Rules of the Air: General Rules, Flight Rules, Signals and Interception
This domain tests Annex 2 and its European counterpart SERA: who gives way to whom, what minima apply, how aircraft are separated by cruising level, and what to do when intercepted. The exam favours scenario questions where two aircraft converge and you must state the right-of-way and the avoiding action.
Right of way
Converging aircraft of the same category give way to the one on the right. Head-on or nearly head-on: both alter heading to the right. Overtaking: the overtaking aircraft, whether climbing, descending or level, keeps clear and passes to the right. Landing: an aircraft at a lower height gives way to one at a higher height, unless the higher aircraft can descend safely and keep clear; an aircraft on the ground gives way to aircraft landing or taking off.
Minimum heights and levels
The general rule is 500 ft above the highest obstacle within a radius of 600 m over congested areas and 1 000 ft elsewhere, keeping 150 m from persons and property. Cruising levels follow the semicircular rule on magnetic track: 000–179 degrees use odd levels, 180–359 degrees use even levels. Reduced vertical separation minimum of 1 000 ft applies between FL 290 and FL 410 in designated airspace; outside it the separation is 2 000 ft.
Visual met conditions and lights
VMC minima vary with airspace class and altitude: for example, at and above 10 000 ft in Class C–G airspace the flight visibility is 8 km, distance from cloud 1 500 m horizontally and 300 m (1 000 ft) vertically. Navigation lights (red port, green starboard, white stern) must be displayed at night or in poor visibility; anti-collision lights are used to attract attention.
Interception
An intercepted aircraft should attempt to contact the controlling unit, select Mode A code 7700 unless instructed otherwise, and listen on 121.5 MHz. The interceptor rocks its wings (day) or flashes navigation lights irregularly (night) to attract attention, then makes an abrupt break-away manoeuvre to acknowledge compliance. The intercepted aircraft acknowledges by rocking wings, flashing lights, or following the interceptor.
Worked example
Two aircraft are converging at the same level in Class G airspace; aircraft A is on the left of aircraft B. B must give way to A, because the aircraft on the right has the right of way. If they were head-on, both would turn right; if A were overtaking B, A would keep clear and pass to the right.
Traps
Overtaking is always to the right regardless of aircraft category or climb state. The lower aircraft gives way to the higher when landing, not the reverse. Distress is 7700, radio failure 7600 and unlawful interference 7500 - do not swap them.