I was thinking about the A4D-6: It was the competitor to the A-7 Corsair
The requirements did specify the plane had to be based on an existent design, but neither Vought nor Douglas really followed it to the letter and basically paid lip-service to the requirement. The aircraft did superficially look like the designs they were based on, but were in reality, very different planes.
The A-7 certainly turned out to be a fine aircraft, with a heavy-payload and the ability to get the living daylights beaten out of it and still return home; the A4D-6 looked to have a number of advantages in that
(provided it was anything like the other A-4's) it had the potential to be more maneuverable, reducing the odds of it getting hit, increasing it's odds to hit its target with it's, albeit inferior, payload.
That being said, I'm wondering if Douglas could have managed to done any of the following
- Stuff more hardpoints under the plane and/or strengthen the existent hardpoints
- Strengthen the plane for damage resistance and/or carry the extra payload by either modifying the existing structure
- Strengthen the plane to take more damage and/or carry extra-payload re-designing various load bearing components of the plane (spars, wings, parts of the center fuselage): After all, both Vought and Douglas paid lip-service to the requirement that it be based on an extant plane...
So as to effectively produce an A4D-6 with an A-7's payload :icon ninja:
The only remaining issue would be maneuverability (both sustained and instantaneous) for the baseline A4D-6: The aircraft would have been heavier than the earlier A-4's which would mean more inertia
(most importantly pitch; roll would probably still be excellent), though the aircraft was significantly different than the earlier A4D's
(Most likely, this would mean redesigned and, hopefully, more effective control surfaces). Though the wing was redesigned, I'm not sure how much bigger or more efficient it was, so it's wing-loading might very well have been heavier; the TF30 was more powerful, but I'm not sure how it factored against the wing
(turbofans also generally lose more thrust at altitude than do turbojets of the same sea level thrust) which might raise implications for sustained turning performance.
For the A4D-6 with an A-7 payload: Even if the baseline had no significant problems
(extra thrust offset the extra weight at all altitudes, wing either was slightly larger or more effective, or offset by the extra thrust; more effective control surfaces dealt with inertia issues), a problem would almost certainly appear in this case. The solutions could include any of the following
- Redesign the slats with a hinge: Effectively it's like a slat with a leading-edge droop. It adds more camber to the wing allowing more lift when they are extended
- Increase the wing-area a bit more: This would have the side effect of pushing the span over the amount needed to avoid a wing-fold. Regardless, if the ailerons aren't extended beyond the 27-something foot area, the fold line will be outside the aileron hinges and I'm not sure how much extra weight this will add for the extra square footage
While long winded, I'm curious as to people's opinions of the feasibility of this fictitious idea for it's time and place...