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Crash at Sharjah airport

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Old 29th Oct 2009, 14:15
  #101 (permalink)  
 
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Thanks Heracles & PJ2.

Yes I noticed the lack of smoke from the other engines, but I know nothing about operating this aircraft, flew around the world as a child in them, but it seems your explanation is the more plausible.

I noted when making the video that the speed I panned the shot to the left, decreased significantly as if the AC is losing speed and it doesn't reappear in the shot where you would expect it to be, given the speed it left the runway.

They probably would have gone further with 4 working engines and no tail. I was in a small twin when we lost control after buzzing the boat club, the control cables didn't have enough tension, well not enough for the stunt, I had this feeling as the AC fishtailed upwards that we were going to crash into the sun not the earth. We had a 3m stinger attached to the tail, and at first we thought we'd lost it, impaled the bartender with the damn thing...

I guess if you have enough forward speed a lot has to fall off before you start heading downwards. My vote is for it may have been falling apart but the lack of engine power is the reason it crashed.
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Old 29th Oct 2009, 15:01
  #102 (permalink)  
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Very well said, Heracles. Loss of two on one side is a very serious emergency requiring swift and accurate handling and control of the bank angle if one is to survive. (for others who may not be familiar with why...): "Control of the bank angle" means sufficient speed for the rudder to be effective to control yaw which in a jet transport will cause instant roll. A powered rudder and adequate training is assumed, of course.

CaptainChaotic;
I guess if you have enough forward speed a lot has to fall off before you start heading downwards. My vote is for it may have been falling apart but the lack of engine power is the reason it crashed.
One possibility then, is a catastrophic failure of #3, (including removal of the engine cowling), with debris being ingested by #4. It has happened at least a few times on the B747. That said, these are much smaller engines and even a catastrophic failure may not "broadcast" debris widely enough for #4 to ingest bits and pieces. Just a thought; it's a bit frustrating to not have accurate information about the parts that fell of the aircraft, but it/they were big parts.

Last edited by PJ2; 29th Oct 2009 at 19:03.
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Old 29th Oct 2009, 15:06
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As far as we can see in the video, the airplane was climbing wings leveled at least until we lost it from the camera view. Any power loss on #1 and/or #2 while in sight should have been apparent. According to the previous Flightglobal article link, the debris felt "onto" the rwy, consistent with a straight out departure, and afterwards the plane was "found to be on a right turn" at around 20 seconds into the flight, which is consistent with the time that still unidentified part separated from the plane.
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Old 29th Oct 2009, 17:39
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I noted when making the video that the speed I panned the shot to the left, decreased significantly as if the AC is losing speed and it doesn't reappear in the shot where you would expect it to be, given the speed it left the runway.
That could be because, as well as passing right-to-left, the aircraft is moving away, so its angular velocity would tend to decrease, probably quite rapidly.
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Old 29th Oct 2009, 19:35
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That could be because, as well as passing right-to-left, the aircraft is moving away, so its angular velocity would tend to decrease, probably quite rapidly.
True but if the distance from subject was at a point where you could no longer visually judge angular velocity, then you probably wouldn't see it increase so dramatically, and in the opposite direction, after the wing dropped.
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Old 30th Oct 2009, 06:11
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I hate to dwell on the mis-fortunes of others,, but this one "set the hook" on me, for my own reasons as stated earlier.
Plus any accident discussions are by thier very nature good, if they consist of mostly facts and observations and not wild speculation. When I was actively flying,, I always found that I learned at least as much from 3 hours in the bar,"hanger flying" than I did in that day's 8 hour annual refresher class.
The exchange of experiences was invaluable.
To that end,, I offer one more observation after lengthy review of the video,,, and a damning theory. (sorry)

I find it very odd that no-one has commented on the angle of climb on the initial runway heading.
That 707 had at least 3 operating engines.

-So,
- A flight to Sudan from SHJ,, not a heavy fuel load.
-A payload well below max.
-A good initial climb angle.
- Below 190-ish? kias, the rudder is still at full power ( 3000 psi)
The crew, evidently from the video, had altitude to trade for airspeed if needed, there are very few obstacles around SHJ.

