Systems and Equipment Malfunctions
Private Pilot ACS · Area IX · Task C · POH/AFM, FAA-H-8083-3
Everything you need to know about Systems and Equipment Malfunctions for your private pilot checkride. Aligned to FAA-S-ACS-6C Task IX-C, covering systems and equipment malfunctions.
Vacuum System Failure §
Signs: Suction gauge below 4.5 in Hg, AI tumbling or showing erroneous bank, HI precessing erratically.
Action: Cover AI and HI. Transition to partial panel immediately. Communicate with ATC. If in IMC, declare emergency. Navigate using turn coordinator (electric), altimeter, VSI, ASI, and magnetic compass.
Action: Cover AI and HI. Transition to partial panel immediately. Communicate with ATC. If in IMC, declare emergency. Navigate using turn coordinator (electric), altimeter, VSI, ASI, and magnetic compass.
PHAK Ch.8; ACS PA.IX.C
Electrical System Failure §
Negative ammeter: Alternator has failed. Battery is discharging. Time remaining varies — typically 30 min or less at full electrical load.
Action: Check alternator circuit breaker and switch. If alternator cannot be restored, shed all non-essential electrical load immediately (avionics, lights, autopilot). Navigate with backup instruments. Land as soon as practicable. Notify ATC.
Action: Check alternator circuit breaker and switch. If alternator cannot be restored, shed all non-essential electrical load immediately (avionics, lights, autopilot). Navigate with backup instruments. Land as soon as practicable. Notify ATC.
PHAK Ch.7; ACS PA.IX.C
Pitot-Static Failures §
Pitot blocked, drain open: ASI reads zero. Altimeter and VSI unaffected.
Pitot blocked, drain also blocked: ASI acts as altimeter — reads high climbing, low descending.
Static port blocked: Altimeter freezes, VSI reads zero, ASI changes but inaccurate.
Action for static blockage: Activate alternate static source. Expect altimeter and ASI to read slightly high. Speeds in POH for alternate static use.
Pitot blocked, drain also blocked: ASI acts as altimeter — reads high climbing, low descending.
Static port blocked: Altimeter freezes, VSI reads zero, ASI changes but inaccurate.
Action for static blockage: Activate alternate static source. Expect altimeter and ASI to read slightly high. Speeds in POH for alternate static use.
PHAK Ch.8; ACS PA.IX.C
Landing Gear & Door Malfunctions §
Gear fails to extend: Follow POH emergency gear extension procedure (manual extension, alternate hydraulic, gravity drop). If gear still cannot be confirmed down-and-locked — declare emergency, notify ATC, plan gear-up landing.
Gear unsafe indication: Fly-by tower (if available), attempt cycling the gear, use alternate extension. Do not land until all options are exhausted.
Door opens in flight: Aircraft remains controllable in most light aircraft. Reduce speed to near Vfe, attempt to close and latch. If unable, fly the aircraft and land at nearest suitable airport — performance effect is typically minor.
Gear unsafe indication: Fly-by tower (if available), attempt cycling the gear, use alternate extension. Do not land until all options are exhausted.
Door opens in flight: Aircraft remains controllable in most light aircraft. Reduce speed to near Vfe, attempt to close and latch. If unable, fly the aircraft and land at nearest suitable airport — performance effect is typically minor.
POH Emergency Procedures; ACS PA.IX.C