Author Topic: Spit 14 turning circle (Read 3504 times)

MiloMorai · « **Reply #60 on:** December 21, 2007, 09:02:37 AM »

Question

If 2 different planes are the same speed and at the same angle of bank, will the turn radius be the same.

Krusty · « **Reply #61 on:** December 21, 2007, 09:18:15 AM »

You mean spits or any?

If "any" then no. That would totally negate differences in wings.

Karnak · « **Reply #62 on:** December 21, 2007, 11:22:40 AM »

Weight will also cause the radius to be different.

dtango · « **Reply #63 on:** December 21, 2007, 12:36:53 PM »

Quote

Originally posted by MiloMorai
Question

If 2 different planes are the same speed and at the same angle of bank, will the turn radius be the same.

Technically yes. Here's another form of the turn radius equation:

Radius = V^2 / gravity * tan(b) ---- where (b) is the bank angle

This equation masks how V and bank angle are limited by the dynamics (e.g. cl/cd, thrust, weight, etc. etc.) because maximum V and bank angle in a level turn are all dependent on a bunch of factors.

Tango, XO
412th FS Braunco Mustangs

gripen · « **Reply #64 on:** December 21, 2007, 01:30:52 PM »

Quote

Originally posted by MiloMorai
If 2 different planes are the same speed and at the same angle of bank, will the turn radius be the same.

Yes, assuming that the altitude is keeped constant and the turn conducted "ball in the middle. But that is pointless; the plane with better turning performance can maintain higher angle of the bank at this speed and therefore turns better.

Angus · « **Reply #65 on:** December 23, 2007, 11:59:09 AM »

More available power with absolutely same weight and airframe will give the availability to tighten a turn.
Now, what the debate is about is whether the increased weight of the Spit XIV is matched with the increased power.
Since the ROC is up with the power, it means that the total lift is more, however the weight starts sagging in when the wing area "reduces" in a banking situation,- there the increased wingloading kicks in (relatively).
Anyway, the test pilots say that there is nothing to choose from. And that was after all, - a test. So I'd put my pennies on that there was not much difference.
About the 109F, - I really thought it was exactly what Krusty said. Rounded tips outside the boxed form. So?

Angus · « **Reply #66 on:** December 23, 2007, 07:27:01 PM »

My first book on the 109 Gives me a 109F with EXTENDED wings due to the rounded tips. On the 109E-7 I have a span of 9.86 (32-4).

Viking · « **Reply #67 on:** December 24, 2007, 11:51:04 AM »

We should get one of the 109 experts in here (if anyone's left). I got chewed out because I claimed the F had bigger wings, but was forced to concede.

Widewing · « **Reply #68 on:** December 24, 2007, 12:44:57 PM »

Quote

Originally posted by Viking
We should get one of the 109 experts in here (if anyone's left). I got chewed out because I claimed the F had bigger wings, but was forced to concede.

No expert here, but I see that the 109F had a span of 9.92 meters, vs 9.86 meters for the 109E... Not much, but certainly different.

My thought was that the 109F had a substantially redesigned wing.

My regards,

Widewing

dtango · « **Reply #69 on:** December 24, 2007, 01:26:54 PM »

Hmm let's see. Two 109 experts I know of are gripen and butch2k.

Tango, XO
412th FS Braunco Mustangs

Angus · « **Reply #70 on:** December 25, 2007, 02:36:13 PM »

Hehe, Izzy had some data on the 109

Anyway, this is data-data. Must be in the books.
BTW, was paging through some and found errors without even looking up (obvious ones). By getting some more books for christmas, I have more data, so I'm still looking though.
One line claimed the 109F had a redisigned and smaller wing.

Angus · « **Reply #71 on:** December 26, 2007, 03:36:55 PM »

Oh, getting back on the topic of the Spit XIV vs the IX, bear in mind that the XIV's power overcomes the weight in terms of ROC.
Now in the case of 109's, this was the case with turn performance however yet getting worse.
The difference between those two however are mostly wing loading and span, where the Spitty is bigger. Now a turn AFAIK relies a bit on those both, - clip a glider's wings and in a given degrees of banks the shorter or the heavier will stall before.
Then there is the enormous power increase.

Charge · « **Reply #72 on:** December 28, 2007, 08:20:01 AM »

"Oh, getting back on the topic of the Spit XIV vs the IX, bear in mind that the XIV's power overcomes the weight in terms of ROC."

Bear in mind? I have a beaver, does it count?

I think that even if there is more weight but there is more power it is possible to stay in the turn with a lighter plane, you just need to pull some more on the stick. If the best turn is achieved near the max permissible AoA you might run into problems because of excessive drag starting to negate the extra power you have and impeding stall dictated by wing design. So the point is: do you have enough excess power to overcome the drag caused by more AoA which is caused by the need to turn the more weight as tightly as less weight?

On practical level it may well be that XIV could just fly a bit bigger circle with better rate and wait for the IX to fall in a stall trying to gain lead for a shot flying a smaller circle.

I'd trade turning circle to RoC any day.

"Now in the case of 109's, this was the case with turn performance however yet getting worse."

Could you explain what you mean by this?

-C+

Angus · « **Reply #73 on:** December 28, 2007, 09:35:28 AM »

ROC has some relation with turning circle.
And the AoA is a bit twisted with almost vertical wings. Not sure which come out better there, span or chord. But wingloading definately counts.
Beer that in mind