My theory,, one engine out on the right side and they probably executed a procedure turn (published departure?), or accepted a vector to the right. Totally disregarding the "raise the dead" rule of engine of 707 ops.
" Step on the good engines, and raise the dead .. Trade altitude for airspeed,, fly the airplane ". " a zero rate of climb with increasing airspeed is the goal,, airspeed is options,, airspeed is life ". Poor airspeed managment and any right turn while slow,, the right wing WILL fall off and nothing will make it come back.

Either that,, or I'm wrong
Perhaps we will get harder evidence at some future date.
-- Heracles

Last edited by Heracles; 30th Oct 2009 at 06:18. Reason: spelling,,lol
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Old 30th Oct 2009, 17:45
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Concerning the aircraft weight on take off, anyone know the price of Jet fuel in Sharja to Kharthom, perhaps they were tankering, unless someone knows how much fuel was declared on the flightplan.

Tankering is pretty common here in Africa, sometimes without regard to performance degredation as accountants sometimes only see, fuel as being cheaper from here to there rather than the cost of carrying the extra weight and increased burn and reduced performance because of it.
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Old 30th Oct 2009, 17:57
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Heracles -
.....I've sat thru uncountable simulator sesions where well qualified co-pilots crashed after any ONE engine failed.....And, yes, I feel qualified to comment.
You might be qualified to comment, but I've sat through hundreds of engine-outs in the sim and NEVER saw anyone crash. I don't know who was flying the sims you were in, but they sure couldn't have been airline pilots. That's all airline pilots do in the sim is fly around with one or more engines out! Hardly ever get to fly a 'normal' airplane.
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Old 30th Oct 2009, 19:27
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My theory,, one engine out on the right side and they probably executed a procedure turn (published departure?), or accepted a vector to the right. Totally disregarding the "raise the dead" rule of engine of 707 ops.
You surely have enough material with a 8 frames video to conclude about the crew disregarding some rules.

Since you're the specialist over there could you please elaborate on why this can't be an in-flight thrust reversion?
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Old 30th Oct 2009, 19:55
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but I've sat through hundreds of engine-outs in the sim and NEVER saw anyone crash
707's ?

I'm sorry Heracles' theory sounds more plausible, your story reminds of the Irish railway engineer who condemned a hundred carriages before he realised his hammer was cracked.
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Old 31st Oct 2009, 01:44
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My Theory:


Main Entry: the·o·ry
Pronunciation: \ˈthē-ə-rē, ˈthir-ē\
Function: noun
Inflected Form(s): plural the·o·ries
Etymology: Late Latin theoria, from Greek theōria, from theōrein
Date: 1592

1 : the analysis of a set of facts in their relation to one another
2 : abstract thought : speculation
3 : the general or abstract principles of a body of fact, a science, or an art <music theory>
5 : a plausible or scientifically acceptable general principle or body of principles offered to explain phenomena <the wave theory of light>
6 a : a hypothesis assumed for the sake of argument or investigation b : an unproved assumption : conjecture c : a body of theorems presenting a concise systematic view of a subject <theory of equations>
synonyms see hypothesis

Sorry,, I ment to indict no-one,, just offer a theory.

As for watching brand new 2nd LTs lose it the first time they experienced a V1 cut in a wide aircraft with no reversers and a partially blocked rudder,,, great fun. The only thing scarier was watching potential Capt. upgrades try to mid-air refuel for the first time.. We used to call it a tail number check. "Same tail number on both sides of the tanker??"
The tankering fuel idea holds some merit too, interesting; but the climb angle just screams at me.
As for an inflight reverse,,,I cannot comment intelligently,, I never had them on the E-3, would have loved them though.
Cheers
--Heracles
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Old 31st Oct 2009, 04:34
  #112 (permalink)  
 
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As for an inflight reverse,,,I cannot comment intelligently,, I never had them on the E-3, would have loved them though.
No you wouldn't...not good, at all.
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Old 31st Oct 2009, 09:00
  #113 (permalink)  
 
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Birds are not generally a problem in this neck of the woods. I have seen about 5 in my 3 years here...... (although I am in dxb, I imagine the same in sharjah)

