Author Topic: Looking for Spitfire I sustained turn rate charts  (Read 1646 times)

Offline Vulcan

  • Plutonium Member
  • *******
  • Posts: 9911
Looking for Spitfire I sustained turn rate charts
« on: October 16, 2004, 06:09:32 PM »
Any help appreciated. cheers.

Offline Wotan

  • Platinum Member
  • ******
  • Posts: 7201
Looking for Spitfire I sustained turn rate charts
« Reply #1 on: October 16, 2004, 07:13:02 PM »
wwiiol issue? :p

Offline Angus

  • Plutonium Member
  • *******
  • Posts: 10057
Looking for Spitfire I sustained turn rate charts
« Reply #2 on: October 17, 2004, 09:50:18 AM »
18 seconds?
It was very interesting to carry out the flight trials at Rechlin with the Spitfire and the Hurricane. Both types are very simple to fly compared to our aircraft, and childishly easy to take-off and land. (Werner Mölders)

Offline Vulcan

  • Plutonium Member
  • *******
  • Posts: 9911
Looking for Spitfire I sustained turn rate charts
« Reply #3 on: October 17, 2004, 07:56:02 PM »
Spit I sustains a 4G turn @ 240mph, 1000ft alt. You think thats right. (No speed or alt loss).

Offline HoHun

  • Gold Member
  • *****
  • Posts: 2182
Looking for Spitfire I sustained turn rate charts
« Reply #4 on: October 18, 2004, 04:10:55 PM »
Hi Vulcan,

>Spit I sustains a 4G turn @ 240mph, 1000ft alt. You think thats right. (No speed or alt loss).

It might be correct, but it's not the quickest turn.

According to my analysis, the quickest turn should be:

Spitfire I (+12 lbs/sqin, 2745 kg) @ 300 m:

- 3.7 G
- 281 km/h TAS
- 26.0 °/s

(Your data gives about 20 °/s, which seems too slow for a Spitfire.)

For comparison:

P-40E (44" Hg, 3911 kg) @ 300 m:

- 2.4 G
- 251 km/h TAS
- 17.6 °/s

Me 109E (1.30 ata, 2610 kg) @ 300 m:

- 2.9 G
- 260 km/h TAS
- 21.4 °/s

Regards,

Henning (HoHun)

Offline Angus

  • Plutonium Member
  • *******
  • Posts: 10057
Looking for Spitfire I sustained turn rate charts
« Reply #5 on: October 18, 2004, 04:22:22 PM »
Whooola...nice numbers....very very nice.
Now, two questions for HoHun:

1. Do you also have similar figures for other planetypes?

2. How about a formula to calculate this into seconds for 360 degrees.


BTW, I remember I started a thread like this ages ago, think it was called turn rate and G calculations or something in the direction....Will look.
It was very interesting to carry out the flight trials at Rechlin with the Spitfire and the Hurricane. Both types are very simple to fly compared to our aircraft, and childishly easy to take-off and land. (Werner Mölders)

Offline Meyer

  • Copper Member
  • **
  • Posts: 156
Looking for Spitfire I sustained turn rate charts
« Reply #6 on: October 18, 2004, 04:32:39 PM »
Quote
Originally posted by Angus

2. How about a formula to calculate this into seconds for 360 degrees.


     



That's easy, just: 360/angular speed.

For example, for the 109E 360/21.4 °/s = 16.8s :)


@Hohun: Thx for the numbers, those are coming from tests or they are your calculations?

Offline HoHun

  • Gold Member
  • *****
  • Posts: 2182
Looking for Spitfire I sustained turn rate charts
« Reply #7 on: October 18, 2004, 05:12:04 PM »
Hi Angus,

>1. Do you also have similar figures for other planetypes?

Since they require a very detailed analysis, I have them only for these three types with the degree of reliability I consider good enough for posting them :-)

I've run a detailed analysis on the P-40E and the Me 109E, and fortunately, the Spitfire is well documented so it was easy to add.

>2. How about a formula to calculate this into seconds for 360 degrees.

Just divide 360° by the turn rate to get the seconds for a full circle.

Regards,

Henning (HoHun)

Offline HoHun

  • Gold Member
  • *****
  • Posts: 2182
Looking for Spitfire I sustained turn rate charts
« Reply #8 on: October 18, 2004, 05:18:36 PM »
Hi Meyer,

>@Hohun: Thx for the numbers, those are coming from tests or they are your calculations?

