The Aviation Historian — January 2018

6 THE AVIATION HISTORIAN Issue No 22

AIR CORRESPONDENCE

Letters to the Editor

A narrow squeak

SIR — Your excellent article Further Out on a

Lympne in TAH19 brings back strong memories

of visits to Skyways in the dim past. I was a

flight test engineer with Avro in the 1960s, and

was given the task of assessing modifications to

the inverter mountings on Skyways HS 748

G-ARMV, based at Lympne. This aircraft was to

be used as no prototype was available at

Woodford at the time, and Aerolineas Argentinas

were reporting inverter failures on their 748s.

Accompanied by an instrumentation engineer,

we recorded vibration levels in the existing

configuration, and then those applicable to the

changes we made to the mounting each evening,

after the Beauvais sorties. On a daily flight, I was

perched in the baggage space with a control box

to record the output of the instrumentation we

had fitted.

On the final flight of this job, I was surprised

and somewhat unnerved by the fact that the

stick-shaker (stall warning) could clearly be

heard rattling away right down as we came into

Lympne, all the way to touchdown. Back at

Woodford, I had been engineer on many stall test

flights in several aircraft configurations of the

prototype 748, and such experiences would

surely cure any hint of constipation.

I recall that the prototype cabin was largely

untrimmed internally, and, as heavy pre-stall

buffet set in, fuselage formers could deflect from

round to oval and back.The usual end product,

if incidence increase was persisted with, was a

starboard wing drop, which could be very rapid.

On that occasion G-ARMV must have been

ultra-close to a dramatic landing with a

potentially disastrous result, and I was glad

our task had finished.

Imagine my thoughts when, soon afterwards,

the accident which wrote G-ARMV off occurred.

As a footnote, our recordings showed no

excessive vibration levels on the inverter

mountings, and it was subsequently found that

the manufacturer of the instruments had been

supplying incorrectly-set-up inverters, so our

experience was unnecessary. Nevertheless, I

thought the people at Skyways were a great

group, who could not have been more helpful.

In fact I’m sorry Lympne has gone the way of

so many airfields, including Avro’s Woodford

airfield. Is nowhere safe?

Ian McDonald Alresford, Hampshire

First production Hawker Siddeley

748 Series 1 G-ARMV the day after

its crash at Lympne in July 1965, as

described in TAH19. Avro flight test

engineer Ian McDonald had a

foretaste — see his letter

on this page.

TOM SINGFIELD