KJ_Lesnick
ACCESS: Top Secret
- Joined
- 13 February 2008
- Messages
- 1,042
- Reaction score
- 97
I'm wondering if anybody has any idea how the F-108 would have behaved from a maneuverability standpoint?
I understand a version of the F-14 (when it was still the VFX) was offered to the USAF as an interceptor at one point. Although details are rather rare, in fact I only have one photo of it. When exactly did the USAF decide they didn't need a true interceptor?
SOC said:I think the USAF decided it didn't need (or maybe didn't want to pay for) the AWG-9/AIM-54 combination. The F-14 proposed to the USAF would've retained both. It wasn't a direct F-15 competitor if I remember right, but maybe an F-106 replacement? Then again they could've both been competing with each other to a small degree, F-14s and F-15s in various guises were offered to both services.
F-14D said:SOC said:I think the USAF decided it didn't need (or maybe didn't want to pay for) the AWG-9/AIM-54 combination. The F-14 proposed to the USAF would've retained both. It wasn't a direct F-15 competitor if I remember right, but maybe an F-106 replacement? Then again they could've both been competing with each other to a small degree, F-14s and F-15s in various guises were offered to both services.
Hey! It was a Navy plane! AF didn't want to buy those (F-4 was forced on them, A-3 had to be turned into B-66 to be acceptable, and although A-7 was really perfected by AF in the A-7D version, they had an unseemly haste to get rid of it). Besides, there was the perception that if any version of F-14 was used by AF, it would threaten funding for F-15. Given the climate of the times, this was probably correct.
Rosdivan said:F-14D said:SOC said:I think the USAF decided it didn't need (or maybe didn't want to pay for) the AWG-9/AIM-54 combination. The F-14 proposed to the USAF would've retained both. It wasn't a direct F-15 competitor if I remember right, but maybe an F-106 replacement? Then again they could've both been competing with each other to a small degree, F-14s and F-15s in various guises were offered to both services.
Hey! It was a Navy plane! AF didn't want to buy those (F-4 was forced on them, A-3 had to be turned into B-66 to be acceptable, and although A-7 was really perfected by AF in the A-7D version, they had an unseemly haste to get rid of it). Besides, there was the perception that if any version of F-14 was used by AF, it would threaten funding for F-15. Given the climate of the times, this was probably correct.
I believe I've also seen it mentioned before that the F-15 option was cheaper, while their was a spirit of "Ignorance is bliss" when presenting that fact without mentioning that F-14 with AIM-54 was far more effective.
Speaking of A-7s though, what happened to the A-7F info you kept promising?
Real fast in a straight line. It was not designed to be a dogfighter.
KJ_Lesnick said:Orionblamblam,
Real fast in a straight line. It was not designed to be a dogfighter.
Instinctively, I would normally be inclined to agree with you, but when you consider that
- Interceptors, such as the F-102A and F-106A, which despite being exceptionally fast, were actually quite agile -- and from what it would seem had a number of the dedicated air superiority fighters of the century-series beat in terms of maneuverability.
The XF-108, like the F-102A and F-106A, had delta wings, with very large wing-areas (650-700 square feet, IIRC for the F-102A and F-106A, and like 1800 or 1900 square feet for the F-108)
KJ_Lesnick said:Orionblamblam,
Real fast in a straight line. It was not designed to be a dogfighter.
Instinctively, I would normally be inclined to agree with you, but when you consider that
- Interceptors, such as the F-102A and F-106A, which despite being exceptionally fast, were actually quite agile -- and from what it would seem had a number of the dedicated air superiority fighters of the century-series beat in terms of maneuverability.
- The XF-108, like the F-102A and F-106A, had delta wings, with very large wing-areas (650-700 square feet, IIRC for the F-102A and F-106A, and like 1800 or 1900 square feet for the F-108)
KJ Lesnick
They were also *relatively* small.
The F-108 was much more like the B-70, which coudl hardly be described as nimble... especially at Mach 3.
As they say in Starfleet, "Faster than light, no left or right." Maneuvering at such high speeds is not advisable.
That's true, in the sense that a delta wing usually has a higher instantaneous turn rate than a conventional winged aircraft, but they suffer in sustained turn rate due to the large drag created by the vortices shed over the leading edge which give them good high alpha capability, in a similar sense as strakes induce over the wing of modern fighters.
But, unlike modern fighters with strakes, the older delta's were limited by lack of control power and a limited T/W ratio.
The F-106 was a better dogfighter than the F-4 above approximately 32k ft., mainly due to it's large wing area.
However, below 32k ft., the F-4 had the advantage.
Almost a whole page of posts about the F-108 Rapier flight performance and no one's mentioned wing loading?
But at lower speeds with a combat weight of around 75,000 lbs (50% fuel) it would have a wing loading of 40 lb/sqf and a thrust to weight ratio of 0.78 which is much better than a Miro (Mirage IIIE) at combat weight (~19,000 lbs) with 50 lb/sqf wing loading and TW of 0.68.
So the F-108 could potentially outfly circa 1960 no. 1 hotrod.
KJ_Lesnick said:Well, I'm guessing you're just taking the wing-area figures and dividing that by the weight of the aircraft -- that isn't actually the only factor that determines wing-loading.
The Mirage IIIE was the most maneuverable fighter in the world?
Ahh actually it is. The only other variable in wing loading other than wing area and weight is gravity and since we aren't flying on Mars its pretty much a given... Wing loading is however not lift or drag or the overall aerodynamic performance of an aircraft.
Probably not, but it was the best selling fighter jet of the early 1960s. This was because of its superlative performance in air combat manoeuvres.
A more similar aircraft to the F-108 that actually flew was the Avro Arrow. It was capable of a sustained 2G turn at Mach 1.5 and 50,000 feet without loss of speed and altitude.
The F-108 would have a similar sustained rate of turn thanks to its wing loading (better) and TW (lower).
KJ_Lesnick said:What airspeed would Mach 1.5 at 50,000 feet amount to, roughly?
KJ_Lesnick said:At least if you just measure out the wing-loading figures, the CF-105 has a lighter wing-loading than the F-108
Using the US Standard Atmosphere 1976 it would be 860.3540095850143 knots (TAS) which is 1,593.375 6257 kph.
KJ_Lesnick said:When I said airspeed, I meant like equivalent airspeed.
Abraham Gubler and KJ_Lesnick,
please don't go personal
KJ_Lesnick said:At altitude, the air gets thinner so the airspeed levels read lower, not to mention there's less airflow over the wing. Indicated Airspeed is commonly used but to my knowledge Equivalent Airspeed better factors in compressability effects...
pometablava said:please don't go personal
Of course... but what's your problem? I've given you the Mach number and the altitude? After further sponging I've given you the TAS... Why can't you work out the EAS? Its just a formulaic relationship...
I didn't exactly pull out a slide rule to work out the TAS!
I'm not personal I'm just dismayed at KJL's conduct. Apart from the constant sponging - made worse by him taking answers and then posting them on another forum (What If) - he is making demands of me to work out the particular airspeed he wants...
KJ_Lesnick said:Abraham Gubler,
Of course... but what's your problem? I've given you the Mach number and the altitude? After further sponging I've given you the TAS... Why can't you work out the EAS? Its just a formulaic relationship...
Pometablava has specifically instructed me not to say anything personal, so I will try to avoid that.
With that said, I do not know the formula to convert TAS to EAS, I only know of some basic rules of thumb... M=0.95 @ 25,000 is about 350 kts, and M=1.0 @ 60,000 feet is about 196-198 kts.