Looks like a bit of a no-no

Snowgoose · Post by **Snowgoose** » Tue Jun 21, 2005 7:24 am

Did this guy have a bad bounce or did he go to reverse in the air? Spoilers aren't up that I can see. Quote says landing on short runway in YYZ.

http://www.airliners.net/open.file/863076/L/

Mitch Cronin · Post by **Mitch Cronin** » Tue Jun 21, 2005 7:48 am

I'm not 340 endorsed, but I believe the reversers will not deploy until the tilt switches on the main gear are sensed "far"... ie. the aft wheels have contacted the surface and have begun to untilt the bogies. ... And I think you wouldn't see the spoilers at that angle.

Snowgoose · Post by **Snowgoose** » Tue Jun 21, 2005 8:13 am

That means that you have to have the throttles in reverse in the air to get them to deploy at the instance that tilt switch closes. I think it's risky. If the plane start to slow in that the position I think there is a possibility of hitting hard. Correct me if I'm wrong.

bizjet_mania · Post by **bizjet_mania** » Tue Jun 21, 2005 8:16 am

I believe on the Airbus you can arm the reversers to automatically deploy once the back main wheel have made contact.

Jaques Strappe · Post by **Jaques Strappe** » Tue Jun 21, 2005 9:21 am

Notice that the center wheel is not on yet. If spoilers deployed with it still 6 ft in the air, she would come down like a ton of bricks.

There is no automatic reverser deployment.

Snowgoose · Post by **Snowgoose** » Tue Jun 21, 2005 9:35 am

That's why I trying to figure if it was a bounce. The spoilers would have gone up on the first touchdown. Do they automatically retract again if she gets airborne again?

Jaques Strappe · Post by **Jaques Strappe** » Tue Jun 21, 2005 9:51 am

I don't think it was a bounce. At least no evidence to suggest that. Looks like a nice landing to me. Mains are on allowing reverse and as soon as that center bogey is on the spoilers will deploy.

YYZ Tower · Post by **YYZ Tower** » Tue Jun 21, 2005 10:08 am

I remember this landing as I was working at the time. He sure wanted to slow down fast as he didn't touch down until past F2 which would leave him about 4500-5000 feet to stop in! There was traffic just airborne from 24R at the same time, so an overshoot would have been "interesting". It was a smooth touchdown though, just a little deep.

Snowgoose · Post by **Snowgoose** » Tue Jun 21, 2005 10:12 am

I guess I am just a little shocked to see the reversers open without all the wheels on the ground, or at least most of them. Knowing the Airbus and it's software I am surprised that this picture is possible.

SierraPoppa · Post by **SierraPoppa** » Tue Jun 21, 2005 10:57 am

I am not sure that this is all that unusual.
Here is a similar shot that I captured at Calgary in 2003. There was nothing unusual at all about the landing.

Cheers
Steve

desksgo · Post by **desksgo** » Tue Jun 21, 2005 11:07 am

I think it's standard procedure...stop trying to fault other people's work

groundtoflightdeck · Post by **groundtoflightdeck** » Tue Jun 21, 2005 3:49 pm

I don't think those cascade style reversers would make a whole lot of drag without the engines spooled up. Proabably no worse then pushing your props forward just before touching down.

20DMEYYZ · Post by **20DMEYYZ** » Tue Jun 21, 2005 4:33 pm

I have seen this type go to idle reverse in the flare . werked-out to be a nice touch on 23 ! maybe the 743 or boeing acft allow the door's to slide back on the round-out ?? comments .........

ypph · Post by **ypph** » Tue Jun 21, 2005 4:54 pm

This is how the manual for the A330 reads in regards to spoiler deployment/retraction:

"Full Extension: The ground spoilers automatically extend during a rejected takeoff at a speed greater then 72 knots, or at landing, when both main landing gear have touched down and: all thrust levers are set to idle provided they are armed, or reverse is selected on at least one engine (other engine at idle)"

"Partial Extension: the ground spoilers partially extend when reverse is selected on at least one engine (other engine at idle) and one main landing gear is compressed. This partial extension, by decreasing the lift, will ease the compression of the second main landing gear, and consequently will lead to the noraml ground spoiler extension"

"Retracion: the ground spoilers retract when: one thrus ;ever is above idle or, both thrust levers are at forward idle and the speedbrakes control lever is pushed down. Consequently after an aircraft bounce (aircraft airborne) if the spoilers are extended: the remain extended with thrust lever at idle, the retract if thrust is increased above idle (go around) and extend again after the next touch down"

Hopefully that can help explain the pic. You are able to select idle reverse as soon as the mains touch,and full reverse once the buckets are fully deployed. No more study required today know me thinks!!!

