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Hi – clam doors opening during flight have caused torn wings and resulting aircraft losses – There were two losses of early P-51D’s from BAD-2 (Warton) in 1944 which were the result from a changed mechanism from the B/C-model to the D. If the cause for these crashes wouldn’t have been discovered soon, the D-models would have been grounded…..

I remember an article with the title “…and not a shot was fired” telling this story.

also see here:

http://web.ukonline.co.uk/lait/site/P-51%2044-13593%20article.htm

Martin

Thanks for the article you linked,i live just up the road from Madingley i may pop in and pay my respects to his cross many thanks.No more just a cross and a number but a person and a story. 🙂

Hi – clam doors opening during flight have caused torn wings and resulting aircraft losses – There were two losses of early P-51D’s from BAD-2 (Warton) in 1944 which were the result from a changed mechanism from the B/C-model to the D. If the cause for these crashes wouldn’t have been discovered soon, the D-models would have been grounded…..

I remember an article with the title “…and not a shot was fired” telling this story.

also see here:

http://web.ukonline.co.uk/lait/site/P-51%2044-13593%20article.htm

Martin

Thank you all! I’m a happy camper now 🙂

JC

The clam doors are held up by hydraulic pressure, when parked it is generally standard practice to release the hydraulic pressure in the system via the pressure dump handle, hence the doors then drop. This also saves you from retracting the undercarriage etc in error on the ground.
If the dump valve is not pulled then as the pressure drops off the doors will start to drop but not evenly.

Actually, its common practice to vent all the pressure out of the system when you shut down, so the gear doors will come down as soon as this happens.

Bruce

It’s hydrallic pressure, and a number of a/c have the same setup. <-This bit is true. In flight, I think the P-51 main door closes over the wheel door, and the u/c uplock does the rest in keeping it all away… <- from the following posts, I think this bit is balls.

Must not pontificate,
must not pontificate…

So, in the case of a fault or combat damage, the doors could drop in flight? Can’t be good…

JC

However even though they should be up when the aircraft is shut down they soon begin to droop down as hydraulic

This sounds about right – as if you look at shots of parked Mustangs, the gear doors are often lop-sided, with one having lost more pressure than the other.

P51 Inner Gear doors

The inner doors should be closed at all times except when the gear is travelling. This is, I believe, to prevent them from shrouding the radiator intake. However even though they should be up when the aircraft is shut down they soon begin to droop down as hydraulic (or is it pneumatic? – can’t remember) pressure bleeds away.

NiallC