Since I almost never have to hand prop, I’d always want to take the maximum precautions (last time I had to hand prop was when I had a Gill battery – never had to do it since replacing it with an SLA).
I have chocks which I made with a rope long enough I can pull them away from inside the aircraft. So the aircraft would be chocked. After priming, I’d also set the fuel to OFF (since the aircraft will run at idle for 30 seconds quite happily with the fuel off). If somewhere with a handy tiedown or place to attach a rope, I’d also tie the tail down by the glider tow hook, which can be released from inside the plane. This is probably the most bullet proof way of solo hand propping :-)
Does anyone remember the one at Canterbury airfield a few years ago?
If I recall correctly the pilot had flown in (C172?) from Biggin and forgot to turn off the master switch so when he returned the battery was flat so he hand propped it left the brake on with the engine running and went for a 15 min walk while the battery recharged.
Returning to the airfield the plane was missing, he called the police reporting it stolen and they said to get another pilot to fly around to see if it was flying around anywhere.
They found the plane stuck up the top of a tree off the end of the runway, having flown there all by itself.
Pilot said he did it because the CFI would have given him a right bol .. ing if he had returned the aircraft with a flat battery.
3 things comes to mind: was avgas that cheap back then? why not fly two circuits? did he log 0.25h P1 on that flight?
So, is there a consensus that there is no way to cold start (by hand propping) any fuel injected engine?
Peter wrote:
So, is there a consensus that there is no way to cold start (by hand propping) any fuel injected engine?
The Lycoming/Continental fuel injection isn’t exactly fuel injection in the correct sense of the word. Fuel isn’t injected, so hand propping should be possible, even on an empty battery. Use some start gas spray and it will ignite and run 
(or maybe not). The Rotax 912 iS and ULPower are injected. No way to start them, and run them, without the high pressure electric pump. As long as the pump runs, they probably could be hand propped as well?
It’s more to do with the ignition I would think. Electronic ignition may not work at very low RPMs, making hand propping impossible.
LeSving wrote:
Electronic ignition may not work at very low RPMs, making hand propping impossible.
Wouldn’t electronic ignition work better than magnetos ar very low RPMs?
Wouldn’t electronic ignition work better than magnetos ar very low RPMs?
Not necessarily. Typically a minimum rpm of 2-300 is needed. A mag work by just flicking the propeller across one single timing point.
Depends on how the electronic ignition is powered. In the automotive sphere it is powered from… the battery In aviation this is poor risk management (you get the DA42 flat battery = dual engine failure scenario) so you would need a little alternator for the ignition, and that is likely to need “some rpm”.
Peter wrote:
Depends on how the electronic ignition is powered. In the automotive sphere it is powered from… the battery In aviation this is poor risk management (you get the DA42 flat battery = dual engine failure scenario) so you would need a little alternator for the ignition, and that is likely to need “some rpm”.
The Electroair electronic ignition runs off the main aircraft battery. Obviously only one of the two magnetos can be replaced by electronic ignition but apparently that is enough to reap the benefits.
LeSving wrote:
Not necessarily. Typically a minimum rpm of 2-300 is needed. A mag work by just flicking the propeller across one single timing point.And why would that be? The speed of “just flicking” the magneto determines the spark voltage. That’s why an impulse magneto is needed for starting. A battery-driven electronic ignition should be able to provide a full power spark at zero rpm.
If you think differently, please provide some substantial argument.
Also some electronic ignitions will retard the spark until after top-dead-centre which is nice for your fingers.
