From the Flight Safety Foundation's ALAR Tool Kit
Elements of a Stabilised Approach
“All flights shall be stabilised by 1,000 feet height above touchdown (HAT) in instrument meteorological conditions (IMC) and by 500 feet HAT in visual meteorological conditions (VMC).” An approach is considered stabilised when all of the following criteria are met:
1. The aircraft is on the correct flight path;
2. Only small changes in heading and pitch are required to maintain that path;
3. The aircraft speed is not more than V REF + 20 knots indicated airspeed (KIAS) and not less than VREF ;
4. The aircraft is in the proper landing configuration (approach configuration for small twins);
5. Sink rate is maximum 1,000 feet per minute; if an approach requires a sink rate greater than 1,000 feet per minute, a special briefing should be performed;
6. Power setting appropriate for configuration and not below the minimum power for approach as defined by the aircraft operations manual;
7. All briefings and checklists have been performed;
8. Specific types of approaches are considered stabilised if they also fulfil the following: instrument landing system (ILS) approaches — must be flown within one dot of the glideslope or localizer; a Category II or III approach must be flown within the expanded localizer band. Visual approaches — wings must be level on final when the aircraft reaches 500 feet HAT. Circling approaches —wings must be level on final when aircraft reaches 300 feet HAT; and,
9. Unique approaches such as the “old” Hong Kong Airport and the DCA (Washington, D.C.) river visual approach to Runway 18 require a special briefing.