Project AS 14/02 - Miscellaneous Changes to MOS Part 139 - Aerodromes
Project closed 16 February 2015.
All industry feedback received to date on this project will be incorporated into the recently announced full Post Implementation Review of Part 139 Regulations and Manual of Standards.
Since the introduction of the Manual of Standards Part 139 (MOS 139), a number of issues have arisen in regard to the misinterpretation of some rules and the misapplication of others. Application of the MOS has also lead to the discovery of some errors within MOS 139 that need addressing.
This new project aims to introduce a few new provisions to allow more flexibility in regard to the application of some rules and also to clarify others so as to more accurately reflect the intent of existing rules.
Issues that have come to light include discrepancies or misinterpretation of the following standards:
- Apron Parking Clearances
- Apron Lighting Levels
- Approach Slope Guidance for large aircraft
- Wind Direction Indicators
- Location of Movement Area Guidance Signs (MAGS)
A number of minor editorial changes are also to be addressed that will clarify existing rules and negate the need for operators to hold exemptions due to non-compliance with the existing wording of MOS 139. Addressing these issues will clarify CASA's requirements, and increase industry compliance with minimal to no cost to industry.
Apart from a number of mechanical amendments to improve clarity there are a number of specific areas, outlined below, that will be targeted by this project.
Historically CASA has required Apron Parking Clearances to be determined using the ICAO coding method whereby the most demanding of the aircrafts wingspan or outer main gear wheel span (OMGWS) determines the coding for all aerodrome facilities. CASA acknowledges the fact that the wing span is generally the more critical dimension on an apron. The application of the most demanding characteristic has resulted in excessive clearances being applied to parking positions for smaller aircraft simply because of the width of the OMGWS. This project proposes to permit the wingspan to be considered the critical dimension for apron parking design subject to CASA agreement, thereby freeing up space on an existing apron to cater for the introduction of larger or more aircraft as desired by the aerodrome operator and without the need for an exemption to be issued as is currently the case.
ICAO requires 20 lux apron lighting for all aircraft. Australia has traditionally permitted 5 lux to be used on aprons for aircraft of Code 3C or smaller. In order to move closer to ICAO compliance and also to ensure an adequate level of lighting for the large Code 3C aircraft that now service Australian regional aerodromes, CASA proposes to increase the lighting levels. This would be a phased approach and would not require existing facilities to be upgraded to the new standard until replaced.
With the increase in passenger numbers being catered for by high speed turboprop aircraft, it is proposed to require these aircraft, if they exceed 20,000 kg certified MTOW, to be provided with slope guidance to provide increased safety. This would only be required for new operations. Where these operations currently exist, the aerodrome operator would be required to plan to introduce approach slope guidance by 2020.
A number of changes are proposed for the location of Wind Direction Indicators and the standards surrounding the design of Illuminated Wind Direction Indicators are to be reviewed to improve clarity in regard to CASA's requirements.
With larger aircraft now servicing aerodromes with narrower runways than they were originally designed for, a number of aerodromes have had their Movement and Guidance Signs (MAGS) damaged or destroyed due to their proximity to aircraft engines during the take-off or landing roll. This would be addressed by requiring the MAGS to be relocated to the distance that would be required if the runway dimensions matched the coding of the large aircraft that are using that runway.
MOS Part 139
This project was approved by Rick Leeds, A/g EM SD on 16 December 2013.
Project Leader: Matthew Windebank, Aerodrome Standards Engineer, Airspace and Aerodromes Regulation
Project Sponsor/s: Peter Boyd, Executive Manager, Standards Division
Standards Officer/s: Roy Tuomela, Manager ATMS Standards
Standards Consultative Committee (SCC)
|Consultation updates in 2015|
|Project AS 14/02 - Miscellaneous Changes to MOS Part 139 - Aerodromes|| This project is now closed
Refer to the project closure notes for further information.
|19 Feb 2015|
|Consultation updates in 2014|
|Project AS 14/02 - Miscellaneous Changes to MOS Part 139 - Aerodromes||Project approved.||7 Jan 2014|