WW2 Aircraft more successful in secondary role

[Shortround6]

I would also like to see an official reports or correspondence or something about the P-40 being intended to be a ground attack fighter.
Not rumors or quotes from a book.
In Early 1940 only one engine in service had a significantly higher critical altitude than the Allison and that was the Merlin.
In 1939 when the P-40 was first ordered the situation was the same.
Early P-40s also had about zip for a bomb load (that came with the "C" and with the Later Tomahawks) so a "better" P-40 using the same engine was likewise not "optimized" for ground attack or army co-operation.
In fact when NA was given the go-ahead to build the prototype NA-73 The British were urging Westland to build Lysanders for army Co-operation as fast as possible. NA-73s (or Mustang Is) would have been a sight see picking up messages with hooks

 

[GrauGeist]

From Joe Baugher:
"Following the outbreak of war in Europe, the British Purchasing Commission, headed by Sir Henry Self, was posted to New York to determine if American combat aircraft could be of any use to the Royal Air Force.
One of the corporations that Self had contacted had been the North American Aviation corporation. North American had already been building NA-16 trainers, and the British ordered a number of them for the RAF as the Harvard. In April of 1940, the manager of NAA James H. "Dutch" Kindelberger was summoned by the British Air Purchasing Commision and asked to manufacture the Curtiss Hawk 87 (P-40D) under license for the RAF.
Kindelberger, who was an excellent businessman as well as aeronautical engineer, responded that NAA could do that if it were really required, but countered that he and his company could build a better fighter than the P-40 and that they could design a real fighter in the same time that it would take to put the P-40 into production."

To continue:
"The NA-73X prototype contract was signed on May 23, 1940. The British insisted that a heavy eight-gun armament be fitted, somewhat heavier than American standards of the day. Two 0.5-inch M2 Browning machine guns were installed in the underside of the nose beside the engine crankcase, synchronized to fire through the propeller arc. The left gun was staggered ahead of the right in order that the magazines could lie one behind the other. Two 0.50-inch guns were mounted upright inside the wings, outboard of the landing gears. Four 0.30-inch Browning machine guns were mounted further outboard on the wing, with each inboard 0.30-inch gun being mounted lower so that its muzzle was below the leading edge.
The British also specified that a liquid-cooled inline engine be used, and the Allison V-1710 twelve-cylinder Vee was the only American-built engine which fit the bill. The Allison V-1710 was a little bigger than the Merlin, slightly lighter, and similar in power at low altitudes. However, at higher altitudes the Allison suffered from a rapid drop in power in comparison to the Merlin. NAA briefly considered using a turbosupercharger to improve high-altitude performance, but ruled against it on the grounds of a tight schedule."

Now we fast forward to the finished product:
The NA-73X (Mustang I) was produced in limited numbers and most were held back for evaluation and photo recon roles, the first arriving at Liverpool on 24 October 1941. The NA-83 were a slightly modified version of the Mustang I and the British ordered 300 of them in December of 1940.

On 11 March 1941, the lend/lease act was passed, and the next batch of Mustangs, designated NA-91 (Mustang IA) had the MGs traded for 4 Hispano 20mm cannon in the wings.

At this point, the British had been able to actively employ their Mustangs in combat and came to a conclusion on it's performance.

From Joe Baugher:
"The British decided that the relatively poor high altitude performance of the Mustang was more than just a minor deficiency, since most aerial combat over Europe at that time was taking place at medium to high altitudes. Consequently, the Mustang I was used for low-level tactical reconnaissance and ground attack, where full advantage could be taken of its exceptional low-altitude performance."

Now, let's fast forward to 16 April 1942, when the U.S. Army Air Force placed an order for 500 NA-97, specifically designed for ground attack and designated the A-36. The RAF was given one in March 1943 for evaluation (EW998).

August 1942 saw a USAAF order for 1,200 NA-99 (P-51A) which was the start of the Mustang's legacy with the USAAF.

The British didn't ask for a low level ground support aircraft, they were looking for a fighter. They discovered that their new fighter was not suitable for the type of air warfare that had evolved in the skies over Britain between the time they ordered it and the time they were able to put it to work. They did, however, exploit it's strengths which were "its exceptional low-altitude performance".

 

[wuzak]

It just dawned on me, what secondary designation do I give my wife's mini van with
all the four rear chairs out and a queen size mattress added? I mean in a PG-13 sort
of way so that we can keep this a family friendly site.

