- Thread starter
- #21
Bf-109 vs Spitfire vs Fw-190 vs P-51
- Thread starter Soren
- Start date
Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
drgondog
Major
I would use the lower wind tunnel results from Ames which I believe is as you just noted - at approximately 15 degrees angle of attack... same for both birds. I would also use posted wind tunnel results for all of the aircraft..
On the weight disucussion, particularly with respect to fuel, frequently Mustangs based on the Continent (such as 352nd FG) during the time the 109K was in service didn't need external tanks unless and until they were tasked to go deep... so fights around Bremen and Hamburg and Hannover/Misburg would reduce the fuel considerably at take off, many medium range missions were done without external fuel.... and 40% of the internal 192 gallons might be burned away by the time that point was reached.
For the same fight from UK over the same region basically all the wing fuel of 192 gallons would be in the airplane.. so why not run 'fighting conditions for all of them?
- Thread starter
- #24
Bada,
Thanks but I already have it.
Bill,
We can also do it with full fuselage tank but that would be abit unfair I think seeing that the pilots were adviced to empty this first so as to correct the CG. We can also simulate the 40% reduction of fuel load at the time period you mention.
By comparison it wasn't uncommon for German fighters to take off with half fuel tanks, fuel being in desperate demand.
Thanks but I already have it.
Bill,
We can also do it with full fuselage tank but that would be abit unfair I think seeing that the pilots were adviced to empty this first so as to correct the CG. We can also simulate the 40% reduction of fuel load at the time period you mention.
By comparison it wasn't uncommon for German fighters to take off with half fuel tanks, fuel being in desperate demand.
drgondog
Major
Actually, until you reduce the Free Body diagram of the turning ship in terms of Thrust, Weight, Lift (to precisely offset Weight) and Drag to get the angles you can't apply the resultant lift loads required to exactly offset the vertical weight at assumed CLmax - so Hp by and itself while an indicator, still isn't thrust.
- Thread starter
- #26
I'm sorry but your information is incorrect:
http://www.wwiiaircraftperformance.org/mustang/combat-reports/129-davis-23march45.jpg
http://www.wwiiaircraftperformance.org/mustang/mustang-pilotsnotes.jpg
http://www.wwiiaircraftperformance.org/mustang/mustang3-clearance-25lbs.jpg
http://www.wwiiaircraftperformance.org/150grade/316sqdn-orb.jpg
- Thread starter
- #28
The USAF used 72" of map in their Ponies. It didn't matter if it was a 1650-3 or 1650-7. You do have to remember that the FTH for 72" will be lower than the FTH for 67" or 61" of course. Also those 2 engines have different power curves and different FTH's, plus as engines were changed out you never knew which engine it was replaced with.
The few of P-51 pilots I've spoken to said they'd run the fuse. tank till 25 gallons or so was left; then run off the wing tanks changing tanks every 15/20 min. It made flying alot easier on them.
My suggestion is that if it can be done is to compare the aircraft at different alts., say at 25-27k (the bombers alt), at maybe 20k and then 10k and 5k. There will be different alts. that each airframe will be at it's best. More power/less power/thrust, more air resistance/less air resistance, better/worse control at high alts.
Then also you have to consider the speeds. Probably a good major fights were at high speed (250-400 mph), but yes you could figure out just low speed handling, but the whole picture wouldn't be shown. Also most know that turn fights always ended up going lower...nose down to keep speed up.
FWIW
The few of P-51 pilots I've spoken to said they'd run the fuse. tank till 25 gallons or so was left; then run off the wing tanks changing tanks every 15/20 min. It made flying alot easier on them.
My suggestion is that if it can be done is to compare the aircraft at different alts., say at 25-27k (the bombers alt), at maybe 20k and then 10k and 5k. There will be different alts. that each airframe will be at it's best. More power/less power/thrust, more air resistance/less air resistance, better/worse control at high alts.
Then also you have to consider the speeds. Probably a good major fights were at high speed (250-400 mph), but yes you could figure out just low speed handling, but the whole picture wouldn't be shown. Also most know that turn fights always ended up going lower...nose down to keep speed up.
FWIW
It would be a mistake to think 'Mustang III' equates to P-51D just because D is the third letter of the alphabet.
The RAF was the first operator of the Mustang and the Mustang I was never ordered by the USA. The P-51A was the Mustang II and so the P-51D was called the Mustang IV in the UK.
The RAF was the first operator of the Mustang and the Mustang I was never ordered by the USA. The P-51A was the Mustang II and so the P-51D was called the Mustang IV in the UK.
claidemore
Senior Airman
Mustang IVs were cleared for 25 lb boost, 1940 HP, as were the Mustang IIIs, they both used the same 1650-7 engine.
