Cobra III

[skybolt2003]

I remember as a kid going to Reno with my dad, probably in '72 and seeing Mira Slovak's P-39, Mr. Mennon. There was a lot of buzz that it was going to be a Mustang beater. It didn't race, then or ever as far as I know. I also had the Air Race series of book, by I think Reed Kinert and remember a couple pictures and description of Cobra III. Mike Carroll who flew the flamed Sea Fury was modifying it to break the piston engine speed record. I've heard it described as highly modified, but wonder what was actually done to it? He was tragically killed in its first test flight – I think E.D. Weiner was flying chase in his -51 (it was a long time since I had the book) I've always wondered about it and what happened, and P-39's in general. If anyone knows any details or has pictures I'd be really interested. Thanks,
-Bret

[Steve T]

Bret--

You were fortunate indeed to see P-39 "Mr.Mennen". As you say, she never competed that year or any other (excepting a later visit in the ownership of the CAF, and she could not be said really to have "competed" then either). What apparently happened was that Slovak flew the Cobra in after the arrival deadline had passed and was prohibited from competing; the owner disgustedly retired the aircraft from racing, so "Mr.Mennen" never raced in earnest. (Well not afterward, anyway: the same Cobra had been an entrant in the early postwar National Air Races at Cleveland, being one of the few warbird racers to enter races in both eras). The former "Mr.Mennen" flew with the CAF for a number of years then passed to the Kalamazoo "Air Zoo" (Parish collection), where she continued to fly for a time but is now on static display in the new "Zoo" building, painted as a 5th Air Force USAAF P-400 export-model Cobra.

I too would love to see post-Cleveland NAR photos of the '46 Thompson champ "Cobra II" (not "III"...though perhaps Mike Carroll renamed her?) as I have never seen such a shot. What I know of Carroll's project comes from a Bill Johnson article on racing Sea Furies...namely that the same outfit (Vern Barker/Pylon Air) as customised Carroll's Sea Fury also did the P-39, and that the mods consisted (in part) of a further reduction in wingspan from its 1949 state, and the use of an evaporative oil cooler. As you say something went terribly wrong on the first test flight and Carroll baled out, whereupon the worst happened and he hit the tailplane, being killed. (The Cobra apparently came down on property used by the Navy for nuclear weapon storage! Yikes...)

Another thing I'd love to see is a restored P-39 in the colours and configuration of "Cobra II" as she was in '46. That'd be a heck of a sight parked alongside Mr Odegaard's magnificent red F2G on the Reno ramp...

Cheers

S.

[L. Thompson]

The September 1968 Volume 2, No. 9 issue of SPORT FLYING (pages 24-27, 64) had a 10-photograph article on the rebuild of the Cobra. Shown was a rough looking bare metal P-39 on a trailer after Mike Carroll purchased it from Ed Maloney in 1965 or 1967 (both dates given in article). Then photos of the transformation and close-ups of the modifications. I believe an issue or two later the magazine had a follow-on article with photos of the finished airplane ready for flight. I have seen that magazine years ago but don't have a copy. If you'd like scans of the Sept 68 article, however I could send them. PM me your E-mail.

It was not referred to as Cobra III at all in this article.

Lowell

[mennie]

Cobra III ?
http://www.warbirdregistry.org/p39-p63registry/p39-4220869.html
http://www.ntsb.gov/ntsb/brief.asp?ev_id=10805&key=0
I would like to see photo's too.

[skybolt2003]

The pictures I remember were in the Air Racing series of books by Aero Publishers. It was a yearly series. (I sure wish I had them today) I remember it had 2 or 3 pictures if the modified Cobra which looked to be in grey primer (B&W photos). I wonder if it had any chance at the speed record? That NTSB report is pretty blunt – I wonder how they knew that was the cause anyway? He obviously had some high performance fighter experience with the Sea Fury.

