Help! Dudley! I can't execute a loop!

[renaissanceman]

OK, I don't have much stick time in the P-51. Having said that, I still should be able to fumble my way through a loop. So far I have not been able to. Here is my technique:

Altitude about 20,000'
MP to 45"
RPM to 2600
Shallow dive until I reach 260 MPH
Pull up trying to keep both the wingtips on the horizon and the bubble centered
MP to 55" as I go vertical
As the nose goes over the top I run out of airspeed and fall off into a spin, usually to the left

I have tried this at various speed and MP settings including war emergency power breaking the wire.

I know I should be looking for 4 Gs on the pull up but I seem to be so busy watching everything else that I don't look at the G meter. I don't see this as a problem with the flight model, just a problem with my handling of the aircraft. I am able to loop the Spit and the P-47, I'm not sure I have tried with the P-40.

I'd appreciate any advise from the experts out there. Thanks.

Jim

[JoeS475]

I have found loops quite tricky also, and it is easy to run out of speed at the top. My technique (pure trial and error, nothing official) is to dive to about 300mph at 55" with enough altitude to recover a stall. Then I pull back on the stick until I start to blackout, and keep it on the edge of blacking out the whole way up... I usually find this way I have about 150mph at the top, which must be handled delicately because of the high power, and I can make a nice loop.

I'll be interested to hear from Dudley how it should really be done!

Joe

[wothan]

It´s very important that Your fuselage tank is empty in order to do any aerobatic like maneuvres.

FinnJ

[Musicman]

I can do the loop pretty easy. Besides just keeping the speed up I point the nose up in a 45 degree for a second then go up to 90 degree vertical at full throttle and pull back hard as you're vertical. Sorta like a slow motion loop not forcing the plane. Come back out with nose down vertical speed will increase quickly and you can even go right back into another loop. Works for me. Don't know if it's correct or not.

[VulcanB2]

260 MPH is too slow for loop entry. You want at least 300 MPH (dive if necessary), and pull at least 4 g initially on entry, aiming to be at 1 g at the top of the loop (inverted) to get a round loop, otherwise you end up with a squashed loop if you try and maintain 4 g throughout.

Best regards,
Robin.

[Roadburner426]

Definately need more than 260mph to do it. Today I was doing them from about 14,000ft. Would get my speed up to about the beginning part of the yellow (somewhere over 300mph), and then I would nose up eventually pulling through the top somewhere below 200mph. I wound up a little slow at the top, but I recommend 3000RPM at your highest power setting for these. I too am interested to hear from Dudley how it is really supposed to be done.

[trucker17]

some stunts are almost impossible to do with a heavy fighter.....The p-51D falls into this catagory....I personally only know 3 pilots who can pull a Hammerhead with the mustang.....Mind you this is a non cliped wing mustang, and in full fighter configeration...Stunts like the hammerhead have resulted in the wings being torn off the plane while trying to execute......
I have executed the loop, with a dive to 325 slowing to just above stall at the top of the loop.....
But it can be done...Keep practicing you'll get the right method for you....

[renaissanceman]

Thanks everyone for your input!

I do have the fuselage tank either empty or with less than 20 gal.

The 260 MPH came from a Stallion51 video. The instructor pilot had the pilot enter the loop at that speed. It's possible this was knots, that would be 299 MPH - I did not think of that until just now!

It also sounds like I am just not pulling enough Gs. I'll try the 300 MPH and pull until I start to black out.

[seaniam81]

Lets not forget that FSX will fight you on anything other strait and level.

[VulcanB2]

I suggest you disable the g effects - it is wholly unrealistic.

Best regards,
Robin.

[CAPFlyer]

Just did one earlier in pretty hot weather starting the loop doing ~260 mph with no probs. Just kept a smooth pull all the way through and kept plenty of energy. The trick in fighters to do a loop is that you keep constant G to the top, meaning you will pull harder as you loose airspeed. Many forget to do this and that is why they run out of speed.

[DHenriques_]

OK, I don't have much stick time in the P-51. Having said that, I still should be able to fumble my way through a loop. So far I have not been able to. Here is my technique:

Altitude about 20,000'
MP to 45"
RPM to 2600
Shallow dive until I reach 260 MPH
Pull up trying to keep both the wingtips on the horizon and the bubble centered
MP to 55" as I go vertical
As the nose goes over the top I run out of airspeed and fall off into a spin, usually to the left

I have tried this at various speed and MP settings including war emergency power breaking the wire.

