As is often the case, I am offered or find more material than I can use in an Aircrew feature for Aeroplane magazine.
Thanks to Group Captain John ‘Bushy’ Bushell, RAAF (Ret), we are able to present his account of a typical RAAF Canberra bombing mission in the Vietnam War era. The following words are John's, and the illustrations via the RAAF Museum Archive. The Aircrew feature which this account supports is in the November 2012 issue of Aeroplane magazine.
RAAF CANBERRA NAV IN VIETNAM
As the first jet bomber from Britain, and being named after Australia’s capital, all would be familiar with the striking lines of Australia’s front line strike aircraft for the 1950s and 60s. Beautiful in flight and frequently a highlight of air shows in the era. But what was it like to operate?
The Crew & Tools
RAAF Canberras were operated by a two man crew: a pilot who flew it all the way - since there was no autopilot; and a navigator who did just about everything else. The nav had a Martin Baker Mk 1 ejection seat towards the port side behind the pilot’s seat. To his right was a radio rack that housed the HF radio, the Green Satin Doppler controller and the ground position indicator Mk IV. Ahead of his folding nav table was an instrument panel mounting the G4B compass master indicator, altimeter, airspeed indicator, DME, outside air temperature, ADF, and the air position indicator. To his left were the ADF controller, IFF controller and of course the hatch jettison switch. Not to forget the small window carefully positioned so that the view was minimal. As well as the den in the back the nav also spent time in the nose where the bomb sight was positioned. On the starboard wall were found a number of other panels that were the province of the nav, since the pilot could not reach them, including the 12/24 Way bombing selection and control panel and the electrical control panel for AC power. The DC power controls were on yet another panel on the port side of the nav’s route from his navigating position to his bomb aiming position. A long oxygen tube and intercom lead was provided for the nav when down the nose or moving around the aircraft.
RAAF Museum archive.
So what was it like to operate? Some suggest the Poms had the design already to build when someone reminded them they needed to fit crew stations. It certainly gained none of the benefits of the science of ergonomics. The nav carried out many tasks that would be handled by the copilot in other aircraft. He read the check list for the pilot as required before, after and in flight and calculated take off performance, carried the fuel plot and similar tasks to assist the pilot.
RAAF Canberras between 1967 to 1971 flew missions throughout South Vietnam in support of the various ground forces opposing the Viet Cong and North Vietnamese forces. Initially the aircraft was employed on ‘sky spot’ missions under radar control and primarily at night. Bombs were dropped from 20,000 feet and the radar controller gave the pilot headings to fly to arrive at release point then counted down to release when the nav pressed the button to release the bombs. The sky spot controllers thought highly of the Canberra due to the fine heading changes possible – they asked for a quarter of a degree at times - and stability compared to the other aircraft such as F-100 or F-4 they worked with.
However, the night sky spot missions rarely achieved significant destruction of enemy equipment and the No 2 Squadron crews itched to switch to daylight bombing under the guidance of a forward air controller (FAC). Approval was gained for trial missions and in view of the results achieved the 8th Air Force approved the adoption of this role for the Canberra. Sky spot sorties were still flown, but the ratio was normally 1:7.
Early in the No 2 Sqn deployment to South Vietnam war reserve bombs, many dating from the 1940s, were dropped. These were short in length and six could be carried in the bomb bay with one on each wing tip. Once this stock of bombs was exhausted the Canberra dropped US M117 bombs weighing 750 pounds, but only four would fit in the bomb bay so the load became six 750 pounders.
In the briefing the crew was given a rendezvous point with a FAC. In most case there was little more information imparted. The aircraft was navigated to the rendezvous using point to point TACAN and flight progress was monitored by the US tactical radar distributed throughout the country. Approaching the R/V the radar would advise a frequency to contact the FAC and the strike would progress. On first contact the strike aircraft advised the FAC of details of ordnance on board and routine operational data. The FAC would describe the target and his plan of attack. Some FACS were well accustomed to working with Magpies and would give detailed instructions. Others were less aware and lefty much to the Canberra crew. The Canberra was well suited to destroying bunkers and fortifications that the VC built all over the country.
A replica Canberra nose in the Australian War Memorial. [J Kightly]
As the pilot made contact with the FAC the nav would move forward and begin preparing the bombing gear. He would also note the FAC’s instruction on a plastic covered card using a grease pencil. The FAC goes on:
“This is David 31. So today Magpie we have a fortified position on the banks of a canal. See that patch of trees in a T shape off my nose?”
