Dudley HenriquesInternational Fighter Pilots FellowshipCommercial Pilot. CFI RetiredI've received considerable email from some of you requesting information on aerobatics in propeller driven fighters. I know many of you have purchased the RealAir Griffon Spitfire and are out there turnin and burnin having lots of fun, and I'm just as sure that some of you by now might have even discovered a few new maneuvers that R.J. Mitchell didn't think the Spit could do :-) Anyway, I'll do what I can to get you started off on the right foot, which BTW won't help you much flying the Griffon. I'd be better off getting you off on the LEFT foot!Since I demonstrated the P51D Mustang in real life, if you don't mind,let me use this airplane at least in part for the explanations I give you, and I'll assume that because you were smart enough to purchase the RealAir Spitfire, you are also smart enough to convert inches of mercury to lbs/sq in. (1lb/sq in. boost= 2.036 in. mercury)and know that the torque side is reversed for the Griffon :-)For all practical purposes, you can devide aerobatics for an aircraft like a P51 into vertical maneuvers and rolls. Snaps are possible in airplanes like the 51 and the Spit, and indeed, flick rolls (snaps) have been done in combat, but because the maneuvering speed decreases with a decrease in gross weight as fuel is burned, finding a Va that won't over g the airplane is a bit tricky, so in normal demonstration flying, we don't do snap rolls in these airplanes as a rule.So basically, when you demonstrate a fighter of this type, you are restricted to maneuvers such as loops, Immalmanns, Cuban Eights, and Reverse Cuban's. You can fly variations of these maneuvers, but these are the basic verticals.Rolls; you can do aileron rolls, slow rolls, and hesitation point rolls very nicely in a P51 or a Spit.Spins are possible in these fighters, but only power off. There are pilots spinning Mustangs, and the airplane will spin power off quite nicely, but the altitude losses are horrendous. I never did spins in demonstration work and have never recommended doing them in the Mustang except to pilots with large amounts of 51 time.Let me stop here for a moment and talk about sim controllers a bit.Many of the aerobatics in the Mustang require a fair degree of cross controlling. Hesitation rolls are a good example. Naturally, in the sim, having a good set of rudder pedals helps a lot. Without pedals, it's extremely hard to perform a good hesitation roll, or even a good slow roll. It can be done, but it takes a lot of practice to get it right.One more thing; to perform vertical maneuvers in these airplanes at the low altitudes I used for demonstration work, a g meter is an absolute must. As the Spit, being a period airplane, dosen't have a g meter, you will have to do what the pilots of the day did with the Spitfire, and go vertical looking for a specific airspeed at the top.As long as you're working the airplane high enough, you can get away with this technique quite well, so plan on doing that. More on this later.OK, let's do a loop the RIGHT WAY!! First of all, find a nice long road or landmark that gives you a straight line for some distance on which to practice. Remember, I only had the length of a runway to work with, so you're lucky here!! :-)For the Mustang, I'd be using Meto (Maximum except take off)power at entry which is 46 inches and 2700 RPM. Remember, with the power setting at METO and the prop full forward in fine pitch, you have power available on the way up if you need it. In the Mustang, I could go all the way to 61 inches if I needed to. In the Spitfire, you can go to +18lbs boost if you wanted to. The IAS at g onset in the initial pull for the 51 is a little higher than for the Spitfire; about 375. The maneuver profile is at +4g's with both the Spitfire and the P51. The Mustang is a bit heavier, so you would carry a bit more IAS into the maneuver. Density altitude can also be a factor in demonstration aerobatics, and entry airspeeds should be adjusted up accordingly. The higher the elevation, the higher the entry speed. I usually added about 25 to 50mph extra for demos at higher elevations in the United States.Now, for you Griffon drivers out there; if you are going to do acro, go with half tanks. You want the airplane light in the air. Plan for an entry speed of 320 to 350mph and use a power setting of about +8lbs boost at entry. Make sure the prop is all the way forward in fine pitch. I believe it's programmed automatically by RealAir, but I'm still a great fan of making sure that prop is FORWARD!Now here's the trick with the Griffon. You DON'T have a g meter and you are going to be estimating a 4g pull. You DO have an ASI however and you will have a RATE DECREASE on the way up the vertical line.What this means is that if you have what we call in the demonstration business a "high target gate", which is an airspeed you're looking for at the top inverted, you can PLAY the airspeed against the loop profile going up. Now, how do you do this? Well, in the sim, it's actually harder than it is in the airplane believe it or not. Your wingtip is your reference guide to where the airplane is both in pitch and in roll as you go up the vertical line, and panning between the tip and the ASI, isn't a job for the faint of heart :-) I suggest using the number keys for the tip reference so you can spring back to the panel and get an eyeball on the ASI.Anyway, what you have to do is keep the airplane straight in roll which means neutral ailerons, and keep it straight in yaw, which means a centered ball for the 51, or in the case of the Spitfire, a centered yaw indicator. The airspeed you will be looking for on the top inverted should be about 130 to 150mph. Never under 100! What you will be doing is playing all these things together to get the airplane inverted at the top at the right airspeed. If you do that, you're half way to doing the loop correctly. Also, as to torque, remember, in these prop fighters, you will have torque, P factor, gyroscopic precession and slipstream effect all working on the airplane as you pull through the first half of any vertical maneuver, and the forces are considerable. In the P51, you will have a right rudder correction on the way up and in the Griffon Spitfire, you should be needing a fairly good LEFT rudder correction on the front side of a vertical maneuver. If in doubt in either airplane, glance at the ball in the 51, and the yaw indicator in the Spit to verify you are holding in the right amount of corrective rudder!!Now, say you pull into the vertical at the right IAS and are watching the left wingtip and the IAS. You're just past vertical and the airspeed is down to 120. What's this tell you? You're NOT going to make it to full inverted before you break 100mph are you? The way to correct this is to increase the g. If you're at +4, you have some g left to work with, BUT you don't want to yank it back hard enough to enter a high speed stall either. So it's a trade off. If you're busting the maneuver, throw everything in the corner and ROLL to the nearest horizon, plug in some power and go do it again.Now.....the wingtips! On the way up, you're watching the LEFT tip. If the tip dips INTO the ground, you're holding too much LEFT RUDDER.If the tip is in the sky, you're holding too much RIGHT RUDDER. If you were watching the other tip, the reverse would be true. Get in the habit of using one wingtip all the time. It standardizes your procedure and minimizes mistakes.Now, say you've reached the top and are about to go inverted, EASE OFF the g, and let the airplane float through the top. Go to the forward view and pick up the inverted horizon and check your airspeed. As you pick up the inverted horizon, make any adjustment to wings level inverted you need to center the airplane. You should be dead on your highway or whatever you're using for the maneuver checkpoint inverted.Now, ease off the power and ease in another +4g's for the down line.Don't rush the recovery. Watch the altimeter. It and the ASI are the two instruments you're playing one against the other in the recovery.You want to reach level flight at your entry airspeed and at your entry altitude on the right heading, so play all this to achieve that goal. Plan to ease in the power back to cruise as you recover level flight. If everything's as it should be, you are back in level flight looking down the same highway you used for entry at the entry airspeed and at the entry altitude.I hope this helps fill in any gaps you might have on the subject of loops in prop fighters.I'll cover rolls if you like in another thread.

