Aviation safety issues and actions
Recommendation issued to: Civil Aviation Safety Authority
|Date issued:||05 November 1998|
|Safety action status:|
The Bureau of Air Safety Investigation recommends that the Civil
Aviation Safety Authority develop and publish an effective
procedure by which pilots can ensure radio equipment is fully
functional prior to flight.
In addition, the Bureau has also issued the following recommendation:
The Bureau of Air Safety Investigation recommends that the Civil Aviation Safety Authority consider the need to ensure that knowledge and use of a recommended radio serviceability test procedure forms part of initial and ongoing flying training.
|Date issued:||07 June 1999|
|Response from:||Civil Aviation Safety Authority|
The Authority has not been able to devise a practicable procedure which will guarantee that radio equipment is fully functional before flight. Training in radio operation using competency based standards will assist in establishing serviceability (see below), but circumstances will not always permit voice transmission capability to be confirmed.
Radio serviceability is testable at a controlled aerodrome or one with a certified air/ground operator, but a test transmission at the majority of uncontrolled aerodromes would not provide an indication that the radio equipment was functional unless reacted to by another aircraft. As noted in the occurrence brief, a transmit light does not necessarily indicate that a modulated signal is being broadcast. While the presence of a sidetone is generally indicative of a modulated voice transmission, this may not always be evident when using a hand held microphone.
The occurrence brief also notes that while aerodrome frequency response or "beep-back" units provide an assurance that the correct frequency has been selected, they cannot distinguish between carrier wave and modulated transmissions. Technical advice available to the Authority is that it would not be practicable to modify these units to respond only to voice transmissions.
The following correspondence was forwarded to the Civil Aviation Safety Authority on 27 August 1999:
Thank you for your responses to the Bureau's recommendations, R19980143 and R19980144. The Bureau considers that the intent of R19980144 has been satisfied and CASA's response to the recommendation has therefore been classified Closed - Accepted.
The Bureau notes that CASA commented that "a test transmission at the majority of uncontrolled aerodromes would not provide an indication that the radio equipment was functional unless reacted to by another aircraft." The Bureau fully agrees with this statement. However, the possibility of other aircraft in the area that may be conflicting traffic is the very reason that pilots are encouraged to utilise alerted see-and-avoid procedures wherever possible. In most cases, other aircraft will be equipped with functional radio equipment, thus providing pilots with the opportunity to establish two-way communication or, alternatively, alert pilots to the possibility that aircraft radio equipment is malfunctioning. The Bureau accepts that there is currently no practicable procedure that will guarantee pilots that aircraft radio equipment is functioning correctly. However, in most cases, a test transmission would provide an additional defence that may prevent a collision.
The Bureau considers that regularly used CASA publications should contain a suggested method by which pilots, where possible and appropriate, can ensure that radio equipment is fully functional. Therefore, the Bureau has classified the CASA response to R19980143 as OPEN and request that it be reconsidered. Another copy of R19980143 is attached.
|Date issued:||27 September 1999|
|Response from:||Civil Aviation Safety Authority|
|Response status:||Closed - Accepted|
In relation to R19980143, you have requested that CASA reconsider its previous response, and include within CASA publications a method, to be used where possible and appropriate, by which pilots can ensure that radio equipment is fully functional.
Existing procedures for all aircraft require a taxi clearance at controlled aerodromes, and mandatory taxying broadcasts in MBZs and CTAFs; these provide assurance of radio serviceability at all controlled aerodromes and at non-controlled aerodromes where there is a manned radio service such as a Certified Air/Ground Radio operator or Unicom operator. In addition, where an ARFU installed at an aerodrome, a high, but not absolute level of assurance is also provided. AFRUs have been installed at more than 120 aerodromes used by two-pilot aircraft providing RPT services. IFR aircraft are also subject to further communications requirements in regard to contacting Air Traffic Services.
In general terms, therefore, the issue relates primarily to VFR aircraft at uncontrolled aerodromes that do not have such facilities. CAR 242 notwithstanding, whilst CASA supports the intent of R19980143, it contends that it is not practical to provide a defined process whereby pilots always have absolute assurance of the full functionality of their aircraft's radio equipment in every such type of operational circumstance.
Whilst additional 'test' transmissions could be recommended, or indeed mandated, CASA doubts that these would provide any worthwhile increase in the overall safety-of aircraft operations and at the same time could impose operational complexities.
CASA would welcome any specific suggestions that BASI might make which would result in a quantifiable enhancement in surety of radio serviceability in such circumstances.