[Peetwo]

The semantics of aircraft in the lounge room.

It depends which team you support how you regard last nights Estimates session with CASA. When we have the Hansard and video it will be a lot easier to pick out the bones, but one major topic for the BRB will be the way in which ‘responsibility’ for the dreadful safety state of our airports has been passed about like a parcel.  Old ‘Shifty’ Tique & Co. played a merry tune to go with the parcel passing.  Carmody was so quick to unload it he almost shoved Halfwit under the Senate bus (MTF).

For the lay person, the easiest thing to understand will be ‘buffer zones’ and the lack thereof. Essentially ‘tis but a ‘fenced off’ no building area, either side of the runway, precisely designed to prevent exactly the kind of accident we witnessed last week in Melbourne. The UK, USA and most ‘grown up’ aviation nations have these areas; for what must now be, to all, blindingly obvious reasons – Australia does not.

Where CASA took their lame defence was to what are known as Pans-Ops (PO). ICAO produce these and Australia does comply. What PO provide is an obstacle free area from the runway end out to a specified distance. The area is known as ‘the splay’. The splay widens progressively at a predetermined angle to that distance; like a fan if you will, laid out on the ground. There are maximum heights for man made structures within the fan, so to maintain a minimum clearance in the vertical (obstacle clear gradient).  Simply put, you may place a two story building at mile from the end of the runway, or; a ten story building at five miles within the ‘splay’ area. So ‘obstacle clear’ flight paths and buildings may coexist; and, provided the aircraft can maintain the gradient prescribed, in theory, all is well. This is where CASA deem their ‘safety’ responsibility to end.

Consider the Melbourne crash; the aircraft’s problems did not manifest within the ‘splay’ but within the aerodrome confines, without the protection of a ‘buffer’ zone, inevitably the aircraft crashed into whatever was ahead of it. Be it the DFO, the Freeway or a residential area, there is no protection afforded for either aircraft or the public from behind or outside of the minimum prescribed splay area; starting at the runway end.

The runway used by the crash aircraft is some 1500 meters long; the aircraft would be safely airborne and accelerating toward the splay within 1000 to 1100 meters, normally the remaining runway distance is travelled in a matter of seconds and the aircraft enters the ‘safe’ obstacle clear splay; even with an inoperative engine, given clear space the aircraft should obtain a safe height using the obstacle clear distances within that area (pilot responsibility). But the crashed aircraft did not enter the ‘splay’; whatever went wrong happened behind the ‘splay’ and the flight path was, quite legally, obstructed. Whether or not 500 meters of obstacle clear (buffer) area, to the side of the runway would have produced and different result is, as yet, hard to determine; but, given that time and distance the aircraft may well have accelerated to a speed which allowed a climb. This is why ‘buffer’ zones are mandated in other countries. If you are keen, take a look at the aerial view of Archerfield, then imagine you are in a single engine aircraft. Normally, the aircraft is airborne and climbing away within about 60% of the available runway; then engine failure. The right procedure is to land ‘straight ahead’ or as close as possible to straight.  Measure off two thirds of any Archerfield runway, then work out (roughly) the glide distance needed to land ahead, from about 60 feet and see where you finish up – mostly in Mrs. Smith’s front parlour; that’s where. Just in time for tea.

That is as close to describing the ‘problem’ for non aviation folk as I can get; and I’ve probably offended the ‘purists’, using a thumb nail dipped in tar to outline the situation, but that’s Ok. When Hansard do their thing we will take a closer look at just who is responsible for what; but CASA have made it clear they are, so far as they are concerned – off the hook.

Toot – MTF – toot.

Hansard to follow...


MTF...P2