LH 744 TK nose gear down
 

Uli reports on flyertalk:

"some minutes ago the nose gear of LH 744 TK broke down. Pax bound for DEL had already boarded. TK was still at the gate.

744 now sittings on her nose at the gate.
Hope seat bealts were applied already.

happened at FRA during push back"

Profit Max

Hope the tug driver is ok.

Lufthansa jumbo jet collapses on nose at Frankfurt
Mon May 15, 2006 3:12 PM ET

FRANKFURT, May 15 (Reuters) - A Lufthansa AG jumbo jet collapsed on its nose at Frankfurt airport when the front landing gear gave way as it was preparing to fly to New Delhi, an airline spokesman said on Monday.

The 242 passengers and 16 crew members on board the Boeing 747-400 had to abandon the plane after the nose sank down onto a waiting tow truck.

"No one was injured. Everyone was able to leave the aircraft via the passenger bridge," the spokesman said.

The passengers were being put up in Frankfurt hotels on Monday night and were due to take a different flight to New Delhi on Tuesday morning. The original flight -- LH760 -- had been due for takeoff at 1150 GMT Monday.

"The cause of the fall is not yet known. It's very unusual," said the spokesman.

The plane was relatively new and had been delivered to Lufthansa in December 2001.

The spokesman added that the incident had been reported to German air accident investigators.

Boeing spokespeople in Berlin and Brussels were not immediately reachable for comment.

idle chit chat and pics here

http://img459.imageshack.us/img459/1...apsed011pi.jpg

http://img179.imageshack.us/img179/6...apsed023mr.jpg

LH use the tugs that lift the nosewheel clear of the ground before pushback. Does anyone know if there is any form of 'weak link' release mechanism on this type of tug in case of a pushback with the brakes applied? I'm not saying that this is what happened, I'm just interested to know what would happen if it did.

Airclues

Since the 747 nose gear retracts forward, even such a weak link would not work when pushing "back".

AFAIK, there is no such weak link on the 747 itself or any other airliner. There IS a weak link in the tow bar normally used with a conventional tug, but I don't know if there is such a mechanism in the sort of tug that lifts the nosegear.

The shear-pins (the weak link) on a conventional towbar will not prevent the tug-driver from ripping the nosegear out of the airplane. The shear-pins are there to prevent the towbar from trying to turn the nosegear if the steering is pressurized, or to turn the nosegear past maximum angle.

As for pushing and pulling, the aircraft will either move it or loose it...

Ever stomped on a beer-can? That's the sound right there.. Horrible.. :uhoh:

Bartender,
That is exactly what the tow bar shear pin does. It stops the tug from ripping the nose leg out if for example the brakes are on. The "head" latches onto the nose gear and that is connected to the towbar by the shear pin.
If the shear load is exceeded the Tug goes on its merry way with the towbar leaving the head firmly attached to the nose leg.
I had one shear one night and the head dropped down onto the tarmac but before the guy could hit the brakes the head dug into the tarmac and jacked the nose wheels clear of the ground :}
Some towbars have a secondary link that prevents the head from becoming completely detached. Probably to avoid just that !:)

About a year or so ago, a VirginBlue 73 had its nose wheels lifted off the ground during push back at YPDN.

The story I heard through the grapevine was, that some weeks prior a "pushback person" replaced a sheared shearpin with a bolt and forgot to remove the bolt. On the night of the incident the pushback commenced with the brakes still applied, and the nose wheels were lifted clear of the ground as the aircraft rotated about the main wheel axles.

I believe the aircraft ferried to BNE for inspection with the gear down, after blocking one of only three aerobridges for most of the ensuing day. :eek:

It's not a good time for the 747 nose section these days:E

Nose Gear
 

Looking at the damage in those pictures, i would say that unfortunately this plane will be a write off!:{

That's the one, and it is not designed to fail on the designs i've seen... The result is that the shear-pins give protection for the steering and max angle, but the bolt keeping the head attached to the towbar will not prevent pushing or pulling the nosegear out of the aircraft..

Mate if they got VH-OJH (the Bangkok golf cart) going again, this'll be a very small bit of panel work by comparison.

Isn't this the Germans just practising their nose dive routine before the World Cup??:ok:

bartender,

most towbars (and all large aircraft bars such as B747) have two types of shear pins. axial which shear when the turn pressure is too great, and torque which shear when the straight line push or pull is too great.

so if you push when the brakes are on the torque should shear before damage to the gear. not an expert in towbarless tugs, but somebody from douglas, goldhoffer etc must lurk on here.

A poster on airliners.de (quoting "usually well-informed LH sources"...) reports that the nose gear gave way during a leak check being performed on conclusion of some hydraulics repairs. All this immediately prior to push-back (or lift-and-carry-back in this case).

I remember going up to the viewing deck at FRA some years ago with my lad who was beginning to show an interest in aviation (he is now doing his ATPL).

One thing that raised my eyebrows that day was the sheer speed at which the LH tug drivers were pushing aircraft back including 747s. Michael Schumaker would have found it difficult to keep up.

I have no idea of how many thousands of times I have been pushed back since 1978 and I was quite frankly astonished.

Has anyone else out there noticed this phenomenon?

I agree JW. They seem to be faster at FRA than in other places which is why I was interested to know about the 'weak link' sysem on these tugs. Not as dangerous as doing the external checks on the FRA cargo ramp at night though. :ouch:

Airclues

Yesterday a tugdriver clocked 10 knots on the IRS, pushing my 752. A bit on the faster side, I´d say. At CDG, Paris.

Checks were performed on hydraulic system one. The gear lever was selected up according maintenance procedure. You all know what happened thereafter.

Nobody was hurt, passengers left the aircraft via the airbridge, the tugdriver saw it coming and rushed out of his truck.

Aircraft is now in the hangar, further checks are being performed to access the damage and find out what went wrong.