Alternate F4D WHIF

[KJ_Lesnick]

The F4D was as a very cool aircraft in a number of respects.  The aircraft was quite light, it had a very high thrust/weight ratio, an excellent roll-rate, highly-responsive flight-controls, and a light wing-loading which gave it the ability to accelerate rapidly, climb-like a rocket, and fly well even at very high altitudes -- it also gave the airplane remarkable sustained agility.  It also possessed a very advanced radar and fire-control system for its time, the APQ-50.  Unfortunately the plane was plagued with problems.  The engines the plane was designed to be powered with were lemons; they didn't produce as much thrust as advertised, their spool-up rates were slow, and the engine had a poor surge-margin, and ultimately a J57 was substituted instead.  The modifications and such seemed to have resulted in several years added to the development time (though I don't know if there were any issues with the APQ-50), with the aircraft not entering service until 1956 (When one would have expected such a design to have seen service by 1952-1953).  It was unstable and proved tricky to handle under virtually any circumstance, additionally, at low-speeds, like most delta wings, it flew at a high-alpha and resulted in the tail being blanked out, resulting in large wallowing motions during cross-winds.  The main landing-gear legs retracted asymmetrically producing a yawing motion, which generally resulted in wallowing motions at low-speeds.  The over the nose visibility requirements dictated a fairly short nose, the radar requirement dictated a properly shaped nose, and Douglas seemed to be a bit overly conservative (The F3H had a pointed nose, a radar and did just fine), and the aircraft, while it could apparently get supersonic in level flight, maxed out only at around Mach 1.2 to 1.4.  The cockpit was poorly arranged from the perspective of human-factors (which largely owed to the new radar technology, though the F3H Demon had a much better layout).

Ultimately Douglas developed a more advanced version of the F4D, which was originally called the F4D-2N, and later the F5D.  It had wings which were 30-percent thinner, it featured area-ruling, a longer nose, and a V-shaped canopy, internal fuel capacity was increased to the extent that the drop-tanks that became ubiquitous on the F4D, were unnecessary, the vertical tail was enlarged, avoiding much of the issues the F4D suffered with the wing-blanking much of the tail at low-speeds.  The aircraft was re-designed to be far more stable, and it's flight-controls re-designed to allow the same extraordinary maneuverability possessed by the F4D.  It was a truly superb design, and was capable of out-maneuvering the F8U at any altitude, particularly above 25,000 feet, and was two tenths of a mach-number faster.  Unfortunately, the design's performance overlapped the F8U's too much, the F8U had already generated quite a following, and it would be in service earlier, so it got the axe.

My idea would be to produce an "alternate history" F4D-like aircraft, which would perform the exact same roles the F4D was designed for (Point-Defense Interception/Air-Superiority), but would lack many of the short-comings, and possess much of the strengths the F4D had.  I'm envisioning a basic design coming in the form of a scaled up Northrop N-102 Fang with larger wings, and a length of 53-feet (which was about the same as the F4D and would probably be necessary to get the desired wing-area), without traditional tail-planes or a v-tail, and long-chord/short-span pitch-trimmers mounted as trailing-edge root-extensions (for a similar function exhibited on the F4D), and a single-vertical tail-fin of sufficient size.  Unlike the N-102, the aircraft would have it's engine nozzle right in the back, like on the F4D.  I am undecided about what kind of intake design to use, whether bifurcated or ventrally mounted

The N-102 Fang seemed to be a great design because it looked like it wouldn't land at too high an angle-of-attack judging by the shape of the nose even despite having a delta wing.  Delta wings work well at high-altitudes, at moderate airspeeds, a pointy nose also helps reduce low-drag a lot.

There are of course some issues in terms of realism. 

1.) I don't know how feasible a conically cambered wing would be in that timeframe (I don't know if the knowledge existed to produce such a shape from 1947 to 1951) and I'm not sure if the N-102 had a conically cambered flap (some of the line-drawings seem to suggest it, though I'm not sure). 

2.) The design would feature area-ruling.  Interestingly, there was some knowledge available in the United States as early as 1947 that regarded the uses of area-ruling, though I don't know how seriously it was taken.  By 1951-1952, Richard Witcomb seems to have re-discovered it, and it became much more common knowledge. 

3.) The J40 seriously screwed with the F4D and F3H design.  Unless the "alternate-history" Westinghouse went with a twin-spool engine design instead of a single spool development for it's J40, there's no way around it.


What do you think?
BTW:  Sorry I put it in the profiles and CGI section, I should have put it here.  I deleted the message in that forum, and moved it here.

[rickshaw]

It looks oddly interesting.  Any further info on it?

[MAD]

The Northrop F3T-1 SeaFang (from probably its only photogenic angle) 

Sorry Apophenia, but did you do this work of the SeaFangs or is it something you found on the web

M.A.D

[apophenia]

M.A.D: the SeaFang was a bit of nonsense I made up (and stuck over top of USS Forrestal).
[Image deleted to spare Upload Folder]

Somebody (on Secret Projects perhaps?) suggested that, had US designations nor been unified, naval F-5Es would've been F3Ts. The N-102 Fang preceded the Freedom Fighter so I nicked the designation for my SeaFang.

KJ: personally, I think the N-102 was a bit of a mutt. And there's more than one way to tail a delta. How about revising the F4D instead of dumping it? After all, Roland Payen was designing canard deltas in the '30s.

[MAD]

Thanks Apophenia for the clarification!
Personally I am a N-102 Fang fan, and had not heard of a proposed Sea Fang!
So your clarification clears that up!

