Fighter-bomber versions
F-101A - single pilot; fitted with an MA-7 fire-control radar for both air-to-air and air-to-ground use, augmented by a Low Altitude Bombing System (LABS) for delivering nuclear weapons, and was designed to carry four M39 20mm cannons and a Mk 28 nuclear bomb, or conventional bombs, or AIM-4 missiles. Capable of withstanding only 6.33
g (62 m/s²) maneuvers.
Many were later converted to RF-101G recon birds, and many RF-101As were factory-built.
F-101A (cannon below cockpit):
F-101C - single pilot: introduced in 1957. It had a 500 lb (227 kg) heavier structure to allow 7.33-
g maneuvers as well as a revised fuel system to increase the maximum flight time in afterburner. Like the F-101A, it was also fitted with an underfuselage pylon for carrying nuclear weapons, as well as two hardpoints for 450-US-gallon (1,700 L) drop tanks.
Recon versions were both factory-built (RF-101C) and converted from F-101Cs (those were RF-101H).
F-101C:
Interceptor versions
F-101B - crew of two, with a larger and more rounded forward fuselage to hold the Hughes MG-13 fire control radar of the F-102. It had a data link to the Semi-Automatic Ground Environment (SAGE) system, allowing ground controllers to steer the aircraft towards its targets by making adjustments through the plane's autopilot.
The F-101B was stripped of the four M39 cannons and
carried four AIM-4 Falcon air-air missiles instead, arranged two apiece on a rotating pallet in the fuselage weapons bay.
Late-production examples were fitted for 2 AIR-2 Genie nuclear rockets (1.7kt yield) and 2 AIM-4.
TF-101B - some were built as trainers, which were later redesignated TF-101F.
F-101B:
Test with rotating missile pallet - originally intended for 6 missiles, but restricted to 4 in service:
F-101B launching test-dummy AIR-2 Genie: