PA-28 Cherokee/Archer/Dakota/Pillan/Warrior
Maintenance Powerplant; Maintenance Airframe
Maintenance Technician 1
Situational Awareness
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor; Inflight Event / Encounter Other / Unknown
Aircraft Aircraft Damaged; Flight Crew Returned To Departure Airport; General Maintenance Action
Aircraft; Human Factors
I performed a 100-hour inspection on a Piper PA28-140 aircraft. I found the exhaust system to be in an unairworthy condition. Inspection Authorized (IA) Technician chose to ignore my findings and signed the aircraft as Airworthy.The exhaust had a dent in a pipe that was deemed unairworthy according to Piper Cherokee service manual. This ultimately led to the failure of the exhaust system; resulting in an in-flight Emergency.
Reporter stated he was flying the Piper Cherokee when the Inflight Emergency occurred shortly after takeoff. Initially there was a smell; as if something was burning; possibly oil. He looked at the Oil Temperature gauge and noticed the temperature had pegged out beyond red line. Within two minutes he encountered smoke; fumes and most likely carbon monoxide pouring into the cockpit. Luckily; there was a small fold down window on the pilot's side drawing some of the smoke and fumes out. He immediately returned to his departure field.Reporter stated he checked the engine compartment after the in-flight incident and noticed the exhaust duct had sheared right after the collector box; near the original dent that he had previously noted. Even though he had found the dent prior to the inflight event; the IA Inspector had much more experience and so he decided not to argue with the Inspector.
An Aircraft Maintenance Technician (AMT) reports finding a dented exhaust duct on a Piper PA28-140 aircraft during a 100-hour inspection. His concerns about the unairworthy duct per the Piper Cherokee service manual were ignored by an Inspection Authorized (IA) Inspector. The Exhaust duct failed shortly after takeoff; causing smoke and fumes in the cockpit; resulting in an in-flight emergency.