Propeller Systems and Performance
Propeller Systems and Performance
The accident investigator has to understand the primary and secondary systems and
components of the turbine engine, including the induction, fuel delivery, fuel metering, water injection,
ignition, lubrication, starting, electrical, charging, cooling, exhaust, instrumentation, engine overheat,
and fire detection systems. The investigation of the turbine engine induction system focuses on the
engine performance and the scheduling of air and fuel at the time of accident. The level of engine
performance at the time of impact and compare it with the performance level selectedby the flight crew
is the objective of the powerplant investigator. The investigation for the running powerplant can be
determined by checking through the engine for fuel and air intake, ignition, power and recommended
operating performance. If the engine was not running at impact, the powerplant investigator must look
further for the cause of the engine failure before the teardown of the engine.
An examination of the propeller damage is one of the best indications of engine performance.
The investigator must check all unauthorized repairs, repair records, total time hours, and ensure all
overhaul repairs and cycles of the propeller are in compliance with applicable. Improper repair for nicks,
scratches, scars, dents, and cuts will lead to fatigue failure caused by material defects or pre-existing
surface discontinuities. Ground impact damage may be shown by tip curl, bending of the blade,
breakage, chord wise and span wise scratches and ground slash marks. In an accident, the amount of tip curl is an indication to the investigator that the engine was
running and the amount of power it was developing. If a three bladed propeller had consistent tip curl
for all its blades, it is an indication that the engine was probably running and if not, it is an indication
that the engine was
The accident investigator has to understand the primary and secondary systems and
components of the turbine engine, including the induction, fuel delivery, fuel metering, water injection,
ignition, lubrication, starting, electrical, charging, cooling, exhaust, instrumentation, engine overheat,
and fire detection systems. The investigation of the turbine engine induction system focuses on the
engine performance and the scheduling of air and fuel at the time of accident. The level of engine
performance at the time of impact and compare it with the performance level selectedby the flight crew
is the objective of the powerplant investigator. The investigation for the running powerplant can be
determined by checking through the engine for fuel and air intake, ignition, power and recommended
operating performance. If the engine was not running at impact, the powerplant investigator must look
further for the cause of the engine failure before the teardown of the engine.
An examination of the propeller damage is one of the best indications of engine performance.
The investigator must check all unauthorized repairs, repair records, total time hours, and ensure all
overhaul repairs and cycles of the propeller are in compliance with applicable. Improper repair for nicks,
scratches, scars, dents, and cuts will lead to fatigue failure caused by material defects or pre-existing
surface discontinuities. Ground impact damage may be shown by tip curl, bending of the blade,
breakage, chord wise and span wise scratches and ground slash marks. In an accident, the amount of tip curl is an indication to the investigator that the engine was
running and the amount of power it was developing. If a three bladed propeller had consistent tip curl
for all its blades, it is an indication that the engine was probably running and if not, it is an indication
that the engine was
References: : Anderson, K. (2009). Propulsion Plant Accident Investigation. Chapter VI: Reciprocating Engine Operation. Embry -Riddle Aeronautical University - Worldwide Anderson, K. (2009). Propulsion Plant Accident Investigation. Chapter VII: Reciprocating Engine Performance. Embry -Riddle Aeronautical University - Worldwide