“Well your target is to the north of that right along the banks of the canal.”
“OK got it.”
“I would like the six bombs in one stick with a spacing of 200 feet between bombs.”
The nav now does a calculation how long it would take to cover 200 feet. 300 knots is equivalent to 500 feet per second, so if he set 0.4 seconds as the interval he would get the spacing right. That is set on the 12/24 Way panel. The target is fortified, meaning bunkers, so we want to bombs to penetrate before exploding. Since the nose fuse is instantaneous and the tail is delay he sets tail fusing on the control near the 12/24 Way. Then he sets the bombs starting at 1 and finishing at 6. The bomb panel is set so the nav can dive down the nose.
The pilot flies the aircraft to where the FAC is indicating and lines up the direction of the canal.
“OK Magpie. I want you to run from south to north and put the bombs right along the bank. Let me know when you are ready and I will give you a smoke.”
“Roger”. The pilot has descended to 3,000 feet and speed 300 knots. He lines up to the target area. The nav has the bomb sight on and unlocked with the cover clear. He also turns the camera control to ready and gets his bomb release button from its stowage. He has Green Satin (Doppler) indicators down the nose to give him the vital groundspeed and drift readings. He also has a check list page that gives the bombing angle for 3,000 feet above ground at increments of groundspeed. At this stage just set the angle for 320 knots and he will refine on the run.
“OK, David, we have the area and are running in. Request a smoke.”
“OK the smoke is good. I want the first bomb 30 metres short of the smoke right along the bank.”
“Roger David, we have the smoke, are we clear live?”
“Magpie you are clear live.”
Nav to pilot. “OK I have the smoke. Easy to see.”
Pilot to nav. “I am on speed and height”. Drift 2 port groundspeed 315 knots. Sets drift on bomb sight and adjusts bombing angle. The bomb doors come open.
The line on the sight swings onto the target. “Master safety on.”
“Right”. Just a small correction. “A tad left left … Steady, steady, steady - bombs gone.”
They say the pilot could tell when the target was getting close by the tone in the nav’s voice.
RAAF Museum archive.
Bomb doors close. The nav could then look straight down through the small window under the nose. Six bombs falling cleanly. Target and smoke coming up. Bang! First bomb hits followed by five more at intervals of 0.4 of a second as set. Plenty of smoke and spray from the canal water. The nav turns off the camera that began recording automatically at bomb release and locks the bomb sight down and swings the collimator glass cover over the reticle.
“Outstanding bombs Magpie. Right on the money. Standby and I will get your BDA.” BDA is bomb damage assessment: an immediate visual estimate by the FAC which might later be followed up by reports for ground troops if they go in soon after. After a couple of minutes while the Canberra is climbing away from the target and the nav has moved back to set the 12/24 Way controls back to OFF and safe.
“OK Magpie I have your BDA.”
“Coordinates 987 345. 100 over 50. Five bunkers destroyed, four bunkers damaged, six military structure destroyed.” The 100 over 50 means 100% of the bombs fell within the target area and 50% of the target was covered. He couldn’t say 100% covered or he would not be allowed a second strike on that target.
“Copied thanks David. Great to work with you.”
“Good work Magpie. You have a nice day. Call Macon now on 343 decimal 7.”
The nav would then go back to strap into his ejection seat for the return to base. An uneventful sortie. The return was again under the watch of the tactical radars back to channel 75 at an altitude around 20,000 feet. Most bases were known by their TACAN channel and the Canberras operated out of Phan Rang Channel 75. After landing the normal routine of signing off the aircraft and writing up any systems that were not operating at 100% efficiency. The No 2 Squadron ground crew did an exemplary job and the Canberras were always in top notch condition, but some small things would be reported to keep them that way. After signing off the aircraft over to the Ops room to debrief the mission. Primarily a matter of the hours flown, the BDA and anything unusual to report. Later or the next day the nav would go over the photos of the bomb strike with the bombing leader to get an assessment of error. 2 Sqn had a proud record for accuracy and this checking of photographic evidence was one of the factors in maintaining the standard.
The wingtip bomb rack. As seen on the Temora Aviation Museum Canberra. [J Kightly]
Most days the same routine was followed. Occasionally the routine was broken by a night mission, but crews flew five times a week on the average.