Why did the RJ gear collapse?

Four1oh · Post by **Four1oh** » Wed May 30, 2007 3:47 pm

Inverted2 wrote:
Traf wrote:
Holy crap!!! They must have hammered that thing onto the runway. If this was the US there would already be a lawsuit filed.
Get a hold of yourself man!!! That damage is not from the airplane pounding into the ground. There has been no confirmation of a hard landing. The media does not constitute CONFIRMATION!!! The airplane landed, rolled out and the gear collapsed on the hig speed taxi way.

I don't know of many airplanes that have gear collapse like that unless it was from a hard landing. The RJ gear retracts inwards, not backwards and upwards into the wings!!

I agree completely, metal fatigue maybe, but why would both gear fail at the same time?

KAG · Post by **KAG** » Wed May 30, 2007 5:15 pm

Dockjock wrote:I'm with Jeremy.

And all this RJ posturing is making me puke! Good thing there is a sim eval at Jazz because clearly "heroes only" need apply...

Yeah thats my point. All Jazz pilots are hero's.

At least alittle experience is nice to have.
Do you think a new grad could do your job AS safe, AS efficiently as yourself back when you were first hired at AC? I don’t think so. Would you have any issues sending your family on said flight with maybe say a weaker CPT in bad weather?
I won’t even get into what it does for moral among new hires who were hired with experience…
It can be done, but should it?

Traf · Post by **Traf** » Wed May 30, 2007 6:03 pm

Goose757 I would guess that if one gear folds, the other may be under quite a bit of stress.

I would suggest that a hi-speed turn-off is more the culprit than the hard landing theory! How hard would you have to land to unlock both gear legs? If they had landed that hard, passengers would have been all over the news talking about falling from the sky and bullshit like that.

Lost in Saigon · Post by **Lost in Saigon** » Wed May 30, 2007 6:49 pm

I doubt that one gear failure would make the other fail. Besides, RJ gear retracts inwards not BACKWARDS!

It looks to me like something that the gear attached to failed or fell apart. Maybe the forward spar failed?

Big M.A.C. · Post by **Big M.A.C.** » Wed May 30, 2007 9:54 pm

I work for a U.S. carrier that had a similar problem and bombardier tried to pin it on the pilot. Turns out that there was some micro corrosion in the strut assembly and that they had problems with a certain strut batch...

We now have a regular inspection worked into the sched that ensures that no other struts suffer from this situation.

Who knows mabe this is what happened

Just another driver · Wed May 30, 2007 10:43 pm

You look at those PICS and think it had to be a hard landing. But then you think: if it was that hard should it not have collapsed on landing not on the taxiway? Also, the PAX would have been screaming to the media they crashed or hit an air pocket. If it took the corner too fast, you would think it would have folded sideways not backwards.

Maybe this was just structrual failure. Too bad if it is that were slamming the pilot(s) bad landing without all the facts. It is easy to play arm chair pilot and I'd be lieing if I said I didn't do it too.

CD · Post by CD » Thu May 31, 2007 2:56 am

CF-2004-18R1 - Main Landing Gear Main Fittings

Lost in Saigon · Post by **Lost in Saigon** » Thu May 31, 2007 4:56 am

From the "General" forum:
http://www.avcanada.ca/forums2/viewtopic.php?t=31243

According to a friend at TC, it was a hard landing that smashed the gear through/off the wing. The cause is yet to be determined, as is the validity of a rumour that the pilots actually powered up and taxied it clear of the rwy and onto a high speed.

It is starting to make sense now:

Hard landing and/or mechanical failure, then extra power to get clear of the runway. Hit the brakes to slow down and then ............

BANG!!!!

The gear folds backwards.

Brick Head · Post by **Brick Head** » Thu May 31, 2007 8:14 am

I am no investigator but those pictures do not seem to show any rupture on the top of the wing. One would expect to see trauma on the top of the wing, from a hard landing capable of collapsing the gear, since that would have been the direction of force.