Sorry mate but apart of the numerous turkeys going out at night UAE can be a quiet busy place in regards to birds. Some time ago a "birdtam" was on the Dubai airport website. Here is a sample of what can be found through google:


The United Arab Emirates is situated on one of the main migratory routes with birds stopping here from all over Asia, Africa and Europe. The massive greening of the country has made it an attractive stopover for a huge number of birds with many rare species. Exotic birds from Asia and Africa including European birds such as robins, song thrushes and starlings are found here. Over 360 birds of various classifications like, resident breeding birds, passage birds, birds from Europe as well as summer breeding visitors have been spotted here in the lush green parks of Abu Dhabi and Dubai.


@ Heracles, there's most probably something related to an engine trouble since the falling part has been reported to be located very nearby an engine. Now to comment on whether the crew didn't apply a rule or had something else (inflight reverse for example) I think there are too little pieces of evidence to post "theories" which could rapidly end in the high quality newspapers we have in the region. Heroes or zeros, at that time the crew and their relatives deserves some respect.
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Old 31st Oct 2009, 09:25
  #114 (permalink)  
 
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Wasn't there chart a while back in the Jeps showing the bird migration pattern.

My guess is rev deploy in flt, cause a pitch up as well as separation followed by yaw and a stall.... just a guess
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Old 31st Oct 2009, 09:47
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My guess is rev deploy in flt, cause a pitch up as well as separation followed by yaw and a stall
Why pitch up?
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Old 31st Oct 2009, 13:58
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I think there are too little pieces of evidence to post "theories" which could rapidly end in the high quality newspapers we have in the region. Heroes or zeros, at that time the crew and their relatives deserves some respect.
How many investigations would end up as a whitewash if people couldn't speak freely about them ?

The investigations I worked on, involved speaking with as many people as possible and begging them to speculate as to the cause, If people had been unwilling to offer theories and speculate then the hard evidence alone would never be enough to come to any meaningful conclusion.

Speculation makes you examine the evidence again. Political correctness has no place in a science.
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Old 31st Oct 2009, 16:44
  #117 (permalink)  
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fatbus;

Reverser deployment is not, in and of itself, a reason to lose control of the aircraft.

411a and others can correct this but the B707 JT3/4 installation has cascade-type reversers as did the 50-series DC8 JT3D installation. The DC8 reversers for all series except the later 70-series, could be deployed in flight and were used in the emergency descent drill. Thus, while the 707 reversers were not deployable in-flight, that they can be as a matter of routine indicates that reverse deployment does not cause loss of control.

Now a high-thrust situation with reverse deployment which remains at high thrust in a relatively low-speed regime which remains unaddressed by the crew can theoretically, (ie, not specific to the B707), cause loss of control, especially if an outboard engine but in-flight reverse deployment is extremely rare due to robust system design, (mech. interlocks & non-pressurization of pneumatic or hydraulic reverser systems). The 707's reversers would never deploy under just air loads as they are not in the slipstream. The DC8-40 series "ejectors" might but that would be a non-event. (For those wishing to cite the Lauda Air B767 FADEC failure, I am well aware of this failure, but it goes to the "extremely rare" category).

As to speculation, what's to speculate upon? Very few questions are answered by the video. We have no information other than a piece of airplane which still has yet to be identified here.
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Old 31st Oct 2009, 16:53
  #118 (permalink)  
 
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PJ2 -

The DC8 reversers for all series except the later 70-series, could be deployed in flight and were used in the emergency descent drill.
Uh.....don't know about the rest of the -70 Series [I only flew the -71, but I assume they were allowed also], but the -71 was permitted to use reverse [on the inboards only] in flight. You were supposed to make a cabin announcement though as there was a little jolt when they were deployed.
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Old 31st Oct 2009, 16:59
  #119 (permalink)  
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DC-ATE;

Thanks....You've said that to me before in related discussions on in-flight reverser use and I forgot. I flew the 73, (1980) but can't recall if the same applied.
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Old 31st Oct 2009, 17:07
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While they were designed primarily for emergency descent, some used them as "poor planning" devices like the spoilers on the Boeings.
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