"This thing just bucked BIG TIME"http://aafo.com/raci...ews/98/day6.htmhttp://www.avweb.com...pics/dsc066.jpg

Oh, my! Look at that split elevator and mangled left trim-tab! The relevant bit of the Reno 89 (Day 6) Race you posted:

Shortly before the first call from Hannah, he had abruptly pulled up from the pack, then began a slow descending turn back to the race course.... Problem was....Bob was NOT flying the airplane! Voodoo was flying herself. Bob Hannah was sitting in the cockpit unconscious from the 10+ g. load he had just endured when the control rod for the left half of the elevator snapped as the elevator trim tab fluttered and departed the airplane, causing the very sharp pull up! The confused conversation coming from Bob was an indication of his condition as he awoke from the momentary lapse of consciousness. He was in trouble...

Cheers, - jahman.

Oh, my! Look at that split elevator and mangled left trim-tab! The relevant bit of the Reno 89 (Day 6) Race you posted: Cheers, - jahman.

Man if that photo is an accurate depiction, of it's condition before takeoff, then that's damming evidence that this accident, could and should have been prevented by doing a proper walk around inspection. This plane never should have left the ground.

Man if that photo is an accurate depiction, of it's condition before takeoff, then that's damming evidence that this accident, could and should have been prevented by doing a proper walk around inspection. This plane never should have left the ground.

That's not the one that crashed.

Man if that photo is an accurate depiction, of it's condition before takeoff, then that's damming evidence that this accident, could and should have been prevented by doing a proper walk around inspection. This plane never should have left the ground.

That photo is from 1998 of a different plane that had a similar failure but managed to land safely.

That photo is from 1998 of a different plane that had a similar failure but managed to land safely.

Thanks for the clarification Kevin, and Zach, glad to see that wasn't the cause. I couldn't see how such an experienced and respected pilot like Jimmy Leewood, could have missed that in a preflight walk around. I should have looked closer at the markings of the plane in the photo to realize that wasn't the plane. My bad!!

It raises the question as what the aircraft certification requirements are for aircraft that race in "unlimited" classes. It would seem to need more than what an "experimental" would receive. Considering loss of trim tab on this type has been seen before it suggests a possible design weakness. I wonder how much engineering analysis goes into the design of these? Also, what kind of criteria is there for the effective stick control forces the pilot can feel? At some point there must be a need for hydraulic assist or other mechanical advantage? Possibly flutter? Viewing the footage it could have easily resulted in much greater casualties. scott s..

It raises the question as what the aircraft certification requirements are for aircraft that race in "unlimited" classes. It would seem to need more than what an "experimental" would receive. Considering loss of trim tab on this type has been seen before it suggests a possible design weakness. I wonder how much engineering analysis goes into the design of these? Also, what kind of criteria is there for the effective stick control forces the pilot can feel? At some point there must be a need for hydraulic assist or other mechanical advantage? Possibly flutter? Viewing the footage it could have easily resulted in much greater casualties. scott s..

You raise an interesting point and your post made me wonder that it's really strange that a famous and very lethal to the enemy fighter aircraft should have a weakly-designed tail. Rather not, I figured, and at that instant it hit me: The elevator assembly was overstressed because the wings were shortened! Shorter wings have shorter wing cantilevers so overall the aircraft can withstand higher Gs! But pulling higher Gs requires... a higher elevator force! Because the wings were shortened, elevator forces increased beyond their design strength. Recall in fighter aircraft weight saving is at a premium more than in any other type of aircraft, so the P-51 elevator assembly would have been designed with the minimum metal to withstand maximum elevator forces given the original-design wingspan. No need for the elevator assembly to survive elevator forces needed to pull Gs outside the flight envelope since outside the flight envelope the aircraft is destroyed. But elevator forces are also increased for every turn, because with the shorter wingspan the aircraft needs a higher angle of attack to pull the same Gs as compared to original wingspan because of the heavier wing loading. Now when you combine the fact that you can pull higher Gs and that for every G you pull elevator forces will be higher, you can see how these to effects double-up and can easily overstress the elevator assembly. Cheers, - jahman.

