Max Speed of Cold War Era Aircraft

From various sources, I've read different listed top speeds for the Thunderchief. I have an old book that lists it as 1,388 mph, whereas a shirt that you can buy online lists it as 1,480 mph. I even once bought a Micro Machine (c) toy of the Thud which listed its maximum speed as 1,507 mph.

Did the top speed vary according the model of F-105? Which model was the fastest? Was the aircraft's maximum speed drag-limited or turbine inlet temperature-limited?

I know there are one or more pilots here that flew some of the century series aircraft. If that included the Thud, how fast did you ever get one up to?

1,390 MPH was the Thud's top speed. I've heard many pilots say that if it was on the deck, nothing could catch it.

TC wrote:I've heard many pilots say that if it was on the deck, nothing could catch it.

Many "turbojet" powered combat aircraft were/are faster than their replacements down low.

I would often hear how an F-4 would outrun an F-15 on the deck too...

As for "top speeds" the F-106 holds the "official" top speed for a single engine air-breathing aircraft; Ref: http://www.f-106deltadart.com/speedrecord.htm

On 15 December 1959 Maj Joseph Rogers flew F-106A serial number 56-0467 1,525.93 mph (2455.68 km/k) on a straight line course 11 miles long (18km) at an altitude of 40,000 ft (12192 m) setting a new single engine speed record of Mach 2.31

The F-105, and F-106 both used the Pratt & Whitney J75. (In slightly different "P-" variants) The F-107 and F8U-3 would have used them if they had entered production. (The XF8U-3 had an estimated top speed of M2.9! ) All 4 of the aircraft were considered "fast" back when top speed was still very important.

The Pratt & Whitney J75 was a monster of a turbojet. At military thrust a J75 could produce up to 17,500lbs of thrust and with afterburner up to 26,500lbs; more than the original F100 engines of the F-15 and F-16!

Keep 'em flyin'
TEG

The “B” model temporarily held a speed record or two. It was clocked at 1200+mph on a closed course. When you see quoted speeds like this, you’re talking about “clean” aircraft running flat out at altitudes in the mid to high thirties or low forties.

Down low the “D” model was capable of some very high indicated airspeeds.

I wouldn’t pretend to be a real Thud driver (they wear the 100-over-the-North patch), but I have flown the F-105. I also don’t pretend to know what kind of indicated airspeeds they were getting in a clean aircraft with Hanoi in the rearview mirror. Somewhere in the neighborhood of 800K is what you read.

I picked up an F-105D (#259) at McClellan AFB after depot level maintenance and it was configured with only a centerline tank. On the way to Davis-Monthan, I dropped off the airway and into a restricted area to see just how fast it would go.

It did best in the 6000-8000 feet altitude range where it held right at 1.2-1.3 Mach, which was just short of 700K indicated. Pushed over to the deck and eventually the Mach dropped back to just over 1.1, but the indicated was just slightly above 700K. At high indicated speeds with a centerline tank the F-105 shakes and oscillates to some extent laterally but is rock solid stable flight-controlwise. I suspect that without the tank it would have run out close to 800K. I probably exceeded the tank limit as it was.

At D-M next day, the base-ops guy asks me if I’ll wait around while they get some pictures. They tow an A-10 and a P-47 (there for an airshow) into position and the picture ends up in Air Force magazine. They just needed an F-84 to make it complete.

regards, OL

Salute!

We had a Viper dude trying for a stern conversion on one of the Hill Thuds one day during an exercise.

His HUD said his speed about 700 KIAS. Locked on, the "tgt" speed was 100 knots faster. The 'vark could beat that, BTW. And the VooDoo was about like the Thud, with a 800 KIAS placard.

I agree with OL re: the altitudes for best IAS. So up North, I could imagine scooting outta town at 700-800 KIAS. I think most guys retained their racks and any tanks, so who knows how fast they could really go, huh?

