Flight Events
During landing, the nose gear down and locked indication was not achieved. The crew recycled the landing gear, utilized the alternate gear extension system, and performed a fly-by. After being informed that the gear appeared to be extended, the crew landed. However, the nose gear collapsed at the end of the landing roll. Additionally, the right main outboard tire blew out during the landing due to a frozen brake.
Investigation Findings
The investigation revealed that the nose-wheel well was susceptible to ice contamination. The nose gear down lock plunger was frozen and would not extend to the down and locked position. At the departure airport, slush had accumulated on the nose gear down lock and subsequently froze. The use of the alternate extension system would have dumped the 500 psi hydraulic pressure that normally assisted in holding the gear in the extended position.
Procedural Issues
USAir procedures stated that takeoff should not be made if slush or wet snow in excess of one-half inch covered the runway. However, at least one inch of wet snow and slush was reported on the departure runway 22 minutes before departure. The acting station manager did not follow USAir procedures that required reporting this condition to the dispatcher and the captain of the flight.