Camper-van.

 

[BLine22]

B-24 Liberator, secondary role of ASW.

 

[Shortround6]

Actually the P-40 may be a candidate like the Typhoon as it transitioned from fighter to ground attack. Last versions carrying three 500lb bombs (and in the field six 250lb bombs and on occasion two 1000lb bombs) about 4800 of these three bomb aircraft were built and by mid 1943 nobody was under the illusion that the P-40 was a first rate fighter.

 

[rank amateur]

Been reading through this but yesterday it finale struck me: the Polikarpov Po 2. Used as an trainer but much more renowned as a night harrasment bomber even in Korea.

 

[Shortround6]

Well, we have difference in "successful" and "renowned".
For example the Lysander gained quite a bit of "renown" for it's missions as an agent dropper/retriever but with only a few dozen used for that role out of over 1750 built one wonders about the "success"
PO-2 was built in large numbers, somewhere between 20-30,000? how many were used as night raiders? A few hundred?
The Germans pulled He 46s and HS 126s from training schools and used them for similar night attacks, I am not sure this turned them into "successful" aircraft.
The Typhoon was less than what was hoped for as fighter and the bulk of the production (over 2/3rds) was after the decision to use them as "bombers" was made.
Likewise several thousand P-40s were built for ground attack long after the P-40 was considered obsolete as a fighter.

 

[CORSNING]

GrauGeist,
I agree 100% that the British didn't ask for a low-level ground support aircraft, but they new
that was exactly what they were ordering from North American when they stipulated the Allison
engine. That was their call and like it or not the Mustang was designed and accepted as a low-
level air superiority fighter. I also agree that they were hoping to get something along the lines
of the Spitfire. So was every other nation in 1940.

I still stand by my original post, probably dumber than squat, Jeff.

 

[CORSNING]

Shortround,
Only one engine in service in early 1940 had a significantly higher critical altitude than the
Allison...? What about the Daimler-Benz DB-601Aa in the Bf.109E-3 introduced at the end of
1939?
I am not trying to be combative in any way. What was, was. No amount of argument can
change that.

May God bless us all and let the truth (even if I am absolutely wrong) come out, Jeff.

 

[pbehn]

GrauGeist,
I agree 100% that the British didn't ask for a low-level ground support aircraft, but they new
that was exactly what they were ordering from North American when they stipulated the Allison
engine. That was their call and like it or not the Mustang was designed and accepted as a low-
level air superiority fighter. I also agree that they were hoping to get something along the lines
of the Spitfire. So was every other nation in 1940.

I still stand by my original post, probably dumber than squat, Jeff.

The Mustang performed well at Dieppe in 1942, the British ordered a fighter, apart from the strategic bombing conflicts over south east England in 1940 and Germany 1943-45 most air combat was below 15,000ft. The Tempest had a similar altitude problem to the Allison Musang but it was introduced around D-Day and so its battles were around the front on the ground not across a stretch of water.

 

[rank amateur]

Well, we have difference in "successful" and "renowned".
For example the Lysander gained quite a bit of "renown" for it's missions as an agent dropper/retriever but with only a few dozen used for that role out of over 1750 built one wonders about the "success"
PO-2 was built in large numbers, somewhere between 20-30,000? how many were used as night raiders? A few hundred?
The Germans pulled He 46s and HS 126s from training schools and used them for similar night attacks, I am not sure this turned them into "successful" aircraft.

No dispute and I really don't know how many U2/Po-2's were ever used in the night harrasment role and how effective they really were but the fact that the Germans copied the principle with their share of obsolete planes does seem to indicate that they were considered effective.

 

[Shortround6]

Shortround,
Only one engine in service in early 1940 had a significantly higher critical altitude than the
Allison...? What about the Daimler-Benz DB-601Aa in the Bf.109E-3 introduced at the end of
1939?
I am not trying to be combative in any way. What was, was. No amount of argument can
change that.

May God bless us all and let the truth (even if I am absolutely wrong) come out, Jeff.

According to: Kurfürst - DB 601, 603, 605 datasheets - DB 601 Aa

Critical height of the DB 601 Aa was 3700meters at 2400rpm for 1100PS.

The Allison V-1710C-15 as used in the early P-40s had a critical altitude of 14,300ft (4333 meters) at which point it gave 1040hp. Critical altitude was about 2000ft lower than the Merlin.

