Improve That Design: How Aircraft Could Have Been Made Better

Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules

OK, now I'm a bit confused given the info in this post:


I wonder if the F and G figures got mixed up because the G being at least a 1000 lbs lighter than the H (maybe more?) and with similar power should out do the H in terms of climb, though by how much I don't know because to be fair such a comparison would need to be apples to apples.

I do agree that between having a bit more fuel, better aero and a better power to weight ratio, the F and G should, especially under cruse, get better range than a B or D until the fuselage tanks got introduced. That, however, wasn't reflected in the website's figures I found, which IMO may be proven to be in error. Also shows how much the LW Mustang development is a bit of a mystery/hasn't been covered in detail compared to other variants.
 
While I'd almost swear I remember part of this in a discussion before: The best part of the P-51H is that the center tank is better positioned. While it's smaller, it's still quite a benefit anyway.
 
Could there have been a way to strengthen the P-51H's and the other lightweight Mustang's landing gear without too much of a weight penalty or requiring a wing redesign or modification? That seems to be the only true weak point of those aircraft.
 
The F/G/J did also carry full armor, ss fuel tanks, and armament (4x.50 mgs). There's this schematic of the armor on both the F-82 and XP-51J and they carried the same protection.

Though the F-82 got ordered, the XP-51's didn't but they were developed into the longer range H model (F/G/J were more or less longer ranged point interceptors that weren't entirely suited for bomber escort). Drgondog would probably know more since he's done research on the LW Mustang and seems to be getting ready to write a book about them as well as the H and F-82
 
I also wonder if there was anything else that could've been done to improve even further the P-51H's and F-82's agility. From what I've read, especially given their size, they were very maneuverable, but could they maybe have been able to achieve DH Vampire levels of agility (Vampire F1s and F3s were apparently more maneuverable than Spitfires, namely the Spitfire XIV).
 

Jet engine in the nose, akin to this.
 
I only used the Vampire as an example, because the post I read about it claimed that it was down (at least in part) to the Vampire having a lower wing loading. And we do have to remember that aileron design was a bugbear of early P-51s. Maybe I should've said Bearcat levels of aerobatics, but then someone might say put a radial engine in it or something like that (the Fw 190s turn performance improved when the BMW 801 was dropped in favor of the Jumo 213).
 
I guess maybe a better metric is how maneuverable the Mustang (B/D, and H, maybe possibly the F and G) were compared to the P-40, namely the P-40Q? One thing that the P-40 (all variants) were praised for was their turn radius and roll rate (in spite of what was written about it by some commentators--actual USAAF and RAF reports speak positively about it's agility).

I know that the most important thing is that the plane overall outperforms enemy fighters. But things are sort of complicated in that the P-51B/D and even H were often seen as long range fighters, not interceptors (though they were all capable of it). Hence, we may not be seeing or at times making like for like comparisons. You'd need two planes flying in similar conditions to draw much of anything reliable out of it.

I did also mention the Vampire since in terms of weight as an interceptor was nearly the same as (or at least not much different) the P-51H in similar trim.
 
I have a feeling that would have been difficult short of redesigning the wings.
One thing that the P-40 (all variants) were praised for was their turn radius and roll rate (in spite of what was written about it by some commentators--actual USAAF and RAF reports speak positively about it's agility).
From what I recall the P-40's turn radius was slightly better than the Me-109. I'd imagine the Spitfire and Hurricane would easily crank right inside it.
 
compared to the P-40, namely the P-40Q
A real can of worms.
P-40Q went 9000lbs clean with ballast for four .50 cal guns and ballast for 235rpg. The guns were never installed, there were dummies or blast tubes in the wings.
Now the handling is a question, it is reported to have handled much better than earlier versions. But each wing had been clipped by about 1 ft and they added two feet to the fuselage, both in front of the Cockpit and behind. They had to make room for the longer two stage engine and they had to move the tail back to counter act the destabilizing influence of longer nose and 4 bladed prop. This also means that the tail surfaces (both horizontal and vertical) had longer movement arms.

