MA-II Speed Potential

[speeddemon]

Re: MA-II Speed Potential

Obi-Wan,

You are missing a central fact to that year with the Red Baron... It was massively tail heavy. That had, probably, a lot more to do with it.

As you well know, aft cg negatively effects all forms of stability.

Boland's adding the ventral fin was a good try, but I would think the air under there is kinda like a moody woman.

After you buy me that beer, I'll buy you one...

BM

Touche'. :-) Now I'm even more thirsty.

Regardless of the what and the why, ultimately the problem was corrected. And the all-red '75-76 Red Baron is one of my favorites of all time. A classic plane from a classic era of air racing.

[MRussell]

Re: MA-II Speed Potential

The fact that the RB was tail heavy didn't 'cause' Darryl's problem. The plane will take off and land just fine being tail heavy...provided you know about it.

Nobody told Darryl about it because nobody thought he'd try to take off that way.

Classic example of 'failure to communicate'.

Fascinating. I'd imagine you'd have to work up some nerve to brief DG on the handling behavior of anything, given his resume.

[speeddemon]

Re: MA-II Speed Potential

How about the differences between MA11/PM and the Red Baron? Was she maore like a "normal" P51 than the others. PM and the Red Baron deffiently look different to each other.

Aside from the tail, which is the first thing that grabs my eye on the Red Baron, it was significantly different from Precious Metal. One of the first things you can see is that the thrust angle of the RB is zero...while the thrust angle on PM is canted significantly. This made the RB appear 'straight', while both PM and MAII appear to be 'bent down' at the nose.

The RB utilized modified/strengthened P-51 engine mounts (currently in the care of one Randy Goss), while both PM and MAII used custom made tube 'cradles'.

Because the RB used the Mustang engine mounts, a 'heavier' engine was situated farther forward...which resulted in all the weight being added to the tail end of the plane to try to balance it out. PM and MAII mounted moved the firewall farther aft and tucked the engine closer to the c.g. in an attempt to better balance them. That is what gives PM that short, round, 'pregnant salmon' look about her when viewed from the side.

MAII didn't have that same 'short'n stubby' look mostly because they ran the smaller Griffon and was able to keep a slimmer profile (which meant that physically, you couldn't fit the bigger Griffon in MAII). PM had the 'big' Griffons out of the Miss Budweiser hydroplane.

A lot of the 'internal' stuff on the RB was more primitive than the two modern counterparts. She still used essentially a stock 'oil cooler', where PM and MAII utilized a P-51H 'heat exchanger'. It was just stuff that hadn't been learned yet.

The RB had stock P-51D wheels...while PM has lighter weight wheels off of a Beech Queen Air (similar to Strega). MAII, obviously, had the 'cobbled' landing gear off of Vendetta--which was similar in makeup to the landing gear on Tsunami.

There has been a lot said that the Red Baron was significantly 'lightened up' during its modification process. That is a very misleading statement. The airframe was lightened up during the 'deconstruction' of the original Jim Larsen modifications--mainly the big, heavy, fiberglass turtledeck and cockpit canopy which it ran as Miss RJ and Roto-Finish. As a Merlin powered racer, that was a heavy Mustang because of all the fiberglass.

But once they started putting the RB back together, the weight came right back on. The weight of the Griffon added, the placement of the Griffon necessitated the weight in the back that added, they added to the tail, and they strengthened the cockpit area inside the fuselage, which added too. Once done, they came close to a 3500 hp Mustang that weighed over 9,000 lbs.

Both MAII and Precious metal were significantly lighter weight. PM weighs only a few pounds over a 'stock' Mustang' (around 7000 lbs), and MAII was even lighter than that.

[Skyracer]

Re: MA-II Speed Potential

And when they did that for Reno '75, they actually ended up with overkill...a tail that was tall enough to do the job, but with a chord that I would guess actually hindered the turning characteristics of the plane around the course. TOO MUCH tail.

You youngsters just haven't quite got it figured out, there is no such thing as "TOO MUCH tail". Oh, wait a minute, we're still talking about airplanes.

[zeke]

Re: MA-II Speed Potential

Because the RB used the Mustang engine mounts, a 'heavier' engine was situated farther forward...which resulted in all the weight being added to the tail end of the plane to try to balance it out. PM and MAII mounted moved the firewall farther aft and tucked the engine closer to the c.g. in an attempt to better balance them. That is what gives PM that short, round, 'pregnant salmon' look about her when viewed from the side.

MAII didn't have that same 'short'n stubby' look mostly because they ran the smaller Griffon and was able to keep a slimmer profile (which meant that physically, you couldn't fit the bigger Griffon in MAII). PM had the 'big' Griffons out of the Miss Budweiser hydroplane.



Both MAII and Precious metal were significantly lighter weight. PM weighs only a few pounds over a 'stock' Mustang' (around 7000 lbs), and MAII was even lighter than that.

Thanks speeddemon,
Always thought that all the griffion mustangs looked substantially different, now I know why.

Regarding the weight of those aircraft, in what weight range is it conciecable to get a griffion powered racer down to, and how much of an increase would that be over a minimum weight merlin racer (what's the approx weight of the lightest merlin racer, heard stilleto was really ligh?) Don't need to know the trade secreats , just the approx weights and differences.

[Leo]

Re: MA-II Speed Potential

Stiletto was lightened even down to cutting holes in the gear door structures. I dont think anyone would go to that extent again. Cant see where those few pounds (say, a couple hundred) would make that much of a difference.

[speeddemon]

Re: MA-II Speed Potential

Thanks speeddemon,
Always thought that all the griffion mustangs looked substantially different, now I know why.

Look at these of the RB, and note where the firewall is. Then take a look at PM and look at where it is, along with the downward thrust angle.

Two very different approaches.

Another thing to remember about what they did on PM....to help compensate for the weight and balance, in addition to moving the firewall aft, they also moved the cockpit aft a couple of feet. That is another thing that gives PM the 'odd' look.

[jarrodeu]

Re: MA-II Speed Potential

More great pictures Brad! Thanks for posting.

Jarrod

[Peashooter]

Re: MA-II Speed Potential

Look at these of the RB, and note where the firewall is. Then take a look at PM and look at where it is, along with the downward thrust angle.

Two very different approaches.

Another thing to remember about what they did on PM....to help compensate for the weight and balance, in addition to moving the firewall aft, they also moved the cockpit aft a couple of feet. That is another thing that gives PM the 'odd' look.

Did they rework the lower cowl between the two pics? The Darryl pic looks like a smoother curve.

[speeddemon]

Re: MA-II Speed Potential

Did they rework the lower cowl between the two pics? The Darryl pic looks like a smoother curve.

Yes, the 'bulky' cowling was for '75, and they had the smoother one on for '76. Over on Scotty G's site, under the RB-51 photo galleries, there are photos of them fitting/testing the new cowl.

[Peashooter]

Re: MA-II Speed Potential

Ah yes, a little less of the "Bill Cowher" look!

http://www.warbirdaeropress.com/PhGal/nfpicturepro/albums/userpics/RedBaron2/normal_RedBaron34-