Friday, January 18, 2008
Trading Airspeed for Distance
I am a student of aircraft accidents, because, as my British friend Trevor says, "That's what I do." Air carrier accidents are few and far between when compared to the Gilded Age of the airline pilot. Avionics and auto-flight systems are, today, much better. Still, they do happen...Occasionally, I dream about scenarios similar to what happened to two of the Queen's finest pilots. Imagine being on final approach and for some inexplicable reason, both engines (the best engines in the business) begin to spool down. There is no time to warn anybody as the captain scrambles to contain the situation. The seconds are so precious that the crew can only speed read the emergency checklists and hope that something pops out that is obvious. Reverting to basic airmanship skills is the only thing left to do... Trading airspeed for distance, releasing the ram air turbine for hydraulics, starting the APU in a desperate attempt to re-start at least one engine.
Your thoughts are razor sharp at this moment in time and the primeval section of your mind confirms the greatest fear of any airline pilot; it is not going to work. The runway is too far away and the airspeed is slipping away as the nose gets higher and higher.
I usually wake up immediately before impact with a racing heart, clammy skin and a few curse words.
I am quite sure that the British crew must have wondered, "Is this really happening? How can this be? Can both engines quit on a triple seven?"
Apparently so...
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This incident is a reminder that, despite the Star Trek electronics, auto-pilot, fly-by-wire, plane-flies-itself technology, aviation is still at the heart of flight, and every pilot is still an AVIATOR.
At the end of the day--be it a triple-seven or a WWI-era biplane--the principle is the same: the skills of aviation are used to keep the plane in flight, and when it comes time to land, with or without power, to get the bird on the ground and everybody off the plane alive.
At the end of the day--be it a triple-seven or a WWI-era biplane--the principle is the same: the skills of aviation are used to keep the plane in flight, and when it comes time to land, with or without power, to get the bird on the ground and everybody off the plane alive.
Drove past this yesterday, a very strange sight to see! One only need take a look at the surrounding area to realise that it could have been far worse. Funnily enough this incident makes me feel happier to fly, not more nervous. For it shows the crew's instinct to aviate above all else, and only then time permitting to communicate, hence why the passengers didn't have any warning. Well done to all the crew for a text-book job!
# posted by 
: 4:14 PM, January 18, 2008
: 4:14 PM, January 18, 2008
Careful, though - the AAIB statement does NOT say the engines quit.
http://www.aaib.dft.gov.uk/latest_news/accident__heathrow_17_january_2008___initial_report.cfm
Initial indications from the interviews and Flight Recorder analyses show the flight and approach to have progressed normally until the aircraft was established on late finals for Runway 27L. At approximately 600 ft and 2 miles from touch down, the Autothrottle demanded an increase in thrust from the two engines but the engines did not respond. Following further demands for increased thrust from the Autothrottle, and subsequently the flight crew moving the throttle levers, the engines similarly failed to respond. The aircraft speed reduced and the aircraft descended onto the grass short of the paved runway surface.
Seems on the information to date that it was not a power failure but a control problem.
http://www.aaib.dft.gov.uk/latest_news/accident__heathrow_17_january_2008___initial_report.cfm
Initial indications from the interviews and Flight Recorder analyses show the flight and approach to have progressed normally until the aircraft was established on late finals for Runway 27L. At approximately 600 ft and 2 miles from touch down, the Autothrottle demanded an increase in thrust from the two engines but the engines did not respond. Following further demands for increased thrust from the Autothrottle, and subsequently the flight crew moving the throttle levers, the engines similarly failed to respond. The aircraft speed reduced and the aircraft descended onto the grass short of the paved runway surface.
Seems on the information to date that it was not a power failure but a control problem.
# posted by : 5:08 PM, January 18, 2008
: 5:08 PM, January 18, 2008
It certainly says something about both the quality of the 777 design as well as the skill of those who fly it that this was the most serious incident involving one since it was introduced in 1995.
# posted by : 8:25 PM, January 18, 2008
: 8:25 PM, January 18, 2008
rev spooner- I saw some photos of the compressor section and it looks like number two was not turning at impact.
Looks like incredibly skilfull airmanship by the pilots keeping cool heads in a situation that they would have been trained for, but were not likely to ever experience!