[Speedy]

Bret--

You were fortunate indeed to see P-39 "Mr.Mennen". As you say, she never competed that year or any other (excepting a later visit in the ownership of the CAF, and she could not be said really to have "competed" then either). What apparently happened was that Slovak flew the Cobra in after the arrival deadline had passed and was prohibited from competing; the owner disgustedly retired the aircraft from racing, so "Mr.Mennen" never raced in earnest.

Okay, here's what REALLY happened--as told to me by the person on the contest committee who actually made the disqualification of Mira and Mr. Mennen:

Mira had purchased the aircraft from E.D. Weiner and completely gone through to rebuild the Cobra for racing...including bringing on George Mennan as a sponsor. Mira was also a Captain for Continental Airlines at the time, and as the story goes, he informed the Contest Committee that he was going to be 'late' in arriving at Reno because.....yes....if you know Mira at all....he had a date with one of his stewardesses at Continental, and he wanted a 'waiver'.

The Contest Committee members, to a person, all agreed that this was not a reason to 'waive' the arrival deadline for aircraft who were entered, and that if Mira were serious about racing, he'd be there on time. If he showed up late, they would not allow him to qualify or race.

He wasn't.

They did.

But in all seriousness, Mr. Mennen never would have been competitive with the racers of '72. The fastest a P-39 ever went was the super-modified (for the day, at least) Cobra II that Chuck Brown raced at Cleveland in 1948. He qualified at 418 mph on a bigger race course, with a bigger engine, and some trick racing fuel. Mr. Mennan was nothing more than a 'clean-but-stock' P-39, and had no chance of keeping up with Greenamyer's Bearcat or Gunther Balz's Mustang.

[jet1]

...on a test flight. I heard that it had its wings so clipped that it became uncontrollable, but that may also be urban myth.

[Speedy]

...on a test flight. I heard that it had its wings so clipped that it became uncontrollable, but that may also be urban myth.

Somehow that myth has grown over the years that the plane was out of control, but according to E.D., who was flying chase on that flight the plane appeared to be in straight, level flight until AFTER Mike had jumped out and hit the horizontal.

Speculation on the ground with E.D. (as relayed by someone who was there) was that Mike's inexperience in the Cobra was the main problem. The Cobra, of course, has the driveline right underneath the pilot's legs, and has some interesting harmonics and vibrations. Mike was a very low time pilot, with not a whole lot of Warbird experience. Because Cobra III had been equipped with a great big prop and a 'juiced' engine, they all felt that there must have been some kind of bad vibration or shaking--that it was something they had noticed during high power ground runs--and Mike sort of freaked once it was in the air.

No way to prove it, of course, because Mike never said anything over the radio...and virtually ALL of the primaries involved in this project are now long gone. But that was the buzz on the ramp after the fact, and his family members (based on Mike's flying experience) tend to agree with this theory.

[warbird51]

If you read the article about the restoration of Race 21 "Mr Mennan", the P-39 was very stable with a stock P-39 three blade prop. But, when they put the special paddle 3 blade racing prop on it, the aircraft was hard to keep straight. And that was without having the wingspan shortened. The pilot said it was a "handful" to keep the a/c from swapping ends. Now Cobra III had short clipped wings and a 4 blade P-63 prop. The torque effect must have been incredible. Not a good recipe for keeping the a/c flying straight.

[29erFE]

