Bf-109 vs Spitfire vs Fw-190 vs P-51

[drgondog]

Ofcourse HP means nothing without knowing prop efficiency, but the speeds of the a/c compared to the overall drag give a very good idea of this.

.

The problem with having a very good idea about Thrust is that just to obtain the value you have to back it out by matching the level flight max speed at specific altitudes Hp, blower settings then calculate the Drag by adding the Cdwet to Induced drag using the equations - thereby creating a load balance.

Ok - that is good for one altitude, level flight, one RPM, One Boost and trimmed for level flight..

For high angle of attack situations, propellers lose a certain percentage of efficiency.. Turns would be an example of that. It would be different for different a/c and honestly I don't know the difference between the typical three paddle blade common for the 109 and 190 and the 11' four blade Hamilton Standard.

For every altitude and power setting you can solve for thrust, but you have to solve for it. I'm researching my textbooks to see if I can find enough about propeller theory to shed light on efficencies as a function of AoA from the Thrust Line, and whether or not it corresponds to AoA of the wing-body in a linear way.

So, an accurate baseline CDwet for each aircraft has to be established. Lednicer's Report has the figures for 190A-8 and 190d-9 and Spit IX and 51B and D - are those the ones we will use?

Second, which set of Speed versus altitude, Per Hp/Boost condition charts are going to be the common view?

I would propose to use one rpm and boost for all the altitudes to simplify the math and comparisons? and assume that the propeller efficiencies as a funtion of AoA be ignored.

But we need to decide the altitudes to drive the Thrust calculations results, need to have the set of Hp to altitude charts to agree that comparisons in the 'saw tooth context' and note the gross weight of the a/c in the tests above the empty weight..

I am ok to use the USAAF flight test results on both the P-51B and P-51D instead of Manufacturer but if the results, for example, used for German a/c by manufacturer are not aligned with LW Test results we will have a question as to accuracy..

 

[drgondog]

Again, a Mustang III not a P-51D.

The P-51D is the version listed and thus the one we will be comparing first.

But we know that the P-51D ran at 75" MAP, which gave around 1,830 HP.

Remembering the P-51D was inferior in performance to the B/C because of the extra weight and that B/C's still comprised 25+% of the P-51 inventory in January, 1945..

And that the Hp is for one altitude only.

And we must calculate individual thrust for all the a/c in this comparison at the specific altitudes we agree to look at?

 

[Kurfürst]

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.

I am not sure I am getting it all right - we are comparing operational aircraft, but for some aircraft, unlike the others, it isn`t a requiirement that they would be operational in any meaningful numbers...

Anyway, I have a simply questions, since this is all interesting as well: How many Mustang Squadrons in the RAF, and how many operating at +25 lbs...?

Funny, but I am asking this question for years, and while appearantly there is a lot of info emerging about boosted P-38s, P-47s, P-51s in the USAAF, there is absolutely nothing emerging about the wide scale use of 150 grade in the RAF, which Mike and Neil is claimig for years. Odd isn`t it, they dig the British National Archieves for years, and can`t seem to find anything on it... well perhaps they are looking for something that doesn`t exist but in their wishful thinking.

V-1's or some grudge is all quite irrelevant to the linked report showing +25 lbs employed by Mustangs over Germany.

.. and similiarly, a single or two boosted Mustang Squadrons doing occasional missions over Germany and otherwise stationed in Britain for anti-diver duties is all quite irrevelant to the big picture, and typical engagements.

 

[mad_max]

Use the USAF Merlin at 72 damn inches then. Sheeze cut the BS about what Mike and Neal say. I'm so tired of all the bad mouthing a few folks do about others when I see each has their own agendas.

We still don't have any numbers of the "supposed" usage of 1.98 ata 109K. Can't be more than a couple Brit squads flying at 25 inches you say. So using that train of thought then we can't use that version of the 109 then either.

So use 72" with the Merlin and the 605 with 1.80 ata. See that was easy yes?

 

[Kurfürst]

We still don't have any numbers of the "supposed" usage of 1.98 ata 109K.

Supposed...?

I believe we have seen the transcript of the order that clears 1,98ata for four Luftwaffe fighter wings in March 1945, for what... 3+ years..?

