Why is the Eurofighter Typhoon's nose gear door shorter than the bay?

Question

The Eurofighter Typhoon has an interesting "feature" in that the nose gear door is shorter than the nose gear bay itself by a good few inches, as shown here:

Can anyone shed any light on the reason for this gap? It isn't a simple case of the aircraft in the photo having a maintenance issue, as this gap is consistent across all aircraft tranches and customers.

Looks like no one else out there knows either. Some say it is APU others say some other stuff, but no one knows for real. — SMS von der Tann, Nov 27 '15 at 14:13
@SMSvonderTann thats why I asked here :) I have asked on several aviation forums and no one knows the answer, which is a bit odd... — Moo, Nov 27 '15 at 14:30
@Moo It might be buried somewhere deep within classified docs. o:) — SMS von der Tann, Nov 27 '15 at 14:32
@SMSvonderTann Some say it is APU. Really? Where? People who don't know aircraft design? — Simon, Nov 27 '15 at 20:08
Would there be any potential cooling needs? Anything hot that gets routed near enough to the nose gear bay that it can be used for cooling? That seems like a very inefficient heat vent, but that's the only thing that occurs to me. — FreeMan, Nov 30 '15 at 17:47
From PPRuNE (Typhoon nose gear door question...), it's to evacuate heat created by the proximity with the engine intake (as suggested by @GürkanÇetin). — mins, Mar 03 '16 at 13:47

score 6 · Answer 1 · answered Dec 11 '17 at 17:40

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Some fighters and as well civil airliners have fans ending in the gear bay. To allow for pressure relief some sort of opening needs to be created to vent to atmosphere. Various designs are available to achieve this, like the well known grills or mesh on carbon or aluminum structure skin. Or, just shorten a nose gear bay door if you have no place to accommodate the mesh and suck it through top part (see holes in the top where cables is routed) If you stick your head into a F18 nose gear bay and it is electrically powered, it will be quite noisy. Seems as the Eurofighters have the same design.

answered Dec 11 '17 at 17:40

Alex

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A video of the Super Hornet's gear swing and a picture of the Super Hornet's underside seems to support your answer. Specifically, a mesh is visible in the nose gear door in the video, and the picture does not show the same gap present in ymb1's Hornet picture. – aerobot Dec 12 '17 at 02:03
@aerobot - the mesh is farther ahead, same mesh on the F/A-18 in my answer. I guess that's the avionics bay ventilation. – May 19 '18 at 14:51
@ymb1 - are we looking at the same mesh? In the video and picture I linked, the mesh is longitudinal (on the strut portion of the gear door), which is definitely not present in the F/A-18A Hornet picture in your answer, unless I'm missing somethIng. – aerobot May 19 '18 at 18:45
@aerobot - I see what you mean now, makes sense. – May 20 '18 at 00:48

score 2 · Answer 2 · answered May 19 '18 at 14:38

Could it also be a vent for tire smoke? Most Nose Gears do not have brakes and therefore utilize some form of fixed resistance pad inside the gear bay to spin down the wheel, since this generates heat and smoke the opening could assist in venting this effect.

Why is the Eurofighter Typhoon's nose gear door shorter than the bay?

2 Answers2