"SPEEDY" only thinks he knows what really happened to Mr. Mennen. First off, Mira got 44-3908 from Don Randall not E.D. Weiner. It was rebuilt at Dick Martin's at VNY. On the first flight, Mira found that with the P-51H prop installed if you tried a right bank it would would try to do an outside snap roll. Mira flew a left pattern and landed on the other runway. Compare this to the Mike Carrol incident with the same prop with less wing and very short ailerons. E.D. said they took off heading south and over Seal Beach were going to turn right and go out over the water. That is when Mike attempted to bail out. I don't think Mike was ready for something like that. It was 3 years later when we found out what that light airplane and big heavy prop combination would do. It was decided to put 3 51H blades in a 3 blade hub as they did on Cobra II in 1948. The prop was sent out but we never got it back before Reno. An orignal "toothpick" 3 blade was installed and Mira flew it that way for thirty minutes on wednesday about 20:00. Everything else worked fine. We were not going to Reno until the president of the PRPA came by and said to bring it and they would see that we would race. We loaded up the pickups and the crew headed for Reno. Mira went home and so did I. Mira got it ready and left for Reno Thursday AM. I went up on Western. Early the next morning we stared getting it ready to qualify. Mira went to the pilot's meeting then came back and told us we couldn't race. I am told that all the pilots except one said "let him qualify and race where ever he qualifies". Anyway,we were getting it ready to ferry home when Jerry Duty asked Mira to "open" the show with it on Saturday and Sunday. Mira's first reply was "we came to race, if we don't race we're going home. Jerry said at least that would get your sponsorers name in front of people so Mira agreed. Mira asked if he was limited to the race course and was told "the airport is yours, put on a show". The FAA gave him a violation for breaking the deadline and numerous other things. Mira fought that for two years and many thousand dollars. It was appealed to the supreme court where it lacked one vote of being heard. Of course the FAA went to Continental and our illustrious Sr. V.P. put the bite on Mira to quit racing. So, Mr. Mennen got parked at Santa Paula until Dec. 73

[29erFE]

Mira rented a hangar at Torrence, CA so Mr. Mennen would be closer to me so I could finish some things that never got done in the rush to get to Reno. Would you beleive when Mira left Santa Paula a retired FAA man filed 9 violations on him. There was not one that would hold water. The GADO told the guy that they were rediculess and they recommended he withdraw them which, he did. The bad part was that the FAA attorney that tried for Mira at Reno picked up on it and went to our illustrious Sr. VP again. He called Mira in and told him that "you will get rid of that airplane". Of course, he couldn't force him to but Mira felt Continental had been good to him and didn't want to take them on. I'd had many dealings with that VP and I would have fought him all the way. He was one of the top management that lost our airline to Texas International and Frank Lorenzo. At least I had Mr. Mennen to play with for a year. Then Mira sold it to Ed Messick and the CAF. So that is why Mr. Mennen didn't race any more.

There was mention of the possible drive shaft problem with Carrol's P-39. To my knowledge that was never a problem. the noises they were talking about are just "normal" P-39 noises. The engine is practically mounted solid, the spur gear gearbox whines like hell and the engine is only 6 to 8 inches behind your back. Originally there was armour plate between the seat and the engine but converted ones only have a thin sheet of aluminum.

The "ill handling" of a P-39 with the big paddle bladed Aeroprops (the paddle bladed P-63 and the P-51H props are nearly identical) is caused by gyroscopic precession rather than torque. Mira's P-39 only weighed 6995 pounds fully loaded. No P-39 would be competitive now days. It has a "slow" airfoil and will only accomodate a limited amount of horsepower. Carrol's airplane was really being built for a straightline speed record. It had most of the acess holes sealed up, even the left door, and it was covered in bondo. Mira was able to buy the wreckage of Carrol's airplane. The P-39 was probably the nicest airplane I ever worked on. The acessability was great. Loved that airplane, especially Mr. Mennen.

[skybolt2003]

Great stuff 29er. Keep it coming!
I used to fly into Santa Paula a lot in the mid-late 70's. Mira's hangar was always closed when I'd go by.

[jet1]

Mira rented a hangar at Torrence, CA so Mr. Mennen would be closer to me so I could finish some things that never got done in the rush to get to Reno. Would you beleive when Mira left Santa Paula a retired FAA man filed 9 violations on him. There was not one that would hold water. The GADO told the guy that they were rediculess and they recommended he withdraw them which, he did. The bad part was that the FAA attorney that tried for Mira at Reno picked up on it and went to our illustrious Sr. VP again. He called Mira in and told him that "you will get rid of that airplane". Of course, he couldn't force him to but Mira felt Continental had been good to him and didn't want to take them on. I'd had many dealings with that VP and I would have fought him all the way. He was one of the top management that lost our airline to Texas International and Frank Lorenzo. At least I had Mr. Mennen to play with for a year. Then Mira sold it to Ed Messick and the CAF. So that is why Mr. Mennen didn't race any more.

