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Deo Gratias. That all are alive is thanks enough. The rest shall sort itself out in due course.
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How much?
Huck: "What would it have cost to put a couple of trained flight test pilots in the front seats....."
What's the answer to this question? |
LedZeppelin;
Re "What's the answer to this question? " If I may, hard to say exactly as it depends on rates but hypothetically, at 4hrs minimum per day x 2 type-qualified pilots x $200/hr each, roughly $1600. |
http://i508.photobucket.com/albums/s...gle44/a340.jpg
Its time to cheer those poor guys up and put and put a smile back on there faces! |
jumping the chocks!
I've seen a Handley Page Hastings jump the chocks and have done it myself in a Provost... golden rule off engine runs..Brakes 'on' and adequate brake pressure available ! Carried out engine runs at max power on many other big jet types ..
power equalised across the aircraft and feet on brakes ..usually never causes problems!! Hope these guys are ok!!!:ok: |
Post # 404
" fool! that's [B]not[B] what was meant by "do a run-up" " |
Chocks away?
.... mm, that is less than I thought.
Thanks PJ2 |
Any chance Airbus will start doing these max power engine runs while the plane is positioned on an unused taxiway? Just in case of another run away?
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Originally Posted by armchairpilot94116
Any chance Airbus will start doing these max power engine runs while the plane is positioned on an unused taxiway? Just in case of another run away?
I think Airbus would prefer not to have brand-new out-of-control aircraft careening across Blagnac airport. Loose cannons and bulls in china shops come to mind. Not to mention noise issues.... CJ |
Question from a novice in Aircraft testing : Are there any benefits of testing /running all 4 engines at the same time at max power ?
Looking for vibrations ? Testing the brakes ? |
Testing the brakes ?...
Well, they got their answer, didn't they! :zzz: Jim |
BEA Final Report Issued
PDF of full report available here (French).
Article at Flightglobal re findings include: ...power of the Rolls-Royce Trent 500 engines was increased to an engine pressure ratio of 1.25 - with the thrust levers corresponding to a position between maximum continuous thrust and maximum take-off thrust. All four engines were operating. While the parking brake was on, registering 2,600psi, the inquiry says the applied thrust was around the limit of the parking-brake capacity. At the time of the accident an Airbus employee was occupying the right-hand seat of the jet while an Abu Dhabi Aircraft Technologies technician was in the left-hand seat. Flight-recorder data shows that, shortly after 16:02, the person in the left-hand seat warned that the aircraft was moving. The ground speed began gradually increasing to 4kt over the next few seconds and, after a second call that the aircraft was moving, the recorder registered pedal-braking and the deactivation of the parking brake. Brakes on the A340-600 are linked to two hydraulic circuits: the 'green' normal circuit and the 'blue' alternate. The parking brake is on the blue circuit and only applies to the left- and right-hand main undercarriage bogies, not the centre bogie. If the parking brake is released and the brake pedals applied, the 'green' circuit comes into play. The pedals act on all three main bogies. Recorder data shows that 'green' circuit brake pressure on the A340 rapidly rose to 2,500psi while the 'blue' circuit pressure dropped. About seven seconds after the first movement warning the nose-wheel was turned sharply right. Activating the nose-wheel steering inhibits braking on the central bogie, becoming completely ineffective past 20° of steering. The aircraft swung 37° to the right but continued to accelerate, its speed increasing from 4kt to 31kt in seven seconds, before the aircraft struck the test-pen wall, demolishing its forward fuselage. |
Hello,
lomapaseo write ages ago .... Why can't you just chop the engines in 5 secs or so and that would be enough to keep it from going that far over a barrier in front of you. Valcon Its time to cheer those poor guys up and put and put a smile back on there faces! Regards. |
Activating the nose-wheel steering inhibits braking on the central bogie, becoming completely ineffective past 20° of steering. A lot of these Airbus features which generally are pretty good seem to have major ramifications at rather inconvenient times. A couple of caveats before the usual B vs A debate: Neither manufacturer is immune from these "gotchas", and is this incident clearly a few protocols were overlooked and lastly reducing the thrust might have seemed like a good idea too. |
From the report -- no, I'm not translating the whole thing
The observer in the jump seat was a licensed pilot with AB type ratings but was leaving the conduct of the flight test to the guy in charge (who unfortunately got fixated); so, did not pull the throttles until he saw the wall coming up [and self preservation instincts took over].