Also the pax statement does not corroborate the very hard landing idea.

Possibly a harder than normal landing took place to finish off the gear but I have my doubts to was the route cause.

It looks like the force that tore the gear went straight back. Likely happened during braking. Maybe a combination of braking and side load on the high speed exit.

Goose757 · Post by **Goose757** » Thu May 31, 2007 10:44 am

Brick Head wrote:I am no investigator but those pictures do not seem to show any rupture on the top of the wing. One would expect to see trauma on the top of the wing, from a hard landing capable of collapsing the gear, since that would have been the direction of force.

Also the pax statement does not corroborate the very hard landing idea.

Possibly a harder than normal landing took place to finish off the gear but I have my doubts to was the route cause.

It looks like the force that tore the gear went straight back. Likely happened during braking. Maybe a combination of braking and side load on the high speed exit.

The RJ also has "articulated" landing gear which would reduce the vertical forces produced in a hard landing situation. Thats why the pilots prefer the 100/200 to the 705, much easier to grease it on. Thats what makes it all the more shocking if this does turn out the be a hard landing.

Like people have said, (and I tend to agree), it was probably a combination of wear, harder than normal landing and perhaps a high speed turnoff.

Clothesliner · Post by **Clothesliner** » Thu May 31, 2007 11:29 am

Inverted2 wrote: I don't know of many airplanes that have gear collapse like that unless it was from a hard landing. The RJ gear retracts inwards, not backwards and upwards into the wings!!

I saw footage once of a pilot jamming the brakes on too hard, causing the gear to collapse. I think it was a documentary called Airplane.

Four1oh · Post by **Four1oh** » Thu May 31, 2007 6:17 pm

here's something to think of, if it was a hard landing, and hard enough to do that kind of damage to the gear, then the fuselage definitely would be wrinkled. I know this because I was up in YZF when 7F wrote off a 200 with a hard landing. On that one, the main gear was fine, but the nose gear was damaged; it was canted off to one side, but still worked. The nose section ahead of the nose gear and the aft fuselage rear of the main gear all wrinkled quite substantially.

Traf · Post by **Traf** » Thu May 31, 2007 7:05 pm

All the AVForum experts are making assumptions that it was a hard landing. Do you know how hard you would have to hit to collapse both gear? Come on guys, use you brain a little. Yes the gear is folded back but the rest of the plane is flawless.

If they had landed hard enough to break both gear off, the fuselage and upper surfaces of the wings would be showing it.

Let the investigators figure out before you clowns jump to any more conclusions.

Goose757 · Post by **Goose757** » Fri Jun 01, 2007 7:29 am

Four1oh wrote:here's something to think of, if it was a hard landing, and hard enough to do that kind of damage to the gear, then the fuselage definitely would be wrinkled. I know this because I was up in YZF when 7F wrote off a 200 with a hard landing. On that one, the main gear was fine, but the nose gear was damaged; it was canted off to one side, but still worked. The nose section ahead of the nose gear and the aft fuselage rear of the main gear all wrinkled quite substantially.

Sounds like they landed on the nose gear. Completely different story there.

Traf wrote:All the AVForum experts are making assumptions that it was a hard landing. Do you know how hard you would have to hit to collapse both gear? Come on guys, use you brain a little. Yes the gear is folded back but the rest of the plane is flawless.

If they had landed hard enough to break both gear off, the fuselage and upper surfaces of the wings would be showing it.

Let the investigators figure out before you clowns jump to any more conclusions.

Whats the big deal? Its all speculation, people have mentioned things that I didn't know about the RJ, people have made good points, people have made bad points. I'm sure a lot of people, (myself included), have learned something about the RJ that they didn't know before. No one is calling for heads to roll, no one is naming names. Heck, if it does turn out to be a high speed turning error, then we'll all know not to do that next time we're flying the RJ

737daytripper · Post by **737daytripper** » Fri Jun 01, 2007 11:54 am

If the gear was selected up as the RJ was entering a high speed taxiway at 40kts and for some reason (such as hitting a bump) the aircraft didn't detect weight on wheels, wouldn't the gear begin its retraction cycle and when the gear could no longer support the weight of the aircaft then the gear would fold backwards as the aircraft was travelling forward. The nose gear would remain down because of the weight and angle of the aircraft on the nose gear. This is assuming the main gear retracts first followed by the nose.

