What just happened at Reno?

Red Tail · **Joined:** Mon Jan 31, 2011 5:56 pm **Posts:** 138

Speedy wrote:

Red Tail wrote:

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.

Speedy,

Gotcha. I’m real familiar with the Merlin…just not the race slang. Thanks for the clarity. Not sure I’m on board with the explanation that they are striving for a hotter intake charge. It defies logic, physics and everything I was taught and learned the hard way working on extreme performance engines…but I’m not inside their heads either and do not know what their prevailing thoughts are. I would submit that the aftercooler is taken out of the system to remove a major cork from the intake tract and cooling the intake charge is left to the addition of ADI after the supercharger (Typically water and methanol blend)…latent heat of evaporation. The ADI does two things a) cools the intake charge and b) adds oxygen to the combustion cycle.

John
C/C Red Tail Mustang

Speedy · **Posted:** Thu Sep 22, 2011 3:41 pm

Red Tail wrote:

Speedy wrote:

Red Tail wrote:

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.

Speedy,

Gotcha. I’m real familiar with the Merlin…just not the race slang. Thanks for the clarity. Not sure I’m on board with the explanation that they are striving for a hotter intake charge. It defies logic, physics and everything I was taught and learned the hard way working on extreme performance engines…but I’m not inside their heads either and do not know what their prevailing thoughts are. I would submit that the aftercooler is taken out of the system to remove a major cork from the intake tract and cooling the intake charge is left to the addition of ADI after the supercharger (Typically water and methanol blend)…latent heat of evaporation. The ADI does two things a) cools the intake charge and b) adds oxygen to the combustion cycle.

John
C/C Red Tail Mustang

John, it is a TOTAL layman's explanation and understanding on my part. I've had guys that have built the tube motors explain it to me before, and it's just one of those things where you nod your head a lot and try to soak up as much as you can...so your explanation may very well have just as much merit.

Randy Haskin · **Posted:** Thu Sep 22, 2011 8:40 pm

Fearless Tower wrote:

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

Hopefully he can chime in, as I know he at least reads/participates on forums like AAFO, and explain what he means by comments like this:

Quote:

“I always tell the pilots that we don’t touch the trim tabs on any of the fast airplanes,” Jackson said. “Apparently he was using the trim tab. It snapped off. That’s the pop we heard.”

I have zero race experience at Reno, so perhaps this is common knowledge amongst Unlimited pilots. This quote makes it sound like there is a "no trimming during the race" rule of thumb.

Ploesti · **Joined:** Tue Aug 02, 2011 9:26 am **Posts:** 152

Fearless Tower wrote:

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

Could this be a well conceived lawyer infested plan to lay blame away from Jackson's group for several reasons? I'd like to hear more about his investigation as well. And BTW is this very long thread helping us all to cope and understand or is it time to back away for a while to recover and then come back to discuss further? I'm OK with it because It's been very respectful and insightful with very little speculation IMO. Just asking!

RyanShort1 · **Posted:** Thu Sep 22, 2011 10:24 pm

Ploesti wrote:

Could this be a well conceived lawyer infested plan to lay blame away from Jackson's group for several reasons? I'd like to hear more about his investigation as well. And BTW is this very long thread helping us all to cope and understand or is it time to back away for a while to recover and then come back to discuss further? I'm OK with it because It's been very respectful and insightful with very little speculation IMO. Just asking!

The NTSB is supposed to have some sort of initial report out tomorrow, I think.
From a few things said over on AAFO, I think that this will have a wider impact on warbirds in general over time as a result of it's affect on insurance companies. I hope that's not true, but I fear it is.

Ryan

JDK · **Posted:** Thu Sep 22, 2011 10:31 pm

Beyond the reactions so far, part of the issue will be - as touched on by the Jackson link - the definition and liability related to 'Experimental'. Flying an experimental aircraft anywhere near the public does not go over well.

