Cessna 402 flying over The Bahamas
Common Cessna 402 malfunctions involve fatigue cracking on wing spars, hydraulic-induced landing gear failures (including pressure leaks and nose gear jams), and fuel system issues such as worn float valves or unmetered air leaks. Engine problems like detonation-induced piston failures are also significant concerns. [1, 2, 3, 4, 5, 6, 7]
Specific technical and mechanical malfunctions associated with the Cessna 402 include:
- Wing Spar Fatigue and Cracking: The FAA has issued several Airworthiness Directives (ADs) due to stress fatigue and cracking found on the lower wing skins and auxiliary spar caps. If unaddressed, this can lead to catastrophic wing failure. [1, 2, 3, 4]
- Landing Gear System Malfunctions:
- Electrical/Hydraulic Pressure: The hydraulic landing gear system (especially on the 402C) is prone to pressure build-ups that can melt reservoir sight tubes, introducing smoke and fumes into the cockpit.
- Mechanical Jamming: Nose struts can jam in the wheel well if deflated before takeoff, preventing the gear from extending. [1, 2]
- Fuel Valve and Feed Line Wear: Excessive wear on fuel float valve actuators can allow unmetered air into the fuel lines, potentially causing fuel starvation or erratic engine performance. Furthermore, auxiliary fuel tank bladders are known to leak if not kept adequately filled when parked. [1, 2]
- Engine and Auxiliary Pump Flooding: Operating auxiliary electric fuel pumps on "high" during mechanical pump failures while advancing the mixture can result in sudden, unintended engine flooding. [1]
©A. Derek Catalano/Gemini
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