Beagle, I'm no barrack room lawyer but again, the term "should" has never been used by the UK CAA to denote a mandatory action. The term "shall" has always been used for that purpose, as you will no doubt recall. It is important to understand the difference.
Not my personal interpretation, but that of the CAA.
Edit: For the benefit of those who like quotes, I dug out my copy of "Aviation Law For Pilots", which dates back to 1971. At the time I was studying for my commercial licence (late 1980s) this was the CAA recommended study guide. I remember taking their advice and pre-ordered the impending new sixth edition so it was bang up to date and had to drive quite along way to collect it!
Section 1 is VFR/IFR and a summary "tree" is on page 3.
Quote (carefully copied word for word):
IFR
If the flight is INSIDE CONTROLLED AIRSPACE
The pilot must comply with the following requirements:
1. He must hold an Instrument Rating.
2. He must file a flight plan with the appropriate ATC.
3. He must obtain ATC clearance to proceed or to enter the airspace and he must obey the instructions.
4. He must make position reports in accordance with notified procedures or as required by the appropriate ATCC.
5. Unless he is on a notified route, taking off/landing or authorised otherwise by an ATSU, he must maintain adequate ground clearance, i.e. clearance by 1000 ft (minimum) of the highest obstacle within 5 nm of the aircraft.
(and)
If the flight is OUTSIDE CONTROLLED AIRSPACE
at 3000 ft amsl and below
1. Fly at least 1000 ft above the highest obstacle within 5nm of the aircraft, unless the aircraft is clear of cloud and in sight of the surface, or is on a notified route or taking off/landing or authorised by an ATSU.
Obviously some things have changed since then; for a start we have women pilots (!) and we have gone over to the metric system and via JAR to SERA. However, the same principle has been maintained.
Last edited by ShyTorque; 4th Feb 2017 at 09:14.