The DB 601A-1 engine had a critical altitude of 4500 meters giving 1020PS. 167 meter difference isn't enough to get excited about.

You could swap a DB 601A-1 for an Allison and hardly change the performance of the planes involved.

What gave the 109 it's altitude performance was it's light weight. A P-40B empty (no fuel, oil, ammo OR GUNS, no pilot) weighed about what a 109E did loaded with full fuel, oil ammo and pilot. Stick 1700lbs into a 109 and watch the altitude performance go right in the toilet.

 

[fastmongrel]

GrauGeist,
I agree 100% that the British didn't ask for a low-level ground support aircraft, but they new
that was exactly what they were ordering from North American when they stipulated the Allison
engine. That was their call and like it or not the Mustang was designed and accepted as a low-
level air superiority fighter. I also agree that they were hoping to get something along the lines
of the Spitfire. So was every other nation in 1940.

I still stand by my original post, probably dumber than squat, Jeff.

Were the British Purchasing Commison using a Crystal Ball Mark 1 when they ordered the Mustang because who knew that in March 1940 that the Alison V1710 was going to be left behind in the altitude race. Even when the prototype was rolled out in September I doubt anyone knew for certain that combat would be going so high, as most combat in August still took place at around 20,000feet where most of the bombers flew.

 

[CORSNING]

Fastmongrel,
I agree, but that doesn't change the abilities of the NA-73 and that both North American
and UK were aware of those abilities at the time of delivery.

 

[fastmongrel]

Fastmongrel,
I agree, but that doesn't change the abilities of the NA-73 and that both North American
and UK were aware of those abilities at the time of delivery.

Yes at time of delivery but you dont order an aircraft with the foresight of 18 months. When ordered the British Purchasing Commision thought it was ordering an all round air superiority fighter to defend Great Britain. If they had wanted an Army Co-Op Fighter/Recce aircraft dont you think they would have ordered it with Bomb Racks, Bomb Sight, Army waveband radios and Cameras.

If I knew what was happening 18 months ahead I would be stinking rich and have Scarlett Johansenn keeping my bed warm.

 

[CORSNING]

A men to that brother.

 

[Shortround6]

Time of delivery and time of order are off by about a year and half.
The Mustang I was to use the same engine as the P-40D and not the earlier long nose engines used in the P-40B/C/Tomahawk.
The British had ordered 500 Hawk 87As in May of 1940 (basically P-40D/Es) or during the Battle for France.
I don't know which P-40 the British were interested in having North American build as obviously if the British were signing orders for the Hawk 87A instead of the Hawk 81 something must have at least existed on paper at that point.
The "new" Allison engine offered a bit more power lower down but in fact may very well have suffered no loss in power at higher altitudes than the long nose Allisons. It used the same supercharger drive gears and few, if any modifications to the supercharger itself.
The -39 engine was allowed to use 44in (?) pressure for military power instead of the 37-40in (?) used by the -33(C-15) engine.
While the -39 was able to hit 1150hp at 11,700-12,000ft ( no ram) it might very well have been capable of making 1040hp at 14,300ft.
With the first 5 Mustang Is not making it to England until Oct/Nov of 1941 operational conditions had changed considerably since they were ordered. Main opponents would be 109F-2/F-4s rather than 109Es.

 

[CORSNING]

Mustang 'A' was very good in 1942, low, long legs and fast. Mustang 'M' was/became superior and
different in 1943, High or low, long legs and very fast.
That's just a fact that they were both first rate contenders in their times, but they were two different
kinds of fighters.

 

[gjs238]

If I knew what was happening 18 months ahead I would be stinking rich and have Scarlett Johansenn keeping my bed warm.

I took you for a Keira Knightley kinda guy

 

[CORSNING]

Allison V-1710-39 (-F3R): Critical altitude is 10,800 ft. (3.292 m./1,150 hp. @ 43.9"Hg).
That does not mean a whole lot though. The Middle East pilots were pushing that engine
to 66"Hg/3,000 rpm (1,570 hp.), Australian pilots pushing theirs to 70"Hg (1,780 hp.)
for prolonged periods at very low levels. The later V-1710-81, -83 and -85 could not
be pushed to these limits

The main difference came with the Merlin that could take this kind of power 1,555 hp.
to 17,750 ft. (it was a different animal).