There was mention of the possible drive shaft problem with Carrol's P-39. To my knowledge that was never a problem. the noises they were talking about are just "normal" P-39 noises. The engine is practically mounted solid, the spur gear gearbox whines like heck and the engine is only 6 to 8 inches behind your back. Originally there was armour plate between the seat and the engine but converted ones only have a thin sheet of aluminum.

The "ill handling" of a P-39 with the big paddle bladed Aeroprops (the paddle bladed P-63 and the P-51H props are nearly identical) is caused by gyroscopic precession rather than torque. Mira's P-39 only weighed 6995 pounds fully loaded. No P-39 would be competitive now days. It has a "slow" airfoil and will only accomodate a limited amount of horsepower. Carrol's airplane was really being built for a straightline speed record. It had most of the acess holes sealed up, even the left door, and it was covered in bondo. Mira was able to buy the wreckage of Carrol's airplane. The P-39 was probably the nicest airplane I ever worked on. The acessability was great. Loved that airplane, especially Mr. Mennen.

those were the days eh!

[29erFE]

I'll throw in some more trials and tribulations concerning Mr. Mennen. Dick Martin, who I liked imensely, and his crew at Van Nuys, CA rebuilt the P-39 that would become Mr. Mennen. They did great work but with all things mechanical some things happen. On the first flight they towed Mira to the T/O end of 16R. Mira immediately took off as P-39's overheat quickly. After T/O he kept going farther and farther south. I kept thinking "Mira, stay close"! About that time he turned left and joined downwind for 16L. On downwind it looked like it was "dutch rolling". Mira later said it felt like trying to stand on a beach ball. After landing Mira took everyone to lunch at the old Skytrails. I was late as I was finishing up the smoke system on Mira's Bucker for an airshow the next weekend. When I got there it was a real solemn crowd. We knew the prop was the reason for the handling and started to realize what probably happened to Mike Carrol. The overheating was no suprise but it took a while to realize why the Carb air temp was so high. Unlike Merlins, Allisons don't run an intercooler and with the high ratio blower drive gears they will have high CAT.

Mira flew it again four days later and had another "adventure". Right after T/O a coolant hose blew off. Mira called a Mayday, turned LEFT and landed downwind on 16R under a departing ANG C-130. Mira's skills again saved the airplane. No way would a P-39 make a full pattern without coolant. To help the cooling problem we tried get the cooling system as full as possible. The header tank was mounted too low and that allowed no expansion space. The hose "hydrauliced" off even though it was double clamped. During this episode Mira hit his elbow on a temporariy mounted radio on the side of the seat. It put a big lump on his elbow.

When I got to the hangar on Saturday I mounted the radio lower. When Mira got there I asked him to get in the seat and see if he could see to set a frequency. I hadn't known Mira long at that time but found he had a sense of humor. He said "Donald, just set 121.5 and leave it, that's all I need with ths SOB"! Shortly thereafter the airport fire truck stopped in front of the hangar. The Chief came in and said " If you guys are going to fly it today, we're handy". Thanks a bunch!

Mira and Dick got together about the prop situation. Mira said " no way will I race with that prop installed, if for some reason I would have to turn right I could kill someone, maybe even me". That was when it was decide to try the 3 paddle blades. To see Mira back away from a potentially dangerous situation elevated my esteem for him greatly. Maybe that is why he has been my closest friend for 36 years. Wow, i can't believe this was that long ago!

[bdk]

Note: An increase in blade area on a tractor prop is destabilizing due to the increased polar moment of inertia (as would be spacing the prop forward which increases the arm). You might need to add additional stabilizer area to compensate. I'll bet the P-63 has a larger tail for use with the 4-bladed prop.