Description
Object description
An instructional/training film presenting the operational procedures that must be adopted by both the pilots and maintenance crew to maximise the life of aero-engines. The majority of the film illustrates the huge variety of defects and faults, and why they occur. The remainder of the film is devoted to procedures for landing and closing down an aircraft.
Content description
Reel 1:
"Aerobatics and after flight procedures": When performing aerobatics, conditions are set up which can cause the engine to cut out or overspeed due to the effect of reduced or negative values of G (gravity). Film of a Harvard performing aerobatics is seen. Cut to an animated diagram of a carburettor showing the inlet ports. Negative G will lead to a temporary cut off of fuel, and the engine may briefly cut out, followed by a rich supply of fuel to the carburettor resulting in temporary overspeeding of the engine. This can be reduced by the pilot operating a hand pump to boost fuel supply when recovering from a temporary loss of fuel due to negative G. During periods of negative G, the engine oil pressure must be monitored for air locks in the oil supply pipes; this can be overcome with a negative G oil tank fitted to the engine.
The function of the accelerator and delayed action pumps are explained.
The narrator reviews the effects of negative G on the engine with the aid of animated diagrams interspersed with photographic clips of the pilot's actions in the Harvard cockpit as he weaves about the sky.
"Effects of mishandling": A chart showing the analysis of forced landings is seen: about 75% of landings are attributed to mechanical failures or 'cause not established'. These failures are largely due to the pilot mishandling his aircraft. Reference is made to the 'Pilot's Notes', an operational manual that is unique to each aircraft type, describing the procedures - and the operational limits - for flying the aircraft safely. The pilot has full responsibility to implement the procedures once aboard the aircraft. Failure to do so can result in operational overload (exceeding limitations).
A list of the causes of mechanical failures is seen: hydraulic lock, detonation, high cylinder temperature, high revolutions, low boost, over speeding, low oil pressure, high oil temperatures, over priming: these are just a few symptoms that lead to mechanical failure.
"Fractured cylinder": Close up view of a severely cracked cylinder – explained in detail – the cylinder retaining studs have fractured.
"Sparking plug adapters loose, and later, blown out".
"Loss of compression".
"Rocker gear failure".
This partial list of failures is augmented by a comprehensive list of failures that appears on the screen. Extensive close up photography and animated diagrams are devoted to each item in the list. The film conveys the message that most of the failures can be avoided.
Content description
Reel 2:
The comprehensive list continues:
"Reduction gear, due to bevel gear bearing failure".
"Broken and damaged connection rods".
"Piston seizure and piston ring disintegration".
"Worn bearings".
"Bearing failure".
"Metal debris in oil filter".
"Failure of auxiliary drives".
"Defective valve head and stem".
"Sparking plug failures".
"Failure due to high cylinder head temperatures".
"Mechanical effects of high (engine) revolutions and low boost": Function of piston rings (to give a gas tight seal) explained, damaged and broken rings can result from high revolutions and low boost.
"Operational overload – exceeding limitations": examples given that include the multitude of items that combine to make an engine, a brief explanation plus diagrams/photographs given for each. The onus is on the pilot not to exceed the operational procedures/limits as set out in the Pilot's Notes. Any excursion from these limits made whilst the aircraft is in flight must be reported by the pilot completing Form 700, passing it to the maintenance crew as he relinquishes the aircraft to them. Any problems thus reported will be attended to before the next flight.
Content description
Reel 3:
A Harvard aircraft is seen coming to land; the pilot recalling the instructions in the Pilot's Notes. Cut to view of the pilot surrounded the operational controls and instruments (i.e. gauges, dials, etc) for the engine. The pilot is seen adjusting various levers: checks the brakes, lowers the under-carriage, mixture control to normal, select maximum climbing revolutions, fully fine pitch of the propeller (provides a braking effect), set flaps, monitor cylinder temperature. The consequence of not adhering to the procedure is explained in detail. The Harvard lands and taxis to the hard-standing, a tradesman at each wingtip to stabilise the Harvard. Remaining in the cockpit, the pilot and the tradesmen close down the engine, the narrator explaining each step as they proceed. The pilot climbs out, chats to the maintenance crew, signs Form 700 if a limit/limits have been exceeded during the flight and departs.
Oil dilution. During periods of cold weather, the engine oil may be diluted so it quickly reaches all components to prevent wear at potentially un-lubricated surfaces. The procedure is explained at length for cold oil. An alternative, avoided if possible, is described when the oil is hot.
The narrator concludes: 'If you observe the precautions and methods seen in this film, you will have completed your part of the contract'.
The film closes with the Harvard flying around, watched by the ground crew.