USA produces a Mosquito-like bomber: pros and cons

[SHOOTER]

Quote; "Basically the Merlin (and the Allison) was designed from the start as a military engine, capable of widely varying power settings, including extreme levels for periods of time.
A side affect was being able to run at very lean levels (ie high combustion chamber temp levels) and enable very good cruising fuel consumption.

The big radials were basically militarised commercial engines and one result of the compromises made to achieve the performance required, was far greater fuel consumption for a given power level." Un quote.
My reply is that the ultimate restriction on Recip engine power is the heat input into the piston crown, everything else is insignificant! At cruise settings the two engines have very similar SFCs. It is only at much higher power levels that the air cooled engines must burn more fuel and ADI fluid. But when you take the weight of the entire cooling system into account, there is not much difference between the LC and AC engines, with a slight edge going to the Air Cooled types. ( Think radiator, hoses, ducting, pumps, etc.) Think about the R-2800 with 2,800 HP in a Bearcat then comp it with a any LC engine plane with the same range and loiter numbers. Only the P-51H is close, but not quite there.

 

[SHOOTER]

I was just seeing how close I could come to the specifications that was posted and noted that I failed.

My thought is if the USA needs something like a Mosquito why not an actual Mosquito instead of trying to reinvent the wheel?

I understand that the Mosquito was not available in number until 1942 so I would think it would also be at least 1943 for even larger numbers of Mosquito's to be available but that is fine.

I would have no problem with the USA flying Canadian built Mosquito's if it makes sense to do so.

Why not use a P-38 as the starting point? All it needs to blow the Mossy's doors off in any category is the Mk-84 streamlined bombs for external carriage.

 

[wuzak]

Overview[edit]

The Mosquito was a fast, twin-engined aircraft with shoulder-mounted wings.[57] The most produced variant, designated the FB Mk VI (Fighter-bomber Mark 6), was powered by two Merlin Mk 23 or Mk 25 engines driving three-bladed de Havilland hydromatic propellers. The typical fixed armament for an FB Mk VI was four Browning .303 machine guns and four 20 mm Hispano cannon while the offensive load consisted of up to 2,000 pounds (910 kg) of bombs, or eight RP-3 unguided rockets.[58]
Flight characteristics[edit]

The design was noted for having light and effective control surfaces which allowed for good manoeuvrability. It was noted that the rudder should not be used aggressively at high speeds, and the poor aileron control at low speeds when landing and taking off was also a problem for inexperienced crews.[86] For flying at low speeds, the flaps had to be set at 15°, speed reduced to 201 miles per hour (323 km/h) and rpm set to 2,650. The speed could be reduced to an acceptable 150 miles per hour (240 km/h) for low speed flying.[87] For cruising the maximum speed for obtaining maximum range was 200 miles per hour (320 km/h) at 17,000 lb (7,700 kg) weight.[87]
DH.98 Mosquito B Mk XVI[edit]

Mosquito P.R.34.

Data from Jane's Fighting Aircraft of World War II[160] and World War II Warbirds[163]

General characteristics
Crew: 2: pilot, bombardier/navigator
Length: 44 ft 6 in (13.57 m)
Wingspan: 54 ft 2 in (16.52 m)
Height: 17 ft 5 in (5.3 m)
Wing area: 454 ft2 (42.18 m2)
Empty weight: 14,300 lb (6,490 kg)
Loaded weight: 18,100 lb (8,210 kg)
Max. takeoff weight: 25,000 lb (11,000 kg)
Powerplant: 2 × Rolls-Royce Merlin 76/77 (left/right) liquid-cooled V12 engine, 1,710 hp (1,280 kW) each

Performance
Maximum speed: 361 kn (415 mph (668 km/h)) at 28,000 ft (8,500 m)
Range: 1,300 nmi (1,500 mi (2,400 km))with full weapons load
Service ceiling: 37,000 ft (11,000 m)
Rate of climb: 2,850 ft/min (14.5 m/s)
Wing loading: 39.9 lb/ft2 (195 kg/m2)
Power/mass: 0.189 hp/lb (311 W/kg)

Armament

Bombs: 4,000 pounds (1,800 kg) Only with bulged bomb bay doors which reduced top speed by 4-8 MPH.
The salient points are that the MTO is 25,000 pounds or more depending on the exact date of manufacture and that the cruising speed for maximum range is 200 MPH!

