PFL's & Rule 5
Pboyall has just about covered this, there was a statement in GASIL to the effect that the CAA would not take action if PFL's were being conducted is a sensble way.
The reason for this was that a court case that took action aganst a flying instructor failed in some style and in the view of most people should not have been taken in the first place.
In this case the instructor was teaching EFATO when a person (who was known for complaning to the airfield) got together two witnesses, the CAA took the action on the basis of these people's evidence.
When the case came to court the main complaners wife failed to turn up (calling in sick) his evidence was sutch that you would have the wheels of the aircraft just a few feet above the house and the third witness (remember the aircraft was just above the house by only feet) could not tell the court if the aircraft was a high or low wing type!
It became clear that from evidence of other complants made by the main witness that there was an agenda that had nothing to do with low flying.
Quite frankly after sitting through two days of this case it was clear to all that the CAA's leagal team had built a very poor case and had to pay the defendants costs after the verdict had been reached.
The GASIL statment was writen aganst this background so I take from this that your most likely way to get into trouble with PFL or EFATO work is to repetedly use the same location for the practice as it is unlikely that a bystander will get your registration or take action on the first pass.
I go around above 500ft if I spot livestock or people in the area or if the student has picked a field near buildings.
If the above conditions have been made and a safe landing could be made in the event of the engine not responding I am quite happy to let the student go down to 20-30ft before going around.
It instructors should keep in mind that they have a responsability to provide realistic training so that in the event of the student having an engine failure they are fully equiped to carry out a forced landing, this is a duty of care that instructors have not only to the student pilot but also to the PUBLIC ON THE GROUND who might be unfortunate to be in the location of an aircraft that has suffered an engine failure.