Forum: F-16 Procedures

ACMIguy wrote:

Talking speed....did someone forget the SR-71? Not Worthy

Naw, this is still evolving Wink

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SR-71's a nice jet, but the A-12 takes the cake Thumb

! Only jet I know of that routinely hit 90+K feet and Mach 3.2+ during training and was able to withstand having the gear dropped at Mach 3.2 Cool

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a plane that, when you take the pilots words for it, had an operational speed of 3.6 Mach! Thats a F***ING fast plane!!

Aw, nobody wants to mention the wonderful MiG-25 Foxbat? Crying or Very sad

I love MiGs and Sukhois, but even a fast load is a load nonetheless. Laughing

Anyone want to take a wager as to how fast an SR-71 could *sustain*
flight at say 500-1000 feet AGL? Say, sustained 1,000-1,150 mph ground speed...
It most certainly had the aero/thermo dynamics to deal with heating issues
involving high speed flight, but I always wondered how fast it could sustain
flight at low altitude.

jetblast16 wrote:

Anyone want to take a wager as to how fast an SR-71 could *sustain*
flight at say 500-1000 feet AGL? Say, sustained 1,000-1,150 mph ground speed...
It most certainly had the aero/thermo dynamics to deal with heating issues
involving high speed flight, but I always wondered how fast it could sustain
flight at low altitude.

At low altitude, the J58s would consume MASSIVE amounts of fuel. Don't forget in the thin air up around 90K feet the engine's fuel flow is dramatically low compared to take-off.

Two Cents

I would think the ride would be so rough at low level, the aircraft (and crew) would be pounded to death in no time. The best place to run fast is up high, in smooth cold thin air. Cool

jetblast16 wrote:

Anyone want to take a wager as to how fast an SR-71 could *sustain*
flight at say 500-1000 feet AGL? Say, sustained 1,000-1,150 mph ground speed...
It most certainly had the aero/thermo dynamics to deal with heating issues
involving high speed flight, but I always wondered how fast it could sustain
flight at low altitude.

The effect of air density (i.e. altitude) can never be ignored when making these kinds of comparisons and extrapolations...

For instance: Mach 3.2 at 80K sounds fast, and it is - in reference to the ground (over 2,100 mph groundspeed). In reference to dynamic pressure (aka qbar, an indication of the number of air molecules the airplane is 'hitting' in a given time ), though, it's not that fast. At 3.2/80k, qbar is only about 420 psf, or about 440 Knots calibrated. To put that in perspective, at low altitude (say 500 feet MSL) that same qbar corresponds to a whopping Mach 0.54 (about 350 Knots calibrated).
Again, for reference, your 1,000-1,150 MPH groundspeed (for low altitude flight) corresponds to 'only' Mach 1.32-1.51 (numbers that aren't too out-of-bed for recent/current high performance aircraft). The qbars for these speeds range from about 2500-3330 psf, or about 6 to 8 times higher than the 3.2/80K point. So, if you were to make the conservative assumption that the SR-71 had no Mach drag rise at all (i.e. Cd was the same everywhere) it would still need (roughly) 6-8 times as much thrust (for 1.51 down low, versus 3.2 at 80k).
In short, you would need a lot of missing information to make a reasonable estimate - most notably engine performance versus Mach and altitude, but my gut feel is that with engines optimized for high altitude, high supersonic flight, the performance down low would be nowhere near Mach 1.3.... But of course, it's fun to speculate...

parrothead wrote:

ACMIguy wrote:

Talking speed....did someone forget the SR-71? Not Worthy

Naw, this is still evolving Wink

.

SR-71's a nice jet, but the A-12 takes the cake Thumb

! Only jet I know of that routinely hit 90+K feet and Mach 3.2+ during training and was able to withstand having the gear dropped at Mach 3.2 Cool

I know you have great affection for that one Parrothead In Love

we've talked about this before I think.
I also admire the MIG 25 and 35 for their pure brute force in flight. With all those rivets and exposed steel panels sticking out and it still could do M3.
It would have been nice to see what it could do had they cleaned them up aerodynamically Cool

To bad we don't have the figures on that space saucer at Area 51 to compare low level speed with. Whistle

Those were rather poor comments about the old F104, Straight line speed and all. Too bad those making such comments obviously haven't any time in the type or you'd have a different [Link pending approval] you'd know other tactics to employ instead of turning square corners. For what it had (avionics wise) and little armament, it was very capable of holding its own. And probably could hold its own against an F-16 prior to Block 52.
Cheers,
ZipperPs

Zipper, I take it from your name that you are an F-104 fan and new the F-16.net. Welcome!! The Starfighter had a wing that was too small and too thin to produce the lift needed to REALLY turn, what it had was the lowest Cdo possible, which when combined with the small wing area means it had less drag than most anything. As such it could really haul a$$ and fight using energy tactics. You mention none of us having flown them, have you? if so by all means share stories, we love em. Again, welcome to the boards.