The aircraft data sheet, provided by Neil Stirling, shows that the Mosquito B.XVI had a most economical cruising speed of 245mph (Merlin 72/73) to 250mph (Merlin 76/77) at 15,000ft. Not sure if that means that it was the best altitude for economy, or that it was a standard test altitude. Cruising speed is at mean weight (19,100lb).

Maximum weak mixture (ie continuous) cruise was 321mph (Merlin 72/73) to 358mph (Merlin 76/77). Again at 15,000ft.

In case you were wiondering, this is clearly with the bulged bomb bay, as maximum bomb loads listed are:
1 x 4000lb (fuselage) + 2 x 500lb (wings) = 5000lb or
4 x 500lb (fuselage) + 2 x 500lb (wings) = 3000lb

Range at most economical speed and maximum bomb load (5000lb) is 1370 miles.

 

[wuzak]

Why not use a P-38 as the starting point? All it needs to blow the Mossy's doors off in any category is the Mk-84 streamlined bombs for external carriage.

Yep, wait for 20+ years to have a bomber with lower performance than the Mosquito.

Apart from the length of the Mk 84 bomb, two could fit inside the Mosquito's bomb bay.

 

[SHOOTER]

If the USA were to build a Mosquito like bomber? Just imagine a smaller, twin engined version of this, say turbo-R-2800s:

The Republic XF-12 also shows how truly refined some radial engined installations were by the mid 1940s - 4 x R-4360s.

How about a four engine plane that beats the crap out of B-29s? A scaled XF-12 with two R2800s out of the P-47N? Makes the Mossy look like a slug! I love this idea! I will do the scale drawings now that the idea has been put into my head! Great idea! How is that for streamlined?

 

[SHOOTER]

You have to remember the US was a very different place back then. Yes it was the world largest economy by that time, but in many technological areas it was very far behind. Aerodynamics, engines, superchargers, electronics, weapons, etc, etc, etc. There was a massive technological transfer from the British which bootstrapped their tech areas to a whole new level. if you look at the list of technological transfer they got for basically nothing during the war you cant help but think that Lend Lease was a bargain.This entire statement is not true. Aerodynamics? The first fighter plane to exceed 400 MPH? World record holders from both Hughes and Douglas. The off the shelf DC-3 comes with in an inch of beating the De Havilland Comet racer to Australia, etc. The worlds first 1000 HP Production engine. Effective turbochargers in 1931. Right!

They had a tremendous potential capacity, because of the large motor vehicle, radio, etc industries, but were well behind Europe technologically.More BS. Even post war, the US had to use and/or license Rolls Royce jet engines because it couldn't design/make any itself. Basically it did a Jaapan/China thing. Copy and build foreign designs and then later make its own designs.Part of this was done to ease British repayment of Lend Lease.

In many ways and many areas it was still a 2nd World nation, with areas of concentrated (and very large) industries, but many other areas of incredible poverty and, basically, primitiveness. Take one example, the national road system was virtually non-existent, that came later in the Eisenhower era. If you read, for example, Yeager's biography about the standard of living when he was growing up, not that much different from an (say) eastern European peasant of the time.Except that there was no starvation here.

Makes you wonder though, if WW2 hadn't happened would it have become so dominant?

Fatally flawed in so many ways.

 

[Rufus123]

"....So a civilization is to be judged by the sophistication of it's plumbing ??"

Yes. May seem humorous ... may seem simplistic ... but without a planned, disciplined means of human waste removal .... it ain't much of a civilization. It leaves itself open to epidemic and disease. BUT ... flush toilets are not synonymous with civilization. Spoiling 2+ gallons of water to dispose of a cup of urine is self-indulgence.

There is not much in the way of civilization in much of North America, being Canadian you should know that. I lived in civilization a couple of times and it drove me nuts. Canada will have the places I have lived beat on isolation but here goes.

in my my late thirty's early forty's I lived how no person should live (well, in my opinion ) I lived 7 miles from an artificial light source. There was also a paved road that went by the place. It was sooooo crowded, 2 homes on almost every square mile. I did have a septic system.


Before that I was in a 1000sq mile country with 4,000 people in it, still too crowded but a much better. The counties to the North, South, and West were thinner, to the East it got a little thicker with 10,000 people in 1200sq miles. Humans should not have to live within 10 miles of even a dirt road. There is a problem with that area, you were two counties away from an interstate.