Of course there are now new procedures:
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Chocks always to be used -- people stopped using them because they tend to get jammed and the a/c has to be subsequently pushed back to retrieve the chocks. We've been through this before. Chocks should not be placed against wheels during engine run-ups. Boeing warns against this in their Maintenance Manuals. Airbus doesn't. Boeing has my vote. |
The first sentence of the report recommendation :
L’enquête a mis en évidence des dérives répétitives par rapport aux procédures opérationnelles écrites au sein de la direction des essais pour la réalisation des essais au sol Anyway lessons have been learned as those procedures have since been re-written , ( max 2 engines at a time, chocks in place.etc.. ) according the report, and now even the ground controllers have to verify on the R/T that chocks are in place before giving authorization to start an engine test run . |
We've been through this before. Chocks should not be placed against wheels during engine run-ups. Boeing warns against this in their Maintenance Manuals. Airbus doesn't. Boeing has my vote. |
.......... and now even the ground controllers have to verify on the R/T that chocks are in place before giving authorization to start an engine test run. Thanks to Spanner Turner, Post 213. :D Quote below is from the Maintenance Manual. (a 747 manual, but you get the picture). C. Prepare for Engine Operation. (1) Check that airplane is parked in clean area with wheels on areas that are free of oil, grease, or other slippery substances. (2) Make sure the wheel chocks are installed at the main landing gear wheels and ground locks are installed. (a) Do these steps if you will operate the engines for a high power engine run. 1) Make sure that the forward wheel chock is six to twelve inches in front of the tires. NOTE: This will cause the thrust of the engine to be held by the frictional force between the airplane tires and the ground, and not the wheel chock. The wheel chocks do not have the same frictional force as the tires. If the tires touch the wheel chock, some of the frictional force between the tires and the ground is lost, and the airplane can skid. The wheel chocks are only used to prevent the airplane from rolling if the airplane brakes were accidentally released before or after the engine run. |
There are sections of it's fuselage at the 380 section delivery bay at lagaderre on the back of low loaders today..........................................yesterday two A380 section 19 lowers, guess it's spring clean time.......
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All the procedures in the world will not help them if the person that has his hands on the controls is not smart enough to wipe off the power.....
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Huck,
Grossly unfair remark.... Count off thirteen seconds, and tell me what you would have done in that time. Twenty-twenty hindsight doesn't count. Three seconds to get the message the aircraft is moving, after a three-minute engine run. Two seconds for " oh *****, the brakes ", and starting to stamp on them. Eight seconds left. The pit wall looming up, so you try to turn. Somehow chopping the throttles gets left out.... Read the report for the rest. CJ PS: For those with sufficient technical knowledge, the somewhat warped translations being provided by babelfish and similar, should be enough to get the essentials. Others shouldn't be commenting here in the first place. And no, I'm not going to translate the entire report either, unless somebody pays me. |
I'm sorry to contradict you but what they did was THICK, plain and simple. If your car is accelerating towards something out of control you are expected to have the presence of mind to take your foot off the accelerator before jamming on the brakes, this is really no different.
If the person(s) in the cockpit didn't appreciate the relationship between the thrust lever position ( that THEY had set ) and the forward motion taking place then they had no bloody business to be sitting there in the first place. Is that not the crux of the matter ? ? :ugh: |
Des traces de freinage symétrique des deux trains principaux sont présentes depuis environ soixante mètres jusqu’au mur. |
If your car is accelerating towards something out of control you are expected to have the presence of mind to take your foot off the accelerator before jamming on the brakes, this is really no different. I think the crew really didn't expect the aircraft to move, so the crew hadn't thougt what to do in case the aircraft would move. If you have to think first, you are too late.............. |
Not only did they fail to follow SOPs for ground runs, they were plain stupid and incompetent. Maybe they'll roster a qualified pilot to assist engine runs in future?
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The issue is not about putting a "qualified pilot" at the controls during engine runs, the issue is ensuring that those at the controls have the necessary training to carry out those tasks and that they follow the procedures necessary for the task concerned. Start shortcutting procedures and sooner or later, something will happen. You would be amazed how much different a high power engine run is from an aircraft during a takeoff run. I can't comment on a 340 engine run, but I can assure you 320's and 767's bounce all over the place, and thats only two engines. In a restricted run bay such as at Toulouse (I've been there so I know what it's like) you have very little time to react if something is going wrong.
The biggest problem a lot of engineers face is that a lot of companies don't want to train us in simulators. We learn "on the job". So training to recognise things like brake failure and aircraft movement after jumping chocks may never be carried out. It's always in the back of your mind if you are aware of it's possibility. It all comes down to being competent at what you are doing, following procedures and maintaining situational awareness. Some of these things can never be learnt out of a book. |
There doesnt seem to be any mention of any ground crew in all this.
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CAPTPLAYSTATION You are right there run procedures were very poor.Engineers running engines can become pretty complacent after doing up-teen runs and nothing ever going wrong and thats when it bites you.
