John Bushell joined the RAAF in 1964, graduating from No 28 Navigator Course in February 1965 and posted to No 82 Wing for flying duties on Canberra bombers he served in No 1 Sqn and No 6 Sqn before posting to No 2 Sqn in 1968. Flying on Canberra bombers in Vietnam 1968 and 1969. In 1970 John was posted to No 6 Sqn for flying duties on F-4E Phantom 1970 to 72 Then flying duties again with No 6 Sqn on F-111C 1973 to 75 as Nav instructor. John then went on to serve in various roles including ARDU and as Commander of the School of Air Navigation School and finally as Air Attaché Australian Embassy Jakarta 1990 to 91 whereupon he resigned to take up a position in private enterprise. John had 28 years’ service 4840 hours flying. 2000 hours on Canberras. Here he gives a fascinating account of the Butterworth mission which gives a detailed insight into the operation of the Canberra in The RAAF.
The Lone Ranger exercises for Canberra crews were intended to give them experience in operating the aircraft away from base and an opportunity to gain knowledge from discussions with Canberra crews at other locations. No 82 Wing crews participated in Lone Ranger flights to Butterworth, where No 2 Sqn RAAF was based or Ohakea where No 14 Sqn RNZAF was operating their version of the Canberra. This story concerns a Butterworth Lone Ranger in November 1966, which was my first experience operating alone to an overseas destination. Previously I had been to Papua New Guinea, but with other squadron aircraft.
Getting the opportunity to fly a Lone Ranger was a sought after reward for sound achievement in squadron flying and working one’s way through the categorisation scheme. Before leaving on a Lone Ranger a crew needed to be capable of the post flight and preflight procedures to turn an aircraft around without the ground crew support available at home base. The pilot would do the “black hander” jobs on the engines and airframes and the nav looked after the “queer trades” items of instruments and radio.
At the time of this Lone ranger I was with No 1 Sqn, a unit of No 82 Wing, having completed Canberra conversion in July 1965. My total flying hours were 880 with 672 on Canberras. The pilot for this journey was Pilot Officer Max McGregor who was my regular pilot at the time. In the interests of achieving better operational capability Canberras were usually operated by a pilot and navigator who were assigned to form a crew. However, the aircrew also flew many sorties with a crew member who was not their assigned pilot or nav.
Canberra A84-242 crewed by PLT OFF Max McGregor and PLT OFF John Bushell set out from Amberley on 10 November 1966 for Edinburgh near Adelaide. This was an easy leg with reasonable availability of radio navigation aids and features on the ground for visual fixing. The primary navigation system was Doppler radar known by the RAF code name of Green Satin which fed groundspeed and drift to the ground position indicator (GPI) Mk 4. The GPI Mk 4 also received aircraft heading from the G4B gyro compass, and the initial coordinates of departure point were set. It would then automatically update the coordinates using the drift, groundspeed and heading information. As well as the GPI the Canberra had an air position indicator (API). This was fed by an air mileage unit and the G4B heading and maintained coordinates for where the aircraft would be if there was no wind. The same instrument had been used in World War 2 bombers, and at the time was an important navigation system. In the Canberra it was a backup and suffered from accuracy deficiency because of errors in the air mileage unit as a result of air compressibility.
In the Canberra the nav took a fix from the GPI Mk 4 each 10 minutes and plotted that on his chart together with a record of heading, altitude groundspeed and drift. A wind velocity was computed on the Dalton computer, a type of circular slide rule and logged as well. ETA for the next waypoint could be revised and if necessary a change of heading to maintain track made. Information was all recorded on the chart rather than in a separate navigation log because space was limited. One set of data that had its own log was the fuel. Fuel remaining was recorded at planned turning points and plotted on a graph to compare with flight plan, and the estimate for fuel remaining at destination would be revised. Each half hour the position given by the GPI was checked against an external fix, and revised if necessary. The external fix could be from radio aids (ADF and DME) or visual fix of features identified on the map.
Edinburgh was reached after two and a half hours flying time. The aircraft was then refuelled for the next leg to Pearce just north of Perth. Assistance at the RAAF base was available from the duty crew, but the aircrew needed to check the turnaround had been carried out correctly since the Edinburgh duty crew might not be familiar with the Canberra.
Set heading for Pearce was at 15:00 local time and the leg required three and a half hours flying. This was still a relatively routine leg from the navigator’s point of view with adequate radio aids and visual features. The travel from Amberley to Pearce had been split due to the prevailing strong westerly winds across southern Australia at height. The Canberra usually operated at or above 40,000 feet for transit flights and it would not be unusual to encounter head winds more than 100 knots at those levels.
On arrival at Pearce the aircraft was put to bed and left in the hands of the duty crew. The aircrew adjourned to the officers’ mess to have a beer and a yarn with the locals. At the time Pearce was the home of Advanced Flying Training School where pilots underwent the second phase of their course flying Vampires.
On 11 November A84-242 departed Pearce at 0800 heading for Cocos Island. This leg was more challenging for the navigator being over water most of the way. The leg duration was four hours, which was nowhere near the maximum. However, if the airfield at Cocos was closed diversion to another field would be problematical. Safe diversion points to other airfield on the west coast had been calculated, but the weather was clear and no reason to divert arose. While position reporting could be made over VHF radio on the domestic legs, the over ocean legs required use of the HF. The HF radio fitted to the Canberra was not a modern dial a frequency type like I later became used to in the F-111. The Marconi HF in the Canberra had to be tuned to frequency and it had no single side band mode. Communications were not reliable and position reporting could take up time that the nav might otherwise have used on navigation matters. However, keeping the authorities aware of one’s position was an important task, and in one’s own interest in case of emergency.
Cocos had an airfield with an 8,000 foot asphalt runaway that had been built by the Allies late in World War 2. It is still in use today. This island airfield provided a convenient transit point for RAAF aircraft flying from Australia to Malaya since overflight of Indonesia was not permitted at the time.
After arrival at Cocos the aircrew refuelled and serviced the aircraft since there was no RAAF duty crew on hand. This was achieved ready for take off again by 1430. That allowed to crew to “refuel“as well. In flight rations in the Canberra were limited to sandwiches and orange juice, usually provided in a substantial cardboard box. However, the pilot had to fly the aircraft all the way since it had no autopilot, and the nav was busy most of the time finding fixes or doing calculations of some sort. Hence it was more convenient to eat the in-flight rations after the flight: except for the chocolate bar that generally did not make it to destination.
A84-242 being an Mk 109 engined Canberra had a triple breech starter, so it was not essential to replace the one cartridge that had been used for start at Pearce. Nevertheless spare cartridges were carried in a rack in the camera bay behind the bomb bay. With the Mk 1 engined aircraft (up to A84-227) there was only one cartridge so reloading on turnaround was essential.
So the engines were fired up in the normal noisy fashion, but there were few people at Cocos to witness the departure. During taxi for take the nav would set up his GPI coordinates and log the start and initial fuel. Note down airways clearances if applicable. He calculated a refusal speed and a safety speed using graphs in the check list, and read the check list to the pilot. Refusal speed was the speed that the aircraft could accelerate to and then stop within the remaining runway length. The graph took into account runway length, elevation, temperature, aircraft weight and wind down the runway. The second speed of vital interest was safety speed, the speed at which a pilot could maintain directional control with one engine at full thrust and the other dead. The period between refusal and safety speeds on each take off was one of suspense. Fortunately Messrs Rolls and Royce had done a good job developing the Avon engine and the only concern in practice was birds committing suicide by flying into the engine intake.
On line up the nav would turn on the undercarriage circuit breaker and be ready on the aircraft stopwatch, the GPI and the Green Satin. He had already given the pilot initial track to intercept after take-off. The pilot would run the engines up and check all gauges within limits. As the pilot released brakes the nav started the stop watch and turned the GPI and API on. He monitored the airspeed indicator and time and called refusal speed and safety speed to the pilot. After 100 knots the Green Satin groundspeed was inched up to follow airspeed until the aircraft was about 200 feet clear of the ground then the Green Satin could be turned to transmit and receive. Allowing it to operate on the ground could cause damage to the equipment since the returned signal could swamp the receiver.
The undercarriage circuit breaker that was part of the pre-takeoff checklist could be a little amusing if it was overlooked. That circuit breaker was normally turned off on the ground to prevent inadvertent retraction of the undercarriage. In truth the undercarriage circuit already included a safeguard so that if weight was on the wheels the undercarriage could not be selected up, but standard practice was to turn that circuit breaker off “just in case”. When the circuit breaker was off the button the pilot pressed to raise the wheels could not be depressed. Hence the amusement to the navigator and distress from the pilot if that circuit breaker was not set. Most pilots would punch the button with some enthusiasm when he decided it was time to put the wheels in the well. Consequently a rather sore bent finger and harsh words resulted if the button would not depress.
Once airborne the nav checked that Green Satin had locked on, the altitude was increasing and the outbound track was being intercepted. Then check all systems working and passing transition level set the altimeter to standard 1013.2. The aircraft would normally be climbed at 300 knots indicated until Mach 0.74 was reached and then that Mach number maintained for climb and cruise.
The Green Satin was an X band radar for which the transmitter and receivers units were housed in the rear fuselage accessed via the camera hatch; the antenna was recessed under the wing inboard of the starboard engine and the control and indicator in the radio rack to the right of the nav. The beam was transmitted in a pattern ahead and behind the aircraft and frequency shift on return measured. The antenna was driven so that port and starboard lobes gave equal ground speed analogues and so drift was determined and also groundspeed by means of the Doppler shift. One of the vulnerabilities of the system came into evidence on this leg from Cocos to Butterworth. When the sea surface was smooth the reflected signal was inadequate for the receiver and so the system was effectively inoperable. All that could be done was switch to memory and inch the values of groundspeed and drift to the best known values.
The non-directional beacon at Butterworth was strong and could be tuned at long range. This provided a bearing to check the GPI position in preparation for the 90 degree turn towards Butterworth after clearing the northern tip of Sumatera. The other most useful radio aid at Butterworth was Australian distance measuring equipment (DME), because at that time the Canberra was not fitted with TACAN.
After four hours flying Canberra bomber A84-242 was landed at Butterworth and parked in the No 2 Sqn lines. The next ten days were occupied with discussions with the experienced crews at No 2 Sqn and in exploring Georgetown on Penang Island. There was no bridge at the time so a ferry across to the island was the normal transport. One had to make sure to catch the last one after a night out. The city was an eye opener to the young crew on their first overseas visit, being one of the last remnants of empire. The Runnymead operated as an officer’s club giving one the impression of luxuries of the past, and of course shopping duty free for cameras and watches was an attraction.
The time in Butterworth passed all too quickly and the crew of A84-242 set off on the return flight on 21 November. The flying time to Cocos was much the same as the outward leg at four hours, but from Cocos to Pearce was much faster at three hours. After an overnight stop at Pearce, Amberley was reached the next day in four and a half hours direct flying.
The aircraft had not missed a beat in the 12 days absence from base. Of course it was serviced by No 2 Sqn while at Butterworth, but otherwise turnarounds had been done by the crew. The trip had been most enjoyable and of value in experience and confidence building for the crew. There was no rest on return because I see from my log book I flew two post E Servicing test flights the next day with a 3 AD pilot.
© John Parker 2013