Version 2, 25 SEPTEMBER 2011


Whilst re-reading Leslie Keane's 2010 book "UFOs" (Harmony Books, New York), I came across reference to the 22 August 1968 Australian, Zanthus case which involved an aircraft.  There are many references in the UFO literature to this event. The usual summary they provide goes something like this:

"Captains Smith and Gardin were flying near Zanthus, Western Australia when they spotted "a formation of aircraft," which appeared to be keeping station with their plane.  There was one large object and several smaller ones.  Local air traffic control advised the pilots that there was no known traffic in the area.  For several minutes the aircraft was unable to communicate with air traffic control.  During this time the larger object split into two, and the smaller objects seemed to move around.  Finally, the whole formation joined together and departed at tremendous speed."

RAAF documentation:

Few people are aware of the full details of this intriguing event.  I found a two page report written by Captain Smith on file series A703, control symbol 580/1/1 part 10 pages 145, 160 and 218-223.  This was a RAAF Department of Defence file.  The Captain's statement reads as follows.

"Captain Walter Gardin and myself were returning from Adelaide to Perth on a charter flight.  The aircraft was an 8 place Piper Navajo, registration VH-RTO, and were returning empty from Adelaide.  At the first sighting I was asleep in the cabin, Walter was at the controls.  We were cruising at 8000' with a true airspeed of 190-195kts, tracking 270 degrees magnetic.

"At 0940GMT (1740WST) Walter abruptly woke me up in great excitement and asked me to come into the cockpit quickly.  I did so, and he asked me if I could see what he was looking at.  At first I didn't because I was still suffering from the effect of sleep, however after about 30 seconds I could see what he was excited about.  Some distance ahead at the same level and about 50 degrees to my right (I was in the right seat) I saw a formation of aircraft.  In the middle was a larger aircraft, and formatted to the right and left and above were 4 or 5 smaller aircraft.  We were on a track of 270 degrees (M) and these aircraft appeared to be maintaining station with us.

"Because we hadn't been notified of this traffic I radioed Kalgoorlie D.C.A. communications centre asking them what traffic they or RAAF had in our area.  The answer was none.  So I then notified Kalgoorlie that we had this formation in sight, and they in turn notified some eastbound traffic of the danger of unidentified traffic 130nm East of Kalgoorlie.

"At about this time we lost communications with Kalgoorlie on all frequencies.  We were getting Kalgoorlie carrier wave with no voice propagation, only a hash and static.

"In the next ten minutes I transmitted about 7 times and I believe Walter did about 6 times with no results.  Also at about this time we noticed that the main ship split into two sections still maintaining the same level, and the smaller aircraft then flew out left and right, but staying at the same level, and coming back to the two main halves of the bigger ship.  At this time there appeared to be about 6 smaller aircraft taking turns of going out and coming back and formatting on the two halves.  Sometimes the two halves joined and split, and the whol cycle continued for ten minutes.

"The shape of the main ship seemed to have the ability to change, not dramatically, but a change from say, spherical to a slightly elongated form with the colour maintaining a constant dark grey to black.  However, the smaller craft had a constant cigar shape, and were of a very dark colour.  Their travel out and back had a peculiarity not associated with normal aircraft in fact they appeared to travel out and come back without actually turning like a normal aeroplane would have to.

"At 0950GMT the whole formation joined together as if at a single command, then departed at a tremendous speed.  Not disappeared as say, gas would, but departed in about 3 or 4 seconds, diminishing in size till out of sight.

"The weather at the time of sighting was fine, with no haze above 6000' and about 2/8 altostratus cloud to the south of us and the other aircraft."

  "Notes on UFO:

  1. The distance from our aircraft of the UFO would be impossible to gauge, because the prerequisite to establishing distance is to know size, and the size of these objects are unknown.  However, for comparison size, the main ship compared to that of Boeing 707from about 10 miles.

  2. Immediately after the departure of the UFO radio communications were restored.

  3. Neither Walter or myself had the presence of mind to check if any deviation existed in our magnetic compass or automatic direction finding equipment whilst in the presence of the UFOs.

  4. The whole formation maintained the same distance and bearing from our aircraft during the whole time of the sighting.

Captain Gardin and myself discussed the sighting at length during and after and came to these conclusions:

Whether the UFOs were:
  1. Balloons.
  2. Gases.
  3. Trick of lights.
  4. Aircraft.

  1. If the sightings were balloons we considered it impossible to see these balloons from 30 miles, because this would have been the distance covered by the aircraft from the first sighting to the disappearance. 

    The UFO maintained the same distance throughout, whereas a free balloon would have a closure rate with us of 195kts our true airspeed and would have at least passed us.

