Hey guys... 1st thing, my last post, silly me, I copied numbers for CL, not images, from the wrong fields of the data sets, ‘my bad’; corrections below... Way below.
paul.kachurak in the beginning of this I thought as you... I built a safety margin that seemed to be reasonable, & actually concluded as you, that 6 Gs should about do it, also concluding that even if the aircraft is rated to 7.5 – 8 Gs this had to be sufficient; then I stumbled upon my 1st flight manual and out the window went my comparison table version 1. I was reminded that the aircraft had a negative G rating of -4 G. When we (I) applied our safety margin we right off the bat exceeded by -2 Gs the airframe’s capability.
Things grew from here, as I acquired more data I stared reading that the aircraft’s loading effected what the aircraft can do, for example the 51’s manual advises the following (my synopsis): With the fuselage tank at 40 gallons or more CG moves so far back that it is next to impossible to trim the aircraft for hands off level flight, also, & more importantly, as soon as you enter a tight turn (no actual definition of ‘tight’ given) or attempt a pull out, stick forces reverse. The same thing happens in a dive, the manual goes on. These factors do not lie within your (our) ‘reasonable’ conclusion that applying an under G rating to the ‘turn rate figures’ provides a sufficient margin of error to provide an accurate envelope of our targeted aircraft. There are also bank angles, power-plant anomalies, induced drag (not from the airfoil) and ‘prop thrust’ factors that are involved, that the G force safety margin can not even begin to address...
I also use an excel spread sheet, designed by Jerry Beckwith. It was designed to build ‘1% flight models’ for Microsoft Flight Simulators, the version I use is accurate to CFS-2 / FS-2000 flight envelope programming. The spread sheet has an NACA airfoil database ‘engine’ built into its macros, & I rely a great deal on this engine, as it can ‘extrapolate’ for me, as I’ve got to admit, after some four years I still don’t fully understand all of the math, but I’m still ‘learning’, cool stuff... As the output of the sheet is an ‘air file’ I use my MS Access pivot table to ‘re-bias’ and my own Excel sheet to convert to ‘normal’ units of measure, so I understand both the desire to send, & the need to explain your data sheet, I only wish I had the time to do something with it. I would like you to send it to me, if you’d like, as I know someday I’ll remember, & look it up. This is how I am, not at all to be misunderstood as neglect, think of it as passion, only anally focused to one thing at a time; for example with most of my free time now I’m back to paying attention to things of interest at
www.ww2aircraft.net, not flying my sim, or modifying one of it’s aircraft models, or damage profiles, another ‘hobbie’ requiring mega-time, or re-painting them, mega mega time.
So that you (all) may understand me a bit better, we have data differences, but that is not my point at all, what I’m trying to display is not my version of the numbers, but some of the figures used to determine ‘turn rates’ as insight to my thoughts on building them, as it would be quite silly to explain either Jerry’s or my spread sheets, I’m ashamed to admit I understand this stuff, to most, much less express it... again. I'll find the posting if your intrested.
FW190D-9
CL = 1.5794 @ 20.10 degrees (my reference weight = Empty Weight}
Empty Weight (No Fuel Or Ammo): 8605 Lbs
Combat Weight (Full Fuel & Ammo, Clean): 9822 Lbs
Max Weight: 10670 Lbs
Wing Span: 34 ft 5.5 In
Root Airfoil: NACA 23015
Tip Airfoil: NACA 23009
Root/Tip Area Ratio: 66%
Wing Twist (Washout): -1 Degree
Aspect Ratio: 5.98
Wing Dihedral: 5 Degrees
Wing Area: 197 Sq Ft
Wing Stall Speed: 145.47 Ft Per Sec (Aircraft Stall = 99.18 MPH)
Tail Surface: 31.6 Sq Ft
Tail Span: 151.97 inches
Tail Distance (CG): 20.832 Ft
P-51D30
CL = 1.4794 @ 19.95 degrees (my reference weight = Empty Weight}
Empty Weight (No Fuel Or Ammo): 7959 Lbs
Combat Weight (Full Fuel & Ammo, Clean): 9600 Lbs
Max Weight: 11400 Lbs
Root Airfoil: NACA 63-415
Tip Airfoil: NACA 65-215
Root/Tip Area Ratio: 66%
Aspect Ratio: 5.77
Wing Dihedral: 5 Degrees
Wing Area: 235.8 Sq Ft
Wing Stall Speed: 132.01 Ft Per Sec (Aircraft Stall = 90.01 MPH)
Wing Twist (Washout): -1.25 Degrees
Tail Surface: 41 Sq Ft
Tail Span: 158 inches
Tail Distance (CG): 15.9 Ft CG
…bored yet? K. On to other things…
This cruising speed thing will be resolved with the images provided below. My comment on some of your postings, with regard to sustained cruse speeds in the 400 MPH range is LOL. Realize that here the table shows a ‘clean’ aircraft with wing racks & a bit of numerical theory; as for example, you can not operate a P-51 above 300 MPH @ 30,000 Ft, as for the wing tanks, attached to the ’51 until the last minute, due to the mass of internal gas, & the need to burn it off 1st, who of you believe they were designed to say attached at those speeds? The gentleman, who posted the table he posted as evidence, did not post the whole story. I won’t post that table again, just the following; See Images below…
Glad to have had this exchange with you!
Linear Mode
