...and with that image and text in mind, why use chocks at all....? If what the image says is true, and the aircraft moves forward to touch the chocks, friction will be lost and the aircraft will accellerate even further...?:hmm:

Just asking... :rolleyes:

Chocks
 

I suppose it comes down to what chocks are supposed to do, stop an aircraft if the parking brake has failed or is not fully operative.
Probably not designed to halt an aircraft with N engines pushing amount X newtons of thrust.

Nowhere near as much - because the tyre is already distorted against the brakes before it reaches the chock - and so will not try to ride up the chock.

@ forget
I guess you are working on B737.
A320 Fam. AMM do not mention any space between wheel and chocks:
Normally the parking brake is able to hold the A/C at its position with 1 engine at high power setting. (even by the A320 Fam.) :zzz:
I prefer the space between wheel and chocks not in conjunction with friction. As i mention above the parking brake is all i need and when she fails during high power you feel a bump when the wheels touch the chocks. It is like a wake up call to retard the throttle(s). ;)

It is wise not to do a high power run toward solid objects, however some planes have a limitation that if the wind is over a certain speed, the aircraft is to be into or within a certain number of degrees of the wind direction. Running all four at the same time, especially if at a light weight is something to avoid if possible. Perhaps symmetrical engines only. Was there a specific reason to do all four at once? One person should be looking outside at all times to see if there is any forward movement. And of course, consideration of ground conditions such as slippery surfaces among other things.

It all comes from this and this !

Position in precedent post is the one at the initial nose impact

… and below is the position 55 meters before impact :

http://i28.servimg.com/u/f28/11/75/17/84/tls_0211.jpg

Considering the pad setting, initial engine test position, from where all started, was pretty close, I would say MAX an additional 20 meters back in direct line or not.

Official information published on November 20th by Airbus and BEA (and lately forwarded by unidentified senior insider from Toulouse) does NOT quite tell the same story than those pictures which surfaced … 10 days later !?

As I said earlier everything is known already, why so many obvious discrepancies ?

What else is purposely retained that could prevent to exclusively blame the guys seated in front ?

I'm not interested in "BLAME".

But as an engineer, I still simply cannot get my mind around running up all four engines against the parking brakes to the earlier quoted thrust, and then NOT slamming all throttles shut the very instant the aircraft started to move, rather than ELEVEN seconds later.

OK, I'm a dinosaur, because I still know Concorde at T/O power plus reheat could NOT be held against the brakes. But I would have hoped some of our experience would have filtered down the ages.....

Yes, I also cannot understand the lack of SA

+1

glad rag

In one of the late BA038 thread
Such a statement would be harder to pronounce regarding … the French BEA

Christiaan
 

Re: "I would have hoped some of our experience would have filtered down the ages....."

No chance, Sir, there's no mechanism for that, and no-one wants to learn from the old farts.

I think this is the correct reasoning for chock positioning fwd of the wheels.

I note the procedure don't specify a 'lookout' dedciated to warning of unexpected movement at all times...

4 engines at once saves time (but that's cynical).. once again, no lives lost thankfully

As for old farts being listened to... they should always be an integral part of operating procedures! - you don't get old by being particularly stupid :)

DysagHow beautifully put. :(

I have been in telecommunications for 25+ years and my friends and I find that our experience is often considered irrelevant as it is from so long ago. As in IT, as in aircraft, the fundamentals do not change. And one of those fundamentals is that we do not listen to men that are old enough to be our fathers. :hmm:

When I was 20 something, I'm sure that I knew it all. :rolleyes:

A senior German chap in Toulouse once said to me "I wish I was 17 again! I knew absolutely everything then - but now I feel I know so little"

I know what he means!

christiaanJ
 

As an older fart and engineer used to running four far less powerful engines than either the Olympus or the CFM56 on ground runs, to retract the throttles from full power was an instinctive action if the aircraft moved, wall or no wall in front of the aircraft!

As to experience and youth, I suppose it can depend on who taught you in the first place. As an RAF Apprentice, there were hords of old boys in brown dust coats that droned on and on for hours followed, once on a squadron, or in this case, a manufacurers working party, more old farts in overalls. It certainly stopped me being cocky until I should have known better!

Today, the youth are not interested in listening whether you in a suit or overalls.

Continuing thread drift but not altogether away from the seat of the topic ...

Whilst working in the financial district of London in the late 1980s, I noticed the process of pensioning off the 'old farts' and promoting those in their 20s. It was done to save money and the idea that the new boys would have new ideas. What actually happened was that the companies lost the people who remembered what happened the last time it all went wrong.

Those times when the old geezer (RAF or commerce or politics) would scratch his head and say something like, "The last time that happened, we found that the <ITEM> had failed and there is no warning light on it because it is supposed not to fail and just be replaced every 10,000 hours." Thus the problem was fixed and the new boy learnt a lesson.

In the mid 1990s, I heard a most interesting discussion about this from the head of Personnel (probably called Human Resources :rolleyes:) of a major UK finance group say on BBC R4, "We realised that, in letting go so many senior people, we had lost our 'corporate memory' of what happened before and we were having to learn lessons all over again."

QED.

If you get rid of the 'old farts' the re-invention of the wheel becomes an original idea!

Those 'old farts' in brown overalls were worth their weight in gold!

As a pilot under training, one day when I turned on the battery master in my Jet Provost, the AC inverter didn't respond. Cycling the battery didn't help and the young lad outside hadn't a clue..... So he sensibly went and fetched help.

Out came an elderly chap in a brown coat. He opened up the nose, reached inside and gave something an almighty clout with his fist. I felt the aircraft actually move.

"Try it now!"... Click, whiiiiizzz - and the inverter started up as normal. After I got back from an hour scaring myself over the Bardney sugar beet factory, I spoke to the line chief. It seems the old boy had remembered that trick - he said he hadn't seen it for a few years though; in fact it must have been about 12 years since he'd last seen that particular snag when some even older fart in a brown coat had taught him the trick.

Old age and treachery will always outfox youthful enthusiasm!

ChristiaanJ
You and me both. But as others have pointed out, there are people of fewer years who know it all, so who needs experience?

What Airbus have managed to suppress successfully so far is that a note was found sellotaped to the remains of the nose of that aircraft. It was short and simple. It said;


Gotcha.

I'm still around.

Yours till hell freezes,

Murphy.

Thanks....
I've met Murphy a few times....

Lessons (not always) handed down
 

Quote from ChristiaanJ:
But I would have hoped some of our experience would have filtered down the ages.....

Something about those ignoring the lessons of history being condemned to watch it repeating itself?

http://www.pprune.org/forums/showthr...=313707&page=4

27 years ago, an empty rear-engined passenger jet was doing high-speed taxiing trials, following a nosewheel-steering malfunction. The aircraft had not been prepared (or configured) for flight, but there was (one) pilot on the tiller. You can guess the rest...

We must be just about due for the next one?