Author Topic: Glide performance of AH fighters (Read 1862 times)

beet1e · « **on:** January 25, 2002, 03:17:08 AM »

I read this board from time to time, and notice posts concerning flight performance of various planes such as rudder drag, but this is piffling stuff compared to some glaring misrepresentations of various flight characteristics.

Am I alone in shaking my head in disbelief at the glide performance of the fighters? I was recently piloting a Spitfire 9, and attacked a B26. I escaped under the belly of the B26, but my radiator was pinged out and my engine quit shortly afterwards. (Stupid for water cooling to be used in fighter aircraft!) I have no idea about the best glide speed for the Spitfire 9, so I trimmed out at about 120-130mph. Well, just as in Warbirds, the glide performance of fighters is ridiculously overmodelled! I was able to glide all the way back to home base, which took about 10-15 minutes! I don’t recall the altitude at the start of that glide, but it wasn’t huge. Assuming still wind conditions, that’s at least 20 miles!!! I don’t have any figures for the wing loading factor of a Spitfire 9, but I do know from my RL flying days that no way could such a glide be possible in real life. In a 22 metre open class sailplane, maybe. But in a high performance plane with high wing loading and low aspect wings? No way.

DarkglamJG52 · « **Reply #1 on:** January 25, 2002, 04:12:48 AM »

AH Spit IX? You can go too the moon and back.

funkedup · « **Reply #2 on:** January 25, 2002, 04:57:42 AM »

I've got it in my head that P-51 had a glide ratio of 10:1. I can't remember where I read it though. Anybody have any sources?

PS Aircraft and Vehicles forum is a better place to post this question. There are some pretty smart guys who frequent that forum but never read this one.

Fariz · « **Reply #3 on:** January 25, 2002, 04:57:44 AM »

Try to get to the same altitude and just switch engine off. You will glide twice shorter.

For some reason in some cases when your engine dies you can glide forever. I think it is bug?

Fariz

Maniac · « **Reply #4 on:** January 25, 2002, 05:25:24 AM »

Yes you really can glide forever in AH.... i dont know anything about aerodynamics and such but could this be an E-retention problem?

CJ · « **Reply #5 on:** January 25, 2002, 07:00:47 AM »

Heres what I came up with for the Spit 9. I used 50% fuel, and set my airspeed to 170 on auto.. shut the engine off, reduced the prop RPM fully, and waited for it to stabilize. TAS was a little higher than 170, and the speed worked out to 249 ft/sec. The vertical speed was around -1700 fpm, which worked out to 28.333 ft/sec. L/D, which is the same as glide ratio = 249/28 = 8.89:1.

This seems pretty reasonable to me.

At 140 MPH I got closer to 10:1.

That seems pretty good, but my dad's M20E got around 13 with gear and flaps up, and even a cessna 182 can get around 11, so I don't see why a clean fighter like a Spitfire couldn't get similar glide ratios. The 182 has its gear hanging out.

Maybe what happened is that when your engines got shot out, you were going 300 MPH or something. This isn't a fair test. Get it stabilized in a descent with the autopilot on speed, and determine how fast it's moving vs how fast its falling.

CJ · « **Reply #6 on:** January 25, 2002, 07:09:14 AM »

Just ran a glide test at 150 in the P-38, and got 12.8 to one. rate of descent was about 1100 fpm. This was 50% fuel. Did the P-38 have a higher L/D than the spitfire? I'd imagine so because of the higher aspect ratio wings, and the fully feathering prop. Those two things alone would make a decent difference. I wonder if anyone else already ran these tests. I seem to remember something.

Ripsnort · « **Reply #7 on:** January 25, 2002, 07:43:18 AM »

Try out the glide performance in the Typhoon or the F4U.

Can you say "Lead Balloon" ?

popeye · « **Reply #8 on:** January 25, 2002, 08:53:53 AM »

So, why do AH planes glide so much better with a dead engine, than with the engine shut down? Or is that just my imagination?

Tac · « **Reply #9 on:** January 25, 2002, 09:15:02 AM »

The props stop, no drag from props. thus u glide longer.

Mitsu · « **Reply #10 on:** January 25, 2002, 09:41:13 AM »

Good Gliders:
Ta-152
Ki-61
La-7

Pyro · « **Reply #11 on:** January 25, 2002, 09:42:37 AM »

Try the P-51 at 175 IAS. The P-51 manual gives a glide of approximately 14.5 statute miles for every 5000 feet of altitude with no wind. That's a ratio of 15.3:1. From 35000 feet, you should be able to glide 100 miles(each sector is 25 miles across). I think you're more likely to find that AH planes tend to not glide well enough rather than glide too well.

Mitsu · « **Reply #12 on:** January 25, 2002, 10:03:45 AM »

Great Info Pyro!
I will try it in other planes...

-Mitsu

MANDOBLE · « **Reply #13 on:** January 25, 2002, 10:06:00 AM »

I'm waiting for Wulfe, Leph, ammo and some others to storm here calling you whinners, painting your experiences of "anecdotal" colour and asking you for videos and controled tests

Cmon Leph, where are your comments??

Back to the topic, in my experience, some planes glide forever while some others go down like stones (109).

AKSWulfe · « **Reply #14 on:** January 25, 2002, 10:09:41 AM »

Mandoble you maroon, I never called you a whiner.

As far as this thread is concerned, some evidence is required. Saying "but this plane glides forver while mine can't!" is ludicrous. All planes are aerodynamically different. Some have very smooth lines, while others have lots of drag.

Mandoble, data is required- whether you like it or not.
-SW