These are my calculations, based on tests of the maximum lift coefficients of the three aircraft, a somewhat generic wing model, and the applicable engine powers. I've cross-checked my model pretty thoroughly, and it seems to provide fairly accurate numbers as far as I can tell.

Regards,

Henning (HoHun)

Offline HoHun

  • Gold Member
  • *****
  • Posts: 2182
Looking for Spitfire I sustained turn rate charts
« Reply #9 on: October 18, 2004, 05:33:24 PM »
Hi again,

Here's my Me 109E/Spitfire I comparison.

Note that there are 3 different Emil variants in the picture, and at different power settings.

- DB601A-1 (4.0 km) - early DB601A-1 with low full throttle height
- DB601A-1 (4.5 km) - late DB601A-1 with higher full throttle height, available for the Battle of Britain
- DB601N - 100 octane engine probably introduced while the Battle of Britain was fought. High altitude power looks like it fades too slowly, but there are several sets of engine curves showing that kind of power so I left it that way (for now).

The Spitfire I has two boost settings:

- +6.25 lbs/sqin - maximum using 87 octane fuel, up to mid-1940
- +12 lbs/sqin - cleared mid-1940, avaiable for the Battle of Britain

http://www.x-plane.org/users/hohun/spit_vs_me109_speed.gif

http://www.x-plane.org/users/hohun/me109e_vs_spitfirei_climb.jpg

Regards,

Henning (HoHun)

Offline Angus

  • Plutonium Member
  • *******
  • Posts: 10057
Looking for Spitfire I sustained turn rate charts
« Reply #10 on: October 18, 2004, 06:22:00 PM »
Lovely, lovely.
I did once a Spit I and 109E climb calculations, - i.e. climb converted to NM and NM divided with time.
If I haven't already, I'll mail it to you.
Want it?
It was very interesting to carry out the flight trials at Rechlin with the Spitfire and the Hurricane. Both types are very simple to fly compared to our aircraft, and childishly easy to take-off and land. (Werner Mölders)

Offline Vulcan

  • Plutonium Member
  • *******
  • Posts: 9911
Looking for Spitfire I sustained turn rate charts
« Reply #11 on: October 19, 2004, 12:21:13 AM »
Errr Hohun the question isn't the quickest turn... the problem is if you take a Spit I to 1000feet, get it to 240mph, put it into a 4G turn, it does not lose any speed, nor altitude, and can do so til its gas runs out.

Offline HoHun

  • Gold Member
  • *****
  • Posts: 2182
Looking for Spitfire I sustained turn rate charts
« Reply #12 on: October 19, 2004, 12:51:43 AM »
Hi Vulcan,

>Errr Hohun the question isn't the quickest turn... the problem is if you take a Spit I to 1000feet, get it to 240mph, put it into a 4G turn, it does not lose any speed, nor altitude, and can do so til its gas runs out.

Well, here's my answer: Impossible.

Spitfire I (+12 lbs/sqin, 2747 kg) @ 300 m:

- 4 G
- 386 km/h TAS
- 20.3 °/s
- -4.0 m/s

It should lose altitue at 4 m/s (ca. 800 fpm) in that turn.

Regards,

Henning (HoHun)

Offline F4UDOA

  • Silver Member
  • ****
  • Posts: 1731
      • http://mywebpages.comcast.net/markw4/index.html
Looking for Spitfire I sustained turn rate charts
« Reply #13 on: October 19, 2004, 08:06:00 AM »
HoHun,

Hate to be a best but could you show the calculation you preformed to get your results??

How do you know where to find the best sustained turn based on Clmax and engine power at alt?

There should be a simple ratio to come up with a turning "index" like Clmax / wingloading * powerloading. Of course that makes no sense but you get the idea.

Offline straffo

  • Persona Non Grata
  • Plutonium Member
  • *******
  • Posts: 10029
Looking for Spitfire I sustained turn rate charts
« Reply #14 on: October 19, 2004, 08:50:40 AM »
Vulcan I suppose your inquiry come from this thread

Please point dochk and warpd to this article :

http://www.simhq.com/_air/air_011a.html