Also, 65 Squadron combat report with Mustang IV using 70 inches.
http://www.wwiiaircraftperformance.org/mustang/combat-reports/65-pearson-5april45.jpg
Also, 65 Squadron combat report with Mustang IV using 70 inches.
http://www.wwiiaircraftperformance.org/mustang/combat-reports/65-pearson-5april45.jpg
- Thread starter
- #32
Nope, not all of them are for Mustang III. That Pilots Notes scan/copy/photo is shown as from Air 10/2873 of the National Archives which a quick search shows it to be is listed as follows: "Pilot's Notes for Mustang IV Packard Merlin 1650-7 Engine". Anyway, the thread is titled "Bf-109 vs Spitfire vs Fw-190 vs P-51". I didn't see any qualifier excluding the Mustang III. But so what if they were all Mustang III (they weren't and the RAF did operate Mustang IV's)? That doesn't change the fact that the RAF had operational Mustangs employing +25 lbs boost with BHP of 1940 BHP.
Nope, wrong again. You must not have read those previous links. Read this one again:
http://www.wwiiaircraftperformance.org/mustang/combat-reports/129-davis-23march45.jpg
F/Lt. G.M. Davis of 129 Squadron flying a Mustang III S.W. of Bremen "opened up to +25 lbs. of boost 3,000 revs and dived down to engage" ... an Me 262.
- Thread starter
- #35
can check in the polish book "skies in fire" from bogdan arct, a polish pilot that flew in the 145/PFT and was squadron leader of the 316 in the mustang3 period.
His poney3 (a replacement airframe, hated by all the pilots
)had a gizmo and his engine stopped above germany
...he talks about the poney3, he liked it very much because of it's great performance and explain some things about it (a bit like clostermann).So, the admission pressure should be cited.(the 316 beeing a "normal" squadron, the poneys3 should be "standard" with max performance allowable for fighter sweeps above ennemy teritory. )
His poney3 (a replacement airframe, hated by all the pilots
)had a gizmo and his engine stopped above germany ...he talks about the poney3, he liked it very much because of it's great performance and explain some things about it (a bit like clostermann).So, the admission pressure should be cited.(the 316 beeing a "normal" squadron, the poneys3 should be "standard" with max performance allowable for fighter sweeps above ennemy teritory. )
Kurfürst
Staff Sergeant
Question is, how many of them? I understand two RAF Mustang III Squadrons used 150 grade fuel in conjunction with +25 lbs boost in the anti-diver campaign.
And though Mike tries to push their operations in the summer of 1944 as if V-1 hunting was something of a passtime when they had nothing better to do, a little research reveals that something like 95% of their sorties in the summer were anti-diver operations (I have the exact number of sorties somewhere), while Mike has been quoting those two missions which belong to that 5%.. again its the sort of typical manipulation Mike has a reputation for.
I am rather sceptical about that +25 lbs saw any sort of meaningful scale outside the anti-diver campaign. That a dozen or two planes were specially boosted for a special task hardly justifies a comparison of them against widely used standard types.
OTOH, there`s no doubt the USAAF had used widely in the 8th FC the moderate 72" boost pressure with 150 grade, although spark plug fouling caused considerable trouble as I understand.
I don't know which is more peculiar, that rant or the numbers machinations/games employed to dismiss/deflect/obfuscate the performance comparisons of operational aircraft. It isn't even a requirement that they be operational as far as I'm concerned, it's all interesting. V-1's or some grudge is all quite irrelevant to the linked report showing +25 lbs employed by Mustangs over Germany. Again for those without some odd agenda and with an interest in learning check: http://www.wwiiaircraftperformance.org/mustang/combat-reports/129-davis-23march45.jpg Case closed as far as I'm concerned.
- Thread starter
- #39
drgondog
Major
You might have misunderstood my point - it was almost unheard of for German Gighters to engage either B's or D's before they crossed the Channel as they were flying toward R/V for target Escort.. all or most of the fuse tank would be burned first, then external, then internal in that order. In that circumstance (for example Munich, they woul have burned fuse, external and be into internal fuel. Just TO, forming up, climbing to altitude and getting to the coast would take most of the fuselage tank - which did have the 85 gallon capacity but SOP for Europe was fill only 65 .. at 25 Gal the cg was back in acceptable limits
Worst case for either the B or D would be empty fuse tank, full external and full internal wing tanks (184 gallons) - punch external immediately - that could be for example crossing the Dutch or Danish Coast.
Average for the battles in eastern Germany would be using internal fuel near Central Germany
