Improve That Design: How Aircraft Could Have Been Made Better

[llemon]

Messerschmitt 109

1. fit "all-round" vision canopy as designed for the 209 with cut down rear fuselage. This was proposed for the F
2. New wing with twin spars, inward retracting gear and thinner section at root and tip. Such a wing was test flown on the v31. Make it square tipped, same planform as the E.
3. Single radiator in belly slightly behind wing, This volume is occupied by the fuel tank so move the tanks between the wing spars soviet style. Later move to drum type radiator.
4. Armament 1 MG151 + 2 MG 131 or 3 MG 131
5. Enlarged vert stab with pilot adjustable trim tab
6. Replace slats with fence

 

[Kevin J]

Messerschmitt 109

1. fit "all-round" vision canopy as designed for the 209 with cut down rear fuselage. This was proposed for the F
2. New wing with twin spars, inward retracting gear and thinner section at root and tip. Such a wing was test flown on the v31. Make it square tipped, same planform as the E.
3. Single radiator in belly slightly behind wing, This volume is occupied by the fuel tank so move the tanks between the wing spars soviet style. Later move to drum type radiator.
4. Armament 1 MG151 + 2 MG 131 or 3 MG 131
5. Enlarged vert stab with pilot adjustable trim tab
6. Replace slats with fence

So its a completely new design that enters service in 1941 when you need to contest the Spitfire immediately which outclasses the Bf 109E. That's not a good idea. Why not put a liquid cooled engine in the Fw 190.

 

[Shortround6]

It has always been a wonder to me that the germans could not come up with blown canopy or didn't until very late.
A Malcom style hood on the 109 might of done wonders for visibility and/or pilots ability to operate in the cockpit if even heading to towards being tall
fixing that rather appalling windscreen shouldn't have been that hard either. I mean it would be hard to actually do worse.

Wing fences probably won't do the job the the slats do.

three MG 131s is pretty poor armament. The MG 131 using the least powerful 12.7mm-13.2mm cartridge of the war. Lowest velocity=longest times of flight to target just to get hits.

Lack of trim tabs is harder to comprehend.

 

[pbehn]

So its a completely new design that enters service in 1941 when you need to contest the Spitfire immediately which outclasses the Bf 109E. That's not a good idea. Why not put a liquid cooled engine in the Fw 190.

Probably because if you do every additional new FW190 is one less Bf109.

 

[Kevin J]

Probably because if you do every additional new FW190 is one less Bf109.

I mean like a Jumo 213 or Db 603.

 

[pbehn]

I mean like a Jumo 213 or Db 603.

I didn't realise the Germans had a few thousand lying about.

 

[NVSMITH]

-A couple of things about the P-38 have always had me curious:
1) Why was so much effort wasted on the "Chain Lightning" when a balanced two seat cockpit made more sense? I don't mean the shoe-horn version made for the P-38M, but a real, extended but balanced, two seater.
2) Did anyone ever posit using radial engines on the bird? It would have made a heck of a ground attack ship given some pilot protection.

 

[NVSMITH]

-A couple of things about the P-38 have always had me curious:
1) Why was so much effort wasted on the "Chain Lightning" when a balanced two seat cockpit made more sense? I don't mean the shoe-horn version made for the P-38M, but a real, extended but balanced, two seater.
2) Did anyone ever posit using radial engines on the bird? It would have made a heck of a ground attack ship given some pilot protection.

 

[tomo pauk]

-A couple of things about the P-38 have always had me curious:
1) Why was so much effort wasted on the "Chain Lightning" when a balanced two seat cockpit made more sense? I don't mean the shoe-horn version made for the P-38M, but a real, extended but balanced, two seater.
2) Did anyone ever posit using radial engines on the bird? It would have made a heck of a ground attack ship given some pilot protection.

1. - The (X)P-58 was supposed to represent a new advance in performance and firepower. Like many aircraft before or after it, it was not exactly what people were expecting. It took time for realities of the war to settle in, too.
2. - I did It was hard enough for Lockheed to manufacture enough of V-1710-powered P-38s historically, so even if the radial-powered version is designed, it will not be produced until/unless there is a factory available to make them.

 

[pinsog]

I have always liked the P38, but it was a very difficult aircraft to maintain for ground personnel. I also like the idea of a radial twin engine fighter, but if your going to do that why not just turbocharge the XF5F Skyrocket?