Dudley,This is fascinating stuff. I for one would love to see the next installment.Best Regards,KenP.S. I assume that the snap roll discussion was in response to comments you had received? I tried doing one this weekend just for grins, and it actually did one! Wow! Then I tried a few more to make sure it wasn't a one time occurance, and it was very consistent. This airplane just continues to amaze.

Thanks Dudley!Please continue, your posts are the most interesting ever!Regards,JR

THANKS AGAIN. It's great to get the real deal from the real deal!Regards,Jim

I'm looking forward to Dudley's tutorial on the hammerhead, maybe the most difficult thing to get right, and one of those maneouvres that needs a bt of luck to help you on your way.Rob Young

Rob,It's out and I just read it. Suffice to say that I anticipate a long learning curve and many botched attempts before my hammerhead and slow roll are ready for Broadway!Ken

Very very cool. Please do continue.

Much obliged,Dudley !! Like Ken said this is fascinating stuff to read and even more enhances the enormous pleasure it is to virtually fly this awesome and beautiful piece of machinery RealAir has givin us ! ( the first edition of Looking Glass' Flight Unlimited series springs to mind which concentrated on aerobatics and which i have enjoyed tremendously )Just out of curiosity, did you, by any chance, fly the F-86 (A,E or F ) ?? Saw your post over at the F-86 Sabre Pilots Association. Hope you did find information about your 142nd friend !Best regards,Jan

>Much obliged,Dudley !! Like Ken said this is fascinating>stuff to read and even more enhances the enormous pleasure it>is to virtually fly this awesome and beautiful piece of>machinery RealAir has givin us ! ( the first edition of>Looking Glass' Flight Unlimited series springs to mind which>concentrated on aerobatics and which i have enjoyed>tremendously )>>Just out of curiosity, did you, by any chance, fly the F-86>(A,E or F ) ?? >>Saw your post over at the F-86 Sabre Pilots Association. Hope>you did find information about your 142nd friend !>>Best regards,>Jan >>>>Dudley HenriquesInternational Fighter Pilots FellowshipCommercial Pilot. CFI RetiredThank you. No one ever wrote in about Jim Shotwell. He was a great guy. I was hoping to find someone still alive who knew him. he was killed in an 86A when one of those old J47 maintainence nightmares swallowed a bucket on him right after pitchout at new Castle AFB in 55.I'm flying out of that airport in the simulator and live fairly close to it. On a left base to runway 1, I usually overfly the exact spot where he went in.About the 86, I have a bit of time in the Canadair hard wing. Ferried one down to Texas once and got a little time in it before I turned it over. Great airplane! Most of my jet time is in T38's amd I did a bit of test work in the F14A.All the best,Dudley

Dudley,Sorry to hear your inquiry at the F86 SPA didn't produce any result, i wish you the best of luck with your further search on info about your very unfortunate colleague.If you have no objections i'd like to contact you with a few questions pertaining to flying the 86.Thank you very much on forehand.Best regards,Jan

>Dudley,>>Sorry to hear your inquiry at the F86 SPA didn't produce any>result, i wish you the best of luck with your further search>on info about your very unfortunate colleague.If you have no>objections i'd like to contact you with a few questions>pertaining to flying the 86.>>Thank you very much on forehand.>>Best regards,>Jan>Dudley HenriquesInternational Fighter Pilots FellowshipCommercial Pilot. CFI RetiredThank you. I appreciate your concern about Capt.Shotwell. As for the 86, I have no objections to discussing the 86, but as I said, I only had a few hours in the bird, and that was a LONG time ago!:-) I would think the Sabre guys would be a much better source of information. My experience in the Sabre involved 30 min. in the T Bird and a cockpit checkout on the Sabre for a ferry flight. I did play with it a bit, but not to where I could discuss the airplane with any degree of authority.If you ever want to discuss the T38, I'd be a much better source of information for you :-)DH