I joined the 2.5 club in the back of a F-4E in 79. Beer

From reading section V of the SR-71A-1, I couldn't find anything other than max airspeed of 425KEAS or Mach 3.2 "unless otherwise authorized by the Wing Commander". The SR-71 was not aerobatic, couldn't pull a lot of g's, and I truly believe that its max airspeed was in the 425kt range whether equivalent or indicated. In other words, it was not supersonic at low level.

I have heard that on at least one occasion the Blackbird has made supersonic passes before an audience. This makes me wonder. I glean my information from www.sr-71.org which has the dash one available on line.

This is in contrast with most fighters from the F-105/106 onward which have airspeed/mach limitations listed as approx. "800 KIAS or Mach 2.XX, whichever comes first". That would indicate to me that a Viper will easily outrun a Habu at low level.

I had the "honor" of being in General Davis's retirement parade at Offutt afb in 1985. Part of the ceremony was a flyby of all SAC aircraft including the SR71. He was the last of the birds to make his pass but was much more memorable than the parade of 135 variants and the buff. Near as I could tell without turning my head (I was at parade rest in the middle of the formation) he came in low and fast and immediately pulled into a climb, lit the burners, and disappeared. Just as you lost sight of him you heard the boom of him going mach. It sent chills up this airman's spine, that's for sure!

Hello James "sprstdlyscottsmn" and thanks for the welcome! Yes, I'm an F104 fan but only a couple hours in [Link pending approval], am quiet versed in her abilities as a weapon system. I spent a few years with the Starfighters Team and got to know the aircraft and was educated by a retired Lockheed 104 / F117 Tech Rep (Ben McAvoy). 'Was also the Crew Chief for Tom Delashaw. In the time I was with those guys, I met a few 104 vets and they confermed what it could do. BTW, Delashaw flew some of the Project FeatherDuster sorties. As it goes, I believe the F104 was superior to all fighters of that era below ? 25k. [Link pending approval] only in a straight line.
Cheers,
ZipperPs

To the poster way up there, it's pretty much been answered, but yeah, the SR couldn't put up the big numbers on the deck. That's not what she was designed for. Remember, up at 85K+, the air temp is low, and there isn't much air resistance to deal with. Helped big in the speed equation, along with many other variables. I saw the SR go transonic at low level, back in 1990. That's probably about as fast as you could get it to go, that low to the ground.

Way back there, someone mentioned the 106 that landed itself. That one happened near Malmstrom, out in some Montana farmer's field. When the recovery team came out to the field, the engine was still running. The jet flew another 14 years or so, before it went to Wright Pat.

As for the single engine record for a jet...Darryl Greenamyer set the low level record in a...get this...*HOME BUILT* F-104, 998 MPH at 80 Ft AGL in 1977. If JR, our resident Zipper driver chimes in, he has some pics of it.

The Six has the record at altitude for a production-built jet. In 1959, Major Joseph Rogers reached 1,525.96 mph in a Six at 40,500 ft.

That's moving! Cool

TC,

Here is a pic of the 859 knot run... Before it warmed up Darryl made record setting runs at 869 kts, 1,000 mph, but some of the sanctioned measuring equipment failed so they had to settle for the 859 run... Not too shabby!!! Wink

Darryl was a very cool guy to meet and talk with.

SprstdlyScottsmn,

Remember Sharkbait set a squadron record for 1,588 indicating Mach 2.5 on the airspeed/Mach meter for over two minutes then he pushed it up and had a compressor stall at 2.6 indicated. He also zoom climbed to over 92,000 feet on the same flight.

For everyone else,

That was with his stock F-104C wearing wingtip mounted missile rails and no special prep. Tom did say he singed every insignia on the jet! Cool

The F-106... I used to fly with a great friend that flew the 6. He and Tom were talking about the differences in the 6 and the Zipper. He said he was in a shallow descent with his left hand against the stops chasing two Zippers and they ran off and left him...

The F-16... Sharkbait flew against the Viper and Eagle. There were doing a little testing against an actual high speed fighter that they could get access to. Since the Zipper can easily operate at the Speed of Heat, it was a natural choice. The Viper was holding Mach 1.6 while Tom was walking away and they asked the Viper driver to push it up and he said, "That's all I've got". We were told Tom keyed his mic and chuckled his characteristic "He he he..." Only Sharkbait! That reminds me of the time a congressman wanted him court martialed as Tom beat up an F-5 in the HUD cam footage doing ACM F-5 vs. F-104. Tom had been told to loose against the F-5 so they could sell more F-5's over seas. Tom said, "No way was I going to let them beat me in my jet on purpose!!!"

Forum: F-16 Procedures

Mach 2 - Rarely done, always trouble?