Ghost photo w/out trimtab

[wyhdah]

Re: Ghost photo w/out trimtab

Good read Rich, thanks for posting.

[wolfee]

Re: Ghost photo w/out trimtab

Thank you for the info on the history of the p-51 trim tab Rich. Great info!

[sctybdy]

Re: Ghost photo w/out trimtab

Okay, I need help. Last night.. night before... heck, I can't remember...someone posted information regarding the P-51's having trim tab problems that were documented when they were first manufactured. Or something to that effect.

To save me, I can't find that post. I told someone about it, and he'd like the info and the website it came from. I apologize for being vague, but I feel like I have to be careful due to the ongoing investigation.

So, if someone can point me in the right direction, or PM that website, I'd really appreciate it.

After the installation of the Merlins starting with the B models, a large Weight was put on the elevator control lines. Reason being that pilots were tearing off tails over controlling the mustang in combat. The weight gave a heavier "Feel" and control forces at higher speeds. This solved the problem.

Another problem that arose in combat with the mustang was when the D Model gear uplocks were redesigned. If not perfectly locked up, the gear doors would come out into the slipstream at high speeds, yanking the gear down and bending the leading edge downward. This happend to several mustangs at high speeds causing them to dive right into the ground. Another redesign happend and problem solved.

[51fixer]

Re: Ghost photo w/out trimtab

After the installation of the Merlins starting with the B models, a large Weight was put on the elevator control lines. Reason being that pilots were tearing off tails over controlling the mustang in combat. The weight gave a heavier "Feel" and control forces at higher speeds. This solved the problem.

Another problem that arose in combat with the mustang was when the D Model gear uplocks were redesigned. If not perfectly locked up, the gear doors would come out into the slipstream at high speeds, yanking the gear down and bending the leading edge downward. This happend to several mustangs at high speeds causing them to dive right into the ground. Another redesign happend and problem solved.

Lets watch how we word these things-
The introduction of the bobweight is actually described as an inertia control. It isn't related to the tail problems at all. What I described in an earlier post is directly from Army Tech Orders relating to how excess control movements in rolling maneuvers lead to the failure of the horizontal stab.
The inertia weight acts as a stabilizing force in pitch. This is primarily designed as a gun platform. This weight works as follows- if the P-51 hits some unstable air and the nose is lifted there is a G load applied, the mass of the the inertia weight being attached to the elevator control system is affected by the G load and would act on the controls by putting an input opposite so to push the nose down.
If the nose should drop due to some dirty air or turbulence the mass of the weight would push the nose up.
Being able to keep a stable bearing on a target was the primary purpose of the weight.
The landing gear problem on the earliest D model aircraft isn't related to any tail issues and really doesn't belong in discussion when the media is focused on the current crash with the possible trim tab failure as a cause. If they see discussions of wing failures on a P-51 they could start throwing that into articles and P-51 owners will have to deal with that
as well as the current threat of FAA action if they over react to this tragedy.

[flyingjibus]

Re: Ghost photo w/out trimtab

Seems to be a lot of armchair NTSB people out there. I have now read where some are saying the tail wheel came out between pylon 6 and 7. Well this shot is from pylon 8, just before it all went bad, lap #3. As he passed us photogs by, everything looked good.

Damn that plane was beautiful....

[GeeBeeZ1931]

Re: Ghost photo w/out trimtab

Everyone has there own view/ opinion of what happened. All I know is that there was no change in throttle from the time he left the course. Much like many other people I thought he was headed right for our group in the box seats as well and am very lucky to have walked away with a few cuts and nothing else.

I spoke too soon and apologize for my error. After reading Matt Jacksons explanation and looking at available pics I realized I should not have spoken so hastily. It became obvious to me that at the very least Jimmy was unconscious and there was no conscious control of the aircraft. Maybe it was just hope that made it look to me like a control correction. Again I admit I was wrong.