For all the newbies, true airspeed and indicated airspeed depend upon your density altitude and temperature. At 50,000 feet, your true speed thru the air is about twice as fast as what you read on the old-fashioned speedometer, maybe faster. The Blackbird flew someplace between 300 to 375 knots indicated, but was zooming along at mach 3! You can look it up on the SR-71 Dash-1 site. Ask Habu or Parrothead about it.

later, and Merry Christmas.

Gums sends ...

Gums sends ...

I guess it makes sense that some instruments could get fooled into thinking that you're going slow because the air is thin. Do modern aircraft have any absolute indicaters of air speed? Perhaps using GPS or something instead of the outside air?

I always thought the F-111 was the low level speed master, but doesn't the F-4 still hold the low level speed record?

It's not a matter of being "fooled", it's a measure of the "force" of the air going past the aircraft. This is useful to a pilot for a variety of reasons. Mainly because the air going past the aircraft is directly responsible for the aircraft's ability to stay IN the air.

For example, an aircraft that stalls at 100 knots will stall at 100 knots indicated at 10 feet or 10,000 feet. Or when the -1 says "your wings will tear off at 800 knots", that's 800 knots indicated. Handy info to know.

Lightndattic wrote:I always thought the F-111 was the low level speed master, but doesn't the F-4 still hold the low level speed record?

The "Sageburner" F-4 may still hold one record, the 3KM low altitude (below 100 meters) speed record.

It did 902 MPH over a 3KM stretch at 140 feet AGL. (3 passes with reversals at no higher than 500 meters)

If you do the math, covering 3 KM takes about 7-8 seconds so he didn't have to maintain it for very long. He obviously had a running start and 902 is probably an average, but over 7-8 seconds, maybe 904 down to 900. Heh, heh.

His indicated airspeed would have been about 790 KIAS.

What's impressive is considering how sensitive the F-4 flight controls are, he was able BOTH to stay below 300 feet and avoid ricocheting off the ground at that speed. Also impressive is there was a guy riding along in back.

I thought the F-111 was faster also. Maybe they just never tried for this record. I think they lost an F-4 on the first try.

regards, OL

Somewhere in my stacks of keepsakes I have a photo of an F-111 panel during a low level test flight over the Gulf test range off Galveston. It shows 890 KIAS, 1.37 M, 3500 ft. As far as I know, there was never any attempt to set a record. No matter what, I gotta admire the F-4 crew for having large solid gold ones.

The newspapers in Galveston reported a possible earthquake that day and several shrimp boats out in the Gulf reported hearing a really loud explosion.

890!!! WOW! Even in the slightly denser air at sea level that must still put out around 850 or 860. Although the only thing as clean as an F-111 all swept up is a zipper, and the Zipper hold the "official" low alt speed record. Have read of F-14Bs doing 1.35 during an excercise, still doesnt beat the Varks 1.37 though.

Gums wrote:The Blackbird flew someplace between 300 to 375 knots indicated, but was zooming along at mach 3!

That's why the Blackbird could put it's gear down at Mach 3.

That_Engine_Guy wrote:Many "turbojet" powered combat aircraft were/are faster than their replacements down low.

I would often hear how an F-4 would outrun an F-15 on the deck too...

The Pratt & Whitney J75 was a monster of a turbojet. At military thrust a J75 could produce up to 17,500lbs of thrust and with afterburner up to 26,500lbs; more than the original F100 engines of the F-15 and F-16!

I also heard about Phantoms outrunning Eagles on the deck, the F-4E GIB said it was due to the skin friction of the Eagle frying the ECM stingers on the tail or something to that effect. The F-4 definately had more performance than it is given credit for as Sage/Skyburner shows.

Oh, TEG, I have a question for ya. If I am understanding this correctly, if you take a turbojet and Low BPR turbofan with the same SLS thrust ratings, that dynamicly the turbojet will always have more thrust at higher speeds(I have now read that it has more LowAlt/HighMach AB thrust as well as HighAlt/HighMach mil thrust)? Is there ever a point where the turbofan would have higher thrust? Is the only benefit of a fan the fuel savings?

I wanna restart this forum. Neat topic. Anyone have any idea how quick the B-1 can move down low (unless classified)?

-N