P-38 or Mosquito? (1 Viewer)

[Procrastintor]

Thanks for the link!

 

[CORSNING]

Last year I did a workup of the performance evolution of the Lightning. Awesome plane by the way. I really wonder how it would have done as anti-shipping with those two torpedoes. I have recently started a workup of the performance evolution of the Mosquito. Another awesome plane. I won't be ready to vote until I have finished. But from what I have read so far, I can't help but wonder why the US did not mass produce the Mosquito under license and use it instead of the B-17/B-24. True they would have had to use a few more to carry the same bomb load (B-17: 6,000 lbs. vs. Mk.IX: 4,000 lbs). But the Mosquito cruising speed was almost 70 mph faster (250 mph), range was at least equal (2,500 mls.) and after dropping load could have hit the deck run like #ell. Fewer airmen (Mk.IX: 2 vs. B-17: 10) would have been put at risk and I believe the survival rate may have been better. I know I'm sort of off topic but you all have pretty much summed up the pros and cons already. I believe the two were pretty close in the ruggedness category (two engines and all). And there shouldn't be any argument over which was the better fighter vs. fighter considering the P-38's acceleration, climb, turn and roll rate. But the Mossie was what was needed where it was needed when it was needed. Lord, I'm just glad we had both of them on our side. So, which was better?............I guess it depends on when and where you were at the time.

Great thread Guys. Thanks, Jeff

 

[FLYBOYJ]

Last year I did a workup of the performance evolution of the Lightning. Awesome plane by the way. I really wonder how it would have done as anti-shipping with those two torpedoes. I have recently started a workup of the performance evolution of the Mosquito. Another awesome plane. I won't be ready to vote until I have finished. But from what I have read so far, I can't help but wonder why the US did not mass produce the Mosquito under license and use it instead of the B-17/B-24. True they would have had to use a few more to carry the same bomb load (B-17: 6,000 lbs. vs. Mk.IX: 4,000 lbs). But the Mosquito cruising speed was almost 70 mph faster (250 mph), range was at least equal (2,500 mls.) and after dropping load could have hit the deck run like #ell. Fewer airmen (Mk.IX: 2 vs. B-17: 10) would have been put at risk and I believe the survival rate may have been better. I know I'm sort of off topic but you all have pretty much summed up the pros and cons already. I believe the two were pretty close in the ruggedness category (two engines and all). And there shouldn't be any argument over which was the better fighter vs. fighter considering the P-38's acceleration, climb, turn and roll rate. But the Mossie was what was needed where it was needed when it was needed. Lord, I'm just glad we had both of them on our side. So, which was better?............I guess it depends on when and where you were at the time.

Great thread Guys. Thanks, Jeff

The Mossie was a great plane but it was not designed to accomplish high altitude precision daylight bombing. If it was used in that same capacity with a bombardier in the lead plane using a Norden bomb sight, it would still have to be flown at substantially slower speeds.

 

[CORSNING]

Thanks for the information FLYBOY. What about fast under the radar with P-51/P-51As as escorts. I'm not real versed on bombing strategies and I know, it shows.
Jeff

 

[Glider]

another site to try

Subject Index: de Havilland Mosquito

 

[CORSNING]

Thank you Glider.

 

[FLYBOYJ]

Thanks for the information FLYBOY. What about fast under the radar with P-51/P-51As as escorts. I'm not real versed on bombing strategies and I know, it shows.
Jeff

Then you have what it did in the war to begin with - a fast capable fighter bomber that could take out precision targets

 

[CORSNING]

There you go sir. Now imagine that on a greater scale.

 

[CORSNING]

Before I even get started, I want you all to know that this is all Glider's fault. I read everything on the sight he posted on #725
that's right this is all your fault (God bless you man). I'll start with the Mosquito B Mk.IX:"When equipped with electronic bombing aids, the Mosquido B Mk IX could bomb from a height of 30,000,". To continue on " Later tests with the Merlin 77 engine saw the prototype reach a speed of 437 mph at 29,000 ft." Just for the record this type reached No.109 squadron on April 21, 1943.
The B Mk.XVI had a pressurised cabin that gave it an operational ceiling of 35,000 ft. "When combined with Gee-H NS H2S, the Mosquito was capable of relatively accurate bombing from this high altitude. More importantly, it could hit a given target on nights when the main bomber stream would be grounded." The B Mk.XVI entered service in December 1943 with No.109 sqd.
LG, I'm sorry man but as a bomber, the Mosquito wins. HANDS DOWN.....PERIOD!
I'm not saying the P-38 couldn't be adapted to do the job. I'm just saying it wasn't at the time the Mosquito was when it was needed and kicking @$$ BIG TIME by the way.