Pluming these places and having modern sewage would have been cost prohibitive back then.

There was more urine in those areas from bobcats than humans, more urine from coyote than humans, more urine from roadrunners than humans, more urine from rattlesnakes than humans, more urine form many other animal species than humans. This area was not a desert but good farm country.

You have places in Canada that would be harder yet to get a modern sewage system for the rural people. You can do it for the great metropolises with a population of 200-300 but not the rural people.

 

[SHOOTER]

"...Makes you wonder though, if WW2 hadn't happened would it have become so dominant?"

That doesn't stand up either, my Friend.

From the moment the 13 Colonies won their independence from the Crown, the USA was headed for dominance ..... not God-Given dominance ... but nonetheless Manifest Destiny dominance.

All WW2 confirmed was what WW1 had already demonstrated ..... that Europe - aka the rest of the world - was in flux .... leaving an open-wide opportunity for America (industry, finance, military, science, etc) to show what it could do. The world needed an america. And for the most part, the world is a better place for what America has done.

MM
Proud Canadian

Thank you!

 

[Aozora]

I would point out that the Alison was a better engine than the Merlin with any set of "Fixes" to the myriad of problems in that the Allison was strangled by GM's refusal to institute the simple quick fixes shown to conclusively fix all the respective defects, as detailed in E. Schmued's book; "Mustang Designer", and when coupled to a turbocharger or a two stage blower could out power the Merlin at any point in history. Top Merlin power in actual service during WW-II was 1720 HP on 115-145 AV Gas, compared to 2220 HP to the Packard Merlin and 2,300 HP for the P-82's Alisons.

The P-82 with Allisons was a post WW2 aircraft while AFAIK the Packard Merlin V-1650-7 used in production P-51s generated a maximum of 1,860 hp on 100/150 grade avgas

http://www.wwiiaircraftperformance.org/150grade/engcleared-matcom-b.jpg
http://www.wwiiaircraftperformance.org/150grade/44-1_Fuel-16March44.pdf

The Merlin 66 used in Spitfire L.F Mk IXs generated 2,000 hp on 100/150 grade avgas:

 

[Rufus123]

By 1939 most UK farms did have electricity as those outside the national grid were given access to Generators and yes the majority did have indoor plumbing to a limited degree. War preperations were very detailed such as farms were given Linoleum for floors to ease cleaning freeing up time for farming. The latest techniques were taught to all farmers, tractors were being ordered to improve production and so on

Some places it would have simply not been practical to do including much of our bread basket.

There are several states in the USA that have more square miles than England but have populations between 575,000 - 3.5 million.

I know a lot of people who drive 7 miles or more in tire ruts to get to a dirt road. There is agricultural land where the people are spaced out many miles apart and the town that they go to to shop might have 300 people in it and be many many miles away. I remember we used to go to the second nearest town to kick up our heals, it was quite a bit of a drive but you got to get up to a 600 person town (The county seat) if you want to go to a town you can get wild in.

A lot of rural American is not near big places like Bugtussle, Tennessee. Heck that state had more than 6 million people in it and there are so many towns near Bugtussle it is darn right crowded in the rural areas around there. The Clampett's lived lived in a civilized area.

I really think it would have been impossible to make rural American except for that which is near large population centers and along highways into modern farms during the 40's. It took until the 90's to do it and it is still septic systems and well water with an electric pump.

 

[SHOOTER]

Spit? With the same engine, the P-51 was 20 mph faster. No, 40 MPH faster. 390 MPH with the Alison Vs 358 for the Merlin Spit. Relative to the P-51, the Spitfire had verypoor aerodynamics.

I am not sure that making an aircraft more fragile is a sign of advanced technology. This came back to bite the P-51H when the more robust P-51D was used in Korea, which was used in a more close support role.The P-51H was not weaker than the P-51D, it used thinner, but much stronger Aluminum alloy in it's construction and was built to a stress standard not matched by any Spit Mk. What crippled it in Korea was the small size of it's wheels and tires which prevented the heavy over load take off weights


It took the airframe and the engine to be the P-51. No, the airframe was faster with the Alison than the Spit was with the Merlin. The only thing the Merlin gave the Mustang was a two speed-two stage blower that we never designed because we were using turbochargers, which have since been shown to be the right choice. The Spitfire with the Merlin engine did not have the speed or the fuel mileage to do the P-51 job.