This is just speculation as I have no knowledge of RJ systems. Flame away.

Traf · Post by **Traf** » Fri Jun 01, 2007 5:19 pm

OK let's further along that line. Everyone is assuming hard landing because the gear is bent nack and not folded inwards.

ANy RJ maintenance guys able to answer a design question? What keeps the gear locked down? Better yet, is there one or a combiation of parts that could fail that would allow the gear to fold back and not inward? Is it possible that such a scenario exists? I don't know the design at all so I would be curious to know that if a certain part of the gear or it's linkages were to fail, could the legs flop back and not in.

bobcaygeon · Post by **bobcaygeon** » Fri Jun 01, 2007 10:04 pm

TRAF

You can't dispute an FDR that recorded +4.5 G's on landing. Call it what you want but .......

KAG · Post by **KAG** » Fri Jun 01, 2007 10:27 pm

How is it the FDR data is public knowledge so fast? Or is this a rumor running around Jazz?

Stinky · Post by **Stinky** » Sat Jun 02, 2007 6:22 am

Regardless of what happened we should all be thankful it wasn't worse. If this had happened while airborne it would have been a real tragedy.

JazzJetDriver · Post by **JazzJetDriver** » Sat Jun 02, 2007 7:29 am

"If this had happened while airborne it would have been a real tragedy."

??? You gonna have to explain that one to me ???

Sage · Post by **Sage** » Sat Jun 02, 2007 7:59 am

What? JJD you don't know? 4.5g hard landings while airborne are the worst!!!

ettw · Post by **ettw** » Sat Jun 02, 2007 8:26 am

After looking at some of the pics that were linked I have to say I'm thinking hard landing is looking less likely.

The pic showing the RH gear straight back and up thru the flaps....the wing to fuselage fairings aren't even wrinkled in the least, as far at the pic can show. I would suggest that if a landing was hard enough to damage or weaken landing gear and its attach structure, it surely should have at least wrinkled the fairings. This is assuming the fairings are aluminum. If they're composite then its possible they may not show damage the same way without a tap test or other NDT but you might expect paint to be flaked off. And generally hard landings result in deformation of other parts of the aircraft, wing skins, fuselage skins between wing and nose gear, engine pylon wrinkles, you get the picture and none of those are apparent in these FEW pics but they're not the best for second guessing purposes.

My early, arm chair quarterback money is on something other than a hard landing.

Cheers,

ETTW

bobcaygeon · Post by **bobcaygeon** » Sun Jun 03, 2007 8:53 pm

KAG wrote:How is it the FDR data is public knowledge so fast? Or is this a rumor running around Jazz?

Aviation is a very small world buddy. +1400 pilots work at Jazz, someone is bound to know someone in the know.

PS If it's on a computer then it can be accessed. For example KAG, from your credit card records I see you bought a 14 inch DILDO & 1 gal. of KY at the sexshop on 16th Ave in YYC while in G/S at WJ. Were you the giver or the taker???

KAG · Post by **KAG** » Sun Jun 03, 2007 9:52 pm

damn, you spoiled my christmas gift for you!!! Apparently the 12 inch I bought you last year wasn't quite big enough.

tonysoprano · Post by **tonysoprano** » Mon Jun 04, 2007 5:57 am

PS If it's on a computer then it can be accessed. For example KAG, from your credit card records I see you bought a 14 inch DILDO & 1 gal. of KY at the sexshop on 16th Ave in YYC while in G/S at WJ. Were you the giver or the taker???

He didn't buy that one. It was a "welcome" present from Clive.