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View Full Version : A tech question to F6F "Hellcat" experts...



Art-J
02-26-2008, 12:19 PM
Hello Gentlemen.

Fellow virtual flyer, a student, preparing a kind of "homework" for his flight mechanics lectures, asks You for help (especially guys who are in love with "Hellcat" and think they know everything about it http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif). My questions are:

a) what was the maximum cross section area of F6F's fuselage?

b) what was the position of the airframe's centre of gravity (as a percentage of mean aerodynamic chord or using any reference point You want)?

I'm going to need these for estimating a lift and drag coefficient of the fuselage and stabilizers. I may use simplified values, of course, but one always has to search for perfection http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif...

... until books in home-library and almighty Google fail to give the precise answer. Then it's time to ask someone who might know better.

Thanks in advance!

Cheers - Art

Art-J
02-26-2008, 12:19 PM
Hello Gentlemen.

Fellow virtual flyer, a student, preparing a kind of "homework" for his flight mechanics lectures, asks You for help (especially guys who are in love with "Hellcat" and think they know everything about it http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif). My questions are:

a) what was the maximum cross section area of F6F's fuselage?

b) what was the position of the airframe's centre of gravity (as a percentage of mean aerodynamic chord or using any reference point You want)?

I'm going to need these for estimating a lift and drag coefficient of the fuselage and stabilizers. I may use simplified values, of course, but one always has to search for perfection http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif...

... until books in home-library and almighty Google fail to give the precise answer. Then it's time to ask someone who might know better.

Thanks in advance!

Cheers - Art

KIMURA
02-26-2008, 01:18 PM
Either the engine-bulkhead or the armored bulkhead behind the cockpit is the largest one(section A-A or B-B). To point out witch one is really larger you have to import that to a CAD progi and measure the areas.

To the CoG I have to stuff.

http://img220.imageshack.us/img220/2388/f6fta9.jpg

JtD
02-26-2008, 10:30 PM
Hi,

I recommend you check this (http://www.wwiiaircraftperformance.org/f6f/f6f.html) site out. Among a lot of thing, it gives you the info on the CoG.

Art-J
02-27-2008, 09:05 AM
I guess I'd choose the bulkhead section, because this way I won't have to add windshield to the final equation... Unless engine section is really bigger. I like the fact that both of these cross-sections can be roughly modeled as two semi-circles connected by trapezoid - that's enough to estimate the area from the scaled drawings.

I'll check the site recommended by JtD as well, looks like there's lots of useful data there! I'll surely use it now and in the future - as a reference for my next homework projects (engine/propeller characteristics, aircraft performance and similar stuff...)

Thanks for the tips, guys.

Cheers - Art

BSS_Sniper
02-28-2008, 11:46 AM
I was just reviewing %MAC for my ATP. I'll see if I can find some info on that. Without having complete aircraft info though, it may be hard to find.

Since %MAC changes with different loadings I'm assuming you want an empty weight %MAC or more than likely LEMAC?

Art-J
02-28-2008, 01:53 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by BSS_Sniper:
I was just reviewing %MAC for my ATP. I'll see if I can find some info on that. Without having complete aircraft info though, it may be hard to find.

Since %MAC changes with different loadings I'm assuming you want an empty weight %MAC or more than likely LEMAC? </div></BLOCKQUOTE>

Thanks BSS, no need to do that anymore. I've made a quick search though a few documents about Hellcat that can be found on the site recommended by Jtd and they indeed do give CoG positions with gear up/down, although they do not always precisely describe loading conditions. That's OK though, differences between given figures in wheels-up config are small and my calculations will be somewhat simplified anyway.

Cheers - Art