If/when we get to the stage of fully automated planes flown by computers monitored from the ground, that's when I stop flying!
If/when we get to the stage of fully automated planes flown by computers monitored from the ground, that's when I stop flying!
I am pretty sure that in a month or so we'll have a report that provides us with more detail about the condition of the engines and flight control systems; just give the AAIB its time to disassemble the plane and test-bench its components. "Lack of thrust" is consistent with "spooled down engine", but it is entirely possible that the pilots secured the engines in the last seconds of flight and so avoided a fire. The investigators will no doubt tell us in time.
# posted by : 3:21 AM, January 19, 2008
: 3:21 AM, January 19, 2008
The good news is that the 777 is still an outstanding design, and probably one of the most data intensive types there is. Given that the airframe is still intact, and the digital flight data recorder records a number of parameters such as throttle position, autothrottle commands etc, we can all be confident they'll find out what happened.
By the way, OUTSTANDING airmanship by the crew and OUTSTANDING work by the flight attendants to get the slides deployed and passengers out. Great job all around.
By the way, OUTSTANDING airmanship by the crew and OUTSTANDING work by the flight attendants to get the slides deployed and passengers out. Great job all around.
# posted by : 11:45 AM, January 19, 2008
: 11:45 AM, January 19, 2008
I usually hate flying BA because the flight attendants are so bossy and certain they're right, but if something like this happens, I think I wouldn't want to be on any other airline ...
A lucky day for everyone involved even though people got injured and the plane suffered serious damage, but if it all happened just a few seconds earlier, it could have been a disaster. So well done to the crew and hope we can all learn from it once the cause is clear.
Rev. Spooner, the second officer reported that after the a/c came to a halt, there was no sound at all from the back, 'no engine noise at all'. Consistent with a spool down.
# posted by : 1:08 PM, January 20, 2008
: 1:08 PM, January 20, 2008
Also consistent with them having ingested a significant amount of earth whilst being used as landing skids!
Lets wait for the AIIB report before jumping to conclusions...
Lets wait for the AIIB report before jumping to conclusions...
# posted by : 1:50 PM, January 20, 2008
: 1:50 PM, January 20, 2008
The one indisputable point that strikes me about this "incident" is that, fortunately, it happened at an airport (LHR) with very generous Runway End Safety Areas (RESAs). Many airports around the world are not so well endowed, with some not even meeting the ICAO minimums.
Thinking about James Reason's "Swiss cheese" safety model, this seems to have been the one "slice" that prevented a disaster.
Like everyone, I look forward to the official conclusions and, as always, hope that we can all learn from them.
Thinking about James Reason's "Swiss cheese" safety model, this seems to have been the one "slice" that prevented a disaster.
Like everyone, I look forward to the official conclusions and, as always, hope that we can all learn from them.
For those that don't fly, the only analogy I can think of that would put you in the same mind as the pilots is approaching an intersection on a highway and having your brakes fail. You can't avoid the accident, you know you're going to have one, and all you can do in the last few seconds is decide how to make the accident survivable.
What a horrible situation these pilots were in and I'm still amazed they managed to bring the aircraft down without killing anyone, but that's why pilots should be paid high wages.
What a horrible situation these pilots were in and I'm still amazed they managed to bring the aircraft down without killing anyone, but that's why pilots should be paid high wages.
# posted by : 2:01 AM, January 21, 2008
: 2:01 AM, January 21, 2008
If I ever had to be in an airline accident, I'd like it to be one like this: on a major airline with a captain and crew that knew what to do.
It would be an experience, to be sure.
It would be an experience, to be sure.
# posted by : 6:33 AM, January 21, 2008
: 6:33 AM, January 21, 2008
I am amazed when I look at that picture that no matter what caused the mal function the aircraft sits there on the ground nearly in tack. Like so many others have said the sheer skill and quick thinking on the part of the BA folks is amazing under such stress. Thanks Dave for explaining this in such a way that it is clear that airline professionals once again saved the day (i.e. the lives of so many souls).
# posted by : 11:16 AM, January 21, 2008
: 11:16 AM, January 21, 2008
Hypothetically, what actions could a pilot take if engine power was lost (or below what was needed, as in this case) on final approach?