I know I should be looking for 4 Gs on the pull up but I seem to be so busy watching everything else that I don't look at the G meter. I don't see this as a problem with the flight model, just a problem with my handling of the aircraft. I am able to loop the Spit and the P-47, I'm not sure I have tried with the P-40.

I'd appreciate any advise from the experts out there. Thanks.

Jim

In the real Mustang your entry speed is predicated on your gross weight and the density altitude. Then the entry speed is coupled with a g profile to produce a good loop. Keep in mind a good round loop and an airshow display loop look a bit different when each are performed correctly.
With a display loop you play the front side for extra height instead of trying to make it a perfect circle.
You always go for altitude at the top of a display loop with the minimum being your established minimum recovery gate inverted at the top.
We have a saying in the business; "When doing vertical maneuvers where you end up impacting the ground, you actually do your dying not at impact but at the top where you blew your gate too low or went through it too fast!
Back to the 51 loop; I liked around 300mph and 4'gs to get a good loop out of the Mustang. You can leave the power set at 46/2700 generally. You can do them a bit slower depending on temperature but 300 is a good all around number.
On g, look for 4 and NO MORE on the front side. Too much g means too much drag and you don't want to pull yourself into drag rise. Take it easy and let the airplane do the work.
Reference your left wingtip for positioning during the initial 100 degrees going around. Keep the wingtip on the horizon with rudder.
What's important to understand about a prop fighter like a Mustang is that as your airspeed bleeds going up the front side the left side forces have to be dealt with. As the prop rotates in pitch you will have gyroscopic precession as a yaw correction. As the prop develops an angle with the relative wind you will have P factor, also a correction in yaw. You will be carrying power and that means spiraling slipstream effect which will also be felt as a yaw correction. These all mean right rudder to center the ball.
There is something else and a lot of pilots miss this when doing verticals in prop fighters. Torque is a ROLL correction. So what you'll be doing to get a decent loop in the 51 is carrying whatever the airplane is telling you it wants in the way of right rudder and right aileron through the first 180 degrees.
VERY IMPORTANT; Ease OFF the g nearing inverted. You can easily get into accelerated stall in a 51 going through the top inverted by not easing off the g. That 4's you WERE carrying on the way up if not eased off as your airspeed bleeds down to around 150mph will stall the wing and can torque roll the airplane off the top.
Just takes practice.
Good luck.
Dudley Henriques

[renaissanceman]

Thanks Dudley and Cap.

We all appreciate Dudley's detailed explanations and insights.

I managed to pull off 2 loops last night:

20,000'
55"
300 MPH entry speed
Full wing tanks and less than 20 gal in fuselage tank.

I pulled smoothly to 4 Gs and noticed I started to buffet at 150 MPH going over the top. I eased the back pressure and she came over still flying. Good call Dudley on the accelerated stall as airspeed is lost! The loops were not pretty but I can work on that.

Thanks again to all!

Jim

[DHenriques_]

Thanks Dudley and Cap.

We all appreciate Dudley's detailed explanations and insights.

I managed to pull off 2 loops last night:

20,000'
55"
300 MPH entry speed
Full wing tanks and less than 20 gal in fuselage tank.

I pulled smoothly to 4 Gs and noticed I started to buffet at 150 MPH going over the top. I eased the back pressure and she came over still flying. Good call Dudley on the accelerated stall as airspeed is lost! The loops were not pretty but I can work on that.

Thanks again to all!

Jim

One of the really fascinating things about having Accusim with you when you fly the A2A aircraft is that every flight can be a learning experience......just like the real thing!
Best of luck with your flights.
Dudley Henriques

[tf51d]

Thanks everyone for your input!

I do have the fuselage tank either empty or with less than 20 gal.

The 260 MPH came from a Stallion51 video. The instructor pilot had the pilot enter the loop at that speed. It's possible this was knots, that would be 299 MPH - I did not think of that until just now!

It also sounds like I am just not pulling enough Gs. I'll try the 300 MPH and pull until I start to black out.

That video may have been mine, and it was knots. Unlike the WWII era 51's (and A2A's models) which speed gauge is in MPH, The ones still flying today in many cases are set in knots. As for flying the loop you need 260kts and in the real Mustang you do pull pretty hard on the stick. ease off a little on the downside, then pull hard again to complete the loop. In FSX though how hard you pull is dependent on your joystick. On mine if I pull back all the way I'll end up in an accelerated stall. If though I just pull till I feel resistance, I can loop pretty easily. Below is the video of my real flight on Crazy Horse performing a loop, as well as other maneuvers

http://www.youtube.com/watch?v=xpaGwxdvs74

If you are interested in all 3 parts of it, click the link to the playlist in my sig!