As is often
the case, I am offered or find more material than I can use in an Aircrew
feature for Aeroplane magazine.
RAAF Museum archive.
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.
In Vietnam
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.
Mission
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?”
“Roger
tally.”
“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.”
“Roger.”
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.”
“Roger”
“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.
“Left
left”.
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.”
“Go ahead”
“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.
John Bushell
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