1. JAR OPS 1.235 Noise Abatement Procedures
Capt. Claude Godel
OST 05-3

2. A non satisfactory rule: JAR-OPS 1.235
Present text ( 1998) JAR-OPS Noise abatement procedures
(a) An operator shall establish operating procedures for noise abatement during instrument flight operations in compliance with ICAO PANS-OPS Volume 1 (Doc 8168-OPS/611).
Take-off climb procedures for noise abatement specified by an operator for any one aeroplane type should be the same for all aerodromes.
Tim Sindall proposal (2001)
 (a) An operator shall establish noise abatement operating procedures that are in compliance with PANS-OPS (Doc 8168) Volume 1, Part V for use when determined necessary by the regulatory authority of the airspace in which the flight is being made.
 (b) The effectiveness of noise abatement procedures employed to suit the requirements of the regulatory authorities shall be monitored by the Quality Manager.
Firts OPSG proposal (2002)
(a) An operator shall establish operating procedures that are in compliance with ICAO PANS OPS Volume 1 (Doc 8168-OPS/611) to comply with aerodrome noise abatement objectives.
Departure procedures shall comprise a maximum of two procedures for each aeroplane type, one of which shall be identified as the normal procedure, and one as the noise abatement procedure.

3. ICAO PANS OPS Volume 1 (Doc 8168-OPS/611)
Part V Chapter c)
c) To minimize the impact on training while maintaining some flexibility to address variations in the location of noise-sensitive areas, sufficient commonality shall exist between the departure procedures specified by the operator. There will be no more than two departure procedures to be used by one operator for an aeroplane type, one of which should be identified as the normal departure procedure and the other as the noise abatement departure procedure.
 d) Normal departure procedures typically include general noise reduction measures that encompass one of the two examples shown in the appendix to this chapter – Noise Abatement Departure Climb Guidance. ….
Noise abatement climb example of a procedure alleviating noise close to the aerodrome (NADP 1)
2.4 On reaching an altitude at or above 240 m (800 ft) above aerodrome elevation, adjust and maintain engine power/thrust in accordance with the noise abatement power/thrust schedule provided in the aircraft operating manual. Maintain a climb speed of V 2 plus 20 to 40 km/h (10 to 20 kt) with flaps and slats in the take-off configuration.
3. Noise abatement climb -Example of a procedure alleviating noise distant from the aerodrome (NADP 2)
3.4 On reaching an altitude equivalent to at least 240 m (800 ft) above aerodrome elevation, decrease aircraft body angle/angle of pitch whilst maintaining a positive rate of climb, accelerate towards V ZF and either:
a) reduce power with the initiation of the first flap/slat retraction; or
b) reduce power after flap/slat retraction.

4. ICAO PANS OPS Volume 1 (Doc 8168-OPS/611)
Close in
NADP 1
Thrust Red
V2 + 10
Flap Retract
Best climb
Distant
NADP 2
Flap Retract
1500ft
3000ft
800ft

5. Manufacturer State of the Art
FMS TAKE OFF Page:
Acceleration
+ Flap retraction
BOEING
AIRBUS
Thrust Reduction

6. Manufacturer Projects
Example of future development:
“Airbus are developing a new FMS function that should be available next year and will have a function called NADP (Standard on A380) which will allow the use of multiple noise abatement procedures optimised for individual runways for a particular set of operating conditions.
The power reduction altitude could be optimised as a function of the weight. It may be possible to uplink the noise abatement procedure to the FMS from the ACARS. There would be a planning tool, called ADAS Airbus Departure Analysis Software, to calculate best procedure. The FMS would have a noise page entered from the performance pages. The reduction altitude is the main parameter to optimise when designing Noise Abatement Procedure. If up-linked by ACARS, no additional workload for pilots. “

7. July 2005 OPSG draft JAR-OPS 1.235 Noise abatement procedures
(a) When establishing noise abatement procedures, an operator shall ensure that they comply with ICAO PANS OPS Volume 1 (Doc 8168-OPS/611) in order to meet aerodrome noise abatement objectives.
The departure noise abatement procedures shall comprise a maximum of two climb profiles for each aeroplane type, one of which shall meet the close-in noise abatement objective and the other the distant noise abatement objective as defined in PANS OPS Volume 1.
Note: climb profile means sequence of actions.
Example: first reduce thrust then accelerate.

8. OPSG comments
The group examined the regulation proposed 2 years ago and thought it needs more work but then failed to produce an acceptable proposed text for the following reasons:
 a) It was unclear if it is acceptable to introduce variable thrust reduction heights and acceleration heights with the advent of modern FMS/autoflight systems for each runway, or even aircraft weight on a particular day.
 b) In adjacent paragraphs of PANS-OPS there appears to be conflicts between the two noise abatement procedures and the normal procedure.
 e) Concerns over the difficulty of applying a simple solution that would apply equally well to older and newer types of aircraft.

9. OPSG request OST advice before further action.
OPSG conclusion
The group concluded that:
 a) The initial climb phase of flight is defined as critical and any changes must be assessed for their safety/workload impact.
 b) We must limit the complexity and number of procedures. The procedures should always have the same philosophy and structure with identical sequence of actions.
 c)  Noise abatement must always come second to safety considerations.
               
OPSG request OST advice before further action.