where the pilot advised a ground mechanic that his airplane was "good to go." The flight crew then disembarked the jet to use facilities in the terminal. The poor weather did not improve as the jet was deiced with type I fluid, a heated 50/50 water/glycol mixture. Following the completion of this process, one of the two deicing trucks delayed the pushback of the jet when it experienced mechanical problems. The vehicle was immobilized for 20 minutes in such a position that it prevented the aircraft from taxiing to the runway following the flight crew's return. After the deicing truck was repaired, the pilot requested a second deicing, though the flight crew did not perform a walkaround of their airplane, and USAir procedures did not require them to do so. Following the second deicing, LaGuardia ground control granted Flight 405 permission to taxi to Runway 13. The flight crew completed the preflight checklist during the taxi. Engine anti-ice protection was turned on for the two engines during taxi. The captain announced to passengers that the flaps would remain up during taxi, and they should not be worried seeing them in the retracted position. He placed an empty coffee cup on the flap handle as a reminder of the position of the flaps, a procedure used by many flight crews. The captain told the first officer they would use standard USAir contaminated runway procedures that included the use of 18° flaps, and also decided that they would take off with a reduced V1 speed of . Weather reports for LaGuardia showed that on the night of the accident, all taxiways were coated with a thin covering of snow. Runway 13 was also covered with a thin layer of wet snow, although it had been plowed, treated with urea, and sanded. The first officer described the snowfall as "not heavy, no large flakes." He told authorities that snow was sliding off the jet and the nose of the airplane was coated in a watery layer. He used a light positioned on the wing of his jet to check for signs of ice several times before they attempted to take off. Neither the pilot nor he saw any evidence of contamination on the wing or on the black strip, so they decided against a third deicing. He told investigators that he checked the wings "maybe 10 times, but at least three." He said