Emirates 343 Question

[DaveMc]

Hi All

First post but have been a long time reader of the site. Find it all quite interesting. My background is not in aviation directly but I do have a keen interest.

I was flying Shanghai-Dubai last Monday night (27th) on an Emirates 340-300. The aircraft was full and the flight time was approx 8.30 hrs. Just after rotation, the aircraft shook for what appeared to be several seconds (guessing I would say 10) and then stopped. It could also be described as a quite a large vibration but this may imply a problem with the aircraft and that is certainly not my intention here. The plane continued to climb out, as what appeared to me to be normal. My question is this, what was the cause of this shaking or vibration as I have described, as I have never had a similar experience before. Just to add that on the Dubai-Shanghai flight this did not occur.

Interested in your opinions

Dave

[Notso Fantastic]

Probably the sound of the nosewheel spinning against the brake in the undercarrige bay following retraction. It only contacts the brake when retracted- can make a racket if you sit near it. Not sure if there is a central main gear on the -300- if that doesn't have a brake there would be noise there too.

[alexban]

Almost sure the vibration that you described was caused by the landing gear being retracted.Where were you seated in the plane?
Right as NSF said

[DaveMc]

Thanks Guys, think you've answered my question. I was sitting in the centre of the plane around the middle of the wing, just above the main landing gear. I would presume that the vibration from what you have discribed about the landing gear would be the greatest here.

Cheers

Dave

[Old Smokey]

DaveMc,

Without having been there, I believe that your 2 respondants got it right. It's quite noticeable on the A340 in your seating position.

I also believe that we need a forum for "Unusual Airbus Noises and Other Things that Go Bump in the Night"

[r304ndy]

For information, the A342/3 have a twin wheel centre landing gear, however it is not a load bearing structure and is not equipped with braking, unlike the A3456.

[square leg]

Nice one Old Smokey :D

[Notso Fantastic]

r304,
the A342/3 have a twin wheel centre landing gear, however it is not a load bearing structure

Just to query this. The whole point of a landing gear is to be 'load bearing' isn't it? I understand not bothering with a brake unit for this leg.

[TwinAisle]

In a previous life, I was responsible for buying this centre gear from Messier Dowty in Toronto on behalf of Airbus....

It is not braked, as correctly stated - but it does bear load at higher weights. If you watch the aircraft being towed empty, there is clearly fresh air under it. It does bear a LOT of load at touchdown and at higher ramp weights tho...

[Snigs]

The very first A340's were near enough identical to the A330 with regards to the fuselage, undercarriage, wing (except for the number of engines) etc.

The centre single bogie addition to the A340-300 was needed as the heavier weight of the A340 couldn't be borne by the two wing landing gear assemblies with a reasonable margin of safety, plus they needed to spread the load with respect to the pavement loading specifications.

So, it is indeed a load bearing structure.

The -500 and -600 have a double bogie centre landing gear, due to their "growth" in MAUW.