Learjet destroyed during engine runs?

[ultrarunner]

I was going through Ft. Worth the other day and there was mention of a Learjet destroyed during a maintenance event at Meacham field. Anyone have any details?

 

[peter185]

Mx techs were doing an engine run on an LR-45 down in the "hole" (southeast part of the airport) and claim they couldn't shut them down. I went down there and the skid marks probably were ~50-75 yards long. They went over a curb that collapsed the nose gear and hit a hanger with the right wing. Don't know much about Lears but can't imagine not just cutting off the fuel to shut down the engines.

 

[SDCFI]

Sounds kinda fishy, that or the techs didn't know what they were doing. If you lose power lever control over the engine (DEEC) you can always push the FIRE button which closes the fuel SOV. I've heard of power lever jams and DEEC malfunctions but never an inability to shut down the engine. Sounds like whatever happened they panicked and forgot about the buttons.

 

[Coool Hand Luke]

I received this from an associate of mine in the maintenance field the day it happend. I am sure more details will come out in due time, but this is what he passed on to me:

Did you see the 40XR that (name omitted) put into the bank yesterday? According to (name omitted), whom I know, he reported both throttles stuck..... NOW.... that sounds strange. I have ran and taxied the L45, with the TFE731-20's. The T/S were NOT deployed, and the nose gear strut was torn free.... ooopssss

 

[ksu_aviator]

Whether or not it was a computer problem, it points to how computers present a new problem. When power levers simply pulled and pushed on a valve, a mechanic could inspect the system and determine if a problem was developing before something like this happened. With a computer, it is very difficult to determine if a failure is forthcoming.

That is not to say that a catastrophic failure couldn't happen with a mechanical system or that problems can't be found before a computer fails, but the job is more difficult.

Having flown both the 35 and the 45, I prefer the 35's systems over the 45's. But, I like old school CB's and large metal switches over cute plastic buttons.

 

[LJ45]

The Learjet 45 engines work like FADEC with the engine computers on, with them off they have traditional hydro-mechanical control just like the Lear 35 and other TFE731's.
It sounds like someone really screwed up. This is not the first time this has happen, heck Airbus wrecked a new A340 testing the engines.

 

[rausda27]

The thrust lever input to the DEEC's are received by a RVDT in the TL quadrant. Regardless, if the RVDT fails, the FWSOV would fix the problem. They could also bypass the DEEC's but putting it into MAN therefore metering fuel hydro-mechanically in the FCU.

Sorry to hear a good airplane got banged up.

 

[Fly91]

Type-rated pilots should be the only people running up engines or taxiing planes around.

 

[fisherpilot]

Type-rated pilots should be the only people running up engines or taxiing planes around.

I agree 100 percent!!! Too many things can go wrong and when someone who doesn't know how to operate the aircraft is put in a situation when things go wrong, well, look at this situation.

 

[yfly]

Type-rated pilots should be the only people running up engines or taxiing planes around.

There is nothing wrong with mechanics conducting engine runs and taxiing airplanes.

You are assuming a pilot would have never let something like this happen, that is a poor assumption. A mistake was made. We don't know what mistake or how; however, let us hope a lesson was learned by all the people involved.

If we restrict the operation of aircraft to the infallible no one will be allowed inside the airport fence.

 

[LJ45]

Even Airbus, one of the worlds largest manufacturers, can screw up engine runs

http://www.airliners.net/photo/Etihad-Airways/Airbus-A340-642/1293784/L/

 

[Fly91]

There is nothing wrong with mechanics conducting engine runs and taxiing airplanes.

You are assuming a pilot would have never let something like this happen, that is a poor assumption. A mistake was made. We don't know what mistake or how; however, let us hope a lesson was learned by all the people involved.

If we restrict the operation of aircraft to the infallible no one will be allowed inside the airport fence.

No, I'm just saying the company paid, trained and current pilots should take a drive to the airport and run up the engines on their bosses multi-million $$$ plane.

This is one of those things that will require people to die before they make it a law. Do you realize the poop-storm that will be started if a mechanic causes a fatal accident while taxiing a plane? It will be the beginning of all new laws being enacted. The public would not stand for it, its just that 99.99% of the public are ignorant that this type of thing is even taking place.


.

 

[Fly91]

Even Airbus, one of the worlds largest manufacturers, can screw up engine runs

http://www.airliners.net/photo/Etihad-Airways/Airbus-A340-642/1293784/L/

I thought there was some funny business involved in that case. I don't remember exactly, but weren't the pilots not trained on that plane and they were sitting up there during testing?

I mean, how on earth can TWO trained pilots, if they were totally sober, not be able to stop a plane they are trained to fly? Its just really not possible without something else being a serious factor. And that Airbus took a pretty long ride before impact.

Can TWO pilots really get that flustered where literally everything they've learned goes right out of their heads and they are rendered 100% useless?

Strange..............


.

 

[svcta]

No, I'm just saying the company paid, trained and current pilots should take a drive to the airport and run up the engines on their bosses multi-million $$$ plane.