It raises the question as what the aircraft certification requirements are for aircraft that race in "unlimited" classes. It would seem to need more than what an "experimental" would receive. Considering loss of trim tab on this type has been seen before it suggests a possible design weakness. I wonder how much engineering analysis goes into the design of these? Also, what kind of criteria is there for the effective stick control forces the pilot can feel? At some point there must be a need for hydraulic assist or other mechanical advantage? Possibly flutter? Viewing the footage it could have easily resulted in much greater casualties. scott s..

I assume you mean with the modifications made to these aircraft. Stock these planes were never designed to fly at the speeds in this race. Also remember they are over 60 years or more old!!

At this stage I don't think we really know what happenned. FWIW the pilot could have been knocked unconscious (see New York Times photo) by the sudden pull-up due to loss of the elevator trim tab and never regained sufficient consciousness to take control of the aircraft defore hitting the ground. Cheers, - jahman.

According to spectators the pilot fought hard to keep the plane from going in the stands creating a greater disaster. I don't think he was asleep before impact, he was a hero though... That picture looks a little doctored to me for some reason...

According to spectators the pilot fought hard to keep the plane from going in the stands creating a greater disaster. I don't think he was asleep before impact, he was a hero though... That picture looks a little doctored to me for some reason...

The picture is sourced from the New York Times and a link is provided so you can check the original for yourself. It is unlikely such a prestigious news source would post a doctored picture. Cheers, - jahman.

According to spectators the pilot fought hard to keep the plane from going in the stands creating a greater disaster. I don't think he was asleep before impact, he was a hero though... That picture looks a little doctored to me for some reason...

I have met Jimmy Leeward in the past and I can tell you without hesitation, had he been able, he would have most assuredly done everything he could to have prevented this very unfortunate accident, but the reality is that Jimmy was unconcious from the moment his trim-tab failed until his aircraft hit the ground. Members of the NTSB today released photos that show, without question, his head down and forward in the cockpit, adding further evidence to the extensive level of G-force he experienced, renduring it virtually impossible he was conscious. That, plus the evidence of the tail-wheel, have the NTSB leading toward the belief Jimmy's aircraft had exceeded 10 Gs of postive force, possibly as much as 14 Gs, sustained. The photo above does show a P-51 with a damaged trim-tab, but unfortunately, that photo is of a P-51 other than the Galloping Ghost. Besides other obvious differences, to me, there is one overtly obvious problem with this photograph, it shows this aircraft's race number to be #5 and the Galloping Ghost's race number was #177. (another difference is the P-51 in the above photo, still retains the stock rear engine air dump cowl and Jimmy's P-51 used a completely different method of air cowling.) Steve (Bear) CartwrightReno, NV

As previously stated, the aircraft in the photo, with the missing left elevator trim tab is Bob Hannah's Voodoo from 1998.

Yes, we're all aware that photo os not from the accident aircraft, but it does show elevator assembly failure that is likely similar to that of the accident aircraft. It would be interesting to know if Bob Hannah's Voodoo from 1998 also had its wings shortened. Cheers, - jahman.

Yes, we're all aware that photo os not from the accident aircraft, but it does show elevator assembly failure that is likely similar to that of the accident aircraft.

Are you referring to a specific report of elevator failure? Or just considering it...So far the trim seems to be the focus.The account of what happened to Bob Hannah's (Voodoo) explains a lot.I've read the stick forces would be nearly unmanageable.And the G-forces involved would quickly bring on unconscious.It's really amazing what these pilots do. Edit: I see now what you mean - I think you mean the elevator in general…the trim specifically

Edit: I see now what you mean - I think you mean the elevator in general…the trim specifically

Yes! Note how odd the forces on Bob Hannah's Voodoo elevator assembly must have been to result in what looks like a 20º left vs. right elevator divergence. Did the left trim tab failure cause the elevator divergence, or did the elevator divergence cause the trim tab failure? What is the elevator assembly structure that could make such an elevator divergence possible? Are the two elevators connected to one shaft actuated by a single bellcrank, or is each elevator actuated by it's own bellcrank for redundancy? Cheers, - jahman.