Incident 1950 British Columbia B-36 crash

plane 44-92075 flying on simulated nuclear strike combat mission against soviet union. b-36 took off eielson afb regular crew of 15 plus weaponeer , bomb commander. plan 24-hour flight fly on north pacific, due west of alaska panhandle , british columbia, head inland on washington state , montana. here b-36 climb 40,000 feet (12,000 m) simulated bomb run southern california , san francisco, continue non-stop flight fort worth, texas. flight plan did not include penetration of canadian airspace. plane carried mark iv atomic bomb, containing substantial quantity of natural uranium , 5,000 pounds (2,300 kg) of conventional explosives. according usaf, bomb did not contain plutonium core necessary nuclear detonation.

cold weather (−40 °f/−40 °c on ground @ eielson afb) adversely affected planes involved in exercise, , minor difficulties 44-92075 noted before takeoff. 7 hours flight, 3 of 6 engines began shooting flames , shut down, , other 3 engines proved incapable of delivering full power. subsequent investigation blamed ice buildup in carburator air intakes.

the crew decided abandon aircraft because not stay aloft 3 engines out of commission while carrying heavy payload. atomic bomb jettisoned , detonated in mid-air, resulting in large conventional explosion on inside passage. usaf later stated fake practice core on board aircraft inserted weapon before dropped.

the aircraft commander steered plane on princess royal island spare crew having parachute cold north pacific, whereupon crew bailed out. before bailing out last, set turning course toward open ocean using autopilot.

the plane had been in constant radio contact strategic air command headquarters @ offutt afb, nebraska, , within minutes of bailout royal canadian air force launched operation brix find missing men. poor weather hampered search efforts; nevertheless 12 of 17 men found alive. 1 of 5 deceased, weaponeer, recovered in 1954 crash site. remaining 4 airmen believed have bailed out of aircraft earlier surviving crew members, , assumed landed in ocean , died of hypothermia. canadian authorities never told aircraft carrying nuclear weapon.