The fact that all race cars can also best be classified as 'experimental' in the same way won't help, and again, aviation is disadvantaged by the impression of the terminology, rather than the fact. (Anyone remember the Richard Bach article on the public perception of 'not filing a flight plan' and 'uncontrolled airport'?)

dougdrivr · **Posted:** Thu Sep 22, 2011 10:50 pm

Randy Haskin wrote:

Quote:

“I always tell the pilots that we don’t touch the trim tabs on any of the fast airplanes,” Jackson said. “Apparently he was using the trim tab. It snapped off. That’s the pop we heard.”

I have zero race experience at Reno, so perhaps this is common knowledge amongst Unlimited pilots. This quote makes it sound like there is a "no trimming during the race" rule of thumb.

Totally unsubstantiated hearsay, but I read or heard somewhere that the GG had an electric pitch trim mod.

Fearless Tower · **Joined:** Thu May 26, 2011 5:14 pm **Posts:** 365

Ploesti wrote:

Fearless Tower wrote:

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

Could this be a well conceived lawyer infested plan to lay blame away from Jackson's group for several reasons? I'd like to hear more about his investigation as well.

I'm sure that is exactly what it is. Just sad to see it.

Invader26 · **Joined:** Wed Aug 11, 2010 7:56 am **Posts:** 843

Matt J. knows a lot about air racing as a builder and pilot.....

I respect his opinion greatly. {I received a report on a "bang" similar to Matt's description from another very well qualified person on the day...}

We will await the NTSB report with respect...

AvroAvian · **Posted:** Fri Sep 23, 2011 8:20 am

Red Tail wrote:

Speedy wrote:

Red Tail wrote:

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.

Speedy,

Gotcha. I’m real familiar with the Merlin…just not the race slang. Thanks for the clarity. Not sure I’m on board with the explanation that they are striving for a hotter intake charge. It defies logic, physics and everything I was taught and learned the hard way working on extreme performance engines…but I’m not inside their heads either and do not know what their prevailing thoughts are. I would submit that the aftercooler is taken out of the system to remove a major cork from the intake tract and cooling the intake charge is left to the addition of ADI after the supercharger (Typically water and methanol blend)…latent heat of evaporation. The ADI does two things a) cools the intake charge and b) adds oxygen to the combustion cycle.

John
C/C Red Tail Mustang

John's on the right track here. To clarify and to add my two bob's worth, the Intercooler is removed on the "tube" engine (guys, you use a motor to start the engine...) to reduce the pressure drop you get across the cooling matrix of the intercooler. The downside is you have to add more ADI to to keep the induction temperature within limits (I believe the magic number is about 85 degrees celcius). This is where the two schools of thought come in. The "tube" guys gain manifold pressure, but have to add ADI, but the intercooler guys contend that adding ADI can reach the point where you start "putting the lights out" and consequently lose power. At the end of the day, it all depends on what part of the compromise you want.

Paul

Speedy · **Posted:** Fri Sep 23, 2011 9:27 am

AvroAvian wrote:

John's on the right track here. To clarify and to add my two bob's worth, the Intercooler is removed on the "tube" engine (guys, you use a motor to start the engine...) to reduce the pressure drop you get across the cooling matrix of the intercooler. The downside is you have to add more ADI to to keep the induction temperature within limits (I believe the magic number is about 85 degrees celcius). This is where the two schools of thought come in. The "tube" guys gain manifold pressure, but have to add ADI, but the intercooler guys contend that adding ADI can reach the point where you start "putting the lights out" and consequently lose power. At the end of the day, it all depends on what part of the compromise you want.

Paul

Thanks, Paul. Have to say, when you made the comment about the motor/engine I had a flashback to my old mentor Ralph Payne who I envisioned looking over the top of his mirrored glasses and lecturing me on the difference between an 'electric motor' and a 'combustables-driven engine'. "Mah boy, you should know better...." followed by a big grin.

