Post by Dave Homewood on Aug 19, 2024 23:19:56 GMT 12
This could have been nasty. From The Press, 26 April 1969.
Air Collision Avoided By Ten Seconds
A National Airways Corporation Viscount narrowly avoided colliding with a flight of five Royal New Zealand Air Force Devons near Christchurch Airport last month. Writing in the April issue of "Alpa,” the official journal of the N.Z. Airline Pilots’ Association, the N.A.C. pilot (Captain P. J. McArthur) said that 10 seconds made the difference between a collision in which there "would have been large lumps of six aeroplanes falling on Templeton Hospital, causing probably over 100 casualties."
"The whole incident is now under investigation," said the regional superintendent of i the Civil Aviation Division (Mr L. E. Duke) on Thursday. "All the reports have been forwarded to Wellington. It is anticipated that a full investigation will have been completed by early next week and that a statement will be issued," he said.
In his letter to the editor of the journal, Captain McArthur said the “very serious incident" occurred on the final stages of flight 521 from Wellington to Christchurch on March 26.
“We were marshalled by the Christchurch radar on to the downwind leg for runway 02, descending to 2000 ft. Whilst passing the airport on our left at this altitude noted we were in and out of a very patchy cloud base with drizzle, making visibility about two miles, decided to remain on instrument flight rules and continue with the radar marshal onto final for visual approach as was originally offered by Christchurch radar," he said
“After about five miles of the extended downwind left I was instructed to turn on to 110 degrees M and descend to 1500 ft. This was the base leg prior to intercepting the 02 runway centre-line for the radar-marshalled final approach, which I intended to monitor on ILS and the Hornby beacon.
“As we reached 1500 ft we were instructed to turn on to 060 degrees M to intercept the centre-line. In this position we were still in the cloud base and drizzle. We were then told, ‘Unldentified aircraft, 12 o’clock, one and a half miles.’
Five Devons
“For a moment we could see nothing because of the patchy cloud base and drizzle. Then as we came into a clearer patch my co-pilot and I simultaneously saw a flight of five Air Force Devon aircraft turning across our flight path dead ahead, on the same level about half a mile ahead,” said Captain McArthur.
“I immediately began to take evasive action but then realised the tum they went in would take them clear to starboard, going away, while our own turn to port would increase the divergence and also bring us on to the 02 runway approach. I was satisfied I had sufficient visibility to continue under visual flight rules.”
Captain McArthur said the time lapse between the sighting of the Devons and radar’s warning reduced the range to about half a mile due to closing speeds. When the first visual contact was made the Viscount was overtaking the Devons on the same heading. The turns being made by both the Viscount and the Devon flight were tangential, and at the point where they touched the Devons would have been no more than 10 seconds ahead.
Had they been 10 seconds later the result could have been a collision, he said. The Viscount was seven minutes later landing at the airport.
False Assumption
Captain McArthur said that later the radar officials — a trainee, and a top supervisor — admitted that they had assumed the Devons’ trace on the screen was an aircraft in the Wigram circuit, that all the aircraft were in communication, and that they could see each other.
Captain McArthur said he could not understand why the radar controllers sat “petrified” watching the radar traces converging on their screen. The instructor, he added, admitted later that by the time they realised the ‘blips’ were getting dangerously close it was too late to do anything. The whole purpose of radar was to avoid such incidents, said Captain McArthur. The five Devons that day were practising formation flying for a fly-past at Wigram during a wings parade held on March 28.
Air Collision Avoided By Ten Seconds
A National Airways Corporation Viscount narrowly avoided colliding with a flight of five Royal New Zealand Air Force Devons near Christchurch Airport last month. Writing in the April issue of "Alpa,” the official journal of the N.Z. Airline Pilots’ Association, the N.A.C. pilot (Captain P. J. McArthur) said that 10 seconds made the difference between a collision in which there "would have been large lumps of six aeroplanes falling on Templeton Hospital, causing probably over 100 casualties."
"The whole incident is now under investigation," said the regional superintendent of i the Civil Aviation Division (Mr L. E. Duke) on Thursday. "All the reports have been forwarded to Wellington. It is anticipated that a full investigation will have been completed by early next week and that a statement will be issued," he said.
In his letter to the editor of the journal, Captain McArthur said the “very serious incident" occurred on the final stages of flight 521 from Wellington to Christchurch on March 26.
“We were marshalled by the Christchurch radar on to the downwind leg for runway 02, descending to 2000 ft. Whilst passing the airport on our left at this altitude noted we were in and out of a very patchy cloud base with drizzle, making visibility about two miles, decided to remain on instrument flight rules and continue with the radar marshal onto final for visual approach as was originally offered by Christchurch radar," he said
“After about five miles of the extended downwind left I was instructed to turn on to 110 degrees M and descend to 1500 ft. This was the base leg prior to intercepting the 02 runway centre-line for the radar-marshalled final approach, which I intended to monitor on ILS and the Hornby beacon.
“As we reached 1500 ft we were instructed to turn on to 060 degrees M to intercept the centre-line. In this position we were still in the cloud base and drizzle. We were then told, ‘Unldentified aircraft, 12 o’clock, one and a half miles.’
Five Devons
“For a moment we could see nothing because of the patchy cloud base and drizzle. Then as we came into a clearer patch my co-pilot and I simultaneously saw a flight of five Air Force Devon aircraft turning across our flight path dead ahead, on the same level about half a mile ahead,” said Captain McArthur.
“I immediately began to take evasive action but then realised the tum they went in would take them clear to starboard, going away, while our own turn to port would increase the divergence and also bring us on to the 02 runway approach. I was satisfied I had sufficient visibility to continue under visual flight rules.”
Captain McArthur said the time lapse between the sighting of the Devons and radar’s warning reduced the range to about half a mile due to closing speeds. When the first visual contact was made the Viscount was overtaking the Devons on the same heading. The turns being made by both the Viscount and the Devon flight were tangential, and at the point where they touched the Devons would have been no more than 10 seconds ahead.
Had they been 10 seconds later the result could have been a collision, he said. The Viscount was seven minutes later landing at the airport.
False Assumption
Captain McArthur said that later the radar officials — a trainee, and a top supervisor — admitted that they had assumed the Devons’ trace on the screen was an aircraft in the Wigram circuit, that all the aircraft were in communication, and that they could see each other.
Captain McArthur said he could not understand why the radar controllers sat “petrified” watching the radar traces converging on their screen. The instructor, he added, admitted later that by the time they realised the ‘blips’ were getting dangerously close it was too late to do anything. The whole purpose of radar was to avoid such incidents, said Captain McArthur. The five Devons that day were practising formation flying for a fly-past at Wigram during a wings parade held on March 28.