OKL, Lw.-Führüngstab, Nr. 937/45 gKdos.(op) 20.03.45

No. Unit Present type Convert to Notes
1. III./ JG 1 Bf 109 G-10 He 162 (April/May) -
2. II. / JG Bf 109 G-10 K-4 when deliveries permit -
3. III. / JG 3 Bf 109 K-4 no change -
4. III. / JG 4 Bf 109 K-4 no change -
5. IV. / JG 4 Bf 109 K-4 K-4 -
6. III. / JG 5 Bf 109 G-14 K-4 when deliveries permit -
7. IV. / JG 5 Bf 109 G-14 K-4 when deliveries permit -
8. III. / JG 6 Bf 109 G-14/AS K-4 when deliveries permit -
9. II. / JG 11 Bf 109 G-10 K-4 when deliveries permit -
10. I. / JG 27 Bf 109 K-4 no change boost increase to 1.98 ata
11. II. / JG 27 Bf 109 G-10 K-4 when deliveries permit -
12. III. / JG 27 Bf 109 G-10 no change boost increase to 1.98 ata
13. I. / JG 51 Bf 109 G-14 K-4 when deliveries permit -
14. III. / JG 51 Bf 109 G-14 K-4 when deliveries permit -
15. IV. / JG 51 Bf 109 G-14 K-4 when deliveries permit -
16. II. / JG 52 Bf 109 G-14/U4 K-4 when deliveries permit -
17. III. / JG 52 Bf 109 G-14 K-4 when deliveries permit -
18. II. / JG 53 Bf 109 K-4 no change -
19. III. / JG 53 Bf 109 K-4 no change boost increase to 1.98 ata
20. IV. / JG 53 Bf 109 K-4 no change boost increase to 1.98 ata
21. I. / JG 77 Bf 109 G-14/U4 K-4 when deliveries permit -
22. II. / JG 77 Bf 109 G-10 K-4 when deliveries permit -
23. III. / JG 77 Bf 109 G-10 K-4 when deliveries permit -
24. III. / JG 300 Bf 109 G-10/R6 via K-4 to Me 262 planned, deadline
25. IV. / JG 300 Bf 109 G-10/R6 via K-4 to Me 262 -
26. I. / KG(J) 6 Bf 109 G-10/R6 K-4/R6 when deliveries permit -
27. II. / KG(J) 6 Bf 109 K-4 K-4/R6 when deliveries permit -
30. I. / KG(J) 27 Bf 109 G-10/R6 K-4/R6 when deliveries permit -
31. I. / KG(J) 55 Bf 109 G-10/R6 - -
32. II. / KG(J) 55 Bf 109 K-4 - to industrial defense
33. Ist Italian FG Bf 109 G-10 K-4 when deliveries permit -
34. IInd Italian FG Bf 109 G-10 K-4 when deliveries permit -
35. IIIrd Italian FG Bf 109 G-10 K-4 when deliveries permit -

That some like to pretend the order does not exist is not my problem..

As I have said I hava absolutely no doubt the 72" boost was used on a wide scale in the USAAF for Mustang (8th AAF Mustang Groups, I believe 15th AAF was 67", as it received 100 octane only).

 

[starling]

so which one has the best climb performance.lee.

 

[davparlr]

Not at 70" MAP

Thanks, found my error.

 

[mad_max]

Do we really need to hear this again for the upteen time? Where's the on strenght numbers? All that is is an order. All we have is the other experts saying could, maybe, you can figure by April 45, 1.98 was used. Nothing else but this order that is held in such regards.

We have the order for Merlin's cleared for 25" and the Griffin for 21", but you don't want to hear that. I don't either but I also don't want to hear about 1.98 ata just because of an order.

All I see is an agenda from anyone that proposes the usage of something just because the order is there.

The truth hurts don't it?

 

[drgondog]

Soren - I suggest 25,000 20,000 15,000 and 5,000 as the altitudes. That gives you the simple task of procuring the top speed versus boosted Hp published for the aircraft in question. Set those as the discussion boundary conditions.

