Last year an event happened in Saarbrucken, Germany which answered another question about flying a plane. What would happen if an aircraft retracts its landing gears while it is still on the ground? A Bombardier Dash8-Q400 was brought back to the hanger with a grated fuselage. The report released by the German NTSB, the BFU, a study done on the landing gear mechanism shows that while other planes have a mechanical lock preventing them to rise while WOW-sensors are activated, the Dash8-Q400 was a bit different.
If even one WOW-signal indicates that the plane is in the air, the plane considers itself airborne, even if it’s not. For this to work, the gear handle in the cockpit needs to be in the up position. For some unknown reason, the gear remained up while the plane was taxying. Since the nose gear is the first thing that lifts off the ground, the WOW-signal started retracting the gears.
The Dash8-Q400 has only two gears in the back and having them retracted, there was no friction for the plane to hold on to. The airplane simply lied down on its belly, sliding and bumping down the runway, stopping just before the end of the runway. Luckily no injuries of passengers or the crew were recorded. However, a directive was issued to Bombardier to change this mechanism.