Horton HO 229 Vs Vampire...

[kool kitty89]

The Vulcan (and B-58, space shuttle, etc) are more akin to the DFS194 and Me163 as the B-2 was to the HoIX, YB-35 and YB-49 types.

The DM-1 or P.13a might be even more applicable given those are all tailless delta wing configurations rather than tailless swept wings. (Northrop's XP-56 is more akin to the swept wing tailless designs used earlier by Lippisch and on the Me 163 -shame Northrop didn't follow that up with a Jet powered aircraft more similar to the XP-56 rather than the more flying-wing-like XP-79)

For that matter, using a much more highly swept delta configuration (with or without fins -but likely some de-facto vertical stabilizers from engine bulges and cockpit) likely would have made for greater stability than the higher aspect ratio and lesser sweep used by the Horten Brothers. Granted, high aspect ratio is critical for good subsonic lift to drag ratio and given the Horten brothers' experience with gliders, it's not surprising they focused more on that.

I wonder if a tailless delta design might have progressed more quickly than the flying wing, especially one with not only fins but proper rudders as well. (with heavy use of wood in construction, the added stealth potential could still be relevant as well -though plenty of other wooden jet designs would allow for that as well, minimizing cockpit cross section for radar visibility would be more significant)

There is only a little truth to the tailless claim. Wings have pressure distribution: much of the upper surface of a wing has a lower pressure than ambient and much of the lower a higher pressure. This generates a wings lift and also its lift distribution (ie pitching moment). As the wing approaches the speed of sound the behaviour of the air becomes non linear, compressible and so the centre of lift moves aft to the shock wave. The aircraft is now nose heavy an may not be able to pull out of a dive. P-38 and P-47's could end up in death dives. The improvised solution was to introduce dive recovery flaps under the leading edges to pitch the wing up.

Spending extended periods within the transonic range above critical mach but below supersonic is one of the biggest problems both for losing control and for stressing the airframe (particularly due to shifts in center of lift that put stress and pressure distribution in ways the airframe was never intended for).

For the few early transsonic aircraft potentially capable of flying through mach one (drag/thrust wise) it was steep (but well short of vertical) near-limiting dives that were most dangerous, 45% dives would be particularly bad. Very shallow dives might allow enough time to slow/correct while in the transsonic range but short of that, getting locked into mach tuck in near level flight could be even worse due to the longer extended period of stress/strain.

Vertical dives are one of the few scenarios where it might be possible to break the sound barrier and regain control long enough to recover, slow down, and ride out the stresses back to sub-critical mach quickly enough to maintain structural integrity. (this was at least theoretically possible on the Me 262 -and there's some pilot accounts that fit well with the expected flight behavior in such situations- and possibly the Me 163 as well)
As far as I know, high-acceleration vertical dives were never attempted on the DH 108, and the potential for it safely breaking Mach 1 rather than tearing itself apart in sustained Mcrit stress was never tested. (likewise vertical dives were avoided during the X-1's testing program ... or even steep unpowered dives it seems -slightly odd as I'd have thought that would have significantly accelerated research prior to the rocket motor being ready, probably capable of breaking mach 1 unpowered too, at least with enough ballast for 'thrust' even with the thicker initial wing - 10% thickeness:chord rather than 8%)

I'm not sure if the De Havilland Venom ever dived through Mach 1, and while it's limiting mach was in the same .84~.86 of the Me 262, it still seems like it should have been able to break the sound barrier and recover under the right conditions. (and it did use a thinner airfoil than the Me 262)
I know the CF-100 managed it. (not sure if the F-94C or F-89 did)

The Vought Cutlass was a tailless supersonic design, Americas first supersonic, after burner equipped, missile carrying fighter was tailless. It had problems but they came from the under powered engines and systems.

While the tailless delta winged F4D Skyray was well known for its good handling characteristics, or even being a joy to fly.

 

[Edgar Brooks]

As far as I know, high-acceleration vertical dives were never attempted on the DH 108, and the potential for it safely breaking Mach 1 rather than tearing itself apart in sustained Mcrit stress was never tested.
I'm not sure if the De Havilland Venom ever dived through Mach 1, and while it's limiting mach was in the same .84~.86 of the Me 262, it still seems like it should have been able to break the sound barrier and recover under the right conditions. (and it did use a thinner airfoil than the Me 262)
I know the CF-100 managed it. (not sure if the F-94C or F-89 did)

Immediately post-war, the then government banned all supersonic flight, and, by the time this order was lifted, the 108 had gone, and the Vampire and Venom were obsolescent.

 

[kool kitty89]

Immediately post-war, the then government banned all supersonic flight, and, by the time this order was lifted, the 108 had gone, and the Vampire and Venom were obsolescent.

That wouldn't apply to the suggestion of attempts at unpowered high mach or supersonic dives in the X-1, but yes, the British Government made a lot of odd, unfortunate, and often short-sighted decisions immediately post-war.

 

[FLYBOYJ]

I know the CF-100 managed it. (not sure if the F-94C or F-89 did).

