What is so difficult about this? A permit aircraft must be flown in accordance with the visual flight rules. The visual flight rules, outside controlled airspace, comprise Rule 28 of the Rules of the Air Regulations 1996, which states:
(1) Subject to paragraph (6), an aircraft flying outside controlled airspace at or above flight level 100 shall remain at least 1,500 metres horizontally and 1,000 feet vertically away from cloud and in a flight visibility of at least 8 km.
(2) Subject to paragraphs (3), (4), (5) and (6), an aircraft flying outside controlled airspace below flight level 100 shall remain at least 1,500 metres horizontally and 1,000 feet vertically away from cloud and in a flight visibility of at least 5 km.
(3) Paragraph (2) shall not apply to an aircraft which:
(a) flies at or below 3,000 feet above mean sea level;
(b) remains clear of cloud with the surface in sight; and
(c) is in a flight visibility of at least 5 km.
(4) Paragraph (2) shall not apply to an aircraft which is not a helicopter and which:
(a) flies at or below 3,000 feet above mean sea level;
(b) flies at a speed which, according to its air speed indicator, is 140 knots or less;
(c) remains clear of cloud with the surface in sight; and
(d) is in a flight visibility of at least 1,500 metres.
(5) Paragraph (2) shall not apply to a helicopter which:
(a) flies at or below 3,000 feet above mean sea level;
(b) flies at a speed which, having regard to the visibility, is reasonable;
(c) remains clear of cloud with the surface in sight; and
(d) is in a flight visibility of at least 1,500 metres.
(6) Paragraphs (1) and (2) shall not apply to a helicopter which is air-taxiing or conducting manoeuvres in accordance with rule 6(i).
It is clear that if the pilot complies with paragraph 2 (i.e. 1500m horizontal and 1000ft vertical clearance from cloud and a flight vis of 5km) then ground contact is not a requirement. Therefore, it is perfectly legal to fly a permit aircraft at, for example, 2500ft amsl above a solid cloud layer with tops at 1500ft amsl provided the flight vis is at least 5km and the pilot is appropriately licensed and rated. Getting there and getting back, however, is a whole other problem!