Run the numbers against the only test we have on the Skyrocket using 2400 hp from SL to 25,000 feet instead of what it actually did and level speed matches a P38E almost exactly. Using overload weight of 10,900 pounds for the XF5F and adding 150 pounds of armor, 200 pounds for selfsealing tanks and 500 pounds for turbochargers you get 11,750. Add 62 gallon tanks in the outer wings like an F4U-1 and you have 400 gallons of fuel internal. 11,750 plus 750 pounds of fuel, say wing tanks and plumbing add 300 pounds and your at 12,800 pounds, 2000 pounds less than an early P38 with 100 more hp and 100 gallons more fuel. Climb should be terrific, top speed equal. No dive issues either, XF5F was dived vertically to 505 mph

 

[davparlr]

I have always been perplexed with the huge wing area of the P-59 an I tend to think that this was one of the major reasons the p-59 was a disappointment in top speed (the meteor may also have been limited by this). Here are some comparisons of early jets wing area:
P-59 386 sq ft
Me 262 234
P-80 237
Meteor 350
I think that if they had built the P-59, which appears to me to be a clean design with better engine airframe integration than either the Me 262 and Meteor, with much smaller wings, say like the P-63 wings (248 sq ft), the AF may have been surprised with the performance of the P-59 which may have been equivalent to the Me 262 and the P-80, and been more timely implemented in countering the Me 262. Since it flew only two and a half months after the Me 262 flew its too bad they didn't try it with smaller wings, they seemed to have time to do so.

 

[Shortround6]

The XP-58 saga was a tragedy of comic proportions or a comedy of tragic proportions, your choice

Go to Joe Baugher's web site.

Lockheed XP-58

Seldom in the course of human history have so many toiled so hard and so long for so little result.

 

[wuzak]

-A couple of things about the P-38 have always had me curious:
1) Why was so much effort wasted on the "Chain Lightning" when a balanced two seat cockpit made more sense? I don't mean the shoe-horn version made for the P-38M, but a real, extended but balanced, two seater.
2) Did anyone ever posit using radial engines on the bird? It would have made a heck of a ground attack ship given some pilot protection.

Why radial engines weren't really considered for the P-38:
https://static.thisdayinaviation.com/wp-content/uploads/tdia//2018/06/XB-38_engine.jpg
Vega XB-38 Archives - This Day in Aviation

That is the V-1710 installed in the Lockheed/Vega XB-38, formerly a B-17E.

The nacelle is designed for the R-1820, and you can see that there is a lot of space around the engine.

As to why radial engines weren't considered for the XP-58, that is a little less clear cut.

Originally it was intended to have the Continental IV-1430, which would have had a similar frontal area to the V-1710.

It was realised that the IV-1430 would be under-powered, so they changed to the Pratt & Whitney X-1800/XH-2600. That was taller, but narrower. It was also cancelled before the XP-58 program was too far along.

Next choice was the Wright R-2160 Tornado. This was a liquid cooled radial engine. It consisted of three 14 cylinder modules. The R-2160 was expected to make more power (2,500hp) than the best available radial (the R-2800) at that time. The R-2160 had a diameter of 36 inches compared to the R-2800's 52.5 inches.

The engine the aircraft actually flew with was the V-3420. At 2,600hp (Lockheed XP-58 Chain Lightning - Wikipedia says 3,000hp) the V-3420 was as powerful, or powerful, than the latest R-2800s.

Of the engines proposed for the XP-58, the V-3420 was closest in size to a radial which could feasibly power the aircraft - the R-2800 or R-3350. It was wider than the radials, but not as tall.

The XP-58 started out as a fighter, either 1 or 2 seat, but its role was being changed all the time. At the end it was to be a low altitude attack aircraft.

 

[wuzak]

The XP-58 saga was a tragedy of comic proportions or a comedy of tragic proportions, your choice

Go to Joe Baugher's web site.

Lockheed XP-58

Seldom in the course of human history have so many toiled so hard and so long for so little result.

So the R-2800 was actually considered, but it was thought that the performance would be insufficient.

 

[Shortround6]

I have always been perplexed with the huge wing area of the P-59 an I tend to think that this was one of the major reasons the p-59 was a disappointment in top speed (the meteor may also have been limited by this). Here are some comparisons of early jets wing area:
P-59 386 sq ft
Me 262 234
P-80 237
Meteor 350
I think that if they had built the P-59, which appears to me to be a clean design with better engine airframe integration than either the Me 262 and Meteor, with much smaller wings, say like the P-63 wings (248 sq ft), the AF may have been surprised with the performance of the P-59 which may have been equivalent to the Me 262 and the P-80, and been more timely implemented in countering the Me 262. Since it flew only two and a half months after the Me 262 flew its too bad they didn't try it with smaller wings, they seemed to have time to do so.

trouble is the early jets were real fuel hogs and

they carried 290 gallons of fuel in the wings. Range was a whopping 240 miles at 20,000ft with a cruising speed of 298mph (?)
A pair of 150 gallon drop tanks got you to 520 miles.

