Loftleidir Flight 509 originated in Stockholm and was destined for New York with intermediate stops in Oslo and Reykjavik. The flight departed Keflavik Airport at 22:14 EDT. The flight from Keflavik to the outer marker of the ILS for runway 31R at New York-JFK was routine. At 03:56 Flight 509 contacted the tower and was cleared to land on runway 31R; the wind was 200 degrees at 3 knots. The captain decided to arm the spoilers just before touchdown rather than just after the landing gear had been extended. The latter is called for in the before-landing checklist. Shortly after the call to arm the spoilers, the aircraft struck the runway, tail first, and in a nose-high attitude. Then, the No. 1 engine separated from the aircraft 720 feet from the initial point of impact. Later, the captain stated that he had called for the spoilers to be armed at an altitude between 20 and 30 feet. After impact, all engines were shut down by means of fire shutoff levers; fire extinguishers were discharged. The first officer stated that because he could not arm the spoilers with his left hand, he had to use both hands. He also stated that he might have pulled back on the activating lever which deployed the spoilers. PROBABLE CAUSE: “The first officer’s inadvertent deployment of the ground spoilers in flight while he was attempting to arm the spoiler system. The captain’s decision to delay arming of the spoilers until just before touchdown was a contributing factor, because the timing varied from normal procedures and required the crewmembers to act quickly, without time for corrective action.”