I was told by Tony LeVeir that the F-94 did go supersonic. He told me he once raced Chuck Yeager (who was flying an F-86) in a diving race in an F-94C without the wing tip pods and beat him.

AFAIK the F-89 was not able to go supersonic.

 

[Koopernic]

I was told by Tony LeVeir that the F-94 did go supersonic. He told me he once raced Chuck Yeager (who was flying an F-86) in a diving race in an F-94C without the wing tip pods and beat him.

AFAIK the F-89 was not able to go supersonic.

The F-94C had a new thinner wing compared to previous models. One could see that Kelly Johnson was heading down the alternate route of ultra thin wings to achieve supersonic flight, the next aircraft Lockheed produced was the F-104 Starfighter and so the F-94C can be seen as part of the progression to the F-104.

Straight wings are in fact regarded as superior above Mach 2.5, the swept wing has become the province of the transonic airliner. The F-18 has a straight wing.

 

[Milosh]

The F-18 has a straight wing.

It does?

 

[GrauGeist]

The F-18 has a straight wing.

The EF-10, F9F and F2H had straight wings, the F/A-18 has a trapezoidal swept wing.

 

[kool kitty89]

The EF-10, F9F and F2H had straight wings, the F/A-18 has a trapezoidal swept wing.

Most modern supersonic aircraft opted for some compromise between full delta wing and low aspect ration tapered (trapezoidal) straight wings, be it tailed, canard, or tailless using elevons. I'm not sure 'swept' would quite apply to the F-16, F-18, or F-5, aside from there technically being some degree of leading-edge sweepback. (the F-16 almost a tailed delta, though, given its greater sweep)

The F-22 and F-15 are more tailed delta in configuration, closer to the F-4 (though the F-22 has a lot of trailing edge taper). F-35 is somewhere in-between.

Wings like the F-104 used were ideal for supersonic flight, but without compromise for the sub and transonic performance range.



But either way I should clarify that my previous comments on straight-winged aircraft was specifically for (relatively) high aspect ratio sub/transonic aircraft capable of controlled supersonic dives.

I believe the F-80 (and T-33, and F-94A/B), Meteor, F-84, F2H, and F9F (straight wing) had critical mach numbers low enough to put too much drag or stress when approaching mach 1 to be able to safely punch through it. The Vampire definitely so, not sure of the Venom.

 

[Koopernic]

The EF-10, F9F and F2H had straight wings, the F/A-18 has a trapezoidal swept wing.

Perhaps by that definition a Curtiss P40 and Mirage III BOTH have a trapezoidal sweep wing?

The F18 has no trailing edge sweep, unlike an Su 27 or Thundercheif. You could argue that the trailing edge forward sweep is less than the leading edge backward sweep as what constitutes swept.

Either way, it's hardly swept at all and probably would have been impossible in aeroelastic terms untill the 60s but I grant you enough sweep to require dogtooth leading edges.

 

[tyrodtom]

This has been one confusing thread.

Horton 229 verses the DH Vampire.

The Horton, only 3 made, and only how many flights between those 3 ? 3 ? 4? 5?

And the Vampire over 3200 made, maybe 100,000 flights between them at least.

And the Vampire has had only how many remarks in the whole 9 pages of the thread ?

 

[GrauGeist]

Perhaps by that definition a Curtiss P40 and Mirage III BOTH have a trapezoidal sweep wing?

For someone who "appears" to have a certain amount of knowledge of aicraft, that comment is just stupid. So is saying that the F/A-18 has a straight wing.

Surely you can do better than that.

 

[Koopernic]

This has been one confusing thread.

Horton 229 verses the DH Vampire.

The Horton, only 3 made, and only how many flights between those 3 ? 3 ? 4? 5?

And the Vampire over 3200 made, maybe 100,000 flights between them at least.

And the Vampire has had only how many remarks in the whole 9 pages of the thread ?

I'll have a go at that. The Vampire was slow, slower than the Meteor, Slower than the Me 262. If confronted with the Arado 234C hauling bombs or a 'true' bomb hauling Ho 229 (not the Ho IX test beds being restored) it wouldn't have been able to intercept it either.

It apparently was manoeuvrable, more so than the Meteor.

The question would be What would the Vampire be like in September 1944, which I am estimating as a plausible entry into service for the Ho 229 with Bombay. My guess would be that the Vampire would be still too slow. DeHaviland's did apparently make improvements.

 

[FLYBOYJ]

I'll have a go at that. The Vampire was slow, slower than the Meteor, Slower than the Me 262. If confronted with the Arado 234C hauling bombs or a 'true' bomb hauling Ho 229 (not the Ho IX test beds being restored) it wouldn't have been able to intercept it either.

It apparently was manoeuvrable, more so than the Meteor.

The question would be What would the Vampire be like in September 1944, which I am estimating as a plausible entry into service for the Ho 229 with Bombay. My guess would be that the Vampire would be still too slow. DeHaviland's did apparently make improvements.

The Vampire was slow when compared to other fighters of the day but consider maneuvering speeds and acceleration during a close in dog fight, that was advantage the Vampire had, sought of like the Zero. Folks I've know who flew them told me they would out accelerate a Meteor and T-33.

This guy has a good story about one flown in private hands, the owner Al Letcher is an old friend.

Model Airplane Memories: Al Letcher's Mojave Meteor and Vampire in 1/48 Scale

 

[Koopernic]

The Vampire was slow when compared to other fighters of the day but consider maneuvering speeds and acceleration during a close in dog fight, that was advantage the Vampire had, sought of like the Zero. Folks I've know who flew them told me they would out accelerate a Meteor and T-33.

This guy has a good story about one flown in private hands, the owner Al Letcher is an old friend.

Model Airplane Memories: Al Letcher's Mojave Meteor and Vampire in 1/48 Scale

Unfortunately there is a tendency to focus purely on top speed as a figure of merit and thence perhaps after turning circle. Yet many factors such as climb rate are just as important and even control harmony factors highly.

If the Ho 229 had of fulfilled its expectation as bomber I suspect the Vampire would not have been the best aircraft to use against it. I don't believe the Ho 229 was seen as a fighter by the Luftwaffe apart from maybe a night fighter. Tailless designs are generally not known for exceptional manoeuvrability since the elevons or ailervators are now acting to reduce lift over the main lifting surfaces. They do have a low wing loading. Deltas such as the F-106 can generate extraordinary high amounts of lift and good tight turns but they soon wash of speed and I suspect that flying wings might be the same.

 

[kool kitty89]

Perhaps by that definition a Curtiss P40 and Mirage III BOTH have a trapezoidal sweep wing?

The F18 has no trailing edge sweep, unlike an Su 27 or Thundercheif. You could argue that the trailing edge forward sweep is less than the leading edge backward sweep as what constitutes swept.

Either way, it's hardly swept at all and probably would have been impossible in aeroelastic terms untill the 60s but I grant you enough sweep to require dogtooth leading edges.

The Saab J29 was only modestly swept and featured a dogtooth, the Venom (which I'd lumped in with straight wings) used wing fences and was only about as 'swept' as the Me 262. (didn't manage a better critical mach number either, though that may not be a fault of the wing -same for the Me 262, I believe it was the fuselage that brought critical mach down to .86, or possible wing-fuselage interaction; I'm not sure if the wing root extensions of the HG-I increased the mach number or just decreased transonic drag in general)

For that matter, the modest sweep on the DC-3 may have been enough to gain some advantages from wing fences, at least considering the Venom.

I'll have a go at that. The Vampire was slow, slower than the Meteor, Slower than the Me 262. If confronted with the Arado 234C hauling bombs or a 'true' bomb hauling Ho 229 (not the Ho IX test beds being restored) it wouldn't have been able to intercept it either.

It apparently was manoeuvrable, more so than the Meteor.

The question would be What would the Vampire be like in September 1944, which I am estimating as a plausible entry into service for the Ho 229 with Bombay. My guess would be that the Vampire would be still too slow. DeHaviland's did apparently make improvements.

In 1944, say the Vampire managed to get into service with the 2,700 lbf Goblin I at similar performance to the initial production Vampire I of 1945 and you've got something considerably faster than the Meteor III, even with the long nacelles, though perhaps slower once the 2,400 lbf Derwent IV is ready. (assuming there's no re-examination of the metrovick engines with the 2,700 lbf F.3 seeming to manage acceptable reliability with the adoption of flame cans).

Acceleration will be poorer due to the lower thrust to weight ratio than anything save the Welland powered Meteor, and range was limited with the initial fuel capacity as well. Wing loading is lower, so stall performance and zoom-climb may be better, and roll rate will probably be better than any jet short of the He 162, and maybe P-80A. (granted, XP-80 development is one of the things that slowed Vampire development in the first place, with diversion of the few working Goblin engines -- had the Goblin itself been higher priority and more heavily funded, this may have been different ... licensed production -and possibly expanded testing/development- though Rolls Royce may have been necessary to really accelerate goblin time to production though)

Roll rate is a big deal to be sure, and with high-speed/energy tactics being the norm for jets (more so than piston engine fighters of the era), roll rate would be more important than sustained turning ability.

Deltas such as the F-106 can generate extraordinary high amounts of lift and good tight turns but they soon wash of speed and I suspect that flying wings might be the same.

The low aspect ratios of delta wings (and extremely poor lift to drag ratio at high AoA -utilizing the wingtip vortex phenomenon) makes for higher drag in these situations than the likes of high aspect ratio flying wings.

Good for high AoA take-off and landing, not so much for turning. (the delta platform itself would have probably been a much more practical design route to persue as aggressively/intensively as the Horton's flying wing concept, even before the supersonic performance advantages were realized -sweep for stability as adopted on earlier tailless designs, but larger area and space for internal stores as well as higher strength and potentially simplified construction)