A photo from MAN today, an A343 from HiFly arriving to carry Man Utd to their Europa League game in Seville, but with something I've never seen before: the centre-main landing gear is not deployed. I understand that the centre-main landing gear isn't necessary for lower weight ops, but I never realised it could be deactivated. Can anyone shed light on how the process works and whether this has been done before?

Don't know about the A340 specifically but on the DC-10 (30 and 40) it was possible to lock out the center gear. I assume the MD-11 is the same.

MrHMSH wrote:

A photo from MAN today, an A343 from HiFly arriving to carry Man Utd to their Europa League game in Seville, but with something I've never seen before: the centre-main landing gear is not deployed. I understand that the centre-main landing gear isn't necessary for lower weight ops, but I never realised it could be deactivated. Can anyone shed light on how the process works and whether this has been done before?

It is a standard MEL procedure. At light weights sometimes the centre gear did not even touch the ground when extended.

zeke wrote:

MrHMSH wrote:

A photo from MAN today, an A343 from HiFly arriving to carry Man Utd to their Europa League game in Seville, but with something I've never seen before: the centre-main landing gear is not deployed. I understand that the centre-main landing gear isn't necessary for lower weight ops, but I never realised it could be deactivated. Can anyone shed light on how the process works and whether this has been done before?

It is a standard MEL procedure. At light weights sometimes the centre gear did not even touch the ground when extended.

I am guessing the A340-500/600 would not have this ability however?

ArcticFlyer wrote:

Don't know about the A340 specifically but on the DC-10 (30 and 40) it was possible to lock out the center gear. I assume the MD-11 is the same.

Yes it's the same with the MD-11. However it comes with a hefty weight penalty (IIRC about 85 tons). Unlike the A343 the CLG of the MD-11 carries a lot of weight.

edit:
I just checked, for the A343 the weight penalty is about 40 tons for MTWO and 5 tons for MLW.
As 77west guessed the Centerline Gear needs to be operational on the A346.

Pretending to be A330 loll

MrHMSH wrote:

and whether this has been done before?

Was done all the time in ferries and the like.

77west wrote:

I am guessing the A340-500/600 would not have this ability however?

Correct.

The -500/600 center gear was designed to bear weight upon landing as well as takeoff.

The -200/300 gear only did so by coincidence; it was designed to supplement weight for takeoff only.
On lite ops, as someone already mentioned, it didn't even touch the ground on takeoff itself, much less landing.

LAX772LR wrote:

MrHMSH wrote:

and whether this has been done before?

Was done all the time in ferries and the like.

77west wrote:

I am guessing the A340-500/600 would not have this ability however?

Correct.

The -500/600 center gear was designed to bear weight upon landing as well as takeoff.

The -200/300 gear only did so by coincidence; it was designed to supplement weight for takeoff only.
On lite ops, as someone already mentioned, it didn't even touch the ground on takeoff itself, much less landing.

Interesting; I wonder what the weight delta on the center gear was on a light vs MTOW takeoff. Obviously at a point if there is air under it, there is no weight on it. Wonder what point that is though.

LAX772LR wrote:

MrHMSH wrote:

and whether this has been done before?

Was done all the time in ferries and the like.

I see. Guessing that it's not a very regular occurrence in service.

77west wrote:

Interesting; I wonder what the weight delta on the center gear was on a light vs MTOW takeoff. Obviously at a point if there is air under it, there is no weight on it. Wonder what point that is though.

My guess is that its use came into effect somewhere at the 235-238tonne range, which was the limitation on A330s back when they were still co-produced alongside the A343X and A343E, prior to the 242t enhancements.

But that's just a guess. Here's the ACAPs if one wishes to do a deeper dive. I scanned, but didn't see the answer.
https://www.airbus.com/sites/g/files/jl ... 00-300.pdf

LAX772LR wrote:

77west wrote:

Interesting; I wonder what the weight delta on the center gear was on a light vs MTOW takeoff. Obviously at a point if there is air under it, there is no weight on it. Wonder what point that is though.

My guess is that its use came into effect somewhere at the 235-238tonne range, which was the limitation on A330s back when they were still co-produced alongside the A343X and A343E, prior to the 242t enhancements.

But that's just a guess. Here's the ACAPs if one wishes to do a deeper dive. I scanned, but didn't see the answer.
https://www.airbus.com/sites/g/files/jl ... 00-300.pdf

I am not claiming this to be the specific case here, but that may not be specifically known. Believe it or not, there are a lot of variables related to weather that will affect that. Wings are designed after all to lift. A very slight breeze can make an aircraft that size literal tons lighter.

Obviously there is an answer as to what the specific inflection point for this. But if Airbus never specifically measured that indoors, then the best they would be able to tell you is a range at which that center gear can lift all the way off.