From the top speed we will balance Cdwet (published) for the a/c in question plus Induced Drag for that a/c at that speed and altitude - and that total will be the Thrust for that a/c at that altitude for the purposes of turn G calcs.

Weight will be empty weight plus mission load (a varaible when you want to play with a 51 light and a 109 light vs a 109 and 51 with full fuel loads.

But ya gotta have the published data for those conditions to develop the Thrust and remove Hp/prop efficiency out of the calcs..

 

[drgondog]

Do we really need to hear this again for the upteen time? Where's the on strenght numbers? All that is is an order. All we have is the other experts saying could, maybe, you can figure by April 45, 1.98 was used. Nothing else but this order that is held in such regards.

We have the order for Merlin's cleared for 25" and the Griffin for 21", but you don't want to hear that. I don't either but I also don't want to hear about 1.98 ata just because of an order.

All I see is an agenda from anyone that proposes the usage of something just because the order is there.

The truth hurts don't it?

Not to mention that production P-51H's were being delivered to operational squadrons in late Feb 1945... capable of 90" for the 1650-9 and the same weight as the 51B with more firepower and cleaner (slightly) airframe, but that isn't in the equation.

 

[Vincenzo]

Not to mention that production P-51H's were being delivered to operational squadrons in late Feb 1945... capable of 90" for the 1650-9 and the same weight as the 51B with more firepower and cleaner (slightly) airframe, but that isn't in the equation.

delivered on late february 1945 to perational squadron, what's the source?
afaik delivery to operational squadron in summer 1945 and no H see a fight

 

[drgondog]

delivered on late february 1945 to perational squadron, what's the source?
afaik delivery to operational squadron in summer 1945 and no H see a fight

Gruenhagen's "Mustang -Story of the P-51 Fighter" and Wagner's "Mustang Designer".

The last of 555 was delivered in November, 1945. The order for 1000 was cut at V Day and approximately 75 were delivered between Sept and November as the line wound down

The first was delivered in February, 1945 and the first to the RAF for evaluation was delivered IIRC on 2 March, 1945.

No, it didn't see combat because it wasn't needed. All went to operational Combat units stationed in US as Interceptor units and served in that capacity through 1951, along with many rotating to Air National Guard Units

 

[Kurfürst]

Do we really need to hear this again for the upteen time?

Because you shared us your doubts about 1.98ata for the upteenth time, mate..

Where's the on strenght numbers?

Well, they are readily available for three years, now, too. But let`s recap.

As per 9th April 1945.

I./JG 27 29
III./JG 27 19
III./JG 53 40
IV./JG 53 54
Total 142.

As per on the nightfall of 14th April 1945 (ie. after daily engagements, before repairs were done in the evening).

I./JG 27 25
III./JG 27 19
III./JG 53 22
IV./JG 53 51
Total 117.

As you can see, the numbers varied even within a few days time.


Now, can we see strenght reports for RAF Merlin Mustang and Spitfire XIV Squadrons? No...? Mike still hasn`t provided them, eh? You start to wonder, why...

All that is is an order. All we have is the other experts saying could, maybe, you can figure by April 45, 1.98 was used. Nothing else but this order that is held in such regards.

Keep weaving your story, the same way you have been weaving it for 3 years... but a blind man`s story has poorly made fabric. 8)

We have the order for Merlin's cleared for 25" and the Griffin for 21", but you don't want to hear that.

May I ask you to keep presenting your own twisted version only, and refrain from twisting mine opionon. Are you capable of that? Oh thank you.

As for the Spit IX`s +25 lbs order, we know it was ordered, and we also know from pilot memoirs who were there that after a series of fatal incididents after its introduction (February 1945) to the 2nd TAF, it was recalled very soon after, and to say the pilots wished the whole 150 grade business to hell is an otherstatements.

BTW I produced these memoirs I have mentioned above to Neil Stirling and Mike Williams... in case if they don`t know of these as they do..
Do you have any idea why they don`t bother to tell that part of the story in their little 150 grade article...?

I don't either but I also don't want to hear about 1.98 ata just because of an order.

