EXHAUST SYSTEM

1
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

2
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

3
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

4
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

5
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

6
EXHAUST SYSTEM

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