  2. The same argument as above.

  3. If it were a trick of light, the colour of the UFO should have changed at somewhere or other, because the Sun had had a considerable traverse, coupled with our westward travel during this time.  Also due to the last two facts any refracted light would have changed form dramatically, whereas the UFO had very little change of shape or colour.

  4. We concluded that the UFOs were in fact aircraft with the solidarity of aircraft except perhaps for the fact of the larger UFO ability to split and change shape slightly."

What the RAAF did with this case:

Captain's Smith's statement was attached to a memo from RAAF Headquarter Pearce, Western Australia to the Department of Air, Canberra, dated 12 November 1968.  This memo stated that Smith's account was received by Pearce on 11 November 1968.

The Department of Air sent a "message form" to Pearce (Flt Lt Martin) and asked Pearce to contact the Department of Civil Aviation in Perth "on whether UFO report filed with any DCA agency in this event.  In particular did Smith or Gardin report facts to DCA.  Request check Kalgoorlie on whether pilots radio reported on UFO on 22 Aug."

A telex passed from HQ Pearce to DOA dated 25 Nov 1968 stated "Ref UFO sighting on 22 Aug 1968.  Enquiries with DCA Perth do not show any reports received.  Am now making enquiries with DCA Kalgoorlie on sighting."

On 9 Dec 1968 a memo went from the DAFI to Flt Lt Martin at Pearce asking for a follow up on the DCA Kalgoorlie angle.

The response from Pearce came in the form of a telex and stated that DCA Kalgoorlie confirmed "that aircraft VH-RTO on 22 Aug at approx 0940GMT enquired from APKG if there were any known traffic Zanthus area.  On being informed there was none the aircraft reported sighting of a UFO in company with six small disc like objects approximately ten miles north of track FT80 KAL on the same heading and keeping pace with them.  The pilots of VH-RTO confirmed this on arrival APKG at 1038GMT.  Before departing for Perth at 1138 they were advised to make a full report to RAAF Pearce."

My comments/analysis:

  1. A check of the RAAF's own published annual summary of UFO reports received by them, fails to locate this case.

  2. To my knowledge, no additional information has ever come forward, either in the form of official documents, or further comments by the pilots concerned in the UFO literature.

  3. I cannot find any record of any UFO group conducting an investigation.

  4. Smith's report states that the initial observation point was 130nm East of Kalgoorlie.  This puts the plane near Zanthus, a locality on the East-West transcontinental railway line.  An atlas puts Zanthus at latitude 31 deg 02 min latitude south and 123 deg 34 min longitude east.

  5. The final observation point's location is not given.  However, at a speed of 195kts and a duration of 10 minutes, the final point would have been approximately 100nm east of Kalgoorlie.

  6. The aircraft was tracking 270 deg(m) and the bearing to the "UFO" was approximately 320 deg (m.)  Smith's observation that "the whole formation maintained the same distance and bearing from our aircraft during the whole time of the sighting " implies that the "formation" was travelling at 195kts tracking 270 deg paralleling the aircraft's track at some unknown distance away.

  7. A check of the astronomical sky using a software program indicated that at 0940GMT the Sun had set and was about 4 degrees below the ground horizon, some 20 degrees to the right of the aircraft's track.  The Moon had set, and was some 23 degrees below the horizon.  The planet Venus was 13 degrees above the horizon at a bearing some 15 degrees to the right of the aircraft's track.  There was nothing astronomical at 50 degrees to the right of the aircraft's track.

  8. I located one potential explanation for the event.  In an article by Martin Shough (at about the classic 29 June 1954 BOAC Labrador sighting of a large object and several smaller ones, a possible cause was suggested of an unusual mirage.  He lists a number of other similar sightings which includes the Zanthus event and comments.

"As with the BOAC Labrador case, the lateral movements of the smaller objects occurred in a very narrow band ("without actually turning like a normal aeroplane would have to.")  Interestingly, this happened at the same time the "main ship split into two sections" which might suggest that the inversion layer became thicker at that point allowing more objects to enter the mirage duct."

This is a particularly interesting case, whether it was an unusual mirage as posited by Shough, or a "true" UFO.

The RAAF, which was the official body charged with looking into UFO reports, did not follow it up according to the official documents, despite the excellent witnesses.

Here was an excellent example of a "UFO" which deserved, but did not receive a proper scientific examination.

A witness located and interviewed:

So far, I have utilised the details of the 22 Aug 1968, Zanthus, Western Australia case, as recorded in the RAAF's UFO files.  However, upon reading those documents there were a few questions which arose in my mind, which I wanted to resolve.  What was the size comparison of the small to large objects? How far to the left and right of the large object did the small objects travel?  Were any radar observations made?

I was fortunate enough, the other day to be able to locate and interview, by phone, one of the pilots involved in this event.  Walter Gardin is now aged 77, being 34 when the event transpired.  He was kind enough to answer my questions.  Here then are my interview notes, which provide some interesting new details which have not seen the light of day in 43 years.

