Corsair vs. BF 109G,K or FW 190's

[AL Schlageter]

Originally Posted by FLYBOYJ

Just a note; I remember reading somewhere that there were late model P-51Bs and Cs (Dallas Built) that had a field conversion where the bubble canopy (Not a Malcolm Hood) was installed in the field basically making them "Ds." If I remember correctly these aircraft along with the first production "Ds" did not have the dorsal fin just in front of the vertical stabilizer. T.O. 01-60J-18 installed the dorsal fin.

That would be some field conversion.

[drgondog]

Originally Posted by FLYBOYJ

Just a note; I remember reading somewhere that there were late model P-51Bs and Cs (Dallas Built) that had a field conversion where the bubble canopy (Not a Malcolm Hood) was installed in the field basically making them "Ds." If I remember correctly these aircraft along with the first production "Ds" did not have the dorsal fin just in front of the vertical stabilizer. T.O. 01-60J-18 installed the dorsal fin.

The very first two (and only)P-51D-1s were 42-106539 and 106540 - both P-51B-10s from California. Both kept the 51B wing intact whereas the subsequent P-51D-5 had neither the 'dorsal' nor the beefed up tail but did the 'more angled leading edge' and upright guns. Both went to Eglin for testing for duration of war.

None of the -5's had the dorsal, but the dorsal modification, production uplocks and beefed up tail marked the break in dash number from -5 to -10.

Joe - I am not aware of a depot/Service Group level mod converting B/D to D's - do you have a notion where I could learn more about such?

[FLYBOYJ]

Originally Posted by drgondog

The very first two (and only)P-51D-1s were 42-106539 and 106540 - both P-51B-10s from California. Both kept the 51B wing intact whereas the subsequent P-51D-5 had neither the 'dorsal' nor the beefed up tail but did the 'more angled leading edge' and upright guns. Both went to Eglin for testing for duration of war.

None of the -5's had the dorsal, but the dorsal modification, production uplocks and beefed up tail marked the break in dash number from -5 to -10.

Joe - I am not aware of a depot/Service Group level mod converting B/D to D's - do you have a notion where I could learn more about such?

I'll look for it Bill - I remember seeing the old photo of "LOU IV" in formation with caption under the photograph about 2 of the aircraft in that photo being converted from a P-51 "C" to "D"?!? Perhaps they were confusing the bubble canopy mod with the dorsal fin mod?????

[FLYBOYJ]

My mistake - I found the reference...

It was the dorsal fin mod being spoken of......



The two P-51Ds in the foreground show a variation in dorsal fin configuration seen on early production "D" models. Both aircraft are P-51D-5-NAs originally produced without the fin, which has been retrofitted on the E2*S. The photo has been taken around end-July 1944, and the aircraft belong to 375th Fighter Squadron, 361st FG

[drgondog]

Originally Posted by FLYBOYJ

My mistake - I found the reference...

It was the dorsal fin mod being spoken of......



The two P-51Ds in the foreground show a variation in dorsal fin configuration seen on early production "D" models. Both aircraft are P-51D-5-NAs originally produced without the fin, which has been retrofitted on the E2*S. The photo has been taken around end-July 1944, and the aircraft belong to 375th Fighter Squadron, 361st FG

You're right about the E2-S - the P-51D-10 with factory ventral started w/44-14053 so that definitely is a -5 with ventral kit.

I heard from Ted Damick. The first D's arrived vi Ferry Pilots May 6-15 at the ETO Service Depots with a few going to 4th, 352nd, 355th and 357th which the CO's sanpped up. The 15th actually got D's in the same timeframe.

Neither one of us can positively identify a D that experienced combat before June 7 for sure.

[Soren]

Very nice charts Crumpp! Thank you for posting them.

Looking forward to you adding the Bf-109 & Spitfire

[Crumpp]

Looking forward to you adding the Bf-109 & Spitfire

I will work on adding the Bf-109. I hope the charts are useful in helping people to gain insight into the nature of aircraft turn performance.

All the best,

Crumpp

[drgondog]

Originally Posted by renrich

Bill, Sorry for my misleading post about P51D deployment. I should have looked further. I am glad to see that Dav has what I consider as a thorough and comprehensive reference on US WW2 fighters, "America's One Hundred Thousand" and it states the June 1944 date as to when P51Ds began to reach the 8th AF in quantity.

Ted Damick gave me March 17, 1944 as the date 44-13254 P-51D-5 (#1) rolled off the California line. It was delivered to Eglin. 44-13257 P-51D-5 (#4) was delivered to Langley.

P-51D-5 44-13258 through 13278 were flown to 15th AF a couple to 9th, 13279 went to ETO (then 355th along with 44-13305) along with most of the 44-13300 through 500 starting May 6. The Air Service Depots started delivery to 8th AF Groups around June 4-6 (no firm date yet) and the first two recorded P-5D-5 accidents were from 363rd (9th AF) and 4th FG on June 7, 1944..

