Recommendation

SUMMARY OF DEFICIENCY



Tamworth airport has two parallel runways that are 760 metres
apart. Runways 12L and 30R are each serviced by a straight-in
instrument approach procedure. There are no instrument approach
procedures to either runway 12L or 30R. Those runways are for use
by single engine circuit training aircraft and for arrivals and
departures by aircraft operating under visual flight rules
(VFR).



The Tamworth control zone is classified as Class D airspace.
Pilots of aircraft that operate in Class D airspace require an air
traffic control clearance and are required to maintain two-way
communications with air traffic control (ATC).



Air traffic controllers in Class D airspace are required to
separate aircraft operating under instrument flight rules (IFR)
from other IFR aircraft and provide a separation service between
IFR aircraft and VFR aircraft. Controllers are also required to
provide traffic information to pilots operating under the VFR 'in
respect of all other flights' in accordance with the Manual of Air
Traffic Services (MATS). Tamworth ATC provides a procedural control
service because Tamworth controlled airspace is beyond radar
coverage.



Tamworth ATC uses separate aerodrome controllers (ADCs) to
facilitate simultaneous independent contra-rotating circuit
operations, and arrivals and departures to the parallel runways.
The procedure relies on the ADCs monitoring aircraft onto the final
approach path of the runway under their respective control and
providing an alert to the other ADC of potential conflicts. There
is no information exchanged by the two ADC's about approaching
aircraft to ensure that a procedural separation standard is
maintained until visual separation can be applied between specific
aircraft tracking for different, but parallel, runways and on
separate radio frequencies. The ADC's expect that aircraft
operating to the parallel runway will remain no closer to their
respective circuit than the adjacent runway centre-line. Traffic
information is only provided when an aircraft strays, or appears
likely to stray, into the other runway approach path or circuit
airspace.



MATS Section 4.8.3 states that 'Simultaneous Parallel Operations
by fixed wing aircraft of more than one landing/take-off path in
the same direction on the one aerodrome is permissible if, the
paths proposed to be used are treated as one runway for separation
purposes. The suitability of a landing area for simultaneous
parallel operations by fixed wing aircraft and the associated
control procedures shall be established in consultation with the
Civil Aviation Safety Authority.'



Separation standards are infringed when two or more aircraft are
assigned the same altitude and a lateral separation standard is not
applied, regardless of the runway or ATC frequency being used,
unless traffic information is provided in accordance with the
procedures in MATS for operations in class D airspace.



Visual separation cannot be applied between an aircraft under the
control of one ADC and another aircraft under the control of
another ADC, about which that controller has no specific details,
and where controllers are operating on separate radio
frequencies.



The use of simultaneous parallel runway operations at Tamworth
does not comply with MATS Section 4.8.3 because controllers are not
treating the parallel landing and take-off paths as one runway (see
ATSB occurrence number BO/200102901).