Interview notes with Walter Gardin 15 Sep 2011:

Q1   What first drew your attention to the formation?

We had heard that a balloon was to be flown from Western Australia to Sydney.  I was flying the aircraft at the time, when I suddenly noticed an object out of the cockpit window.  I looked again but nothing was there.  I was reading a newspaper at the time.  On looking up once again, the object was now present.  Later I learnt that the balloon in questions had not flown on that day.  So, the answer to your question is that I first thought it was a balloon I was seeing.

Q2   The statement said the formation was at the same level as the aircraft.  Does this mean that you looked straight at it, as opposed to needing to look up or down from the aircraft's horizon?


Q3   There was one larger object and several smaller ones.  If the length of the larger object was one unit, what was the length of a smaller object?

1/10th to 1/5th of a unit.

Q4   For the whole ten minutes of viewing, the formation maintained the same distance.  Does this mean that the angular size of both the larger and smaller objects remained constant?


Additional information:

Walter was supposed to provide a position report to DCA Kalgoorlie, during the time they were out of radio contact with DCA Kalgoorlie.  When Kalgoorlie failed to receive this report they were concerned that the aircraft may have crashed.

Q5   The statement reads "the smaller aircraft then flew out left and right."  If the length of the larger object was one unit, how many units to left and right did the smaller objects travel?

About 30 degrees. Two smaller objects went to the right and four to the left.

Q6   "At 0950GMT the whole formation joined together."  Does this mean that they became one, and only one object, which diminished in angular size?

Yes, they all merged.  The smaller objects merged with the larger one by going in to it from underneath.  The one object then departed by going upwards at a 45 degree angle from the aircraft's horizon.  It diminished in size as if receding.

Q7   Was the Sun above the horizon at the time?


Q8   Was the Moon or any other object visible in the sky?

No.  It was a clear blue sky in the direction of the formation.

Q9   The statement said the weather was fine.  Does this equate to clear sky in the direction of the objects?

Yes.  The weather was fine in that direction. Clear blue sky.

Q10   Was there any air turbulence at the time?


Further information:

When they arrived at Kalgoorlie, the police were present, as DCA thought that the aircraft may have crashed.  Walter did not talk to them about his observations.  He understood that Gordon may have appeared later, on TV or in the paper.

Q11   Kalgoorlie told you that there was no traffic in the area, when you asked them.  Would this have been based on their radar observation?

Walter and I discussed this point and came to the conclusion that Kalgoorlie relied on aircraft identifying themselves as being in the area, rather than radar observations from Kalgoorlie.

Using the web, at, I located a copy of a 1967 Department of Civil Aviation chart of Australian controlled airspace and radar coverage.  It shows that, at least in 1967, there was no radar coverage at Kalgoorlie.

Q12   Did your aircraft have radar onboard.


Q13   To your knowledge, was Kaloorlie in receipt of any other observations of unidentified traffic?


Q14   Did any RAAF personnel ever speak to you or Gordon about the observations?

RAAF did.  Walter recalls someone telling them about a case involving the US Dewline and of a building in the US where they looked into UFOs.

Q15   Prior to 22 Aug 1968 what was your opinion of UFOs?

UFOs were "bull," (that is he didn't believe in them.)

Q16   Did you change your opinion as a result of the 22 Aug 1968 observation?

Yes.  After this episode I formed the opinion that there are other inhabited planets out there.

Additional information:

While looking at the formation, Walter had a strange sensation, which lasted for the next six months.  He had the feeling that he was "in the control of people gathering information on people on the earth."

Q17   What radios were onboard the aircraft?

Two UHF and one VHF.

Q17   How many times did the cycle of smaller objects going outwards and inwards occur?

I saw it three times. Gordon twice.

Q18   Do you know if Gordon Smith is still alive?

I don't know.  The last I heard of him he was at a flying school in Perth.

My final comments:

Some very interesting information has emerged from this interview.
  1. That the single, united object left at a 45 degree upwards direction.  I had thought, from the statement given to the RAAF that the one final object had simply gone out of sight still on the aircraft's horizon.

  2. That the smaller objects, when moving left and right of the main object had travelled through about 30 degrees away from the main object.  This is a large angular distance.  I double checked this fact with Walter.

  3. The smaller objects were 1/10th to 1/5th the angular size of the larger object.

  4. The smaller objects merged with the larger one by going into it from underneath.  I had thought from the original statement that the smaller objects came in from left and right, i.e. along the same plane as the aircraft's horizon.

Given all the data, from both from the original 1968 documentation, and this interview, albeit it is 43 years later (why did no one follow this case up at the time?), I don't believe that the mirage hypothesis is valid.

In my opinion, this event represents an excellent example of the "core" UFO phenomenon, and deserved a scientific investigation at the time.