What just happened at Reno?

[CAPFlyer]

As I recall Strega runs 120-130" MP. 102" sounds low to do 500MPH.

Yes, but remember that the point of all of Jimmy's mods was to be able to match Strega and Dago without needing to run as much MP and in his podcast from June, he said he was hoping to run 100"-110" instead of 130"+.

[Speedy]

As I recall Strega runs 120-130" MP. 102" sounds low to do 500MPH.

Yes, but remember that the point of all of Jimmy's mods was to be able to match Strega and Dago without needing to run as much MP and in his podcast from June, he said he was hoping to run 100"-110" instead of 130"+.

This is NOT a dig at all...but I don't think one of Rick's engines can take 130+ inches MAP. His engines are not tube motors like Nixon, Thorn, Barrow type stuff. They are very strong, what I term "Zeuschel +" motors.

[Tim Adams]

After such a traumatic event I don't know if what my head would be thinking whether i'd just freeze up in terror or rush in to help. I like to believe it would be the latter.

One of the videos clearly shows someone in a black shirt rush into the impact zone with his camera up by his face to take photos & then he quickly turns & runs away....

Not everyone is that way.

I had my son with me out at pylon 8 and it was his first time shooting out there with credentials. Once things settled down his exact words were 'Dad, is it bad that as soon as I saw him start to roll over I knew he was going to die, and my only reaction was to lower my camera?'

No, son....it's not bad at all.

The kid's 18. Even at that age, he gets it.

Wow, that put a lump in my throat. In looking at my Friday pics, the last four in order were, GG, GG, Bear, Bear. As I turned to follow the top four for another lap, I saw Jimmy at the top as he was starting to come straight down. Never once was I tempted to raise the camera.

[Paul Krumrei]

One of the videos clearly shows someone in a black shirt rush into the impact zone with his camera up by his face to take photos & then he quickly turns & runs away....

Though tragic, on the other side of the coin is the fact that people were taking photos and video, helps in the investigation much quicker instead of relying on eyewitness accounts.

I can only imagine, that people when shooting, had ZERO idea, what was happening well after impact. I would hope, the "guy in the black shirt" being that close, didn't or wasn't thinking of dollar signs when snapping away. Who knows what the person was thinking, he could have been FAA, he could have been a reporter with a gut instinct to capture the moment, he could have been in combat camera in Vietnam or other wars, we don't know. Talk about throwing speculation around.

[JDK]

The racers are all trimmed prior to entering the course with a large nose up trim bias, the idea being as they approach the race speeds they can relax the push, as the trim will be correct for the speeds, 400 plus, so one less item to think about, in what would be a pretty intense environment.

The problem with that, James, is that at speed an aircraft has nose DOWN trim, not nose UP. Speed increases, nose down trim increases.

If the racers were set up for "race speed trim" as they were entering the course, that would require putting back pressure on the stick to keep it in level flight, with the back pressure decreasing as speed increased...not the other way around, as indicated in this passage.

I understand the idea of a little back pressure trim to assist with the control forces while making the turns, but this, too, would be a comparatively nose down trim condition while they were forming up for the start.

For the airplane to be somewhat manageable in the straight stretches when not in a bank, it would still require a significant amount of nose down trim when compared to "neutral".

Hi Randy - not my original data (I'm definitely not qualified enough to comment!) and the OP on Key has posted this response after similar comments to yours, made over there.

Trim (and CG)
"surely nose down trim and not nose up then as per Canadairs post? or am i miss reading his post on the techno side?"

Sorry, not meaning this to be confusing, the difference is the way I described trim tab position vs what effect the trim tab is meant to produce.

The intent on the course is to use trim to induce a nose down effect, increasing with speed, ie the trim works harder to push the nose down the faster it goes.
But then as mentioned, the loss of the trim, which is pushing nose down, the nose will dramatically and rapidly rise.
So the tab position is UP, the Elevator TE position is DOWN, which pushes the nose DOWN. if the tab lets go, the Elevator TE goes UP, the nose goes UP.

