Sunday, January 20, 2008

Made it Home.

Sunday night and we've made it home. I say this because the journey involved flying into Heathrow this morning - at just about the same time as the Boeing 777 that crash-landed earlier in the week was being moved from the Southern runway. I can imagine people of nervous disposition being worried by this incident - and it says something about the safety record of today's aeroplanes that no-one on board seemed to be in the least bit concerned. After all there has not been a single example of a Boeing 777 crashing in the 10 years the plane has been in service. Its probably the safest form of travel, including walking!

Perhaps I knew a bit more about what had happened at Heathrow than most other passengers. On the day of the crash-landing, we were joined on a mini bus trip in Barbados by another holidaymaker who seemed incredibly well informed. When I asked him, he said that he was a British Airways pilot, (probably on a 'freebie') and had been flying passenger planes into Heathrow for the last 20 years. He was staying in the same hotel as we were. He knew immediately that something serious had gone wrong with the plane, because the scale of error was beyond anything he could imagine. It was just not possible for a pilot to fall a thousand feet short of the runway - when the touchdown point aimed for is a thousand feet along the runway. We now know that all of the Boeing's engines failed to respond when extra power was needed, two miles from touchdown and the plane, in effect glided in. All's well that ends well, but it could have been a real disaster. There is going to be a lot of interest in what caused the crash. I hadn't realised that it had been such a big story in the UK until catching up on the news today.


Aberavon & Neath Liberal Democrats said...

One presumes they were Rolls-Royces. However, there doesn't seem to have been any negative briefing by General Electric, which suggests that the engines were not totally to blame. ;-)

Frank Little

Dr. Christopher Wood said...

I know that many have used the language, "Boeing's engines failed to respond when extra power was needed", but this language is not very precise. The engines may not have received the command to provide extra power, so they couldn't respond because they received no control commands to so respond or there was a problem with an input (could be software or even a fuel issue) to both engines. It seems very unlikely that the problem is actually directly "to do" with the engines. Both engines being at fault in the same time frame is a compound probability approaching zero.

I can recall only one aircraft incident involving a two engine plane where both engines shut down and that was an Egyptian flight out of New York City (NYC), I believe it was a flight from JFK to Cairo. Both engines shut down at about the same time – the investigation concluded a relief pilot at the controls actually shut down the engines. Just looked up the NTSB report, “the engine start lever switches for both engines moved from the run to the cutoff position”; (NTSB's final report was issued March 21, 2002).

I am not saying that anyone at the controls of the 777 that crashed at Heathrow a few days ago interfered with both engines shut-off controls, but the probability that both engines would develop a fault in the same time frame is so low that it is more likely that something else caused both 777 engines not to respond to flight commands to provide more thrust.

Dr. Christopher Wood said...

PS ... good that you and your wife got back safely. Now "refreshed" (more likely: whacked out) you can write a few inches of copy telling the world that while you support Lembit Opik's noble goal of fighting for democracy, that Lembit's efforts, as noble as they might be, will not blind the voters of Monty to Lembit's numerous antics in making a mockery of democracy ... then again, maybe you won't do that. Anyways, good to have you back.

Anonymous said...

Lembit made the Sunday Times yesterday:

Prasit said...

When I asked him, he said that he was a British Airways pilot, (probably on a 'freebie')

hark the farmer and ex Assembly member.
There speaks a man who knows a thing or two about freebies!
Cheeky Sod!!

Dr. Christopher Wood said...

Anon> found that Times article; having read most of it, I kind of feel sorry for the guy ... I'm feeling sick, I need to close my front door on my fingers and thumb - enough times to come back to asteroid-free reality.

Glyn Davies said...

frank - christopher is surely right in that its probably not the engines that were at fault. I'll be interested in the results of investigations.

prasit - you sat on a thistle or what? It wasn't a criticism of the pilot. I believe all pilots have a certain amount of travel as a part of their remuneration package. He certainly knew what he was talking about.

anon - I have not seen this article, but its probably opening shots of his campaign for the Lib Dem presidency. I never like to frustrate a person's ambition, so best of luck to him I say.

Prasit said...

Prasit said...
When I asked him, he said that he was a British Airways pilot, (probably on a 'freebie')

A case of you being presumptious I thing Glyn.
A very irrelevant point to make about free travel.
I do not doubt he knew what he was talking about, pilots unlike Politicians have intense training before they qualify for their jobs.

Dr. Christopher Wood said...

Anyone seen the reports (in several places) today that both engines of the crashed 777 were not at fault. There may be a problem with the fuel pumps that fed fuel to the engines. Inadequate fuel = inadequate burn = inadequate thrust. So fits the fact patter of the engines failing to respond to thrust control commands.

If it turns out to be a fuel pump problem, this is quite serious. There is no way, no how that the fuel pumps should go out together. Fuel pumps can fail, but there should be built in redundancy. Both engines should have independent fuel supply to avoid a single fuel supply fault compromising both engines in the same time frame. Logic dictates that pumps should be on a different replacement cycle so wear and tear is not synchronized. The maintenance logs should be looked at and if they pumps are on the same cycle of replacement one has to wonder about that and whether the maintenance engineers need further guidance on the care and maintenance of critical mechanical systems and subassemblies. If it turns out to be the pumps, then this was an avoidable accident. For now, airlines should check the maintenance schedules of the fuel pumps on 777s (and other aircraft) to ensure the replacements of the pumps are not synchronized, that the pumps are swapped out for new pumps at different scheduled times. Such a simple thing - if the pumps were on the same replacement cycle one has to wonder about that - it would be an insanity to have the pumps replaced at the same time, they should be replaced (perhaps with reconditioned pumps) before they wear out, but not at the same time to negate the possibility of multiple pump failure in the same time frame. This is such basic stuff. I would be appalled if this common-sense approach to maintenance of critical mechanical parts was overlooked.