For the record: I still like the idea of an armada of Mosquitoes flying in at tree top level with an escort of P-51As 800 mls. from home. One group of Mustangs flying top cover and one flying close cover. Now that would be quite a sight.

I may not know what I'm talking about, but I'm just saying, have a great night guys, Jeff.

 

[Glider]

I always get the blame. Anyway back to the P51 escorting the Mosquito. This was often done but there was a problem. The P51 needed drop tanks to get the max range but with drop tanks the P51 was a lot slower than the mossie.

The result was Mosquito had to slow down resulting in the Aircraft being in the danger area longer and, as it would be flying at a less economical cruising speed the bombers range was reduced

 

[CORSNING]

Glider,
I have been mowing the yard and cleaning the garage all day so I haven't done all the research needed. So all I am about to write is as much a question as it is a statement. The P-51A was capable of 2,000 mls. at 266 mph. with two 125 gallon drop tanks. I am early in my studies of the Mosquito but from what I have read so far the Mk. IV's cruising speed is 250-260 mph. After dropping wing tanks the P-51A was capable of 376-380 mph at sea level graduating up to 395-413 mph at 10,000 ft. depending on what engine it had in it,the V-1710-73 or -81. So from what I have read so far the only time the Mustang would have had a rough time staying up with the Mossie is if it pealed off to intercept E/A allowing the Mosquitoes to high tail it out of there. That would have been there job.

We are talking 1943-early 1944.

Jeff

 

[proton45]

It was the Mossie...But I do LOVE the P-38!

 

[wuzak]

Glider,
I have been mowing the yard and cleaning the garage all day so I haven't done all the research needed. So all I am about to write is as much a question as it is a statement. The P-51A was capable of 2,000 mls. at 266 mph. with two 125 gallon drop tanks. I am early in my studies of the Mosquito but from what I have read so far the Mk. IV's cruising speed is 250-260 mph. After dropping wing tanks the P-51A was capable of 376-380 mph at sea level graduating up to 395-413 mph at 10,000 ft. depending on what engine it had in it,the V-1710-73 or -81. So from what I have read so far the only time the Mustang would have had a rough time staying up with the Mossie is if it pealed off to intercept E/A allowing the Mosquitoes to high tail it out of there. That would have been there job.

We are talking 1943-early 1944.

Jeff

There are cruising speeds and then there are cruising speeds.

http://www.wwiiaircraftperformance.org/mosquito/Mosquito_MkIV-merlin21_ads.jpg
http://www.wwiiaircraftperformance.org/mosquito/Mosquito_MkIV_ads.jpg
http://www.wwiiaircraftperformance.org/mosquito/Mosquito_MkXVI_ads.jpg

These are three data sheets for the Mosquito - B.IV (Merlin 21), B.IV (Merlin 23) and B.XVI (Merlin 72/73).

Note that the cruising speeds are all listed at 15,000ft - which may, or may not, be the optimum height for cruise.

Two cruise speeds are listed - most economical and max weak mixture. Most economical gets the best range, obviously. Max weak mixture is a fast cruise using a power level at or near maximum continuous power.

The B.IV's most economical are both 265mph @ 15,000ft. With the Merlin 21 the max weak cruise is 320mph (2650rpm, +4psi boost), whereas the Merlin 23 B.IV could get 327mph (2650rpm, +7psi boost). The B.XVI is listed as 321mph max weak mixture, and 245mph at most economical. I would suggest that 15,000ft is far from the best cruise altitude for the B.XVI.

The B.XVI with the later Merlin 76/77s had a max weak mixture cruise speed of over 350mph TAS.

Speeds at sea/low level are reduced. For the FB.VI (similar engines to the B.IV, but with more drag) the most economical cruise at sea level was about 220-230mph, whilst the max weak mixture cruise was 270-280mph (from my recollection - FB.VI pilots notes).