Red Tail · **Joined:** Mon Jan 31, 2011 5:56 pm **Posts:** 138

Speedy,

You wrote, "...it's been shown that the tube motors can typically handle higher MAP than the intercooler engines."

One thing I forgot to mention is that how either type of engine “handles” manifold pressure is a function of mechanical strength, how well it’s put together and the quality of the parts. Either type done correctly should be equal to the limits of the above boundaries. It was likely a wordsmithing error on your part but I’m guessing you meant how much manifold pressure each design is capable of developing. To that I agree the nod definitely goes to the aftercooler-less engine.
I agree with Paul regarding flame dampening with excessive ADI. It can have detrimental effects beyond that as well.

Hopefully unlimited air racing survives in some manner.

Peace and healing to all affected by this tragic event.

John
C/C Red Tail

StangStung · **Posted:** Fri Sep 23, 2011 9:59 am

To those who've posted very reasoned and detailed explanations of varoius racing topics on this thread: Thank you.

I've probably learned more about racing warbirds in the last 20 pages than I have in the last 20 years reading books. It's tremendously sad that it has to come up in this context (my condolences to the Leeward family, those who lost loved ones, those who were injured both physically and emotionally), but this thread has been a real educational experience for me. Thanks again.

kenair · **Posted:** Fri Sep 23, 2011 11:35 am

NTSB Identification: WPR11MA454
14 CFR Part 91: General Aviation
Accident occurred Friday, September 16, 2011 in Reno, NV
Aircraft: NORTH AMERICAN/AERO CLASSICS P-51D, registration: N79111
Injuries: 11 Fatal, 66 Serious

This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.
On September 16, 2011, about 1626 Pacific daylight time, an experimental North America P-51D, N79111, impacted terrain following a loss of control while maneuvering at Reno Stead Airport, Reno, Nevada. The airplane was registered to Aero-Trans Corp, Ocala, Florida, and operated by the pilot as Race 177 under the provisions of 14 Code of Federal Regulations Part 91. The commercial pilot sustained fatal injuries; the airplane sustained substantial damage. Casualties on the ground included 10 fatalities and 74 injured. As of the time of this preliminary report, eight of the injured remain hospitalized, some in critical condition. Visual meteorological conditions prevailed at the time of the accident, and no flight plan had been filed for the local air race flight, which departed from Reno Stead Airport about 10 minutes before the accident.

The airplane was participating in the Reno National Championship Air Races in the last event of the day. The airplane had completed several laps and was in a steep left turn towards the home pylon when, according to photographic evidence, the airplane suddenly banked momentarily to the left before banking to the right, turning away from the race course, and pitching to a steep nose-high attitude. Witnesses reported and photographic evidence indicates that a piece of the airframe separated during these maneuvers. After roll and pitch variations, the airplane descended in an extremely nose-low attitude and collided with the ground in the box seat area near the center of the grandstand seating area.

Investigators from the National Transportation Safety Board (NTSB) and the Federal Aviation Administration examined the wreckage on site. They documented the debris field and identified various components of the airplane's control system and control surfaces. The wreckage was removed to a secure storage facility for detailed examination at a later date.

The airplane's ground crew noted that the airplane had a telemetry system that broadcast data to a ground station as well as recorded it to a box on board the airplane. The crew provided the ground station telemetry data, which includes engine parameters and global positioning satellite system data to the NTSB for analysis. The onboard data box, which sustained crush damage, was sent to the NTSB's Vehicle Recorder laboratory for examination. Investigators recovered pieces of a camera housing and multiple detached memory cards from the airplane's onboard camera that were in the debris field. The memory cards and numerous still and video image recordings were also sent to the Vehicle Recorders laboratory for evaluation.

The Federal Aviation Administration and the Reno Air Race Association are parties to the investigation.

Paul Krumrei · **Joined:** Sun Apr 03, 2005 11:06 pm **Posts:** 1757

WTH, that is it? WE know more now through the media and people we know than what is on the report.

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