4.1.4. Takeoff Turn Procedure 

Some airports are located in an environment of penalizing obstacles, which may necessitate turning to follow  a specific departure procedure. Turning departures are subject to specific conditions. 

The turn conditions differ between JAR and FAR regulations. Thus, the following paragraphs deal separately with both requirements. 

 

“JAR-OPS 1.495 (c)(1) Track changes shall not be allowed up to the point at which the net take-off flight path has achieved a height equal to one half the wingspan but not less than 50 ft above the elevation of the end of the take-off run available.” 

AIRCRAFT TYPE  WINGSPAN  Minimum height above end ofTORA to start a track change =Max {Half of Wingspan , 50 ft} Half of wingspan = 74 ft  

A300-B2/B4/600  44.84 m (147 ft 1 in)  

A310-200/300  43.90 m (144 ft 1 in)  Half of wingspan = 73 ft  

A318/A319/A320/A321  34.10 m (111 ft 10 in)  Half of wingspan = 56 ft  

A330-200/300  60.30 m (197 ft 10 in)  Half of wingspan = 99 ft  

A340-200/300  60.30 m (197 ft 10 in)  Half of wingspan = 99 ft  

A340-500/600  63.50 m (208 ft 2 in)  Half of wingspan = 105 ft  

Table C5: Minimum Height to Initiate a Track Change 

“JAR-OPS 1.495 (c)(1) Thereafter, up to a height of 400 ft it is assumed that the aeroplane is banked by no more than 15°. Above 400 ft height bank angles greater than 15°, but not more than 25° may be scheduled.” (see table C6) 

“JAR-OPS 1.495 (c)(3) An operator must use special procedures, subject to the approval of the Authority, to apply increased bank angles of not more than 20o between 200 ft and 400 ft, or not more than 30o above 400 ft” 

Maximum Bank angle during a turn (JAR) Standard 

Table C6: Maximum Bank Angle During a Turn 

“FAR 121.189 

(f) For the purpose of this section, it is assumed that the airplane is not banked before reaching a height of 50 ft, […] and thereafter that the maximum bank is not more than 15 degrees1.” 

1 The FAA rule is similar to the ICAO annex 6 recommendations. 

4.2. Obstacle Clearance 

4.2.1. Gross and Net Takeoff Flight Paths 

Most of the time, runways have surrounding obstacles which must be taken into account prior to takeoff, to ascertain that the aircraft is able to clear them. A vertical margin has to be considered between the aircraft and each obstacle in the takeoff flight path. This margin, based on a climb gradient reduction, leads to the definitions of the Gross Takeoff Flight Path and the Net takeoff flight Path. 

GROSS Flight Path = Takeoff flight path actually flown by the aircraft, i.e.: 

“JAR/FAR 25.115 

(a) […] from 35 ft above the takeoff surface at the end of the takeoff distance [to the end of the takeoff path]” 

NET Flight Path = Gross takeoff flight path minus a mandatory reduction. 

“JAR/FAR 25.115 

(b) The net takeoff flight path data must be determined so that they represent the actual [Gross] takeoff flight path reduced at each point by a gradient equal to: 

. 0.8% for two-engine aeroplanes 

. 1.0% for four-engine aeroplanes” 

Net Gradient = Gross Gradient - Gradient Penalty 

Table C7: Values of Gradient Penalties 

The gradient penalty between the net and the gross flight path must be taken into account during the first, second, and final takeoff segments (Figure C17). 

4.2.2. Obstacle Clearance during a Straight Takeoff 

“JAR–OPS 1.495 

(a) An operator shall ensure that the net take-off flight path clears all obstacles by a vertical distance of at least 35 ft.” 

As an example, the minimum required climb gradient during the second segment must be 2.4% for a two-engine aircraft. But, as per regulation, the net flight path must clear any obstacle by at least 35 feet (Figure C17). This may sometimes require the second segment gradient to be greater than 2.4% and, consequently, the Maximum Takeoff Weight may have to be reduced accordingly. This is a case of obstacle limitation. 

4.2.3. Obstacle Clearance during a Turn 

Once again, the obstacle clearance margins during a turn differ between JAR and FAR regulations. The FAR regulation doesn’t consider any additional vertical margin during a turn, as the bank angle is limited to 15o. The following rule is then purely JAR-OPS: 

“JAR-OPS 1.495 

(c)(2) Any part of the net take-off flight path in which the aeroplane is banked by more than 15° must clear all obstacles […] by a vertical distance of at least 50 ft.”