B-777 short landing at Heathrow

I've read a bunch of articles world wide and there has been mention from different sources that the Autothrottle sent a command to the engines to spool up about 2 miles out and 600 feet altitude.

The engines didn't spool up.

(Some snippets from articles)

Another witness said the pilot radioed total power failure which I am assuming he means ENGINE power. No passengers reported power failure in the cabin.

Most were unaware that there was a problem until they hit the dirt. Most of the landing was in the grass BEFORE THE RUNWAY. (Probably why there wasn't any fire)

The Co-pilot did the flying while the Captain worked the problem.

The Co-pilot flew a shortened/turning approach to make the field, landing at about 45 degree angle to the main runway but 1000 feet SHORT.

Clearance to last row of buildings was estimated at 200 feet.

The landing gear was dropped at the very last second to minimize drag. The main gear punched through the wings upon contact.

Estimated speed was only 100 knots.

The flaps were only deployed to 20 degrees, (Drag vs lift)

Pronounced fuel loss after the A/P came to rest.

I talked to numerous engineers at work last night and popular consensus is landing system software failure.

The only other cause offered was running out of fuel but most felt that was pretty remote.

I am amazed at how well the fuselage held up after being slammed into the ground as hard as it was. It didn't break apart but I'm sure it's bent.

Glad everyone made it out okay and there was NO fire!

 

I can't get any statements out of my ex-cohorts at the kite factory but in talking to some pilots we all agree that it was a software problem. There was plenty of fuel in the tanks, the crew exercised timely and appropriate action to gain power, BOTH engines failed to answer inputs simultaneously, BOTH engines were rotating when they hit the ground, So it appears that Auto-throttle and manual inputs failed to produce a response. That's a fly by light system.
Switches

 

That airplane has an ARCO system that transmits real time data on the aircraft's operating systems to the maintenance on the ground and it has a very comprehensive flight recorder that will tell all. They will find it.
Switches

 

I'm not sure that the public will get the whole truth and nuthin' but.
Switches

 

The FAA just released an AD for 777-200 and 300 models with Rolls Royce Trent engines dealing with ice causing possible engine failure.

http://www.avionews.com/pdf_news.php?newsId=1084978

 

And that applies in this situation, HOW? That has to do with EXTERNAL ice accumulation.

 

The experts are looking at fuel contamination as the cause since the engines DID respond to auto throttle and manual inputs but for only 8 seconds and then went back to just above idle speed. The airplane was fueled in Beijing before it's flight to Heathrow. HMMMMMM.
If my ol' head still works correctly in the memory department, all fuel flows from both wings into the centre (British, you know) section tank where it is boosted out to the engines. If contamination is present in either wing fuel cell, BOTH engines will be effected. There many screens and filters but these can be loaded up on a long flight if too much of the wrong stuff is in the fuel or if the contamination is a liquid, like won ton soup.
Switches

 

I found one article that initially mentioned fuel contamination but the possibility seemed remote considering the duration of the flight without ANY anomalies or indications. The timing of the engine failures couldn't have been worse.

Still a possibility though.

 

It doesn't. The three tanks really are not connected. Fuel feeds out of the center tank FIRST then it feeds out of the wing tanks to their respective engines. There is provisions for both engines to feed out of either wing tank or the center tank, but there are no provisions to crossfeed from one tank into another.

Current 777 pilot for 11 years.

 

Thanks Greg, I guess I was thinking about 707's or something older than the 777. I stand corrected since my specialty wasn't fuel systems, I should'a kept my mouth shut. You fly the best thing in the sky!
Switches

"Techinal" Designer 777 five years.....18 years ago.

 

The only way to analyze this situation is to first understand that it is impossible for it to have happened in the First Place. Both engines fail
one kilometre from threshold? This is a TWIN. This is ETOPS. If it is anything other than Human knuckleheadedness, the Fleet would be PARKED. Think about it.

 

To add to that observation, statistically, aircraft incidents/crashes occur 90%+ due to human error.

Considering the redundancies of the design it is baffling.

I would be VERY interested to hear what REALLY happened.

 

My thought initially was limited to crew performance problem/other. Not only are the odds 90% Pilot Error, but in ETOPS, Pilot Error is functionally 100% in incidents. If there is a mechanical source, my feeling is the Fleet would be grounded, temporarily in any case. From fragmented sources of information, it isn't possible to conclude anything, HOWEVER, the odds of losing one engine on an ETOPS aircraft are astronomically prohibitive, to lose TWO ridiculous, losing TWO AT THE SAME TIME IS IMPOSSIBLE. Since no one was hurt, I have no problem proposing that the Flight Crew has some long question sessions ahead.

Greg?

 

Well, I am not sure I totally agree with that. Keep in mind, there are OTHER humans involved with the operation of the airplane than the pilots. Can you say "Mechanics"?

I just got back from my annual recurrent training on the airplane. According to the Pilot Instructor there, the investigation so far found a wire loom that contains some of the computer wiring had been wrapped with an unauthorized covering and had chaffed through, causing some bare wires. No more specific info than that, but that IS a plausible scenario.

