Joined: 11 Dec 2005
|Posted: Fri Apr 02, 2010 7:47 am Post subject: Noise Abatement Procedures
|AEROPLANE OPERATING PROCEDURES - APPROACH
In noise abatement approach procedures which are developed:
a. The aeroplane shall not be required to be in any configuration other than the final landing configuration at any point after passing the outer marker or 5 NM from the threshold of the runway of intended landing, whichever is earlier; and
b. Excessive rates of descent shall not be required.
When it is necessary to develop a noise abatement approach procedure based on currently available (1982) systems and equipment, the following safety considerations shall be take fully into account:
1. Glide path or approach angles should not require an approach to be made:
- Above the ILS glide path angle;
- Above the glide path of the visual approach slope indicator system;
- Above the normal PAR final approach angle; and
- Above an angle of 3 degrees except where it has been necessary to establish, for operational purposes, an ILS with a glide path angle greater than 3 degrees
2. The pilot should not be required to complete a turn on to final approach at distances less than will:
- In the case of visual operations, permit an adequate period of stabilized flight on final approach before crossing the runway threshold; or
- In the case of instrument approaches, permit the aircraft to be established on final approach prior to interception of the glide path.
Compliance with published noise abatement approach procedures should not be required in adverse operating conditions such as:
a. If the runway is not clear and dry, i.e. it is adversely affected by snow, slush, ice or water, mud, rubber, oil or other substances;
b. In conditions when the ceiling is lower than 500 ft above aerodrome elevation, or when the horizontal visibility is less than 1.9 km
c. When the crosswind component, including gusts, exceeds 15 kt;
d. When the tailwind component, including gusts, exceeds 5 kt; and
e. When wind shear has been reported or forecast or when adverse weather conditions, e.g. thunderstorms, are expected to affect the approach.
AEROPLANE OPERATING PROCEDURES - LANDING
Noise abatement procedures shall not contain a prohibition of use of reverse thrust during landing.
The practice of using a displaced runway threshold as a noise abatement measure shall not be employed unless aircraft noise is significantly reduced by such use and the runway length remaining is safe and sufficient for all operational requirements.
CONFIGURATION AND SPEED CHANGES
Deviations from normal configuration and speeds appropriate to the phase of flight shall not be made mandatory.
Noise abatement procedures shall include information on the altitude/height above which they are no longer applicable.
In order not to distract flight crews during the execution of noise abatement procedures, air/ground communications should be kept to a minimum.
NOISE ABATEMENT DEPARTURE CLIMB - EXAMPLE OF A PROCEDURE ALLEVIATING NOISE CLOSE TO THE AERODROME (NADP 1)
This procedure involves a power or thrust reduction at or above the prescribed minimum altitude (800 ft above aerodrome elevation) and the delay of flap/slat retraction until the prescribed maximum altitude is attained. At the prescribed maximum altitude (3000 ft above aerodrome elevation), the aircraft is accelerated and the flaps/slats are retracted on schedule while maintaining a positive rate of climb, to complete the transition to normal en-route climb speed. The initial climbing speed to the noise abatement initiation point is not less than V2 plus 10 kt.
In the example shown below, on reaching an altitude of 800 ft above aerodrome elevation, engine power or thrust is adjusted in accordance with the noise abatement power thrust schedule provided in the aircraft operating manual. A climb speed of V2 plus 10 to 20 kt is maintained with flaps and slats in the take-off configuration.
On reaching an altitude of 3000 ft above aerodrome elevation, the aircraft is accelerated and the flaps/slats are retracted on schedule while maintaining a positive rate of climb to complete the transition to normal en-route climb speed.
NOISE ABATEMENT DEPARTURE CLIMB - EXAMPLE OF A PROCEDURE ALLEVIATING NOISE DISTANT FROM THE AERODROME (NADP 2)
This procedure involves initiation of flap/slat retraction at or above the prescribed minimum altitude (800 ft above aerodrome elevation) but before reaching the prescribed maximum altitude (3000 ft above aerodrome elevation). The flaps/slats are to be retracted on schedule while maintaining a positive rate of climb.
Intermediate flap retraction, if required for performance, may be accomplished below the prescribed minimum altitude. The power or thrust reduction is initiated at a point along the acceleration segment that ensures satisfactory acceleration performance. At the prescribed maximum altitude, a transition is made to normal en-route climb procedures. The initial climbing speed to the noise abatement initiation point is not less than V2 plus 10kt.
In the example shown below, on reaching 800 ft above aerodrome elevation, the aircraft body angle/angle of pitch is decreased, the aeroplane is accelerated towards Vzf , and the flaps/slats are retracted on schedule. Power or thrust reduction is initiated at a point along the acceleration segment that ensures satisfactory acceleration performance. A positive rate of climb is maintained to 3000 ft above aerodrome elevation. On reaching this altitude, a transition is made to normal en-route climb speed.
An aeroplane should not be diverted from its assigned route unless:
1. In the case of a departing aeroplane it has attained the altitude or height which represents the upper limit for noise abatement procedures;
2. It is necessary for the safety of the aeroplane (e.g. for avoidance of severe weather or to resolve a traffic conflict).
SUPERCEDED NOISE ABATEMENT PROCEDURES
NOTE: Many locations continue to prescribe the former Noise Abatement Departure Procedures A and B. Though no longer part of the ICAO PANS-OPS Doc. 8168, they have been reproduced in the following paragraphs as supplementary information.
NOISE ABATEMENT DEPARTURE PROCEDURE A (NADP A)
a. Take-off to 1500 ft above aerodrome elevation:
- Take-off power
- Take-off flap
- Climb at V2 + 10 to 20 kt (or as limited by body angle).
b. At 1500 ft:
- Reduce thrust to not less than climb power/thrust.
c. At 1500 ft to 3000 ft:
- Climb at V2 + 10 to 20 kt.
d. At 3000 ft:
- Accelerate smoothly to enroute climb speed with flap retraction on schedule.
NOISE ABATEMENT DEPARTURE PROCEDURE B (NADP B)
a. Take-off to 1000 ft above aerodrome elevation:
- Take-off power/thrust
- Take-off flap
- Climb at V2 + 10 to 20 kt.
b. At 1000 ft:
- Maintaining a positive rate of climb, accelerate to zero flap minimum safe
manoeuvring speed (VZF ) retracting flap on schedule;
Thereafter, reduce thrust consistent with the following:
1. For high by-pass ration engines reduce to normal climb power/thrust;
2. For low by-pass ratio engines, reduce power/thrust to below normal climb thrust but not less than that necessary to maintain the final take-off engine-out climb gradient; and
3. For aeroplanes with slow flap retracting reduce power/thrust at an intermediate flap setting;
c. Thereafter, 1000 ft to 3000 ft:
- Continue climb at not greater than VZF + 10 kt.
d. At 3000 ft:
- Accelerate smoothly to enroute climb speed.
NOTE: Aeroplanes such as supersonic aeroplanes not using wing flaps for take-off should reduce thrust before attaining 1000 ft but not lower than 500 ft.