Good morning, everyone.

Last night a particular memory came to mind of when I was flying DXB - LHR on a BA 744 back in June 2007. I remember this flight well as something unusual occurred during take-off, causing a few people to get visibly worried. It was a 2 a.m. departure from DXB, a fully loaded 744 in terms of passengers, enough fuel for the 8 hour flight to LHR, and it was searingly hot outside - roughly 35C and awfully humid. Back then I was already an experienced flyer, having logged the now scrapped G-BNLT as the airframe for this particular flight. Here's what happened:

We were rolling down the runway, and it seemed to take forever to get airborne. I began getting slightly worried as we were approaching the end of the runway, rotating, but with the main gears still on the ground. All of a sudden the plane shook rather violently four times in a quick succession, accompanied with that unusual deep, loud rumbling sound of stresses on the hull. The guy next to me jumped up all alarmed, grabbing hold of the seat. A few others let out little yelps. The aircraft got airborne and proceeded to London without further incidents.

Later in the flight I asked one of the cabin crew what had happened on takeoff, to which he simply said: "Don't think about it. We're fine." rather dismissively. I've been wondering to this day whether we suffered a tail strike or not, having probably been close to MTOW on a very hot night at DXB and the flight crew struggling to get the plane off the ground. Looking at Google Maps however, I now see that the end of 12L at DXB has four runway markers that could account for the shudders. So did we nearly overshoot the runway?

Thoughts? Has anyone felt like a B744 was struggling to get off the ground before, shuddering as it did, or was my experience unique?

The 747 sometimes has this shudder on take off, all quite standard.

NDiesel wrote:

Good morning, everyone.

Last night a particular memory came to mind of when I was flying DXB - LHR on a BA 744 back in June 2007. I remember this flight well as something unusual occurred during take-off, causing a few people to get visibly worried. It was a 2 a.m. departure from DXB, a fully loaded 744 in terms of passengers, enough fuel for the 8 hour flight to LHR, and it was searingly hot outside - roughly 35C and awfully humid. Back then I was already an experienced flyer, having logged the now scrapped G-BNLT as the airframe for this particular flight. Here's what happened:

We were rolling down the runway, and it seemed to take forever to get airborne. I began getting slightly worried as we were approaching the end of the runway, rotating, but with the main gears still on the ground. All of a sudden the plane shook rather violently four times in a quick succession, accompanied with that unusual deep, loud rumbling sound of stresses on the hull. The guy next to me jumped up all alarmed, grabbing hold of the seat. A few others let out little yelps. The aircraft got airborne and proceeded to London without further incidents.

Later in the flight I asked one of the cabin crew what had happened on takeoff, to which he simply said: "Don't think about it. We're fine." rather dismissively. I've been wondering to this day whether we suffered a tail strike or not, having probably been close to MTOW on a very hot night at DXB and the flight crew struggling to get the plane off the ground. Looking at Google Maps however, I now see that the end of 12L at DXB has four runway markers that could account for the shudders. So did we nearly overshoot the runway?

Thoughts? Has anyone felt like a B744 was struggling to get off the ground before, shuddering as it did, or was my experience unique?

There is no mention of a maintenance trip in June/July 2007 for that aircraft, nor a report of an accident/incident to be investigated. Almost conclusively I would say no tailstike.

Had a similar experience I still recall quite a few years ago on a TG744. Was just aft of the wing and on rotation, the double 'bang bang' of the gears decompressing on their oleos, accompanied by a massive shudder as the wheels were spinning was quite 'worrying'. Now I know what it was, you realise it is quite normal, and experienced many times since. Evident on this just after 1.50: https://www.youtube.com/watch?v=jVydEEM6oeo

If it happened it certainly would of been reported/found out, no way you could of covered that up in 2007.

https://youtu.be/I2VvcgFsMhE

I think you can hear the shudder after 7:22 in this video.

That is very much standard for both DXB and for the 744. From a Dubai perspective, even now, in March, I can take just shy of 60 seconds for an A380 operating DXB-Europe regardless of load, to reach its point of rotation. This doesn't necessarily mean you're right near the end of the runway upon becoming airborne. From a 744 perspective, the aircraft, pretty much always experiences high levels of vibration numerous times successively between the gear leaving the ground and being retracted. Less so on the -400ER.

Regards
ThomasCook

Leej wrote:

Had a similar experience I still recall quite a few years ago on a TG744. Was just aft of the wing and on rotation, the double 'bang bang' of the gears decompressing on their oleos, accompanied by a massive shudder as the wheels were spinning was quite 'worrying'. Now I know what it was, you realise it is quite normal, and experienced many times since. Evident on this just after 1.50: https://www.youtube.com/watch?v=jVydEEM6oeo

Also had a similar experience on EK A380. I was like you, sitting just aft of the wing and when the gear was extended, there was a very loud bang and some people were gasping. I guess it must be normal given the size of the landing gear.

Also, as a pilot previously flying the A320, I remember how we could sometimes still feel the nosewheel spinning after it was retracted causing some vibration for a few seconds

Planes I have flown apply wheel braking during landing gear retraction to avoid putting spinning wheels into wheel bays. Not sure about 744 but probably similar. The shudder might have been an out of balance wheel but it should not last more than a couple of seconds. Nose wheel has no brake of course and if a tire is worn and out of balance it can shudder for a bit longer as it spins down. I vaguely recall the 737 has a bumper in the nose wheel bay to stop the spinning tires? 747 too?

