VS 747 Pod Stike at LGW

[The Fuzz]

Ok just seeking some clarification on a rumour i heard in the crew room. This is probably 3rd or 4th hand info.....

Last week (possibly week before) a VS 747 landed extremely heavily at LGW scraping engines 3 and 4.

Apparently the heavy landing was not reported, and the ground engineers signed the a/c off for the subsequent flight.

One of the pilots on the walk around noticed bits hanging off the No4 eng and No3 also had damage.

The CAA are investigating as the engineers signed the plane ok in the tech log, and the pilots involved in the scrape have been suspended.

Again this is a rumour doing the rounds in LGW i dont know how true it is, and if this has been discussed on another thread please point me in the right direction (i've not found it) and close this thread.

Cheers

[Intruder]

Unlikely.

While a #4 pod scrape could go unnoticed, to get #3, #4 would likely be heavily damaged.

[bustitagain]

I know that this did happen as I have seen the damaged intake that was replaced on one of the engines. I do have some details but would only be fourtysecond hand so don't want to add any sketchy details unless there is hard fact. The AAIB were around the Virgin hangar for some time so I guess we will just have to wait for the report.

[TheOddOne]

It's as you say. The No 4 cowling was ground down to a razor-fine edge and the no 3 was also heading that way, but less so. Apparently, allegedly, the crrew were 'unaware' at the time of landing that they'd struck the runway, even though the a/c was observed to have rolled right and left (as you would imagine!) to relatively extreme angles.

What concerns me is that there must have been debris left on the runway but by the time it got reported to Airfield Ops and an inspection was carried out, all evidence of the strike had been obliterated by subsequent arrivals. Someone else could easily have pickedup the debris in a tyre, or injested it on departure, creating the possibility of a much bigger incident/accident.

We try and operate a 'no blame' culture to encourage open reporting of incidents in the interests of safety. It's no problem for Airfield Ops and ATC to carry out a quick runway inspection for debris, even at the world's busiest single-runway airport!
Cheers,
TheOddOne

[Mr @ Spotty M]

Why do you imply runway debris?
More likely the intakes and cowlings would be ground to sparks and dust.:ok:

[Albert Driver]

Heavy landings and pod scrapes are forgiveable.

Failure to check out or report even the merest suspicion of either, if true, is not.

Pod scrapes are most often associated with heavy landings (compressed oleos) but the heavy landing alone requires a special check, including the pods.

[TheOddOne]

MR @ Spotty M
Why do you imply runway debris?

...because that's what experience shows is a likely outcome. ANY debris on a runway is bad news for following aircraft. In this particular case, we didn't find any FOD, but that doesn't mean it isn't a significant event that should be reported straight away. That INCLUDES casual witnesses ('oh, yes, I thought it looked a bit odd, but I didn't like to say anything in case it wasn't a problem'). We've had plane spotters ring up and say they've seen something happen and when we've checked it out we've found debris. They are an excellent resource, in my view.

The worst case I've seen with a 747 pod scrape was the whole engine detatched from the pylon and left lying in the middle of the runway. Pan-Am 747, runway 23 at LHR. What a mess! At least I think the crew noticed that one...

Cheers,
TheOddOne

[swordsman]

The 747 is certified to land in almost 40 mph of crosswind on a dry runway.The only thing is that due to the inherent design of the aircraft it has to be landed wings level with the correct amount of drift kicked off at the correct moment,unlike smaller planes like a 737 or 757 which can land with one wing down (a much easier manouvre).
If the drift is kicked off too early the aircraft will have a tendency to drift away from the runway and a natural tendency to apply bank to maintain the centre line results in a pod scrape if the bank angle exceeds 5 degrees (not a lot). Kick the drift off too late or not enough or too much can in certain circumstances buckle the undercarridge especially on a dry runway leading to a lot of red faces/carnage.
Some companies only let Captains land when on crosswind limits,and copilots restricted to 2/3 of the limit.

[Atlanta-Driver]

Boeing aircraft are not certified to land to a maximum allowed cross wind. (Xcept Autoland), they have a demonstrated component that is not restricting.

AD

[Bluebaron]

It is my understanding that you do not 'have' to kick the drift off at all. the aircraft can land with the drift fully applied. (ie: sideways!)
BB:\

[swordsman]

AD
Interesting.In the UK there is a restriction within a company flying manual which forms part of their AOC (air operators certificate).Unless there is a "force majeur" ie no where elso to go it is the same as say breaking landing minima.
Incidentially in one of the larger UK companies the whole of the gust factor is limiting where it used to be factored.Not a bad thing IMHO.

[L337]

These vids on youtube are worth a look. In almost all instances most if not all the drift has been left on by the Boeing Test Pilots.

xwindldg (http://www.youtube.com/watch?v=ljOxo0s33sI)

[Intruder]

The 747 can be landed with wing down, in a "crab" (the American word for the crosswind correction you are calling "drift"; in my mind, the correction REMOVES the tendency to drift off centerline...), or a combination. In fact, the 744 Autoland will apply a wing-down/top-rudder "slip" correction on final, in 2 stages if necessary. It will use crab angle to correct for whatever is needed beyond the slip to retain the centerline.

The 2 important things are:
1) No more than 5 deg bank angle on touchdown, to prevent pod strike
2) Velocity vector down the centerline at touchdown, to provide momentum in the correct direction.

[Litebulbs]

Has an autoland ever got it wrong with kick off drift, decrab or align?

[Flight Detent]

Errr....

Gentlemen, the same 'ol confusion between 'heavy' and 'hard' landings methinks, at least in the initial and the next few P'posts.

Also, I believe Atlanta Driver to be correct, Boeing only quotes a demonstrated Xwind, not limiting with all engines operating.

Cheers, FD :bored: