78 FLYPAST January 2018
1918 2018characteristics of the basket, several
successful contacts on both hoses
were demonstrated.
The way was paved for the next
stage, undertaken by my colleagues
on the fast jet test squadron next
door. By October 1985, an ‘A’
Squadron pilot had completed
the provisional Phantom receiver
clearances. I flew alongside in a
photo-chase Hawk to record the
hose and basket behaviour.TURBOFAN TO
TURBOPROP
With the need to establish early on
the capability of the probe-equipped
Hercules C.1P to top up from the
Tristar, my AAR experience was
called upon once more. In early
October 1985, I accompanied a
Marshall crew on board Hercules
XV210 to assist with its first receiver
trials.
The slower speed of the transport
required specially adapted drogues
to create the extra drag required
to balance the hose and the HDU
motor dynamics. The capabilities
of the turboprop Hercules and
jet tanker spawned complex and
protracted trials.
To give some idea of the intensity
of the programme, I amassed nearly
28 hours flight time in the Hercules
over seven consecutive refuelling
sorties. During those I made a total
of 185 ‘dry’ and 50 ‘wet’ contacts
by day and a handful at night.
Although there would be some
caveats, the capability of the RAF’s
new tanker to replenish the Hercules
had been validated.
As an addendum, on June 25,
1986, I flew the Victor K.2 against
the Tristar K.1, on the fourth sortie
to complete the type’s receiving
clearances. I was able to pass the
former V-bomber to take on fuel
from the Tristar within the two-hour
time frame allocated.ON THE RECEIVING END
The priority was to release the
Tristar K.1 into service as soon
as possible so that it could take
up its role supporting the South
Atlantic air bridge. Interest was also
expressed in obtaining provisional
receiver clearance while the trials
aircraft was at Boscombe Down. I
was briefed that this assessment had
to be done in the most expeditious
and timely manner – in just two
sorties!
This evaluation was slotted in
before the intensive Hercules
receiver trials. On April 8, 1986, I
flew the Tristar against a VC10 K.3
over southwest England. It came
as no surprise that the aircraft was
a delight in both a tight echelon
and in close line astern under the
VC10. There was a superb field of
vision and it is fair to say the Tristar
was much easier to fly in a tight
formation than any of the RAF’s
four-jet receivers.
The massive Rolls-Royce RB211-
524D triple-spool turbofans
were surprisingly responsive,
and precise fore and aft control
was effortless using small power
changes. Although some problems
may have been anticipated with
the high intake of the centrally-mounted No.2 engine, this was only
evidenced by a slight smell of fumes
from the tanker’s jet wash when the
Tristar was deliberately positioned
above the normal refuelling position.
Even though the overhead probe
was positioned well to the right-
hand side in line with the co-pilot’s
seated position, this lateral offset
did not seem to make a successful
contact appreciably more difficult.
The probe and tip were well within
the left-hand seat pilot’s peripheral
vision.
Twenty-two dry contacts were
made. During a nominal wet
contact, 17 tonnes of fuel was
received into the Tristar’s tanks to
prove the probe and fuel gallery
components.HEAVYWEIGHT
A second sortie was flown two
days later, this time to address
the high all-up weight handling
characteristics of the Tristar as a
receiver against both VC10 K.2 and
K.3 variants.
In each case, on joining the
tanker the increase in inertia of the
heavily-laden Tristar was evident.
Controllability and the ability to fly
in a stabilised close formation on the
wing were not noticeably affected.Above
Hercules XV210 getting
ready to tank from
ZD950.Right
Formerly part of the
British Airways fl eet
as G-BFCB, Tristar K.1
ZD949 sits inside the
Marshall hangar at
Cambridge soon after
conversion, 1984. KEY
COLLECTION