R e s e a r c h
Martin SHOUGH & Wim VAN UTRECHT
Below is the full content of a letter sent to the Director of the Melbourne Aviation Meteorology Department on August 13, 1967. The letter was drafted by pilot Frank AUSTIN and filed at the National Archives of Australia as "part 8" of "file series A703 control symbol 580/1/1". Our thanks to Australian researcher and author Keith BASTERFIELD for sending us a digital copy of this and two other RAAF documents on this sighting.
I hesitate to write in case I am considered a "nut". Perhaps your department may have some explanation for what I and my three passengers observed when returning from Queensland on 9/8/67 in my Beach 23 VH-FXH.
We were on a heading of 185°M en route from Rockhampton to Parkes. Area QNH was 1018, Altitude 6300', Temp. + 12°C. TAS 108 Kts C/S 108 Kts. Vis 60 miles into haze, cloudless, nil turbulence. We had just crowned the Queensland border at 2.22 H.S.T. a mile west of TALWOOD. A friend was flying in the H. Seat while I was checking nav. I looked up and ahead and saw what I thought to be a large "mob" of birds about 2 miles ahead at about our altitude. As my friend is not a pilot, I indicated that I would take over to take evasive action. The "mob" was dense in the middle and strung out in echelon to either side, dark grey in colour and tended to concertina in and out horizontally. We all watched with interest as I said they were ibis, from their formation. After about a minute I was surprised to note that the mob was travelling faster than we were, was further away but still dead ahead and same relative height. It continued to change its shape from time to time, either into a round mass, or echelon right or left, and at one stage split in two than rejoined.
At his time my wife noticed a similar mob bearing 45° to starboard. Both "mobs" in many ways resembled the erratic flight of a swarme of bees. For five minutes we followed the "mobs" which were obviously moving away as they were becoming less distinct. The starboard one suddenly disappeared, followed by the appearance of another about 30° to port. At this time I remembered we had field glasses, but they did not allow much more than we had seen when first sighted. The images were more "cloud like" but in continuous motion. We followed the "mob" for 17 minutes until it finally disappeared or merged into the haze horizon.
Had I been by myself I would have been worried, to say the least. As all four of us saw the same thing it was suggested that I try and get an explanation.
I might mention that I have some 2000 hours flying experience, both in WW2 and during the last four years, and never have I seen anything resembling the above, except that the colour was similar to dark "flak" bursts.
FRANK AUSTIN Jnr.
Comment - The account bears a strong resemblance to other pilot sightings in our list. There's the pilot's comparison of the objects' colour with "flak bursts" (Also explicitly mentioned in the 1944 Omaha Beach case, the 1954 Labrador case, the 1959 Green Head case and the 1963 Mitchell case) and once again morphing shapes are mentioned in combination with horizontal motions, typical for a mirage image of a mountain or cloud tops trapped in an undulating inversion duct. The long 17 minutes duration, the fact that the objects always remained visible in the same segment of the sky before they "disappeared or merged into the haze horizon", are also strong indications of a mirage-like phenomenon.
Incuded in the RAAF files is a small weather map showing the pressure patterns "5 hours ahead of incident". From the map it can be seen that the plane was probably in a large high pressure region at the time (1018 mbar/ 30.06" mercury). The map shows the surface pressure field at 9:00 am, 5 hrs 22 min before the sighting and the plane location is then well inside the east edge of a 1018 mbar contour about six or seven hundred miles in diameter. There is general mid-latitude poleward circulation and a tendency of high pressure to flow towards low pressure so we would expect this high to have drifted and spread towards the complex of lows off the south of the country during the day, so by the sighting time the plane was probably if anything more deeply embedded near the centre of the high which would increasingly tend to embrace the mountain ridges encircling the whole Murray-Darling basin.
It is likely that a huge reservoir of subsided very dry and very warm air was collected in the basin during the day, overlain with cooler and moister air brought on southeasterlies circulating clockwise around the low in the Tasman Sea and dragged up ~ 5-6000ft over the coastal Dividing Range to spread like a cold lid over the basin. The topography and weather looks ideal for a stable inversion of very wide horizontal extent to develop near the 6300ft altitude of the plane, surrounded by low pressure weather systems off the coast possibly with lots of cloud development.
However, with the Sun well up and about 30° behind the right wing, there will not have been any backlit cloud silhouettes over the horizon in the sighting directions. So we'd presumably be looking at mountain-top targets. We find plenty of mountains near the flight level to the left of the plane, and ahead also, but not to the right, so this is not conclusive.