F-86 Roll Response

[Igor4U]

The F-86 Sabre doesn't seem to roll cleanly around the longitudinal axis (across the speed envelope). Watching from Chase View - I get a noticeable sloppy Wobble. Even when unloading below 1G, I get a lot of adverse yaw requiring a good amount of same direction Rudder. The Roll Rate isn't bad - but I was expecting a little more crispness and responsiveness.

 

This adverse Yaw Moment that is coupled with commanded Roll may be another reason for the Spin behavior noted below:

 

F-86 Stall/Spin behaviour doesn't seem correct.

http://forums.eagle.ru/showthread.php?t=129558

 

 

I don't know how close our Flight Model is to the real Sabre; but it'd be interesting to get a F-86 Veteran to comment.

[Soulres]

From what the old training videos, if your too rough with with youll get Flutter(think it was called somethin else) they also said you almost should never use the rudder while in flight as it will create additional flutter. since its a older plane dont expect crisp flight lol.

 

thats the challnge of older Planes vs Newer.back in the day you had to do it yourself,now adays your programming a computer to do it. thats why ED having older FMs is a great concept.

[Igor4U]

Roll Rate 120 Degrees/Sec (?)

 

Just finished a little flight testing. I have a couple F-86s in another Flight Sim and wanted to compare their performance against the Belsimtek F-86 (for DCS World). Here's what I noticed:

 

- Acceleration (at 5,000 ft MSL Standard Day 300 to 500 KIAS): Approx 60 seconds for a Clean F-86 (DCS World). Other F-86s about 90 seconds (but they had external fuel tanks). So all-in-all: all models fairly close in performance.

 

- Roll Rate (at 400 KIAS): Here the results were quite different. The DCS World Beta F-86 has a roll rate approximately 120 Degrees / Sec. That is significantly slower that my other F-86s who are closer to 360 Degrees pes Sec. I have no idea which roll performance results are most realistic (only that they differ quite a bit).

 

Again - wish we could get some input from anyone who has had hands on a Sabre Jet and see how our F-86 stacks up to reality. Heck - Belsimtek would probably give em (a few Korean War F-86 Jocks) a free copy of the F-86 for Test & Evaluation and Feedback !

[Wolf_ofthe_North]

I have heard anecdotally that the F-Series roll rate was around 180 degrees/sec.

[mjmorrow]

Someone correct me if I am wrong, but is not the optimal roll rate for the Sabre achievable at or close to the best climb speed for any given altitude? So, for example, assuming a best climb speed schedule for a clean Sabre, the best roll rate will be obtained at sea level (@Mach .69), 5000 feet (@Mach .71), 10, 000 feet (@Mach .72), 15, 000 feet (@Mach .73), 20, 000 feet (@Mach .74), 25, 000 feet (@Mach .75), 30, 000 feet (@Mach .77), 35, 000 feet (@Mach .79), 40, 000 feet (@Mach .81), 45, 000 feet (@Mach .82), ceiling (@Mach .82).

 

P.S. If my climb schedule is in error, I apologize. It is based on my memory. I don't have my copy of the F-86f flight manual on me and I only saw the schedule once. Oh, btw, the Mach numbers are true Mach numbers.

Edited September 12, 2014 by mjmorrow