The Mustang I's cruise speed of 266mph would be at altitude. I would also suggest that the P-51A's sea level max speed was somewhat less than 375-380mph, since that was close to its maximum speed.

 

[wuzak]

After a quick look on P-51 Mustang (Allison Engine) Performance Trials I stand corrected. The Mustang I could do 370-380mph @ sea level.

 

[Glider]

Dont get confused btween max and cruising speed. I dont see a cruising speed of 370 mph with drop tanks anywhere. In one of the papers is a description of a long range (Rhubarbs) mission which I copy here
Specialised pilot training is a very important phase in this operation. New pilots coming with the unit are not allowed to go on an operational flight for several months. They must have become familiar with every phase of the operation before going out on their own. They are thoroughly instructed in radio procedure and discipline. They must know their airplane completely and have the responsibility for keeping their own ground crew on their toes. They are allowed to make changes in their own aircraft for their personal comfort and are encouraged to keep the wings polished and free from scratches. In fact, no one is allowed to climb up on the wings without a pad in place. The pilots enter from the front stepping on the wing at only two designated spots. They must run slow speed fuel consumption tests so that they are convinced that it is possible to operate at 200 mph and approximately 20 gal per if they keep the R.P.M. down to 1100. They must supervise the swinging and checking of their own compass in order to increase their confidence in their equipment. Blind flying practice is carried out at all times. Each pilot is so trained that he can "lay on" a complete mission in all details.

I based my oringinal statement on books that I have read but the following story with a PR Mossie and a P51 B-D Mustang does show the difference in those versions.

Lt. Richard Geary flew the 21 January mission to the Politz Oil Refinery at Stettin, Poland with Lt. Floyd Mann as navigator.

They had been on standby for this particular mission waiting for the weather to clear. The operations room had an enormous map that covered 25 feet or better of one wall. The missions for the day, the next day or when weather permitted, were represented by colored yarn. A different color for each mission was stretched from Watton to the target area. The yarn for the Politz mission went all the way from one end of the map to the other. Geary recalls aircrew members asking, 'Who the hell is going to fly that mission?'

It was a cold winter morning when an orderly awakened Geary at 0400. The weather had cleared and the mission proceeded as scheduled. Geary went to the flight line and then to the parachute room to meet his navigator Floyd Mann.

Watton was covered with a thin layer of snow as they took off at 0920 in NS569. Prior arrangements were made to rendezvous at 0925 with four P-51s from 20th FG at 18,000 feet over Cromer. They would provide escort to Stettin and return.
The Mosquito met the fighter escort as planned; but now heavily loaded with l,000 gallons of fuel, flew at a severe speed disadvantage. Geary attempted to maintain economical cruising speed but outpaced the P-51s and was forced to throttle-back to continue flying formation with them. The Mustangs had long-range drop tanks and were also fully loaded. Once involved with enemy action, they would jettison their tanks, and therefore, were attempting to conserve and obtain maximum range from their fuel supply. This exacerbated the problem. It was a very-long flight to the Polish border, and on three occasions Geary throttled-back and did not receive the mileage planned.

On most missions it wasn't a problem but on the very long range missions it was.

 

[BlackSheepTwoOneFour]

Mosquito. Lightweight and fast enough to do it's job. The P-38 is an awesome aircraft no doubt but you have to be careful in a full all out steep dive.

 

[CORSNING]

Thanks for post #735. I haven't done enough digging yet but it does appear that the maximum cruise of the P-51 / -39 engine was around 275 mph. I haven't located a max.cruise for the P-51A / -73 or -81.

 

[tomo pauk]

Great contribution, Glider et al, many thanks.

 

[nincomp]

They must run slow speed fuel consumption tests so that they are convinced that it is possible to operate at 200 mph and approximately 20 gal per if they keep the R.P.M. down to 1100.

I have read in a number of places that the Merlin engines did not run smoothly at low RPM's. Did the engines run more smoothly with some boost?

What was the cause of the rough running with the Merlins? Was it mainly uneven fuel distribution and/or a poor intake manifold design?

 

[Glider]

Thanks for post #735. I haven't done enough digging yet but it does appear that the maximum cruise of the P-51 / -39 engine was around 275 mph. I haven't located a max.cruise for the P-51A / -73 or -81.

It isn't the max econ cruise of the P51 that is of interest. Its the Max econ cruise of the P51 carrying drop tanks thats of interest.