Aviation News – June 2018

cancellation of the F-108 in September 1959

added greatly to the Valkyrie’s costs and

denied NAA one of the USA’s premier military

aviation programmes. It was also steadily

losing the other.

When President Kennedy was inaugurated

in 1961 he endorsed the B-70, wanting some

tangible return for the $1bn the project had

already consumed, although his Secretary of

Defense, Robert McNamara, cancelled the

dozen development aircraft and slashed the

overall budget for the bomber.

The loss of Francis

Gary Powers’ Lockheed

U-2 to an SA-2 surface-

to-air missile in May

1960 prompted the

realisation that all

high-altitude bombers

would be vulnerable to

salvos of those SAMs.

At Mach 3 sudden

evasive manoeuvres

were impossible and

SA-2s could reach the

Valkyrie’s operational

altitude. (For the

higher flying Lockheed SR-71 Blackbird this

was less of an issue). Another factor was

the realisation that Russia was developing

the MiG-25 Mach 3 interceptor, specifically

designed to destroy fast, high-flying bombers.

As a result, the B-52 force was progressively

reassigned to low-altitude, missile-avoiding

penetration tactics and any new bombers

would have to fly under the radar and

launch stand-off missiles such as the GAM-

87 Skybolt, a procurement process that

eventually led to the Rockwell B-1B Lancer.

Faced with renewed cancellation threats,

LeMay, NAA and other USAF generals

relaunched the Valkyrie as a reconnaissance-

strike aircraft, with AV3 (which was never

completed) being designated the XRSB-

70 prototype. They continued to promote

the XB-70 as a bomber and as a research

vehicle for the planned American supersonic

transport (SST). RSB-70 would have fired

20 air-to-ground missiles from internal rotary

launchers, obliterating targets that the ICBMs

might have missed. In March 1962 the House

Armed Services Committee voted to fund 60

production B-70s, but McNamara refused to

release finance for them and by February

1964 the programme was reduced to two

XB-70s.

Within this

unpromising

scenario

construction of Air

Vehicle 1 (AV1)

and AV2 began.

Although the

revised programme

included no

internal military

equipment such

as radar, ECM and

bombing-navigation

systems, it still

raised formidable technical challenges,

requiring 20 million man-hours of design

effort. Development of military systems did

proceed in parallel and the intended AN/

62 Aviation News incorporating Jets June 2018

Early in the flight test programme North American wanted photographs of the XB-70 with the wing tips in the fully down position. This required it

to exceed Mach 1.2 and the F-104D photo aircraft therefore had to fly ahead of the Valkyrie’s supersonic shockwave to retain stability. NASA

The XB-70’s cockpit was so high above the ground that the crew required escape ropes and a Sky Genie abseiling device for the 17ft descent to

the ramp in an emergency. Access to most parts of the bomber required elaborate, extending maintenance platforms. USAF

Resembling a sinister serpent, AV1 just

before its fifth flight on February 16, 1965 with

White and Cotton at the controls. On this

sortie its wing tips were lowered to 65º for the

first time. AFFTC/Terry Panopalis Collection

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