If I recall correctly, most people pass out reliably around 6-7 g’s. Aerobatic pilots can build up a somewhat greater tolerance.
More fuzzily, I think g-suits are good to 9 or 10 g’s.
Pretty much, 10 g’s and higher LOC is likely if not inevitable.
People have houses out on that side of the course.
Post #114 has the sequence. Photo 6 shows a straight trailing edge on the elevator, with no indication of a trim tab problem. Photo 7 shows the beginning of something going wrong with it, which I feel was caused by the 11g’s.
What’s the “steam” I see in photo #11? Another noted this in the link.
Coolant?
If you’ve ever flown in a small twin engine plane that had nacelle louvers or watched drag racing at night you’d see how hot the exhaust headers get. They glow red from the heat. That plane was a flying fuel/air bomb that should have exploded in a spectacular display of avgas hitting an ignition source. I’m wondering if they used an inert gas in the tanks like the military do.
The Galloping Ghost had a boil off cooling system that submerged the radiators in coolant. As the coolant turned to vapor, it came out the side of the fuselage. Leeward said before the race that if you see a trail behind him, he’s doing okay. If not, he’s in trouble. That’s why he needed as much coolant as he did fuel.
Photo 01 shows the tail wheel already down - a function of +10g.
Most importantly, as you’ve noted, Photo 05 shows the beginning of the trim tab failure. The plane had already rolled 180 degrees clockwise off the racing line by that point, at a roll rate I estimate to be over 500 degrees per second. It appears the trim tab failure was a function of the extraordinary roll and climb off the racing line, not the converse.
This would lead me to believe a heart attack is a major candidate as a source of the problem.
It’s not THAT uncommon regrettably. Denny Hulme, the 1967 Formula One World Champion, suffered a catastrophic heart failure whilst behind the wheel down Mountain Straight in the 1993 Bathurst 1000. His car careened along the wall for at least 400 meters until it came to a gentle non-crash stop. Alas, Denny Hulme had passed away.
Following up on this:
It appears the brother-in-law in question is this man. I don’t know for sure, and I’m not going to pry, but based on what he had told me before (that he was there with a friend who was in critical condition and the ages of the children) it seems pretty clear.
Again, with the caveat that we’re speculating, I don’t think this is correct. Failure of the trim tab doesn’t mean immediate separation from the aircraft. More likely, the linkage between the trim tab and the cockpit controls may have broken. This would have immediately caused the trim system to be completely ineffective, causing the pitch up. The now free-floating trim tab could then have fluttered and ripped itself off the aircraft.
I still think my initial scenario holds - the trim system failed. This resulted in a 10-11 g pullup. The pilot at this point would have been rendered unconscious. The hard pullup would also have caused the tailwheel to unlock and deploy. The airplane ultimately pitched up and rolled towards the crowd - the roll being caused by any number of factors, including engine torque, accidental aileron movement by the pilot’s slumped body, or a rolling torque applied by the now-asymmetrical elevator because of the missing trim tab on the left.
From what I’ve read, there was no mayday call, no change to the throttle position or prop pitch. So the pilot was likely out of the picture through the entire episode after the hard pullup.
I read on the hangartalk forum that Galloping Ghost had fixed the right elevator trim in place, and was only using the left trim tab. That would seem to me to put a lot of extra stress on that trim tab. That, plus the extreme speed of the aircraft imparting even greater aerodynamic loads could have led to a trim tab failure.
I don’t see it. Again, let’s use Occam’s razor here. A previous trim tab failure in a P-51 resulted in a pitch excursion almost exactly like this one. Couple that with the fact that there was a clear trim tab failure here, and I don’t think we need to invoke heart attacks as a probable cause. Are you suggesting that the pilot had a heart attack, and as a result yanked on the stick and caused an 11-g pullup that blacked him out? That doesn’t seem very likely.
I’d say that one heart attack 44 years ago in a different motorsport could be classified as ‘uncommon’. For that to happen and cause a failure mode identical to a trim tab failure, while also causing a trim tab failure after the fact, stretches the imagination.
I saw at least one story saying there was a Mayday call – I’ll look for it. Hard to imagine he’s have time for more than a word or two.
The coolant theory makes sense to me. The airplane’s unique coolant system required it to carry as much (non-flammable) coolant as fuel. So the impact would have created a mix of fuel and coolant.
Also, remember that these aircraft are only carrying enough fuel for the race. That’s still quite a lot - Galloping Ghost consumed 400 gallons per hour at race speeds. And they were on the second-last lap, so there may not have been that much fuel left on board. In addition, the unlimiteds run a very high octane race fuel which may be less susceptible to auto-ignition than standard avgas. There have been other warbird crashes at Reno which did not result in a fireball.
Having read Leeward’s specification page for Galloping Ghost, I have to say that it was a marvel of engineering. The coolant system was brilliant. The plane was said to be capable of at least 550 mph, and one eyewitness says that on that final lap he passed ‘Rare Bear’ at at least 30 knots speed differential. Rare Bear is one of the fastest propeller driven aircraft in the world, and has won Reno many times. I’m wearing a Rare Bear T-Shirt right now.
