Very Good advice.
What I will say that the procedure in a very well disciplined company I worked for was to take the following precautions for any engine ground runs: Park brake applied, chocks in front of each MLG, aircraft pointed towards an “escape route” in case it jumped the chocks, a qualified person in the flightdeck command seat at all times, and, if necessary, a spotter to to keep a general eye on things.
The following is a question only to spark debate so that we may learn from the collective knowledge.
I have discussed on many occasions the way to chock an aircraft. I recall reading some advice from Boeing, allegedly as I do not have the reference to hand right now, that the correct way to chock an aircraft (for engine runs) is to place the chocks about an inch in front of the wheels. The reason for this being that if the chock is tight against the wheel the chock becomes a ramp it is quite likely to ride up over the chock but if there is a small gap when the wheel contacts the chock it pushes down into the chock. The assumption being that if the chocks are placed hard into the wheel then the wheel could ride up over the chock.
Discuss, politely and in an mature adult manner please.
MM