FlyPast 03.2018

TRAINING 100 YEARS OF THE ROYAL AIR FORCE

March 2018 FLYPAST 57

a standby trim motor. In manual,
primary pitch control was achieved
by ‘motoring’ the tailplane electrically,
though slowly, and the stick-controlled
elevators were used only for ‘fine
tuning’.

INSTINCTIVE DRILL
In earlier days, the complexities of
the system had been highlighted in
accidents involving pitch-control
problems. Only instructors were
allowed to attempt a forced landing in
manual. Student pilots had to eject if
they found themselves with both an
engine and hydraulic failure.
A fairly foolproof memory drill
for entering manual control had
been devised – with the acronym
STUPRECC. It was drummed into
the memories of all Gnat pilots until
it was instinctive. I still remember it
fully, nearly four decades and many
different types after my last Gnat
flight.
The HYD warning immediately
sparked me off into the drill:
Speed – below 400kts
Trim – to the ‘ideal’ sector
Unlock the elevators
Power (hydraulic) cock off
Raise the guard on the standby trim
switches
Exhaust the (hydraulic)
accumulators
Check operation of the elevators,
ailerons and standby trim
Changeover switches to standby
The memory drills for flame-out and
seizure are different in several aspects
and we had been obliged to start
with one and switch to the other, so I
asked Mike to get his Flight Reference
Cards out to make sure that we had
completed everything necessary. We
had.

CHANGE OF PLAN
Somewhere in the middle of all the
action, the emergency centre at West
Drayton, near Heathrow Airport, had
answered my call with a triangulated
position five miles north of Llanbedr.
That airfield had just shut for the day
but ’Drayton was trying to contact
them to re-open.
I could now turn more of my
attention to weighing up the two
possible options for landing, limited as
they were.
We had reduced to gliding speed and
had drifted back down to the original
18,000ft. Valley was still about 30
miles away, with a bit of a headwind
at medium altitude and a strong
crosswind (18kts – the limit being
20kts) on the only runway, 32, that we
might reach.
With its very narrow wheel-track

and a high set and highly swept wing,

the Gnat was a bit of a handful in a

crosswind, much more so in manual.

The gliding range, about 1½ to 2

miles per 1,000ft in still air, would

give us little or no margin for error.

On the other hand, Llanbedr was

not only closed but also completely

obscured under cloud. It had only

one runway direction, 18, that was

equipped with a jet barrier to stop us

if needed. Drayton next told us that

Llanbedr were reopening so it was

there we had to go.

With plenty of height in hand, I flew

one orbit overhead Llanbedr in the

hope of finding even a tiny break in

the cloud cover, but there was none.

Terrain rises to 2,500ft a few miles east

of the airfield, so all initial instrument

approaches were made from over the

sea to the west.

With that in mind, and to take full

advantage of Llanbedr’s radar facilities

at the airfield, a special instrument

forced landing procedure had been

developed. It involved flying from

overhead, then out to the west, before

turning back in under ATC direction

to make a ‘low-key’ position at 3,000ft

abeam the downwind end of the

runway in use.

I was happy enough to set off

initially on the westerly heading from

about 11,000ft under ATC direction,

still above cloud. It seemed a bit

unnerving with a dead engine to be

heading away from where I planned

to land!

In manual control, the aircraft was

quite heavy and sluggish to handle. I

was using the smaller and less accurate

standby instruments as the main

gauges had failed and ‘frozen’ when

the alternator came off line.

As we reached about 8,000ft, we

were told there was a cloudbase of

3,500ft over the airfield, which would

not give us much margin.

About four to five miles out to sea,

heading away from the airfield, I felt

very uneasy about the total picture

that was developing. There and

then I decided to bin it, turn back

towards the airfield, dive off the height

through the cloud and gain speed to

give me as much energy as I could get

for visual positioning once we broke

cloud. Llanbedr gave me an inbound

heading.

WINGMAN

Meanwhile, apart from checking in

briefly on the emergency frequency,

Bill in the other Gnat had wisely

avoided getting involved in the radio

chatter. There was little or nothing he

could do to help up to that point.

I caught a glimpse of him

Clockwise

from far left

Valley-based Gnat

T.1 XP506 of 4 FTS

steaming through

the Llanberis Pass in

Snowdonia during the

early 1970s.

KEY COLLECTION

The rear cockpit of a

Gnat T.1.

KEY COLLECTION

A vertical climb

by three of 4 FTS

Gnats. This shot was

taken between mid-

1963, when XR539

(foreground) was

delivered to Valley,

and May 13, 1966

when it crashed in

North Wales.

KEY COLLECTION

A fl ight of four 4 FTS

Gnats in the silver

and Dayglo colours

in which initial

deliveries were made

from 1962.

KEY COLLECTION