Cutting the wing area without cutting the fuel load can be done but you are going to have some short, stumpy wings.

 

[Zipper730]

Regarding the P-38,

P-38: elongated chord of the wing by 20% as suggested by NACA in 1941, coolers in the new leading edge...

The report that you posted listed March, 1942. That also corresponds with the time period that they modified the wind-tunnels in NACA for 0.75 mach. That said, it would have definitely been a nice touch.

Beaten to death: almost every alternative Fw 190 discussed has DB 603A in the nose by some time 1943.

Understood

Why was so much effort wasted on the "Chain Lightning" when a balanced two seat cockpit made more sense? I don't mean the shoe-horn version made for the P-38M, but a real, extended but balanced, two seater.

Like for a night-fighter?

Regarding the Hurricane & Spitfire,

The Updraft carb was probably a mistake in hindsight as any air intake on the bottom of the plane and 4-6 feet behind the propeller is going to catch all kinds of crud the prop blast/swirl kicks up, especially when the tail wheel comes up and the prop is only inches from the sod, dirt, sand, coral, etc, etc.

P-40s and Allison P-51s had the air intake on top and only inches behind the prop so their intake of self made grinding compound was much less, However formation take-offs needed care as your buddy's/wingman's plane could sure kick up enough crap to kill your engine.

Did the US use formation takeoffs to the same effect as the RAF? I'm curious because the RAF seemed to do that very liberally with fighters, and that would explain problems with dust and dirt.

Regarding the XF5F,

No dive issues either, XF5F was dived vertically to 505 mph

At what altitude did it reach 505 if I may ask? I'm just trying to determine mach number...

Regarding the XP-59,

I have always been perplexed with the huge wing area of the P-59 an I tend to think that this was one of the major reasons the p-59 was a disappointment in top speed (the meteor may also have been limited by this).

The reason had to do with the fact that, in order to achieve sufficient thrust, you'd need two engines.

This requires the aircraft to be able to fly decently well with one engine out, and that means L/D has to be low enough to allow the engine to keep the plane level at high altitude, as well as land adequately at low-speed, as well as the ability to keep the plane in a straight-line, but I have a hunch power was more of a concern here, for the following reasons.

• The P-59 & Meteor both had large wings (you list the Meteor as having a wing area of 350 ft^2, though that was from some of the Mk.IV's and on; the earlier's had a wing-area of 375 ft^2) and both had twin-engines, with different installation (P-59: In the wing-root; Meteor: At about 1/3 the span, give or take 10%).
• The Vampire & P-80 had enough engine power to fly with one engine, and both appeared to have smaller and more heavily loaded wings.

I think that if they had built the P-59, which appears to me to be a clean design with better engine airframe integration than either the Me 262 and Meteor

I'm not sure about that, the basic concept of mounting them in the roots isn't bad, but one of the following ultimately served to undermine it

1. Poor inlet design
2. Poor inlet-fuselage interface
3. Poor wing-inlet interface
4. Some mixture of the above

I would have favored a higher aspect ratio wing like the He-280, which would have allowed the same lift in less wing-area: It could exceed 500 mph: The problem with the P-59 was that, it was on a very quick time-table (approximately 9 months), using a new engine, and thanks to secrecy, they were not allowed access to the wind-tunnels at certain times.

They wanted to produce a design that was as simple as possible, without any unknowns.

trouble is the early jets were real fuel hogs and they carried 290 gallons of fuel in the wings. Range was a whopping 240 miles at 20,000ft with a cruising speed of 298mph (?)

If I recall their cruising speed was more like 395 mph, with a range of around 400 if I recall.

 

[pinsog]

No idea on altitude of XF5F 505 mph vertical dive. It was done on February 1, 1941 with "Connie" Converse as the pilot. He had dived it to 487 mph on January 31. All the info available

 

[pinsog]

I believe the problem with the Hurricane and Spitfire ingesting dirt was the intake was under the engine, the intake on a P40 for instance was on top of the engine. Imagine driving down a dirt road in a truck with the air intake either under the truck or on top of the hood. I think it was that simple of a problem

 

[wuzak]

As might be expected for such a revolutionary system of aircraft propulsion, there were serious problems right from the start. The jet engines were too heavy in relation to the amount of power they could develop, and their exhaust was so hot that the turbine blades regularly overheated and often broke off with catastrophic results. The maximum speed was 404 mph at 25,000 feet, somewhat below expectations. The engine installation was found to result in an inordinate amount of aerodynamic interference, and the aircraft was subject to severe directional snaking, making it a poor gun platform. Nevertheless, work on the P-59 continued unabated, and remedies were eventually found for its long list of faults.