A known tail strike usually will result in a no pressurization procedure and a return to the airport.

So specifically, it occurs in Dubai in summer because the takeoff speed is so high? Wheel vibrations become more obvious?

Cool..

NDiesel wrote:

Good morning, everyone.

and it was searingly hot outside - roughly 35C and awfully humid.

Living in Phoenix, I did have to smile at searingly hot ( 35C 95F )

The guys above all hit all the right points. Most likely NOT a tail strike. My experience on the 747 is the same and especially sitting above and just aft of the wings. Remember, there are two bogeys of heat under the fuselage and that’s 8 large tires spinning very fast. When we left the ground out of HNL on my last 747 flight my wife was terrified because of the short lived heavy vibrations and a couple bang noises. It’s the landing gear! Normal stuff.

I am flat out remembering what I did yesterday in such detail at 2 am let alone 11 years ago.

NDiesel wrote:

Good morning, everyone.

Last night a particular memory came to mind of when I was flying DXB - LHR on a BA 744 back in June 2007. I remember this flight well as something unusual occurred during take-off, causing a few people to get visibly worried. It was a 2 a.m. departure from DXB, a fully loaded 744 in terms of passengers, enough fuel for the 8 hour flight to LHR, and it was searingly hot outside - roughly 35C and awfully humid. Back then I was already an experienced flyer, having logged the now scrapped G-BNLT as the airframe for this particular flight. Here's what happened:

We were rolling down the runway, and it seemed to take forever to get airborne. I began getting slightly worried as we were approaching the end of the runway, rotating, but with the main gears still on the ground. All of a sudden the plane shook rather violently four times in a quick succession, accompanied with that unusual deep, loud rumbling sound of stresses on the hull. The guy next to me jumped up all alarmed, grabbing hold of the seat. A few others let out little yelps. The aircraft got airborne and proceeded to London without further incidents.

Later in the flight I asked one of the cabin crew what had happened on takeoff, to which he simply said: "Don't think about it. We're fine." rather dismissively. I've been wondering to this day whether we suffered a tail strike or not, having probably been close to MTOW on a very hot night at DXB and the flight crew struggling to get the plane off the ground. Looking at Google Maps however, I now see that the end of 12L at DXB has four runway markers that could account for the shudders. So did we nearly overshoot the runway?

Thoughts? Has anyone felt like a B744 was struggling to get off the ground before, shuddering as it did, or was my experience unique?

You didn't almost run out of runway. You could have lost an engine at V1 and still got off the runway, even in the warm conditions. Also, plane likely wasn't near MTOW for an 8 hour flight. As others have stated, likely just wheel vibrations and remembering things a little sensationally all these years later.

I remember many 744 shuddering takeoff's, some very disconcerting !! But others quite smooth. I do wonder what exactly is happening on the 747 at that particular moment during takeoff's -- load transfer from gear to wings?, the quad main-gear aerodynamic buffet? something else?

On particular ANA flight from IAD to NRT around 1998 -- the vibrations were so severe and deafening immediately after rotation -- this caused several passengers to start screaming as if this was their final minute. The flight attendants in the jump seats however, were nonchalant , having experience 747 shuddering on take-off many times before.

zeke wrote:

I am flat out remembering what I did yesterday in such detail at 2 am let alone 11 years ago.

This post wins!

Seriously, though, some AV geeks do keep detailed flight journals - aircraft registrations, flight times, notes on the flight. Not me, I couldn't be bothered. But my partner does - and it goes all the way back to 1965! Seriously geeky stuff. I suspect the OP is the same.

While this question seems to have been answered, it is interesting that the 744 in particular has the audible "bang" when rotating. I've flown on a number of other heavies -- 763, 772, 788, 789, A332, A333, and A380 -- and have not heard the bang in the same way I have on the 744. I remember taking off on a 744 for the first time -- a BA 744, in fact -- and hearing the bang followed by shuddering of the wings. I had no idea what it was -- my cousin, a pilot with AA, suggested it might be the runway lights, which provide normal "bumps" when on takeoff or landing roll -- but I soon learned a number of others have had similar experiences.

I had the same thing happen recently on a LH 748i, could also be some wake turbulence, in my case it was a close departure after a 346.

Avaitor wrote:

I had the same thing happen recently on a LH 748i, could also be some wake turbulence, in my case it was a close departure after a 346.

Interesting...

https://www.youtube.com/watch?v=xuvOJ_uqxeA

After 13 years of flying airliners, I’ve occasionally heard this ‘bang’ on everything from regional turboprops to narrowbody jets. I always assumed it was a wheel catching a runway light during rotation just as the wheel leaves the surface. Since there’s no weight on the wheel at that point it becomes a bang versus the normal thump of running over runway lights with the weight of the plane on the wheel. It would make sense the 747 experiences this more frequently as they have a lot more wheels to catch a light. Either way, 13 years of this and never have I or the other pilot ever thought twice about it.

neomax wrote:

Avaitor wrote:

I had the same thing happen recently on a LH 748i, could also be some wake turbulence, in my case it was a close departure after a 346.

Interesting...

https://www.youtube.com/watch?v=xuvOJ_uqxeA

This rattle is fairly common. I've flown on the Lufthansa 747-400 in J, and didn't notice any juddering, but flying the 747-8 in PE (which is situated pretty much directly above the main landing gear) recently, it was very noticeable indeed. Not to the extent displayed in that video, I must say, but very noticeable nonetheless.