Could I request your talent to possibly do me a modification of your 'Sea Fang' art? Please PM me if possible and willing

M.A.D

[KJ_Lesnick]

Apophenia,

Turning the Fang into something useable may be more work than is worth the bother. IMHO, the worst aspect of the N-102 was that gawky, long main gear.

I thought the N-102 was designed for the Navy (The N-156/F-5 was designed for the Air-Force) as a point defense interceptor that could operate off an escort-carrier deck?  Northrop had experience on building carrier-suitable aircraft (The SBD Dauntless was based on the Northrop BT dive-bomber; there were plans to modify an P-61 to carrier suitable requirements, and it only never operated off carrier decks because of the F7F Tigercat), and I never heard anything about the design being unsuitable for carrier use (If I recall it was cancelled because the Navy was junking it's escort carriers).  I could be wrong though.

Honestly, to me the characteristic that puzzles me the most is the delta-wing and the shape of the aircraft's nose.  Delta-winged aircraft tend to climb out and land at a high angle of attack, yet the shape of the nose does not suggest an extremely high angle of attack (The over the nose visibility requirements take angle of attack into account.  Look at the F5D skylancer for comparison)

[rickshaw]

Tailed deltas tend to have a lower angle of attack at low speeds than straight deltas.

[apophenia]

rickshaw: I think Kendra is refering to the tailless delta configuration of the Skyray. My point to her was that Payen's approach could be applied to the F4D design, turning it into a tail-first delta.

KJ: Yes, I know about the naval Black Widow, it's F2T designation partly inspired SeaFang.

Fang wasn't designed for the US Navy, it was a Private Venture interceptor. Northrop submitted the N-102 for a USAF lightweight fighter RFP - hence those mockup photos and company drawings displaying USAF markings.

Northrop's original, T-tailed N-156, and N-156N (N-165NN?) were for the US Navy.

BTW: for the Brits; the N-102 patent refers to the Avro 707-C wing 

[KJ_Lesnick]

Rickshaw,

Tailed deltas tend to have a lower angle of attack at low speeds than straight deltas.

Yeah, but I thought the trimmers could do the same thing a tail-plane could.  I guess there's some issue with downwash


Apophenia,

Yes, I know about the naval Black Widow, it's F2T designation partly inspired SeaFang.

Oh, okay

Fang wasn't designed for the US Navy, it was a Private Venture interceptor. Northrop submitted the N-102 for a USAF lightweight fighter RFP - hence those mockup photos and company drawings displaying USAF markings.

Oh...

Northrop's original, T-tailed N-156, and N-156N (N-165NN?) were for the US Navy.

Oh... perhaps I should re-consider my idea then.

[raafif]

the Ford (F4D) did originally have a longer, pointy nose but in pre-development the wooden mockup was posed in landing attitude in front of a painting of a carrier deck for a preliminary Navy inspection.  Someone sat in the cockpit while it was being hoisted up into position & realised that once in position he couldn't see the carrier at all !!  So they sawed off the nose until the guy could see the deck -- they left it till after the inspection to worry about how they were going to fit the radar in.

[KJ_Lesnick]

Raafif,

Yup.  That's why for an alternate F4D WHIF, I wanted something that had a lower AoA for landing.

[KJ_Lesnick]

Apophenia,

I had thought of
- A low-winged delta-wing with a high-mounted canard.
- A low-winged trapezoidal-wing with a high-mounted canard
- An F9F Cougar like design with big swept wings (with a similar aerodynamic profile to the F3H-2/F3H-3), large wing-fillets, an all-moving cruciform-tail, but with a longer area-ruled fuselage, a redesigned nose similar to the F-11A Tiger
- A single-engined, area-ruled, single-seat fighter, with a wing and tail similar to that of the English Electric Lightning

The United States first came across the concept of Area-ruling in 1946 with the Kuchemann Coke-Bottle; in 1947, Wallace D. Hayes published some articles regarding area-ruling as part of his PhD dissertation.  The knowledge was there before Whitcomb made his discoveries in 1951 or 1952.

[jcf]

The J57-powered F5D-1 was to lead to a later derivative with a GE J79 which promised greater range and fuel economy. To that end, a XF4D-1 testbed was flown fitted with a YJ79 in Dec 1955. The US Navy welcomed the potential speed and range enhancement but with no improvement carrier landing performance or pilot visibility forthcoming, no order was placed for F5Ds.

According to Naval Fighters Number Thirteen: Douglas F4D Skyray by Williams and Ginter, the J79 tests were done by
GE in support of the F-104 program. The aircraft were the XF4D-1s (124586 & 124587) and were bailed by the USN to the
USAF who then bailed them to GE. 587 was chosen to receive the J79 installation (in place of the J40) and 586 was used as
spares support. The J79 was tested for two years and in early 1958 the J79 was replaced by a CJ805 (civil J79) to support
Convair 880 development. In May of 1960 the CJ805, and test instrumentation, was removed and the airframe returned to
the Air Force, who returned it to the Navy.

124587 made 723 flights for a total of 1492 hours while equipped with the CJ805.

[apophenia]

Thanks Jon, that explains it (I was puzzled when I first saw the CJ805 ref).

And since we're now in the Real World, the F5D was ordered (although all but the prototypes and two pre-production examples were quickly cancelled). 

[jcf]

Evidently the old, non-afterburning CJ805 equipped XF4D-1 regularly waxed service USAF and USN fighters
in un-official dogfights.  Much to the enjoyment of the GE test pilots and embarrassment of the service pilots.

The Ginter book relates that a clean F-100 was the only aircraft able to give a good account of itself against the GE Ford,
"other than this, nothing could stay with the Skyray in a turn."