This is much easier to explain with my hands and an imaginary stick, than via words!

On the subject of CG, basic aerodynamics says that the further aft the CG the faster the aircraft will go and the more manueverable it will be, (to aft CG limits vs weight) but this speed is gained at a price, as the further aft the CG, the less pressure required on the elevator for a given result.
So more simply put, it would be very easy to exceed the design limits of the surface with an Aft CG, and near VNE speeds.
This may be a factor regards this accident, as the elevator without trim would have a free float angle which is relative to the speed, with trim it is forced to an angle, but take the trim away and it will return to this angle, but with an aft CG it will induce as perhaps seen, a massive G as a result of rapidly returning to this point, as well inducing a large accompanying "stick force"
As mentioned, the only way to change CG in flight is to consume some weight, in most cases just fuel, but as GG had a boil off cooling system water would also be consumed. Both would affect CG, and I have no doubt they would have biased CG to move aft as both are consumed, as this would have a dual effect, the weight reduction and CG moving aft would essentially increase the speed with each lap.
They were in lap 3 when the accident occurred, so less than 1/2 way, and I would guess that they still planned to burn and boil off quite a bit more, so the CG was not as far aft as it may have been planned to end up.

The ethos of GG was to use aerodynamics to go fast as opposed to MP. While Strega, etc would be running over 100" to get to 490+ speeds, the theory of no radiator scoop, and the other clean up items was that GG could match or exceed those speeds but on 60-70", which has the add on benefit of not working the engine as hard, less fuel required, lower temperatures, etc, all good stuff and certainly excellent thinking.
I think GG was the best designed, best performing, most efficient Unlimited ever developed, it was such an incredible machine, and all involved should be commended for its development, and operation. Its last lap was showing just what it could do, and I bet the telemtry will show it did it at less than 70"

Oh, as also mentioned, I would assume that any telemetry gained or qouted was real time feed already saved, I would not think any useful data will come from the aircraft parts salvaged, but again that is the domain of the NTSB, not me.

I certainly do not want this to in any way take away from the obvious focus, the human tragedy, like everyone else I am just trying to make sense of what may have happened. None of this means a thing to anyone personally affected by this.

http://forum.keypublishing.co.uk/showpo ... tcount=190

Hope its of interest, I have no angle on the details...

Regards,

[Craig59]

Not everyone is that way.

I had my son with me out at pylon 8 and it was his first time shooting out there with credentials. Once things settled down his exact words were 'Dad, is it bad that as soon as I saw him start to roll over I knew he was going to die, and my only reaction was to lower my camera?'

No, son....it's not bad at all.

The kid's 18. Even at that age, he gets it.

A clear case of quality parenting. Well done, sir.

[the330thbg]

After such a traumatic event I don't know if what my head would be thinking whether i'd just freeze up in terror or rush in to help. I like to believe it would be the latter.

One of the videos clearly shows someone in a black shirt rush into the impact zone with his camera up by his face to take photos & then he quickly turns & runs away....

Not everyone is that way.

I had my son with me out at pylon 8 and it was his first time shooting out there with credentials. Once things settled down his exact words were 'Dad, is it bad that as soon as I saw him start to roll over I knew he was going to die, and my only reaction was to lower my camera?'

No, son....it's not bad at all.

The kid's 18. Even at that age, he gets it.

Not all parenting.., that kid was just born 'right'!!! (and parenting by example)

Awesome!!!

[Fearless Tower]

This makes me sick.

Apparently Mr Matt Jackson (VP of the Unlimited Class) has already concluded the investigation and declared it was pilot error.....I guess the NTSB can go home now.

Someone seriously needs to kick this dude in the junk:

http://www.rgj.com/article/20110921/EVE ... l-lawsuits

[Red Tail]

As I recall Strega runs 120-130" MP. 102" sounds low to do 500MPH.

Yes, but remember that the point of all of Jimmy's mods was to be able to match Strega and Dago without needing to run as much MP and in his podcast from June, he said he was hoping to run 100"-110" instead of 130"+.