One difference between the Reno Air Races and other air events is that the Reno Air Races are as much about engineering as they are about flying. The state of the art is actually advanced by the people who build and fly these planes. That’s one reason why it would be tragic if they were to be canceled or slowed down due to this accident.
Oh, and thanks to all the people who expressed their concern for my well-being. But I have to say that I don’t think I was ever in danger. Even if we had arrived on time for that race, our seats were in the small reserved grandstand right behind the box seats, and I don’t think there were any fatalities in the grandstand. There might have been some serious injuries, but the fatalities and major amputations and such appear to have been restricted to the people who were at ground level. It sounds like some heavy bits of the airplane skidded along the ground and took out people’s legs mostly.
Still, I’m glad my daughter didn’t have to see that.
Nope. There are several people in the linked ‘HangarTalk’ forum who were listening on scanners. Lots of race fans listen to the race chatter on aviation radios. All are agreed that there was no mayday.
I’m probably wring about the pilot calling out mayday. I’m seeing quite a few articles using the term “mayday” as a synonym for “emergency situation”, and even as the actions a pilot and responders might take in an emergency situation. I had been under the impression that it was simply a term one used to indicate an emergency situation is developing.
That makes perfect sense. It’s a case of the media not quite understanding the nuance between an actual ‘Mayday’ call and the way pilots talk about ‘mayday situations’ as events that are serious enough to warrant a Mayday call.
The media and me both. Eh, it’s one of the reasons I stick around here.
Would you be so kind please as to explain this in greater detail? Whilst I’m not a dumb guy, I’m a computer programmer by trade, not a pilot - notwithstanding that I did major in physics.
I can understand how trim can angle a nose slightly down or up, what I’m confused by is why the rear elevators were seemingly in maximum up position the moment the plane rolled clockwise off the racing line.
They don’t look far off neutral to me, can you link to a picture where they are at max up?
I don’t know the position of the elevators - I haven’t seen pictures that show them in a full-up position. But you wouldn’t expect them to be in an up position at all, necessarily. To explain, I’ll describe how the trim on the aircraft works:
First, the angle of incidence of the horizontal stabilizer on a plane will be set to allow neutral control at a certain speed. Ideally, this would be cruise speed (or average race speed in a race plane). This would be the minimum drag situation for the aircraft.
At speeds above and below the design speed, you have to add in elevator pressure, either up or down, to keep the aircraft in trimmed condition. If you’re going faster than the natural trim speed, you have to add forward pressure on the stick to keep the nose down. But you don’t want to hold forward pressure on the stick all the time - and in fact the forces may be so great that without some sort of trim assist you can’t hold enough forward pressure.
So, aircraft have two different ways of adding trim - one is to use a set of springs and a control in the cockpit that allows you to change the tension on the springs to offset the force on the stick or yoke. A lot of light aircraft use this kind of system, because it’s simple. Basically you’re just using a spring or bungee to pull the stick or yoke forward or back to maintain a trimmed condition.
On a P-51, the trim tab does the work. The type of trim tab on a P-51 is known as a ‘servo tab’, and it works in the opposite direction of the elevator. So if you want the elevator to be held in a slightly down position to trim the airplane, the servo tab will be rotated up. This puts the trim tab into the airflow and that pushes the entire elevator in the opposite direction. It also reduces the force required to make elevator corrections manually.
So the trim tab is under considerable force on this plane - it’s a piece of metal sticking up into a 500+ MPH air flow, creating enough force to push the entire elevator down into that same airflow.
Now, imagine what happens if the linkage to the trim tab breaks. The trim tab then stops providing the countervaling force to the elevator. The elevator returns to the neutral position, but because of the angle of incidence of the tail assembly, this causes the airplane to pitch up violently because it’s way over its design trim speed.
In the meantime, without the control linkage holding the trim tab firmly in place, it’s free to vibrate in the wind. If it’s not perfectly balanced, it may begin to flutter. Flutter is a self-reinforcing oscillation where every excursion gets larger until the forces build to the point where the control surface destroys itself or departs from the airplane.
So in the scenario of a linkage failure you’d expect to see, in order:
- The trim tab and elevator return to their neutral positions.
- An extreme pitch excursion of the airplane.
- Flutter of the trim tab, followed by the trim tab leaving the airplane.
The rest of the plane’s behavior can be easily explained. Once the airplane slows down from the hard climb, the torque of the engine would start a rolling motion to the right. The airplane’s wings would then cause a force vector pushing it first towards the crowd, then the airplane would roll onto its back or enter a high-speed stall and come straight down. That looks like pretty much exactly what happened.
Now, it’s possible that there was another cause, or other secondary causes that led to the primary failure. We’ll have to wait for the NTSB report to really know all the details. But a trim tab failure is a plausible explanation that fits all the available facts that we layman speculators have. The NTSB investigators may be in possession of a lot of other evidence.
http://www.msnbc.msn.com/id/44556695/ns/us_news-life/t/death-toll-rises-reno-air-show-crash/
This link has the clearest picture.
The torque of the engine (as long as it’s not on a British aircraft) causes a left roll, not right. I think it was the momentary loss of power from fuel starvation that lowered the amount of torque and caused the initial right roll. Leeward’s body weight, multiplied ten times, must have been holding the stick to the left after that.