Date: 201601
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: PA-28 Cherokee/Archer/Dakota/Pillan/Warrior
Operator: FBO
Operating under: Part 91
Flight plan: None
Mission: Training
Flight phase: Parked
Aircraft component: Propeller
Component problem: Improperly Operated
Reporter organization: FBO
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Private
Human factors: Situational Awareness
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Object
Detector: Person Flight Crew
When detected: Pre-flight
Result: Flight Crew Overcame Equipment Problem
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: While receiving instrument ground instruction the aircraft I preflighted was moved by a student pilot requiring use of the club's heated hangar. I was not aware the person moving the aircraft outside of the hangar was a student pilot. This person left a tow bar connected to the nose wheel. The morning of the lesson (and the day prior) I spent 1-1/2 hours total preparing the aircraft for flight and flight planning. I followed the preflight procedures in accordance with both the manufacturer and club guidelines. This included two walk-arounds of the aircraft before the aircraft was moved. I did not perform a third walk-around when the plane was outside nor did my CFII. Unaware of the tow bar I cranked the engine a 1/4 revolution during the normal engine start checklist. The propeller made contact with the tow bar. The engine did not start. My CFII and I surveyed the cowling; propeller; and spinner for signs of damage. A slight nick/ding was observed on the leading edge nearest the top third (of the prop tip). My CFII and I assessed the situation and made a judgement call the aircraft was safe for flight. We flew the aircraft for 2.1 hours. We were unaware of Airworthiness Directive (AD) 2004-10-14; applicable to Lycoming Engines (formerly Textron Lycoming); direct-drive reciprocating engines. Specifically; compliance with the AD is; 'before further flight'. In addition to the AD requirement; Lycoming requires engine disassembly and inspection.Definition of Propeller Strike (from AD 2004-10-14): (i) For the purposes of this AD; a propeller strike is defined as follows:  (1) Any incident; whether or not the engine is operating; that requires repair to the propeller other than minor dressing of the blades.  (2) Any incident during engine operation in which the propeller impacts a solid object that causes a drop in revolutions per minute (RPM) and also requires structural repair of the propeller (incidents requiring only paint touch-up are not included). This is not restricted to propeller strikes against the ground.  (3) A sudden RPM drop while impacting water; tall grass; or similar yielding medium; where propeller damage is not normally incurred.  (j) The preceding definitions include situations where an aircraft is stationary and the landing gear collapses causing one or more blades to be substantially bent; or where a hanger door (or other object) strikes the propeller blade. These cases should be handled as sudden stoppages because of potentially severe side loading on the crankshaft flange; front bearing; and seal.My CFII and I both understood this event was reportable to club leadership and maintenance personnel. Upon completion of the flight we advised our club mechanic; a certificated A&P. He assessed the situation as a propeller strike.In hindsight; neither me nor my CFII were qualified to make the judgement call we made. Focused on meeting our mission objective that day we did not consider factors beyond our knowledge. Although it was early we could have contacted club leadership by cell phone for consult or the club mechanic. Rather than err on the side of caution; we chose to err on the side that 'it didn't look that bad.'Going forward I will maintain a personal standard to perform a final walk-around before boarding the aircraft. Furthermore; when faced with a situation requiring clear/concise judgement I will not make determinations beyond my area of expertise (even if it means challenging a more senior pilot/instructor).




Synopsis: When attempting to start the engine; the pilot of a PA-28 was unaware of a tow bar connected to the nosewheel. Even though the engine did not start the propeller made contact with the tow bar. The plane was then flown in conflict with AD 2004-10-14.