The first recorded LOST IN COMBAT P-51D was June 18 in 44-13307 VF-J Lt Lane (flak)

[lesofprimus]

Bill, unreal ifo ur pumpin out to the masses brother...

Cheers!!!

As for the graphs, Im havin trouble actually understanding what they are interpeting for me....

[Crumpp]

As for the graphs, Im havin trouble actually understanding what they are interpeting for me....

The maximum load factor or number of "G's" an aircraft is capable of sustaining in a turn. It is termed "Nz" for normal accelerations on the z axis.

Load Factor in a Level Turn

All the best,

Crumpp

[Hunter368]

Of course it! How silly of me, I knew that.

[drgondog]

Originally Posted by Crumpp

I will work on adding the Bf-109. I hope the charts are useful in helping people to gain insight into the nature of aircraft turn performance.

All the best,

Crumpp

Crumpp - I forgot to ask whether you have have curves presented several power available/altitude profiles of say the Fw 190A8 vs the P-51D? At first observation it seems like these are normalized to Sea Level??

[Crumpp]

Crumpp - I forgot to ask whether you have have curves presented several power available/altitude profiles of say the Fw 190A8 vs the P-51D? At first observation it seems like these are normalized to Sea Level??

Hi Bill,

Both aircraft have curves for different configurations. The P51D is calculated for the TO weight 9611lb clean configuration overloaded fighter without the rear fuselage tank installed. The FW-190A8 is for a TO weight of 4272Kg termed "Fluggewicht A" on the ladeplane or clean configuration overloaded fighter. There is also one chart of the FW-190A8 in "Fluggewicht B" with ETC501 rack and the 115 liter Zusatzkraftstoffbehälter im rumpf.

Both aircraft are also depicted at combat weight as the USAAF defined it, 60% internal fuel, full ammunition, and consumables.

The speeds are listed in Knots Equivalent Airspeed. Altitude will change the velocity specific performance occurs but not the conclusion or shape of the curve. It is standard to use KEAS in these kind of estimates. All you have to do to convert to TAS is multiply the KEAS by SMOE found on the Atmospheric Table. This corrects for density at altitude.

KEAS is Indicated airspeed with the aircrafts Instrument Position Error Correction and a correction for the compressibility of air.

As you know, there is not nor was there ever a universal or standard method for application of compressibility. By converting the airspeed from IAS, we eliminate this as a factor in our performance estimate. Even today engineering firms set their own standards for the point we move from treating air as an incompressible liquid to a compressible gas. So once the Position Error Correction is accounted for I applied a universal standard for compressibility error onset at 200KTS. This way the playing field is leveled and we are not inducing error due to different firms standards for compressibility.

All the best,

Crumpp

[Crumpp]

Of course it! How silly of me, I knew that.

LOL!

[drgondog]

Originally Posted by Crumpp

Hi Bill,

Both aircraft have curves for different configurations.

Agreed and understood... but it did occur to me that in real life a hard turning manuever with a full fuel tank would be very dangerous in the 51B/C/D

The speeds are listed in Knots Equivalent Airspeed. Altitude will change the velocity specific performance occurs but not the conclusion or shape of the curve. It is standard to use KEAS in these kind of estimates. All you have to do to convert to TAS is multiply the KEAS by SMOE found on the Atmospheric Table. This corrects for density at altitude.

KEAS is Indicated airspeed with the aircrafts Instrument Position Error Correction and a correction for the compressibility of air.

Also agreed and makes sense to develop comparative load factor curves - up to a point. What made me ponder the 'universal' factor is the nagging (for me) question of Power Available in your model.

The thrust of my earlier question is the Power Available for both aircraft is not only not linear (of course) but not the same curve for both fighters at point where for example Low Blower is operating and High blower kicks in - both would likely operate at an advantage/disadvantage from each other in the Power Available/Power required would they not?

So my question "SL under assumption of say Max TO Power available to each Fighter" would be a one curve (each) plot, but is it as you move up each power curve as Function of altitude and use the altitude equivalent max power available in your load factor equations wouldn't you get some interesting results?

Did you go to the trouble of plotting Power Available for the 1650-7, for example and take it up through say 35K? and same for Fw 190A8?

As you know, there is not nor was there ever a universal or standard method for application of compressibility. By converting the airspeed from IAS, we eliminate this as a factor in our performance estimate.

Perfect for modelling or analytical comparisons

Even today engineering firms set their own standards for the point we move from treating air as an incompressible liquid to a compressible gas. So once the Position Error Correction is accounted for I applied a universal standard for compressibility error onset at 200KTS. This way the playing field is leveled and we are not inducing error due to different firms standards for compressibility.

Thanks for taking the time - I've been out of flight mechanics for too long.