Which I bet could be traced back to an operating system designed by Maxim or Lewis, both Americans.

I don't think close is right. There is significant firepower difference. The Garand is as far ahead of the Lee Enfield as the AK-47 is ahead of the Garand.

This last sentence is not even close to being right! There is a very small difference between the M-1 Garand and the AK-47 in effective fire power. The Garand is vastly better in Range, power, accuracy, rate of aimed fire and durability and at that time reliability. The Garand is 4-5 times better than the Lee-Enfield .303 in every aspect.

 

[DerAdlerIstGelandet]

Shooter.

He's Baaaaccckkk.....

 

[SHOOTER]

Not you again!Yes, it's me again.

Merlin 66, 150 grade fuel, 2000hp 1944.Which plane was that engine in service in? By the way, the first Merlin to make over 2,000 HP were those installed in the early Hornit post war. Note that at that time, the Packard V-1650-9 in the P-51H made 2,220 HP. In service and using 115-145 gas, not 115-150.
P-82 Allisons did not appear during WW2, nor did the P-82.Right and Wrong.
The Packard Merlin V-1650-9 (the one with 2200hp) was rated RM16SM - the same as some 100-series Merlins. About the only difference between the -9 and Rolls-Royce engines was that they use ADI to allow the boost to be raised from +25psi to +30psi.First I've heard about the 30 pound boost used, source please. As to "the only difference" being the use of ADI, how come the R-R engines were only rated 400 hours TBO, minus time at full throttle at 10/1 while the Packard built engines were rated at 1000-1200 hours with out the full throttle reductions?

Allison's 2 stage engines compared favourably with 2 stage Merlins - but they were somewhat later in timing.True!

Turbocharged Allisons - I think the best the P-38 got was 2000hp, and that was with ADI. Otherwise most, during the war, had WEP of 1750hp. Turbocharged engines also much heavier installations, and gave up significant exhaust thrust at altitude.

While this is true. Exhaust thrust speed boost is very over rated and not nearly as effective as the same power to the prop. Ie, if the exhaust thrust is 300 pounds, a much over rated number that can not be justified with real world test results in a flying plane, the use of a turbo can add more than 500 HP to the crank at high altitude! Given that nobody on the planet believes that a decent but not great WW-II prop, will give 1.65 pounds of thrust at 450 MPH for every HP input to it! So the net thrust is 300 pounds, Vs 825 pounds? Right. At take off speeds a typical prop will give more than 3.35 pounds of thrust for every HP put into it.

 

[SHOOTER]

MOSQUITO FB.VI. Look it up.

I did, how many sorties did it fly during the Battle of the Bulge over the front lines in the face of Flak??? Right!!!

 

[SHOOTER]

What antennas? Wire radio and it's mast.

Oboe was carried in the nose in Mosquitoes.

H2S required a radome in the rear fuselage - but I don't bellieve many Mosquitoes carried them.Here's one more of the many.

The maximum weight of the Mosquito went up from ~20,000lbs to ~25,000lbs, but they also gained a lot of power to make that possible.And that changes my point how? Did they have MTOs of 25,000 pounds or not?

This is the same for all aircraft. The maximum speeds are usually shown as the maximum WEP or combat speed.

You are right! WEP is not real world speed and is only used to evade, or enable a shoot down, not prevent the interception in the first place. Real world speed is maximum continuous that will permit the mission range to be flown! In some cases that is only 200-220 MPH for long range with heavy loads.

 

[Rufus123]

This last sentence is not even close to being right! There is a very small difference between the M-1 Garand and the AK-47 in effective fire power. The Garand is vastly better in Range, power, accuracy, rate of aimed fire and durability and at that time reliability. The Garand is 4-5 times better than the Lee-Enfield .303 in every aspect.

I don't like AK's and I do like Garand's, Actually I like HK940's but that is another topic. Even though I am not an AK fan the difference in firepower between an Garand and an AK is more then small. The Garand is more accurate, has better range, has more power but does not have more firepower.

On the Lee-Enfield, I don't think the Garand is 4 times better. I think four guys armed with an Enfield can put more fire down range than one guy with a Garand. Enfield is more reliable, with a couple of small tweaks is more accurate. The Enfield is one of the fastest bolt guns to be mass produced.