Yes, yes I have read that part somewhere.. oh it was you a few lines above. I wonder why do you need to repeat yourself, but here`s the deal: we have a lot more than an order. We have the 605DB/DC manual which clears 1.98ata in December 1944. We have the DB Niederschrift that tells it was cleared and issued to the troops by DB. From the same doc we know of the problems occuring, and that II/JG 11 was selected for operational trials. We know that in March 1945 the LW issued an order for four fighter Wings to use the increased 1.98ata boost pressure - quite clearly it was cleared in the meantime again. We have fuel store status for Luftwaffenkommando West that shows C-3 was available to them in sufficient scale and there was no shortage of it compared to B-4, as Neil liked to claim. We have photographic evidence of JG 27 and JG 53 109Ks (and a lot of G-10s from other units BTW) marked for C-3 fuel use in March-April, something they only needed if their engines were configured to DC settings with 1.98ata.


It has been proven far beyond the scope Mike or Neil was able to support their agenda. They can`t show unit strenghts, they don`t have any photograhpic evidence, they try to select between the information as shown above, and as much as they dig the archieves and dug up dozens of Mk XIV combat reports from 1945, they can`t find a single one that says +21 lbs was in use, even less the +25 lbs rating for the Griffon Mike is dreaming about.

Even then, I`d say the use of +21 lbs is probable for the Griffon in 1945. But we still don`t know any details about it, how many units used it, and to what extent - I`d like to remind you that we have already confirmed that +25 lbs was used for the Merlin 66, AND it proved to be a disaster and was soon recalled. I wonder if the story is the same in the case of the Griffon, which had even harder time to cope with even +21. I wonder if Mike and Neil is not aware of that for fact already..

All I see is an agenda from anyone that proposes the usage of something just because the order is there.

The truth hurts don't it?

Well one can see that from how often you repeat your line about 'its only an order.. it doesn`t matter... it doesn`t matter!'..

 

[Vincenzo]

if this is abstract from source that not tell delivered at operational units, tell first delivery at february 1945, delivery is from factory to usaaf.
If i've understood wrong what squadron is the first with P51H?

 

[Kurfürst]

Not to mention that production P-51H's were being delivered to operational squadrons in late Feb 1945...

The first was delivered in February, 1945 and the first to the RAF for evaluation was delivered IIRC on 2 March, 1945.

In other words... it wasn`t operational in February 1945, nor in March when it was still being evaluated and nearing operational service. Not that a few months would count much, had the war continued, but still.. lets have the facts straight.

 

[drgondog]

In other words... it wasn`t operational in February 1945, nor in March when it was still being evaluated and nearing operational service. Not that a few months would count much, had the war continued, but still.. lets have the facts straight.

No - it was 'operational' in late february in context of first P-51H leaving production lines and accepted by USAAF in late Feb. It was operational in squadron strength in March - but I am still tracking details on first squadron to receive it.

The evaluation references was for RAF only, and only one was ever sent to RAE.

I am still trying to validate the source but I believe there were Two Operational P-51H groups at the end of April, 1945. Operational in that two groups had received the aircraft, pilot familiarization completed, groups ready to be deployed overseas and awaiting assignment, but operational as air defense wings at that time.

I don't know how that contrasts with say the Ta 152H-1 but suspect favorably. I don't want to cause a departure from the Thread so we can deal with this question later?

 

[Kurfürst]

Fine with me. Perhaps a very-late/almost made it war über-fighter thread is a better place for it... La-7, Yak-3U, Bf 109K, Ta 152H, Spit 21, Tempest II... dunno for the IJA... Ki 84?

 

[drgondog]

Fine with me. Perhaps a very-late/almost made it war über-fighter thread is a better place for it... La-7, Yak-3U, Bf 109K, Ta 152H, Spit 21, Tempest II... dunno for the IJA... Ki 84?

That would be interesting.. and include 51H, F8F and F7F - anything that was in production and delivering to units before V-J Day. Keeping it conventional probably makes more sense as P-80 vs Me 262 vs Meteor have been thrashed pretty well.

 

[Kurfürst]

Definietely, I wanted to include these one as well, but slipped me mind in the end..

 

[Waynos]

Don't forget to include the Spiteful as this was in production but never delivered due to the wars end.