This is one of those things that will require people to die before they make it a law. Do you realize the poop-storm that will be started if a mechanic causes a fatal accident while taxiing a plane? It will be the beginning of all new laws being enacted. The public would not stand for it, its just that 99.99% of the public are ignorant that this type of thing is even taking place.


.

So a mistake is made and the answer is more laws? C'mon, MOST mechanics are as competent to run and taxi airplanes as MOST pilots are to fly them. There are examples where accidents have happened with both, obviously, but it is not indicative of a systemic problem that requires even more regulation. By your line of reasoning, only pilots should tow airplanes, too. Or service the lavs, or wash airplanes, etc. etc. Afterall, no-one knows better than the pilots what all the little protuberneces are, tow limits, wingspan, how much bllue(green) juice will overflow the lav, blah blah blah. The line has to get drawn somewhere. Hire competent mechanics.

 

[Cat3C]

Isn't this why techs do the engine run and taxi school at FSI or CAE? I have not been part of a discussion regarding this topic but the techs in my flight department are qualified and capable to do this stuff. Additionally if needed a pilot will be with them but there are no hard and fast rules.

Not that it matters but how do the airlines treat this?

 

[SWA tech]

I was a taxi/run-up designee at SWA for 4 years and they would make us go to the sim once a year for a check out and everything they could throw at us. Myself I would take a mechanic to the sim before I would check him or her out and see where they stood and if it was something he should be doing. I have done a lot of high power runs on dc-10 and b-757,767 and 737-700 and the overall thing I think with mechanics is if they are trained to be professional they will be if not they should not do it bottom line.

 

[fisherpilot]

I was a taxi/run-up designee at SWA for 4 years and they would make us go to the sim once a year for a check out and everything they could throw at us. Myself I would take a mechanic to the sim before I would check him or her out and see where they stood and if it was something he should be doing. I have done a lot of high power runs on dc-10 and b-757,767 and 737-700 and the overall thing I think with mechanics is if they are trained to be professional they will be if not they should not do it bottom line.

That sounds like a great idea

 

[Fly91]

So a mistake is made and the answer is more laws? C'mon, MOST mechanics are as competent to run and taxi airplanes as MOST pilots are to fly them.

"MOST" are competent????? Thats just great, what about the incompetent ones????? Well, hopefully you get the incompetent ones, I don't want them. How do you know which mechanic is NOT competent? YUP...after he bends the airframe in a ditch like this Learjet did.

How do you know which mechanic is going to act quickly and appropriately when the brakes fail during an engine run-up? Do your mechanics get any training on how to stop a plane, emergency brake system, SOV's, reversers, etc...? Hell no..... Yeah, they know what they are and where they are...but they aren't like pilots in the proficiency department.

By your line of reasoning, only pilots should tow airplanes, too. Or service the lavs, or wash airplanes, etc. etc.

I can't tell you how stupid of a statement that is. Those are line personnel jobs that take place when an aircraft is "OFF", parked or totally powered down. Don't even need battery power for most of those ops. An aircraft can't go flying across an airfield out of control from line personnel and get totalled, or kill someone.

Afterall, no-one knows better than the pilots what all the little protuberneces are, tow limits, wingspan, how much bllue(green) juice will overflow the lav, blah blah blah.

Again, jobs for line service. They get training on all that stuff.

The line has to get drawn somewhere. Hire competent mechanics.

For the most part, yes, mechanics will do just fine with engine runs. Its the time when a plane gets destroyed where this becomes the topic of discussion. If its not your plane, who cares, right.

A smart company owner would have his pilots taking care of engine runs. If not for total safety...liability. If I was an insurance company, I wouldn't cover non-pilots taxiing a plane around and doing engine runs.

Or, like "SWA tech" said......give the mechanics specific recurrent training on everything they would need to know to avoid a catastrophy. Nobody with half a brain can argue that.

.

 

[LJ45]

what about incompetent pilots? our group tears up airplanes also. :smash:

 

[svcta]

what about incompetent pilots? our group tears up airplanes also. :smash:

this was my main point. Fly91, first of all, you can use all the question marks you like. They're free so why stop at five? Don't kid yourself, about line service guys. Most really don't have nearly the "training" that you think they do. What happens when an airplane leaves the towbar? This happens far more regularly than airplanes shooting off in to ditches under their own power (and without the batteries even on). How are we supposed to handle this crisis? Emergency stimulus package for Line Service Training? Pilots supervising all movements of all aircraft anywhere anytime?

Reread the sentence that seemed to gripe you so badly (according the the question mark indications). Most piltos don't crash airplanes. Some do. Most mechanics don't foul up ground run ops. Some do. Airplanes break all the time in flight, adn I've even been known to call mechanics in flight to get their opinions. Sometimes their opinion helped steer my decision making process. Does that mean that an airplane should never run without a mechanic present?


I've seen airplanes with overflowed lavs because too much fluid was put in. By your line of reaoning there should be a pilot there supervising the lav service.

I've seen the tow limits of an aircraft exceeded, which led to a gear failure. By your line of reasoning there should be a pilot there supervising all towing.

I've seen airplanes crash. By your line of reasoning there should be a Fed there supervising all flight ops. Afterall, all humans can be counted on to make a mistake sooner or later. We ought to regulate them more, right?

My point is that just because you read about an incident on the internet does not mean that there is some out of control situation presenting itself to the world every day that (gasp!) requires regulation in order to keep us safe from mechanics on a (fender) bender.

 

[westwind driver]

Sounds kinda fishy, that or the techs didn't know what they were doing. If you lose power lever control over the engine (DEEC) you can always push the FIRE button which closes the fuel SOV. I've heard of power lever jams and DEEC malfunctions but never an inability to shut down the engine. Sounds like whatever happened they panicked and forgot about the buttons.

LR45 dont have DEEC

 

[westwind driver]

"MOST" are competent????? Thats just great, what about the incompetent ones????? Well, hopefully you get the incompetent ones, I don't want them. How do you know which mechanic is NOT competent? YUP...after he bends the airframe in a ditch like this Learjet did.

How do you know which mechanic is going to act quickly and appropriately when the brakes fail during an engine run-up? Do your mechanics get any training on how to stop a plane, emergency brake system, SOV's, reversers, etc...? Hell no..... Yeah, they know what they are and where they are...but they aren't like pilots in the proficiency department.

I can't tell you how stupid of a statement that is. Those are line personnel jobs that take place when an aircraft is "OFF", parked or totally powered down. Don't even need battery power for most of those ops. An aircraft can't go flying across an airfield out of control from line personnel and get totalled, or kill someone.


Again, jobs for line service. They get training on all that stuff.


For the most part, yes, mechanics will do just fine with engine runs. Its the time when a plane gets destroyed where this becomes the topic of discussion. If its not your plane, who cares, right.

A smart company owner would have his pilots taking care of engine runs. If not for total safety...liability. If I was an insurance company, I wouldn't cover non-pilots taxiing a plane around and doing engine runs.

Or, like "SWA tech" said......give the mechanics specific recurrent training on everything they would need to know to avoid a catastrophy. Nobody with half a brain can argue that.

.

And what about you? How do I know you are a competent pilot? Do I find out you are only incompetent after YOU, as the PILOT, CRASH?

 

[LJ45]

LR45 dont have DEEC

yes they do

The 45's DEEC's act like FADEC, except it still has a throttle cable for Hydromechincal control back up, just like the other 731's. The DEEC's due more then the DEEC's on older generation 731's, but they are still DEEC's

 

[rausda27]

LR45 dont have DEEC

You are right, they have 2 DEEC's.

 

[jet2work]

I thought about it but........

Then I read a thread here on the corporate board that said something like 90% of corporate airplanes have been rolled by pilots. I think I would rather take my chances with the once in a blue moon occurance of a mechanic screwing up a run up:nuts:

That's a joke y'all. I for one don't want to get my A$$ out of bed in the middle of the night to go do a maintenance runup (when does most maintenance occur? - middle of the night)

Most Mechanics (like Most Pilots) are competent and conscientious (then there are those that roll corporate jets). Do we have a few Bozo's among our ranks (uhhhh YES!). When we start making rules because of the lowest common denominator then I might as well have gone to work for the airlines.

If you make something idiot proof, someone will make a better idiot.

 

[bikeguy]

Type-rated pilots should be the only people running up engines or taxiing planes around.

Yeah a typed pilot has never wrecked a Lear....

 

[westwind driver]

yes they do

The 45's DEEC's act like FADEC, except it still has a throttle cable for Hydromechincal control back up, just like the other 731's. The DEEC's due more then the DEEC's on older generation 731's, but they are still DEEC's

Well I'll say I have not flown a LR45 or LR40, so truth be told I don't really know 100%, but I thought they had FADEC with throttle detents.

 

[LJ45]

Well I'll say I have not flown a LR45 or LR40, so truth be told I don't really know 100%, but I thought they had FADEC with throttle detents.

yes... the Lear 45 series does have detents for TO, MCT and MCR. That has nothing to do with FADEC. The "F" in FADEC stands for Full authority which the 45 series does not have. It has a mechanical backup. Small technical detail, but it is a difference.

 

[westwind driver]

yes... the Lear 45 series does have detents for TO, MCT and MCR. That has nothing to do with FADEC. The "F" in FADEC stands for Full authority which the 45 series does not have. It has a mechanical backup. Small technical detail, but it is a difference.

I yield to you because you have experience with the aircraft. So I don't doubt what you are saying to be true.

This is of course getting off topic from the original post, but I would be interested in a brief breakdown of how this pseudo fadec/deec works? The reason I ask, we had DEECs on the Westwind, but it was basically just full throttle and it would set your t/o power. Worked much much better than the EECs.

So I assume on the Lear 45 series, It is like having a 1 channel FADEC, but it's a DEEC because it has mechanical backup and not dual channel?

EDIT: Well I should say it has 1 channel electrical, and then mechanical backup. As where FADEC is dual channel electrical, no mechanical backup, and thus if both channels fail, no turbine turning

So it's like a hybrid in a since. Would this be a proper way to describe it?

Thanks for the knowledge!

 

[GSXR600]

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