 

[SHOOTER]

Oh lordy not the red ink retard again. He has more sock puppets than I have empty beer bottles.

No, it's me in my original sign on since 2003 or so.

 

[SHOOTER]

Actually they are engine parameters.

ie to produce 1275hp @ 11,800ft (critical altitude) the R-2600-23 required 145 USG per hour (I presume per hour, as without the time component it does not make sense).Where did you get this number. I ask because it seems very high to me. I get 68 GPH for one engine, is that for two engines? With what prop in what plane was it measured?

An airframe specific fuel consumption would be in air miles per gallon (ampg), which combines the engine's performance (fuel consumption at specific power setting in gph) and the airframe performance (speed in mph at the same specific power setting).True!

Thus a Spitfire IX and P-51B Mustang using the same engine would have the same engine consumption (gph) but the latter would be faster at the same power setting, meaning that it would have a better ampg figure.

True, if they were the same engine, but the Packard Merlin and R-R Merlin were not the same engines. They were similar, but not the same.

 

[Juha]

Merlin 66, 150 grade fuel, 25lb boost, 2000+hp in 1944. Spitfire LF IX. Also LF VIII would has been capable but because it served in MTO and in FE there were probably no 100/150oct fuel available.

Juha

 

[SHOOTER]

The aircraft data sheet, provided by Neil Stirling, shows that the Mosquito B.XVI had a most economical cruising speed of 245mph (Merlin 72/73) to 250mph (Merlin 76/77) at 15,000ft. Not sure if that means that it was the best altitude for economy, or that it was a standard test altitude. Cruising speed is at mean weight (19,100lb).That is the range altitude. It would be suicide in broad day light and most missions at night were flown at much higher altitudes. At least that is what most have said here. They claim it's combination of speed and altitude made it hard to intercept.

Maximum weak mixture (ie continuous) cruise was 321mph (Merlin 72/73) to 358mph (Merlin 76/77). Again at 15,000ft.

In case you were wiondering, this is clearly with the bulged bomb bay, as maximum bomb loads listed are:
1 x 4000lb (fuselage) + 2 x 500lb (wings) = 5000lb or
4 x 500lb (fuselage) + 2 x 500lb (wings) = 3000lb

Range at most economical speed and maximum bomb load (5000lb) is 1370 miles.

Just to show what under the best possible conditions daylight radius of range is with a "Range of 1370 miles", use 45% of 1,370 = 616.5 miles. From a practical point, this is impossible since the climb out would be over enemy territory at low to medium altitude and speed. Worse yet the cruising speed would be at 245-255 MPH. Do you think that would make it hard to intercept, or shoot down?
But the speeds and weights that you list are mutually exclusive. A 5,000pound load makes the Zero fuel and no crew weight 19,300 pounds, from Wiki, plus two crew at 200 pounds each = 19,700 pounds leaving 5,300 pounds for fuel? Since the plane normally carried 615 to 715 gallons, both with drop tanks, see Wiki below, there is no way to use that total take off weight or bomb load. I would like to see some one post the pilot's manual page for calculating a flight plan to find the real range.

From Wiki; The fuel systems allowed the Mosquito to have a good range and endurance, using up to nine fuel tanks. Two outer wing tanks each contained 58 imperial gallons (260 L) of fuel.[76] These were complemented by two inner wing fuel tanks, each containing 143 imperial gallons (650 L), located between the wing root and engine nacelle. In the central fuselage were twin fuel tanks mounted between bulkhead number two and three aft of the cockpit.[77] In the FB.VI, these tanks contained 25 imperial gallons (110 L) each[76], while in the B.IV and other unarmed Mosquitos each of the two centre tanks contained 68 imperial gallons (310 L).[78][79] Both the inner wing, and fuselage tanks are listed as the "main tanks" and the total internal fuel load of 452 imp gal (2,050 l) was initially deemed appropriate for the type.[76] In addition, the FB Mk VI could have larger fuselage tanks, increasing the capacity to 63 imperial gallons (290 L). Drop tanks of 50 imperial gallons (230 L) or 100 imperial gallons (450 l) could be mounted under each wing, increasing the total fuel load to 615 or 715 imperial gallons (2,800 or 3,250 L).[76]