Well, that depends on the mechanical failure. If it is improper maintenance, the grounding is not warranted.

Nothing is impossible. Depends on the failure.

Well that is true regardless. But you also have the Flight Data Recorder and the Cockpit Voice Recorder that will tell their stories.

I have been flying the airplane for almost 11 years and over 6,500 hours. I can tell you this. There is NOTHING I can think of that the crew can do that would cause the airplane to do what it apparently did. Especially in that phase of flight. Not saying it isn't possible they found something to screw up, but it is HIGHLY unlikely.

 

I , too, am baffled by the simultaneous failure of both engines and I can only think of an anomaly on the flight deck that shut off fuel flow to BOTH engines at the same time. A dual mechanical failure of both engines at the same time doesn't make sense to me. When I was working on the airplane we were attending a constant string of " what if " meetings , going over any possible failure scenario or massaging the design of all the systems including structures to make them as perfect as possible. Right now , I can't feature this as a design failure.

 

Why does it have to be on the flight deck? There are only three ways that a pilot can directly affect fuel flow to the engines.

1) The throttles, and that does not appear to be the case.

2) The start switches, which would completely shut down the engines, and THAT does not appear to be the case.

3) Shutting down the fuel pumps in the fuel tanks. THAT is a feasible scenario, but not real plausible. The only time pumps are shut off in a wing tank is during a crossfeed operation. And there is no reason to be doing crossfeeding on the approach. The the tanks are, for the most part ABOVE the engines and the engines are capable of suction feeding from the tanks. At relatively low power settings, the fuel flow would be sufficient to keep the engines running.

But an ELECTRICAL problem is feasible, and maybe even plausible.

LOL Just as I cannot feature this as being a pilot induced failure.

 

Gregg, I'm not implying crew failure when I say, "Flight Deck." There is a literal bucket of worms beneath the aisle stand and beneath the flight deck. I don't totally dismiss design problems either but if it was something of that nature, it would have surfaced before this.

 

It is assumed the engines were "running" on approach? If so, the problem appears to be their balking at throttle, fuel starvation/contamination, lack of throttle command, or some other thing. It most certainly might NOT be pilot related failure. That leaves, well, Human Failure: Mechanics, Fuelers, TestOps, Chinese oversight of Fuel storage and/or shipping, etc. This thread is very instructive in other than mishap resolution. The solution is probably inevitable, and since, again, no one was seriously hurt, speculation tends to run to "whose ox is being gored". I think most everybody's pets are on display. The 777 Pilot, The 777 mfg. guy, the passenger/pilot, et al. We all depend on technology; sometimes we risk our lives on systems we don't fully understand, getting scared is better than the alternative in an airliner crash. I'll happily read the Accident report. Failure Analysis is an important part of progress. I never liked ETOPS, but became a convert based on personal trust of others and a love of the aircraft involved. That was me pointing fingers at the Humans. I still think homo sapiens is at the bottom of this.

 

Thank you, Airfoil, for your understanding comment. I'm not protecting my turf, I have none now, I'm simply exercising the need for an analytical approach to solve a troublesome problem and I can only base my approach to this on my past experience. I could never challenge a professional with 11 years on the 777 but I love that airplane and after putting 5 years into it working with the greatest and most dedicated guys I have ever been with, I have to feel that there were some, maybe hundreds, of hands that did something to the systems under the flight deck ....or elsewhere.. I just don't know how BOTH engines could simultaneously suffer the same problem. I worked on the configuration and lofted some of the fuselage and crown line in the 41 Section aft of the nose and worked extensively on the Environmental Control System and In Flight Entertainment installation. I was part of the team that did the first digital inboard profile ever done and helped to pave the way for the first digital mock up. Old news now but it was ground breaking.
Thanks,
Switches

 

Thanks for your thoughts, it is a baffling question. When ETOPS was first proposed, my wife was a senior FlightOps manager at United. There was enormous discussion at the time relative to redundancy/systems, two pilot crews, emrgency/ops all that. The Pelicans were incensed, "Deliberate flight over vast expanses of Ocean/Desert with TWO ENGINES???" You can well imagine. It was an evolutionary victory for the two engine types, slowly won, and bit by modeling bit. I can't remember the discussions about two loss scenarios, one engine out seemed to be the only occurence entertained. (Seemed to be). Lose an engine, dive for the Deck (??) and max out the remaining powerplant. Max out? Yeah, who cares about fuel now, there's twice as much as you need. I have such faith in ETOPS (as you do in your 777), that two out is simply unbelievable. I know you've been there for the rest of us, so I won't even speculate about possibilities.

Another fine mess eh, Olly?

 

My concept of ETOPS is basically two highly reliable single engine aircraft sharing the same flight crew and Airframe. Are these A/C fueled from single source? Seems overly redundant on the one hand, and perfectly moronic to rely on one Chinese teenager to fuel a 200M Euro Aircraft.

(Switches) I can relate to your pride of workmanship and loyalty. I built a 1/2 scale F-18 with my son in my shop when times were slow, what a joy.