Recommendations in CASA guidance CAAP 92-1(1) requiring obstacle clearance out to 900 m may lead to circumstances where ALAs meet these requirements however, aircraft are required to manoeuvre below a safe height or be unable to outclimb rising terrain after take-off more than 900 m past the runway end.
On 2 December 2021, as part of a suite of changes to the Civil Aviation Safety Regulations 1998, CASA introduced regulations and guidance relating to obstacle clearance in the approach and take-off areas of Aeroplane Landing Areas (ALAs). At this time, CAAP 92-1(1) was discontinued and was subsequently removed from the CASA website being replaced by Advisory Circular AC 91-02 (the AC). This guidance includes reference to a pilot needing to consider ‘lateral transition areas’ in deciding if an aerodrome is suitable for operations, in contrast to CAAP 92-1(1) that only recommended obstacle clearance assessments of the approach and take-off area 900 metres beyond the runway end. The AC also included that a pilot should be aware of ‘obstacles in the approach and climb-out flight paths’. Further, clause 24.02(1) of Part 91 of the Manual of Standards also introduced on 2 December 2021 included a new requirement that pilots ensure that the aeroplane has the performance to clear all obstacles by a safe margin until at the minimum height for flight. Therefore, these changes address the safety issue, requiring pilots to assess the terrain under the flight path after take-off more than 900 metres past the runway end.
CASA advised the ATSB that on 2 December 2021, legislation relating to obstacle clearance in the approach and take-off areas of ALAs was changed. Specifically, clause 24.02(1) in Part 91 of the Manual of Standards now states:
The pilot in command of an aeroplane during and after take-off must ensure that, until the aeroplane reaches the minimum height for the flight in accordance with regulation 91.265, 91.267, 91.277 or 91.305 (as applicable), the aeroplane has the performance to clear all obstacles by a safe margin.
CASA also advised that additional guidance relating to obstacle clearance was published on 2 December 2021. Section GM 91.795 labelled ‘Take-off performance’ in the acceptable means of compliance and guidance material (AMC/GMs) for CASR Part 91 stated:
In addition to the AFM providing figures for determining the take-off distance required, the PIC should take into consideration obstacles that may be limiting or that may infringe the intended flight path. Consideration should also be given to obstacles that may infringe any flight path intended for use during abnormal situations.
In addition, CASA Advisory Circular AC 91-02 version 1.1 was published in November 2021. This included section 6.2 labelled ‘Deciding to use an aerodrome’ that included:
6.2.1 It is the pilot's responsibility to be satisfied that the aeroplane is able to safely take off from, or land at, an aerodrome. When operating at an aerodrome, the pilot needs to be aware of any potential hazards.
6.2.2 Section 7 of this AC describes factoring in more detail, however the following is a summary of some, although not all, matters that a pilot should consider when deciding whether or not to use an aerodrome:
− obstructions in the approach, take-off and lateral transition areas
− any other obstacles in the vicinity of the aerodrome (such as power lines)
Further, section 8.5 labelled ‘Obstacles on, and in the vicinity of, an aerodrome’. Notably, paragraph 8.5.5 included:
It is recommended that pilots have a thorough awareness of the obstacles in the approach and climb-out flight paths. Where a pilot does not have experience with nonstandard approach and departure angles, it is recommended the pilot consider alternative aerodrome options, or receive training in the special techniques necessary for these kinds of circumstances.
CASA also advised of a ‘Climb/Descent Gradient Graph’ published in the introduction of the ERSA on 21 May 2020 (also published in earlier and subsequent versions of the ERSA). This graph provides information to estimate the climb or descent gradient of an aircraft when the climb rate and ground speed is known. An aircraft climb gradient that is less than the gradient required to clear obstacles after take-off indicates that the aircraft would be unable to outclimb terrain.