24. The Instrument Flight Rules shall be as follows:
(a)Outside controlled airspace
In relation to flights outside controlled airspace Rules 25 and 26 of these Rules shall apply.
(b)Within controlled airspace
In relation to flights within controlled airspace Rules 25, 27 and 28 of these Rules shall apply.
25. Without prejudice to the provisions of Rule 5 of these Rules, in order to comply with the Instrument Flight Rules an aircraft shall not fly at a height of less than 1,000 feet above the highest obstacle within a distance of 5 nautical miles of the aircraft unless:—
(a)it is necessary for the aircraft to do so in order to take off or land; or
(b)the aircraft is flying on a route notified for the purposes of this Rule; or
(c)the aircraft has been otherwise authorised by the competent authority; or
(d)the aircraft is flying at an altitude not exceeding 3,000 feet above mean sea level and remains clear of cloud and in sight of the surface.
26. In order to comply with the Instrument Flight Rules, an aircraft when in level flight above 3,000 feet above mean sea level or above the appropriate transition altitude, whichever is the higher, shall be flown at a level appropriate to its magnetic track, in accordance with the appropriate Table set forth in this Rule. The level of flight shall be measured by an altimeter set according to the system published by the competent authority in relation to the area over which the aircraft is flying:
Provided that an aircraft may be flown at a level other than the level required by this Rule if it is flying in conformity with instructions given by an air traffic control unit or in accordance with notified en-route holding patterns or in accordance with holding procedures notified in relation to an aerodrome.
For the purposes of this Rule “transition altitude” means the altitude so notified in relation to flight over such area or areas as may be notified.
| Magnetic Track | Cruising Level |
|---|---|
| Less than 90° | Odd thousands of feet. |
| 90° but less than 180° | Odd thousands of feet + 500 feet. |
| 180° but less than 270° | Even thousands of feet. |
| 270° but less than 360° | Even thousands of feet + 500 feet. |
| Magnetic Track | Cruising Level |
|---|---|
| Less than 180° | 25,000 feet. |
| 27,000 feet. | |
| 29,000 feet or higher levels at intervals of 4,000 feet. | |
| 180° but less than 360° | 26,000 feet. |
| 28,000 feet. | |
| 31,000 feet or higher levels at intervals of 4,000 feet. |
27.—(1) In order to comply with the Instrument Flight Rules, before an aircraft either takes off from a point within any controlled airspace or otherwise flies within any controlled airspace the commander of the aircraft shall cause a flight plan to be communicated to the appropriate air traffic control unit and shall obtain an air traffic control clearance based on such flight plan.
(2) The flight plan shall contain such particulars of the intended flight as may be necessary to enable the air traffic control unit to issue an air traffic control clearance, or for search and rescue purposes.
(3) The commander of the aircraft shall fly in conformity with—
(a)the air traffic control clearance issued for the flight, as amended by any further instructions given by an air traffic control unit; and
(b)the holding and instrument approach procedures notified in relation to the aerodrome of destination, unless he is otherwise authorised by the air traffic control unit there:
Provided that he shall not be required to comply with the foregoing provisions of this paragraph if—
(i)he is able to fly in uninterrupted Visual Meteorological Conditions for so long as he remains in controlled airspace, and
(ii)he has informed the appropriate air traffic control unit of his intention to continue the flight in compliance with Visual Flight Rules and has requested that unit to cancel his flight plan.
(4) If for the purpose of avoiding immediate danger any departure is made from the provisions of paragraph (3) of this Rule (as is permitted by Article 64(3) of this Order) the commander of the aircraft shall, in addition to causing particulars to be given in accordance with Article 64(4) of this Order, as soon as possible inform the appropriate air traffic control unit of the deviation.
(5) The commander of the aircraft after it has flown in controlled airspace shall, unless he has requested the appropriate air traffic control unit to cancel his flight plan, forthwith inform that unit when the aircraft lands within or leaves the controlled airspace.
28. In order to comply with the Instrument flight Rules the commander of an aircraft in IFR flight who flies in or is intending to enter controlled airspace shall report to the appropriate air traffic control unit the time, and the position and level of the aircraft at such reporting points or at such intervals of time as may be notified for this purpose or as may be directed by the air traffic control unit.