FAA Aviation Mechanic Powerplant (AMP)Engine InspectionEasy
A technician performing an annual inspection finds that the rubber baffle seals around several cylinders on an air-cooled reciprocating engine are cracked, torn, and no longer sealing tightly against the cowling. What is the primary operational concern with this discrepancy?
- AIncreased oil consumption from the affected cylinders
- BLoss of manifold pressure at high altitude
- CReduced fuel flow to the affected cylinders
- DCooling air will bypass the cylinders, leading to elevated cylinder head temperatures
Show answer & explanationAnswer & explanation
Correct answer: D. Cooling air will bypass the cylinders, leading to elevated cylinder head temperatures
Baffles and their seals direct cooling air across the cylinder fins; when seals are torn or missing, cooling air escapes around the cylinders instead of flowing through the fins, reducing cooling effectiveness and causing high cylinder head temperatures, particularly on the cylinders farthest from the inlet.
Why the other options are wrong
- A. Oil consumption is unrelated to baffle seal condition.
- B. Baffles do not affect manifold pressure.
- C. Baffle seals have nothing to do with fuel delivery.
Engine Baffle/Seal Inspection
Baffles direct cooling airflow over cylinder fins on air-cooled engines; damaged or missing seals allow air to bypass the cylinders, reducing cooling.
- Baffle seals are typically flexible rubber or silicone strips
- Torn/missing seals cause localized overheating
- Inspected each 100-hour/annual inspection for cracks, tears, and fit
Memory trick: Torn seal, air steals — heat prevails