What Happened
On Thursday afternoon, 3 February 2022, a pilot and passenger departed Grand Central Aerodrome (FAGC) in a Cessna 177RG Cardinal, registration ZS-IIZ, for a private flight to Brits Aerodrome (FABS). After an uneventful flight, they refuelled with 107 litres of Avgas 100LL, filling the tanks. The pilot then flew back to FAGC via Roodekoppies Dam, Rustenburg, and Carletonville. Upon joining the circuit, the pilot requested and performed two touch-and-go landings. On the third approach for a full-stop landing, the pilot confirmed the landing gear was down and locked (green light illuminated) and selected 30° flaps. After touchdown at about 75 knots ground speed, as the aircraft decelerated, the nose pitched down and the propeller struck the runway. The aircraft slid about 40 metres before stopping in a nose-down attitude. Both occupants were not injured, but the aircraft was substantially damaged.
Aircraft Information
The aircraft was a Cessna 177RG Cardinal (serial number 177RG-0134) with total airframe hours 3433.1. The pilot held a Commercial Pilot Licence with 824.8 total flying hours, including 192.3 hours on type. The flight was conducted under Part 91, VMC day, no flight plan.
Post-Incident Examination
The aircraft was recovered to an AMO at Wonderboom Aerodrome. On jacks, the landing gear unsafe warning horn functioned normally. Hydraulic fluid (MIL-H-5606) was adequate, circuit breakers were intact. The nose gear microswitch was not faulty. During retraction/extension tests using normal procedure, only the main landing gears extended and locked; the nose landing gear did not lock. No hydraulic leaks were found. The emergency extension procedure successfully extended and locked all three landing gears. Inspection of the landing gear pump motor (Part 105932E, serial 9832) located on the aft left fuselage revealed signs of excessive heat on electrical leads and armature. The bonding on pigtails had melted and detached. One brush spring had contracted and the brush detached. The burnt leads and armature indicated the pump motor was operational at the time of the incident.
Landing Gear System Description
The Cessna 177RG landing gear is hydraulically actuated with electrical control. A reversible electric pump supplies fluid to actuators for the nose and main gears. The landing gear selector controls pump direction. Mechanical overcentre locks secure the nose gear in up and down positions; main gears use hydraulic uplocks and electro-mechanical downlocks. A pressure switch maintains main gear uplock. A green light indicates all three gears down and locked, requiring all downlock microswitches and two sequence switches to be made. With the selector down, the pump runs to pressurise down lines if any switch breaks; when properly locked, no hydraulic pressure is needed to maintain the down position.