Jaques Strappe · Post by **Jaques Strappe** » Wed Jun 22, 2005 7:42 am

That is for an A330 which does not have the center bogey.

Mitch Cronin · Post by **Mitch Cronin** » Wed Jun 22, 2005 7:52 am

Jaques... again, I'm not familiar enough with the bird to speak as an expert, but I'd be surprised if the 330 and 340 differed in that regard... for one thing, depending on the weight, sometimes the center gear doesn't make it to the ground... if it's light enough, those wheels are hanging in space when she's sitting on the ground. Squat switches and tilt switches are common both on mains and occasionally on the nose of some birds (37's for example), but that would be unique to see one that had anything dependant on center gear contact... What would be the result of locking that gear up, for instance? (I don't know if that's in the MEL, or if it requires a ferry permit, but I do believe we've done it. - to get home from HNL once)

Jaques Strappe · Post by **Jaques Strappe** » Wed Jun 22, 2005 10:34 am

Hey Mitch

Well the 340 and 330 do differ in so far as the 330 does not have a center bogey. I am not endorsed on the 340 but have a call in to a buddy who is. However......

Looking at that photo and seeing that the mains are on without spoiler extension, tells me that perhaps the center needs to be on. Makes sense if you think about it because if the spoilers did come up with that wheel still 6 to 8 feet in the air, it would hit the runway with an almighty thump. Not to mention the stress on the airframe. Imagine deploying spoilers while in the flare! The A340 can have that wheel locked up under MEL with an imposed weight restriction but I have never in my life seen one not touching the ground because the airplane was empty.

Mitch Cronin · Post by **Mitch Cronin** » Wed Jun 22, 2005 11:11 am

Hey Jaques,

I'm supposed to be hidin' (I think I mighta just pissed off all the water bomber jockeys in the country!), so maybe this is as good a place as any

Jaques Strappe wrote: Looking at that photo and seeing that the mains are on without spoiler extension, tells me that perhaps the center needs to be on. Makes sense if you think about it because if the spoilers did come up with that wheel still 6 to 8 feet in the air, it would hit the runway with an almighty thump. Not to mention the stress on the airframe. Imagine deploying spoilers while in the flare! The A340 can have that wheel locked up under MEL with an imposed weight restriction but I have never in my life seen one not touching the ground because the airplane was empty.

I'm not so sure the spoilers aren't up and you just can't see 'em?... That the aft mains are on the ground, and as I understand the tilt actuator on that beast has some power to it, I doubt the degree of thump from there on would be so bad... Oleo travel combined with that tilt is long on those birds to accomodate the length and help mitigate tailstrikes... I'm certain I've seen the center gear tires off the ground while sitting near empty, might only be as little as an inch or two, but I am certain.... But I guess even while near empty of fuel, with a load of pax, not to mention any feet per second coming down, the center gear will take some load.

You could be right.... Let us know when you learn the truth will ya?

Cheers,

Mitch

Jaques Strappe · Post by **Jaques Strappe** » Thu Jun 23, 2005 12:48 pm

Hey Mitch

Just checked in at Flt Ops for my flight. Asked a 340 driver about the center bogey. He confirms that it needs to be on the ground for spoiler deployment.

I have to admit, he scratched his head a little at first, dusting off the cob webs.

Cheers.

Mitch Cronin · Post by **Mitch Cronin** » Thu Jun 23, 2005 2:43 pm

Interesting... Thanks Jaques. I'll have a look next time we've got one in the barn.

Cheers,

Rebel · Post by **Rebel** » Thu Jun 23, 2005 3:42 pm

Reverse deployment on A -340 requires;

-One FADEC (full authority digital engine control) operating with its associated throttle reverse signal
-aircraft on ground signal from at least one LGCIU (landing gear control interface unit)
-thrust lever angle (TLA) information from the flight primary computers(PRIM) all engines PRIM2 engines 1&4 PRIM3 engines 2&3

In short all pictures were entirely normal main gear first with the training wheels landing second then the nose wheel last . It's a hard bugger to get consistence nice landings with because of the training wheels at least for me.

Looks like a bit of a no-no

Looks like a bit of a no-no

KLM743