The first YP-59A reached Muroc in June of 1943, and the USAAF gave the aircraft the name *Airacomet*. The first YP-59A flew in August of 1943. The YP-59A had more powerful 1650 lb. st. General Electric I-16 (J31) turbojets. However, the YP-59A showed little improvement in performance over the XP-59A. Empty weight increased to 7626 pounds, and maximum speed was a disappointing 409 mph at 35,000 feet. Service ceiling was 43,200 feet. The last four YP-59As had a heavier armament--three 0.50-inch machine guns and a single 37-mm cannon, which had been standardized for the production P-59A.

The production P-59A differed very little from the YP-59A. Only the first twenty of the P-59A order were actually completed as P-59As. Serials were 44-22609/22628. Most of these P-59As were powered by a pair of 1650 lb. s.t. General Electric J31-GE-3 turbojets, although the last few were powered by uprated 2000 lb. st. J31-GE-5 turbojets. The J31-GE-5-powered P-59A had a maximum speed of 413 mph at 30,000 feet and 380 mph at 5000 feet. Range on internal fuel was 240 miles, and range with two 125-Imp. gall. drop tanks was 520 miles. An altitude of 10,000 feet could be reached in 3.2 minutes, and 20,000 feet in 7.4 minutes. Weights were 7950 pounds empty, 10,822 pounds loaded, 12,700 pounds maximum. Dimensions were wingspan 45 feet 6 inches, length 38 feet 10 inches, height 12 feet 4 inches, and wing area 385.8 square feet. Armament consisted of one 37-mm cannon and three 0.50-inch machine guns, all mounted in the nose. In addition, two 1000-pound bombs or eight 60-pound rockets could be carried on underwing racks.

The twenty-first and remaining twenty-nine Airacomets of the P-59A order were completed as P-59Bs. Serials were 44-22629/22658. They had the uprated J31-GE-5 jets of the later P-59As, but had internal fuel capacity increased by 55 Imp gall. Maximum range was increased to 950 miles. Empty weight of the P-59B was increased to 8165 pounds and normal and maximum loaded weights were 11,049 pounds and 13,700 pounds respectively. The last P-59B was delivered in May of 1945.

Bell P-59 Airacomet

Specifications (P-59B)
Data from The American Fighter[17]

General characteristics

• Crew: one
• Length: 38 ft 10 in (11.84 m)
• Wingspan: 45 ft 6 in (13.87 m)
• Height: 12 ft 4 in (3.76 m)
• Wing area: 386 sq ft (35.86 m²)
• Empty weight: 8,165 lb (3,704 kg)
• Loaded weight: 11,040 lb (5,008 kg)
• Max. takeoff weight: 13,700 lb (6,214 kg)
• Powerplant: 2 × General Electric J31-GE-5 turbojets, 2,000 lbf (8.9 kN) each

Performance

• Maximum speed: 413 mph (359 knots, 665 km/h) at 30,000 ft (9,140 m)
• Cruise speed: 375 mph (326 knots, 604 km/h)
• Range: 375 mi (326 nm, 604 km)
• Service ceiling: 46,200 ft (14,080 m)
• Climb to 30,000 ft (9,140 m): 15 min 30 s

Armament

• Guns:
  • 1x 37 mm cannon
  • 3x .50 cal (12.7 mm) machine guns
• Rockets: 8× 60 lb (30 kg) rockets
• Bombs: 2,000 lb (910 kg) bombs

Bell P-59 Airacomet - Wikipedia

 

[Shortround6]

I believe the problem with the Hurricane and Spitfire ingesting dirt was the intake was under the engine, the intake on a P40 for instance was on top of the engine. Imagine driving down a dirt road in a truck with the air intake either under the truck or on top of the hood. I think it was that simple of a problem

The problem pretty much was that simple.

The solution was harder.

for the allison

carb is the black object at the top rear covered with some netting. Air can be brought from the front of the plane across the top of the engine and then one 90 degree turn and it is in the carb with a fair degree of ram.

for the Merlin with the updraft carb things are bit more complicated

Carb is in the bottom right hand corner of the picture and the air needs to be going up when it hits the carb inlet/s.
The under fuselage scoop works great in clean conditions, one 90 degree bend just like the Allison but trying to use a top mounted scoop means two more 90 degree bends or a 180 and the loss of some the RAM effect. For the Spitfire putting an air intake on the top pd the fuselage means a poorer view from the cockpit. You could try side inlets/scoops but you still need to get the air down to the bottom rear of the engine. Low mounted side scoops may not be that much of an improvement on a single engine plane.

Or design/copy a down draft carb and change a bunch of stuff on the back of the engine and in the engine compartments of the planes you want to use it in.