the years. If they had taken the smoke extremely seriously at the start and instead of declaring a PAN, declared a Mayday, and then started coming down like a safe, they might have had a chance. The decision to fly towards a dump area wasted valuable time. The first 10 minutes after the PAN call they had a fairly functional aircraft. If they had been turning final at that point, they might well have made it. Not an easy piloting job at all, but possible. The 66 mile initial distance from Halifax was well inside their normal TOD.

I have no desire to rehash that entire accident on this thread. We all should know just how bad an emergency a fire in flight is, and that extending your time in the air is extremely hazardous.

Of course, I do have significant hindsight bias.:hmm:

ECAM_Actions
17th Apr 2012, 19:22
I seem to recall from the first hint of smoke to the pilots becoming incapacitated due to heat was just 12 minutes. The investigators stated that even if the airfield was ideally situated ahead of the aircraft they still wouldn't make it.

Huck
17th Apr 2012, 20:12
First there was a smell.

Then the smoke.

Two different events.