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Questions tagged [xb-70-valkyrie]

An extremely-high-speed-and-altitude airplane from North American Aviation, capable of flight at over mach 3. It was originally designed in the 1950s to deliver nuclear weapons, but the surface-to-air missile made it obsolete in this role; only 3 were ever built, and only as high-speed research aircraft.

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5 votes
1 answer

Anybody recognise the model of ADI on the XB-70?

Is this a model that was used on other aircrafts of the era, too? Looking for technical information about it and knowing the manufacturer and model number would make that easier. The Interim Flight ...
4 votes
3 answers

XB-70 inlet duct working method

Jenkins and Landis write in their 2004 book about the XB-70, regarding its inlet duct: "Three movable panels, positioned by two hydraulic actuators, opened or closed the throat area to meet ...
20 votes
3 answers

Heating of XB-70 vs. SR-71

The SR-71 was made with not tightly fitting fuel tanks and black paint, etc. to deal with aerodynamic heating. The XB-70 flew at essentially the same altitude and speed range, and was designed with ...
3 votes
4 answers

Did military aircraft in the sixties commonly lack VHF radios?

Investigating the XB-70 cockpit equipment, I notice that it only had (two) UHF radios, of the AN/ARC-50 model, for the 225–399.95 MHz band. No VHF radio that could be used to talk to civilian ATC or ...
3 votes
1 answer

Early "digital" rotating digit wheel type gauges

The XB-70 has a "digital" gauge showing the total fuel quantity using six rotating digit wheels (as in mechanical counters, odometers etc), and another showing the fuel quantity in the tank ...
9 votes
2 answers

How common were (are?) hydraulically driven fuel pumps?

The XB-70 had a large number of fuel transfer pumps (something like 25) to transfer fuel from the 10 other tanks into the sump tank, and then three fuel "boost" pumps to pump it from that to ...
13 votes
3 answers

Why weren't the XB-70's wingtips fixed in the down position?

The XB-70's wing tips folded down in flight to: improve directional stability at supersonic speeds reduce shifting of aerodynamic center at supersonic speeds reduce drag at high supersonic speeds ...
15 votes
1 answer

How were the fuel tanks sealed on the XB-70 Valkyrie?

The Valkyrie flew at Mach 3.1, close to the SR-71's operating speed in cruise. For the SR-71: Fuselage panels were manufactured to fit only loosely with the aircraft on the ground. Proper alignment ...
8 votes
1 answer

Why is the XB-70's Top speed only about 60mph higher than its cruise speed?

The maximum and cruise speeds listed for North American XB-70 Valkyrie are: Maximum speed: Mach 3.1 (2,056 mph, 3,309 km/h) Cruise speed: Mach 3.0 (2,000 mph, 3,200 km/h) Why is there such ...
50 votes
1 answer

What is the purpose of the extra wheel on the XB-70 main gear?

This photo of the XB-70 Valkyrie's main gear shows a small wheel between the two main wheels: Courtsey of This smaller wheel doesn't touch the ground, though I can see where it might as ...