This topic has been the subject of some discussion in the crew room and these are the points put forward;
The shouting "clear prop" will only work when the person it is aimed at can hear, understand and act on the warning.
"Clear Prop" came from an engineering background and was used by engineers turning on the battery as a warning to other people arround the aircraft just in case the prop turned. A similar warning was issued when moving any of the controls or extending flap so that people did not loose fingers or bang heads etc. Another warning is issued when powering up hydrulics if there is powered controls because the controls can move as pressure builds..................No where in this long list of warnings is there a clear prop for starting the engine because no safe pilot will attempt to start an engine unless they are assured that the only people in any close proximity to the aircraft are ground crew associated with starting.
Helicopter pilots never shout "clear tail rotor" even when they can't see the rear of the aircraft.
If flying a twin engined aircraft, people will not hear the pilot shouting "clear prop" over the noise of the first engine already running. Also if a group of aircraft are starting, the same noise problem drowns out the warning call.
If one can't see the engine from the cockpit then one must considder the benifits of having some form of groundcrew to first check if the area is clear and secondly warn of a fire on startup plus having a fire extinguisher to hand.
Places like Popham are accidents waiting to happen with regard to public access to aircraft. Public does not have to be able to touch the airframe to appreciate the aircraft or get the serial number.
What idiot ever walks in front of a propeller aircraft on the apron with the doors closed unless they have checked first...........walking behind may get a blast of slipstream but that is far better than a close encounter with a prop...........We pilots even make this easy by parking in nice neat lines!!
"A Harvard ground crew attempting to attach a tow bar just at the point of start"...........should remember that someone is required to be at the controls (brakes) before attempting to tow. For anyone I know of this means entering the cockpit to check the position of mags, master and brakes before doing anything else..........and staying there to operate the brakes if required during the tow!
So overall, the concensus was that shouting "clear prop" was a waste of time unless there are actually people in the way and in that case, they should be escorted to a safe position before a start is contemplated. Why escorted.........so that you or the groundcrew can check that they have not dropped something or left something behind that either they will rush back for or that you will hit/roll over during taxi.
Regards,
DFC