This is NOT a dig at all...but I don't think one of Rick's engines can take 130+ inches MAP. His engines are not tube motors like Nixon, Thorn, Barrow type stuff. They are very strong, what I term "Zeuschel +" motors.

Speedy,

OK, I’ll bite…I know it’s better to be thought a fool than open ones mouth and remove all doubt, but…what is a “Tube” motor and what makes you believe Rick's engine's can’t take the same MP as the other builders? Not casting stones, just curious what draws you to that opinion.

John

[ZRX61]

I can only imagine, that people when shooting, had ZERO idea, what was happening well after impact. I would hope, the "guy in the black shirt" being that close, didn't or wasn't thinking of dollar signs when snapping away. Who knows what the person was thinking, he could have been FAA, he could have been a reporter with a gut instinct to capture the moment, he could have been in combat camera in Vietnam or other wars, we don't know. Talk about throwing speculation around.

I don't think he took any pictures, he looked like he was running over there to take pictures, but once he got there he changed his mind PDQ.

[John Ceglarek]

OK, I'll ask a stupid question. Mr. Jackson says you're not supposed to use the trim tabs...how then do you control the trim of the aircraft? Is he saying you shouldn't adjust the trim tab once you get to a certain speed, and you have to adjust it prior to getting there? Or am I missing something here, as a non-pilot?

[Speedy]

OK, I’ll bite…I know it’s better to be thought a fool than open ones mouth and remove all doubt, but…what is a “Tube” motor and what makes you believe Rick's engine's can’t take the same MP as the other builders? Not casting stones, just curious what draws you to that opinion.

John

It's a matter of removing the intercooler on the Merlin and replacing it with a tube that runs directly from the supercharger to the motor. The interecooler is the big boxy thing that sits at the rear of the engine, and is a liquid cooled heat exchanger that cools and controls the teperature of the compressed air/fuel mixture from becoming too hot.

Dwight Thorn developed the 'tube' motor back in the 1960's and was used as early as Chuck Lyford's Bardahl Special and on the Bardahl Hydroplanes. Since then, the trend for stuff like Dwight Thorn's "Mouse Motors", and copies like Mike Barrow and Mike Nixon have made, utilize the tube specifically to GET the air/fuel mixture hotter...hopefully for more horsepower.

Rick Shanholzer is a protige' of the late Dave Zeuschel. Big Z 'didn't believe' in using the tube...so all of his motors had the intercooler. Rick builds his the same way. They're still very good engines. And Rick has improved on Z's designs from back in the 80's.

Again, not digging on him...just a philosophical way of building the engines. But it's been shown that the tube motors can typically handle higher MAP than the intercooler engines.

[Fearless Tower]

OK, I'll ask a stupid question. Mr. Jackson says you're not supposed to use the trim tabs...how then do you control the trim of the aircraft? Is he saying you shouldn't adjust the trim tab once you get to a certain speed, and you have to adjust it prior to getting there? Or am I missing something here, as a non-pilot?

I think what he is getting at is that some of the racers have tailfeathers that are adjusted/mounted at such an angle as to require less trim at race speeds....but these airplanes are so custom-modified that I doubt any two are exactly alike.

Someone over at ProPilotWorld was at the races and took photos on the day prior to the accident (I believe you have to be a member/logged on to view them). The photos showed similar angles of three P51s passing the same spot (GG, Voodoo and Strega). The trim tabs on all 3 were very visible and different on all three. Strega appeared to have zero trim deflection. GG had the most nose down trim. What was interesting, is that in those photos, the left trim tab on GG showed heavy nose down trim while the right tab was not deflected. FWIW, I have heard that may have been the way the trim tabs on that airplane are designed - I am no expert on this, just describing what I saw.

Bottom line is, they are all adjusted differently and it is what it is. I still don't see how you can call that 'pilot error'.

[Tim Adams]

According to what I have read, only one trim tab moved on GG, the other one is locked into position.

[Fearless Tower]

According to what I have read, only one trim tab moved on GG, the other one is locked into position.

That is pretty much what I have heard as well, I just can't remember where.