They may have been running into drag problems. Despite the bigger prop and running the engine at 3200rpm and using water injection the "Q" didn't pick up very much speed until it got to thinner air. While climb improved by up to 530fpm. Benefit in climb was from 12,000ft to 32,000ft and benefit in level speed was from 20,000ft to 32,000ft.
Somehow that seems to be poor return for almost 300hp additional HP.

The first P-40Q had been built as a P-40K and was modified several times and used several engines. Nobody has said what the P-40Qs were actually stressed for (G load).
 
So they traded a competitive low altitude fighter for a mediocre high altitude fighter at the cost of its low altitude performance? Sounds like HCEI2* syndrome again.
(Have Cake, Eat It Too)
 
So they traded a competitive low altitude fighter for a mediocre high altitude fighter at the cost of its low altitude performance? Sounds like HCEI2* syndrome again.
(Have Cake, Eat It Too)
They might have had something if they could have got in into production in early 1943 and forgotten about the water injection.
But they had no intercooler so they were behind the two stage Merlin.
Instead of taking the 1180hp at 21,800ft they kept trying for more power down low and 1150hp at 25,000ft and without the intercooler things took too long to sort out.
Same problems helped delay the P-63. And by the time they were sorted out the Merlin P-51 had pretty much relegated them to 3rd place.

And here is some of the difference between BMEB and IMEP
To get 1325hp to the prop at even mid altitudes the fact that the engine has to make several hundred more HP in the cylinders to drive the aux supercharger means a much higher IMEP and all of it's problems.
 
Well, I guess I should ask how each Mustang iteration compared to each other (such as Allison vs first gen. Merlin (B/D) vs second gen. (lightweight and H)), and how they compared to other known fighters of their era of similar performance? For instance, the RAF said that the P-51B had a noticeably better turning performance than the Fw-190, but inferior roll rate. Or the P-51H vs the F8F Bearcat.
 
The USAAF has a performance test somewhere pitting the P-51B, P-38J, some P-47 model, Warhawk, and Airacobra against one another, and the B model did incredibly well: only the Airacobra and Warhawk outturned it, it could keep pace in a dive with the P-47, and speed and climb were both competitive with the US heavyweights.
here's 1 study (not the one I was talking about, but it does show the 38J and 51B: http://www.wwiiaircraftperformance.org/mustang/Performance_Data_on_Fighter_Aircraft.pdf)

here we go: http://cfsops.azurewebsites.net/Reference/P51B-flight-trial.cshtml


On a differentish topic, and one I've probably said before in some form.... to improve the A6M2 with as few "factory" modifications as possible, I'd install a small, 10mm x 10cm x 10cm piece of hardened sheet steel behind the pilot's headrest. This is far from a perfect armor arrangement, but the part of the plane-pilot system that is most vulnerable to immediate incapacitation is the pilot's head. As such, that is the first place that should be protected. Attempting to install a bullet resistant windscreen would require some form of extra development and factory parts, but a "quick and dirty" armored headrest could be installed with relatively little in the way of specialized parts, and would protect pilots from surprise attacks from the rear, giving them a chance to react and make use of their superior performance at this point in the war to quickly turn the tides
 
ahhh - do you think 40mm will stop .50 API? or even ball?
 
My wallet is 8cm x 11cm.
To heck with the thickness, you need 3 times the area just to protect the head/neck. (still leaves the ears sticking out ) and that is from a 6 o'clock firing position.

Anything off to side is going right passed.

Back and head armor that stops .30 cal is not that heavy. 12-15lbs for 30cm x 30cm.
Back armor that is set up so that the bullets have to go through things, battery/radio/flare tube, etc that will disrupt the fight bath, (make the bullet tumble) are much more effective.
head for bubble canopies is harder but with the smaller area isn't that heavy if done as a separate thickness.

BP glass is heavier per unit of area.
 

Users who are viewing this thread