Is the aircraft normally configured for maximum glide range during the landing sequence? If not, what adjustments could be made to extend glide under loss of engine power -- reduce flaps?
Is the aircraft normally configured for maximum glide range during the landing sequence? If not, what adjustments could be made to extend glide under loss of engine power -- reduce flaps?
# posted by : 3:50 PM, January 21, 2008
: 3:50 PM, January 21, 2008
BA - Great Pilots, louse Airline.
They have a history of maintenance "issues" such as the 300 lb 777 door that came off and almost hit a couple on the ground.
My favorite is the 747 that flew from LAX to LHR on 3 engines and had to devert at the end. The same plane lost an engine again from Singapore and they flew it to LHR on 3 engines. At some point the luck will run out if they keep pushing it like that.
You can say I am being reactionary but Alaska MD-80 off pt. mugu and swissair 111 had time to land if they had done so immediately when they had known issue. Flying a plane with any known problem is bad policy and BA allows it.
They have a history of maintenance "issues" such as the 300 lb 777 door that came off and almost hit a couple on the ground.
My favorite is the 747 that flew from LAX to LHR on 3 engines and had to devert at the end. The same plane lost an engine again from Singapore and they flew it to LHR on 3 engines. At some point the luck will run out if they keep pushing it like that.
You can say I am being reactionary but Alaska MD-80 off pt. mugu and swissair 111 had time to land if they had done so immediately when they had known issue. Flying a plane with any known problem is bad policy and BA allows it.
# posted by : 9:19 PM, January 21, 2008
: 9:19 PM, January 21, 2008
ps (i wrote above) - any time economics/schedule takes precedence over safety in airflight is very bad. yet, many pilots are afraid to rock the boat because afterwards they can be second guessed and career ruined. Everyone always blames the pilots if they can in an accident. This industry sucks and it is a credit to the many great pilots like Dave that they continue to do it because they love the flying. The day they replace the pilots with a cpu is the day I quit flying for good.
# posted by : 9:24 PM, January 21, 2008
: 9:24 PM, January 21, 2008
Great flying by the pilots to bring it in without great loss of human life.
But, both engines "spooling down" on a 777 at the same time and no post-accident fire?
Hmmmmm...
Has anyone taken the cap off the fuel tank to see if they can see the bottom?
But, both engines "spooling down" on a 777 at the same time and no post-accident fire?
Hmmmmm...
Has anyone taken the cap off the fuel tank to see if they can see the bottom?
# posted by : 6:01 AM, January 24, 2008
: 6:01 AM, January 24, 2008
http://news.bbc.co.uk/1/hi/england/london/7206596.stm
Both engines were running when the plane crashed. They spooled up for a few seconds when demanded but then went back to idle. Fuel quantity was correct. Investigators concentrating on fuel delivery system.
Both engines were running when the plane crashed. They spooled up for a few seconds when demanded but then went back to idle. Fuel quantity was correct. Investigators concentrating on fuel delivery system.
# posted by : 2:19 PM, January 24, 2008
: 2:19 PM, January 24, 2008
In true british tradition the knocking has started...the Daily Mail (right-wing or republican paper for semi-educated arse-wiping) has today published an article listing all the things it thought the crew should've done but didn't...in the few secons they had...
thx for the post..
via
http://www.savory.de/
blog_jan_08.htm#20080120
what surprised me was that this should happen..
makes me think that there was something happening on the other side of the cockpit that would distract a pilot away from the controls..
like answering the phone w/o a pencil..
via
http://www.savory.de/
blog_jan_08.htm#20080120
what surprised me was that this should happen..
makes me think that there was something happening on the other side of the cockpit that would distract a pilot away from the controls..
like answering the phone w/o a pencil..
Another blog has found/posted an angle I'd not seen before. This shows really vividly just how close it was.
( Thanks, digitalaviator )
http://www.thedigitalaviator.com/blog//wp-content/uploads/short.jpg
LAHS
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( Thanks, digitalaviator )
http://www.thedigitalaviator.com/blog//wp-content/uploads/short.jpg
LAHS
# posted by : 11:02 AM, January 30, 2008
: 11:02 AM, January 30, 2008 << Home
