User avatar
Topic Author
Posts: 126
Joined: Sun Feb 03, 2008 9:55 am

B748 Vibrations Aft Fuselage

Sat Aug 31, 2013 1:36 pm

Hi there,

I just came back on a round trip with the LH B748 FRA-HKG-FRA. Generally a great plane. The interior is up to date. On the first trip I sat right behind the wing. Absolutely quiet flight even during takeoff (the only noisy part was the air conditioning). On my return trip I sat in the last row. I was surprised by the amount of vibration in the fuselage. It started right after lift off. First I thought there were small turbulences, but after 11 hours same vibrations, sometimes quite remarkable, I am sure that it is some normal phenomena due to the long fuselage. I wonder how the crew can rest back there. Has this always been a B747 issue even without any turbulence?
Posts: 346
Joined: Mon May 30, 2011 8:15 am

RE: B748 Vibrations Aft Fuselage

Sat Aug 31, 2013 1:43 pm

I assume you feel more "vibrations" the further you are from the centre of mass.
Posts: 564
Joined: Thu Jan 20, 2011 6:05 am

RE: B748 Vibrations Aft Fuselage

Sat Aug 31, 2013 1:44 pm

Quoting kmz (Thread starter):

I read this article, I am not sure if this is relevant to your observations:

"As Boeing wonders how much faster it can feasibly build 737s and 787s, it is slashing output of the 747-8 and may need to cut it even more. While Boeing received net orders for 428 aircraft so far this year, the firm order backlog for the 747-8 shrank by two units. Although Boeing overcame the 787 battery issue, it still has not implemented a solution for the year-old wing vibration problem on the 747-8 that renders a range-extending fuel tank inoperative."

Posts: 967
Joined: Tue Dec 05, 2000 7:26 pm

RE: B748 Vibrations Aft Fuselage

Sat Aug 31, 2013 1:50 pm

I would guess the poster is referring to the 747 'fish-tailing' which I assume affects the latest 748 as well. It is a gentle left-right rocking/wobble that you can feel at the very back, in turbulence it can be felt much more intensely, but it's there nearly all the time except in the most still air. If I remember correctly it has something to do with some active damper system.
Welcome aboard Malaysia Airlines! Winner of Best Cabin Staff 2001,2002,2003,2004,2007,2009,2012
User avatar
Posts: 25155
Joined: Sun Jul 15, 2012 6:13 pm

RE: B748 Vibrations Aft Fuselage

Sat Aug 31, 2013 2:00 pm

I'm not sure if it's related, but Boeing deactivated the tail tank due to a flutter condition caused by vibration. This will be fixed in the airplanes delivered from next year.

Quoting kmz (Thread starter):
the only noisy part was the air conditioning

That's a known issue and has already been fixed, but LH 748s are not yet retrofitted.
What we leave behind is not as important as how we've lived.
User avatar
Posts: 2221
Joined: Sat Aug 15, 2009 9:13 am

RE: B748 Vibrations Aft Fuselage

Sat Aug 31, 2013 3:09 pm

- In general, on most aircraft - further aft -more noise.

- The dutch roll tendency on all 747 series, previous to the 748, is not very prominent and is counteracted by an upper and lower yaw damper system, installed at both rudders. According the DDG , you may even depart with one system U/S

- The tail tank issue has nothing to do with vibration during normal airline operation.

- The tail tank issue : Boeing could not demonstrate to the authorities during certification (paper excercise) , that - with one failed attachment of an outboard engine - an non normal condition (that has never happened at any of the preceding 747 series) - the airplane doesn't develop flutter with the tailtank more than 30% full, in combination with a FWD CG.

- Because the tailtank is not used at the current Lufthansa 747-8 destinations (and is only to be used with less than 60% payload), Boeing decided not to delay the certification and to certify the tailtank at a later stage (January 2014).

- The 747-8/BBJ aircraft are most likely to use the tail tank more often, but all 747-8/BBJ's are still in VIP cabin refurbishment and not active yet.
Operating a twin over the ocean, you're always one engine failure from a total emergency.
User avatar
Topic Author
Posts: 126
Joined: Sun Feb 03, 2008 9:55 am

RE: B748 Vibrations Aft Fuselage

Sat Aug 31, 2013 3:42 pm

Quoting chrisrad (Reply 3):
I would guess the poster is referring to the 747 'fish-tailing'

actually I don't think it is fish tailing. It was more a vibration which had random frequency and random amplitude. Like on a boat. Kept me from sleeping...

Quoting KarelXWB (Reply 4):
That's a known issue and has already been fixed

That is good to know. It is such a pity to have a quiet plane (engines, aerodynamic) and an air conditioner noise like in a wind tunnel...
Posts: 695
Joined: Sun Aug 22, 2004 12:43 am

RE: B748 Vibrations Aft Fuselage

Sat Aug 31, 2013 3:57 pm

From personal experience of operating on the 747, I know the the main landing gears create quite intense vibration just after rotation up until retraction.

A380 Crew
Posts: 1749
Joined: Tue Nov 21, 2000 10:05 am

RE: B748 Vibrations Aft Fuselage

Sun Sep 01, 2013 7:35 am

Have flown with 777 and 738NG - I also still felt the same vibrations too... It looks like the plane was gonna to start the engines or something I don't know.
The Spirit of AustraliAN - Longreach

Who is online

Users browsing this forum: alaskan9974 and 2 guests

Popular Searches On

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos