"Flying the RAAF's Avon Sabre" (F-86)
By WNGCDR Barry Weymouth (Ret.)
Two ground-crew members chat with Sergeant
Barry Weymouth
of Footscray, Vic. in the cockpit of his Vampire aircraft,
at Malta in the early 50s. [AWM MALTA0163]
Australia's Avon-Sabre was widely regarded as the best of all the F-86 variants operating around the world. - Capable of exceeding Mach 1 (the speed of sound) at high altitude, its main shortcoming was the lack of satellite navigational aids, as found in modern aircraft.
The Sabre had powerful and sensitive hydraulic flight-controls for pitch and roll; the rudder was mechanical only. Some inexperienced pilots over-controlled during their conversion phase. Severe and rapid oscillations could induce bruising should the pilot's harness not be tight enough! The human body was incapable of timing the necessary control corrections.
I have very happy memories of flying the Sabre.
From early days, one incident stands out. (Fortunately, I was an experienced pilot and capable of handling emergencies. At Central Flying School I was a Category-A instructor, equipped with the required skills.) During my Sabre 'type' conversion, engine compressor stalls and surges were not uncommon. At altitude, and inverted, I had a series of three flameouts, one accompanied by an extremely loud bang under my seat ("bang surge") with an immediate misting in the cockpit, disallowing outside vision. I had little trouble in relighting the engine after each flameout - and was too far away from base to do anything else! The last flameout occurred at the end of the landing run...!
The Engineer Officer suggested that 'finger trouble' could be the cause, but I was too experienced and careful to accept that. Indeed, a defective fuel pump was found to be the culprit, previously considered to be 100% reliable. Modifications followed.
Whilst taxiing, the Sabre used fuel at about 1200 pounds per minute. At 40,000 ft., that rate of fuel flow was sufficient to provide a cruising speed of Mach 0.83.
With the large external fuel tanks fitted, the Sabre constantly needed pilot input to the control system to dampen the oscillations. This was tiring for pilots [fighters in that era did not have auto-pilots], especially on a long Instrument-flight, until the drop-tanks were empty. I found it beneficial to cruise-climb to 46,000ft and make a small acceleration to Mach 0.86/0.87 approx.
In the cold temperatures of Equatorial altitude I have flown the the Sabre to 52,000 ft, where directional stability is degraded, the air being so thin. An unpleasant thunderstorm incident happened in Thailand, when a large thunderstorm changed direction and blacked out our Ubon base. The Air Traffic Control / Ground-Controlled Approach people could not see even large aircraft, like the C130 Hercules, and were therefore directing all traffic to alternate airfields with clear conditions.
I was too low on fuel to divert, so I needed Ubon G.C.A. to assist me for the approach to land. Two approaches had to be aborted and my fuel was down to 200 pounds. As I made a third approach, I was facing a possible ejection should the exercise again be unsuccessful. Through the storm I sighted the runway and landed (much relieved) in appalling conditions. Fuel remaining was down to 150 pounds - about 20 Imperial gallons.
In Squadron armament activities I was quite pleased with the good results from the younger pilots. As the Squadron Fighter Combat Instructor I had to use all my experience to produce best results.
Leading aerobatic teams was another satisfying experience. At Butterworth I led a team which performed at the Manila International display.
CLARK AIR BASE, PHILIPPINES. FIVE SABRE AIRCRAFT OF NO. 77 SQUADRON RAAF
ON THE FLIGHT LINE.
THE TWO NEAREST THE CAMERA ARE A94-978 AND A94-967, EACH FITTED WITH A LONG
RANGE DROP-TANK.
ALSO PICTURED ARE SEVERAL F102'S OF THE 509TH SQUADRON USAF. [AWM
P00675.113]
From Williamtown I next led a Sabre team, the 'Black Diamonds', who were a very competent group of RAAF pilots, and included a fifth solo demonstrator, USAF Major Steve Shiner, an exceedingly capable pilot. Among other tight manoeuvres flown, I led the team in an inverted flyover; whilst still in tight formation, I released control pressure to induce a near-zero-G flyover. It apparently looked most impressive!
In the recovery I had to return the team to positive-G flight. So I carried out a quartet turn downwind rollout which enabled me to then lead the team through a tight, low-level turn over the display area. The noise and the closeness of the team was very popular with spectators.
A disciplined inline taxi-return to the tarmac ended the routine. In the landing circuit, at low fuel state, a flare-out speed of 95 knots could be achieved. At heavier fuel levels, and with large drop-tanks fitted, about 125kts was usual.
[Left:] Richmond, NSW. 1961-09-17.
Commonwealth Aircraft Corporation (CAC) Avon Sabres
of the Black Diamonds aerobatic team performing at RAAF Base Richmond
during an Air Force Week display. [AWM P00448.048]
[Right:] Matching flight suits! Circa 1961. L to R: John Pyman, Barry Weymouth, Mick Parer, Maurie Baston. [75 Squadron Assn.]
Promotion to Wing Commander, and a posting away from flying, ended my very happy and contented days of flying the lovely Sabre.