EXHAUST SYSTEM

• (FROM AOPA PILOT MARCH 2001)

• 20% OF POWER LOSSES OR PARTIAL POWER FAILURE DUE TO BAD EXHAUST BAFFLES

• RASH OF FATAL ACCIDENTS IN 1995 AND 1996 TRACED TO INADEQUATE EXHAUST SYTEM MAINTENANCE AND INSPECTION

EXHAUST SYSTEM

• 321 STAINLESS STEEL (CHROMIUM-NICKEL STEEL) USED ON MOST GA AIRCRAFT (NON-TURBOCHARGED ENGINES)

• GOOD STRENGTH AND PERFORMANCE FROM 800 DEGREES TO 1600 DEGREES F

EXHAUST SYSTEM

• EASY TO INSPECT:– LONG-TERM EXPOSURE TO EXHAUST

GASES CHANGES METAL STRUCTURE– WORN-OUT PIPE CHARACTERIZED BY

BLUISH-BLACK COLOR; APPEARANCE OF SMALL ERUPTIONS ON SURFACE

– SEVERELY WORN PIPES LOOK LUMPY AND SAGGY DUE TO METAL “FLOWING” AS IT LOSES STRENGTH

EXHAUST SYSTEM

• SHINE FLASHLIGHT UP EXHAUST PIPE TO CHECK CONDITION OF INTERNAL PARTS (BAFFLES) IN HEAT EXCHANGER

• IF BAFFLE IS WAVY, DISTORTED, OR ERODED, IT REQUIRES REPAIR

• BAFFLE MATERIAL CAN BREAK OFF AND BLOCK EXIT PIPE

• AC 91.59 CITES 20% OF PARTIAL POWER FAILURES DUE TO BAFFLE FAILURES

EXHAUST SYSTEM

• INSPECT OUTER COWL FOR EVIDENCE OF EXHAUST LEAKAGE (#1 EXHAUST SYSTEM PROBLEM)

• GRAYISH OR BROWNISH TRAILS STREAMING AFT SIGNAL LEAK

• GAS IS HOT AND CORROSIVE AND QUICKLY ERODES ALUMINUM FLANGES OF CYLINDER HEAD

EXHAUST SYSTEM

• “UNLIKE OTHER CRITICAL AIRPLANE SYSTEMS, THERE IS NO REDUNDANCY WHERE YOUR EXHAUST SYSTEM IS CONCERNED”