Peninsula Aero Club

Procedures at Non-towered Aerodromes

There are new procedures at non-towered aerodromes which came into force on 3 June this year.  Non-towered aerodromes obviously include Tyabb.  The differences are not large and for the most part, I think better.

The first difference.  There is a change in circuit speed for the 1,000 AGL circuit.  The top speed has been increased from 120 knots up to 150 knots.  This now means, for all practical purposes at places like Tyabb, the bulk of aircraft should now operate at the 1,000 foot circuit height.  (Prior to this, aircraft with a circuit speed above 120 knots should have been at 1,500 feet AGL).

So when it is required, there are now two good reasons to overfly at 1,500 feet AGL (1,600 AMSL) at Tyabb.  Firstly, most aircraft will now be in the circuit at 1,000' AGL (1,100 AMSL), so to overfly at 1,600' AMSL will normally give 500' separation.  Secondly, Tyabb is virtually on the direct track between Moorabbin and Cowes navigation aids.  The published lowest safe altitude for IFR aircraft on this track is 2,100 feet.  This is a busy route, so overflying the airport at 1,600' AMSL gives a useful 500' separation below this route.

The second difference.  It is now legal to join on base leg.  So now a pilot may join the circuit on downwind, base or final.  The rules associated with joining the circuit are:

(a)     Wind direction, and therefore circuit direction, must be ascertained prior to entering the circuit.

(b)     An aircraft in the circuit has priority over an aircraft joining the circuit.

(c)     If making a straight in approach, make a call at 3nm.

The preferred option at Tyabb is to make a downwind entry to the circuit.

The third difference.  It is no longer a requirement to be established on final 500 metres from the perimeter of the aerodrome.  The only requirement is to complete the turn onto final not below 500 feet AGL.

The fourth difference.  Only one call in the circuit is now required (either downwind or base), as distinct from the three calls previously required, downwind, base and final.  Currently, having only just got used to the three calls, the flying school will stick to the three calls at this stage.

So to summarise.  Although there are changes, in practical terms, sticking with out standard operating procedures and the application of common sense should ensure you remain well within these changes!