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Maybe they'll roster a qualified pilot to assist engine runs in future? I have run engines for 35 years. Small engines are easy. Run a Jt8D in a B732 and its like being in a simulator. No noise or vibration. But go out and run a B777 Trent up to take off on the brakes. Its mostly guess work with the whole aircraft leaping around. You have to take a print out of the readings because there is no way you can read the figures. Luckily here we can use the runway for engine runs. Feels much safer looking at 8000ft of tarmac. We used to have a run bay where you were 50ft from a wall. I hated it in there, felt very unsafe. Also running engines for maint, they are usually faulty. There is a reason for running them and it is not like a normal take off, you are on edge looking for a defect. And with todays reliable engines, we don't do it very often. |
The biggest problem a lot of engineers face is that a lot of companies don't want to train us in simulators. Able to practice things like brake failures and engine fires, helped people understand some of the risks, including using too few people. You really need someone in a front seat who is not doing the test or the readings , just there to be the safety net. |
Is everybody OK though??
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[QUOTEQuote:Activating the nose-wheel steering inhibits braking on the central bogie, becoming completely ineffective past 20° of steering.
Another little "gotcha". Presumably a good reason for this in normal ops...but when the proverbial hits the fan surely you want all stopping capabilities..... usually if you are swerving to avoid something that would be an indication you need a large stopping force.... A lot of these Airbus features which generally are pretty good seem to have major ramifications at rather inconvenient times.][/QUOTE] above from post #414. Have you considered that there would be an enormous side-thrust generated on the leg?....Perhaps the design enginers decided there was a better chance of control without the tyres rolled off the rims /sidethrust exceeding structural strength of wheels/sidewalls being ripped through by tarmac. It's unrealistic to expect a/c landing-gear to be designed to take stresses beyond the max sustainable by the airframe......in this case, the limiting-factor is the friction between tyre and runway...unless you propose "grooves" for the bogies to slot in and treat grounded a/c as trams! wonder if the company will give the crew a christmas bonus this year :E |
Originally Posted by whatbolt
There doesnt seem to be any mention of any ground crew in all this.
Not that they could have done anything to prevent it happening, actually. They did manage to stop one of the engines after the crash, though, by smothering it with water and foam. Two engines had already stopped by themselves (damaged). The remaining one was up against the blast wall, and thet couldn't get enough water and foam in to stop it, so it ran on until the feeder tank was empty. |
They did manage to stop one of the engines after the crash, though, by smothering it with water and foam. Two engines had already stopped by themselves (damaged). The remaining one was up against the blast wall, and thet couldn't get enough water and foam in to stop it, so it ran on until the feeder tank was empty. |
Is this aircraft insured? Does Ethiad get a replacement without paying anything from airbus? And who takes the fall for this?
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Hands On The Throttles?
It's hard to understand why the person who put the throttles forward didn't KEEP HIS HAND THERE, ready to pull the power back in the event of a problem. :ugh: :mad:
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Huck, Grossly unfair remark.... Count off thirteen seconds, and tell me what you would have done in that time. I am a maintenance test pilot on MD-11F aircraft. I execute max power ground runs about twice a month. What would I have done? Same thing I always plan on doing - Throttles idle, max manual braking, shut down one or more engines if things don't get better. If you're cinched down hard in your seat with your hands and feet on the controls (and you damn well should be) I can do all that in a second or two. In other words, if you're not a pilot, you better be prepared to act like one if you ever start moving during a high power ground run. I have absolutely no concept of what distraction or thought process could delay these vital reactions. I could give the same scenario to a 10-hour private pilot student in a Cessna 150 and his/her reaction would be the same - wipe off power, max braking. What happened here? I have no concept whatsoever. Unless both front-enders fell out of their seats, somebody should have been on the throttles within 2 seconds. If not them, the jumpseater. |
Simple basics need to be applied . Ignore the rubbish spouted about Boeing V Airbus in previous posts ref chocks , both manufacturers procedures specify chocks for high power runs . The difference is you leave a gap on Boeings as you have full parking brake pressure and if the aircraft moves it will slide into the chocks and enable them to grip properly . Because all the Airbus widebodies use a lower park brake pressure you have specialist large chocks which are used differently. And basically commercial pressure is the biggest problem as you need a heavy a/c with ballast or fuel which makes the job much easier as the aircraft doesnt bounce around and you can read the gauges !! The basics of high power runs as i was taught and insist on when running is the guy in the left seat has his hands on throttles any time power above idle. Man in right seat is experienced and when at high power keeps lookout for a/c moving and feet ready on pedals. If you're on a type with complex figure recording to be done then you need someone on the jumpseat to assist with that. This incident had diferent people from diferent companies , how comprehensive a brief was given before?
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Smilin_Ed, Huck,
Have you read the report? If not I can try and pull out the relevant bits and translate them. In brief, they had been running all four engines for about three minutes already, waiting for the oil to get warm enough to check for a leak. So by that time their hands would have come off the throttles, thinking the parking brake was holding the aircraft adequately. In reality, the engine thrust equated almost exactly the holding power of the brakes for those three minutes, and then (possibly because the fuel burned, hence a/c becoming lighter) overcame the brakes. CJ |
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