Unfortunately Dave Scrimgeour's
10th May talk on the Tripartite Evaluation Squadron had to be postponed
due to his short-term illness. However, Members were treated to a
fascinating 'last minute' substitute presentation by the ever willing
John Farley. It was a kind of aeronautical scrap-book of items
collected by John and saved on Powerpoint.
There were 10 items starting with some RAE WW2 film of ditching trials
of a Mustang model to determine the best technique. The models,
launched by a falling-weight powered catapult, covering a range of
speeds, flight path angles and angles of incidence, showed that the
aircraft invariably dived under the water so bailing out was the best
bet.
Next came film of the Sukhoi Su 27 with foreplanes performing at the
1989 Paris Air Show. There were 360 degree turns in 10 seconds, pulls
to 90-110 deg alpha on the approach, a full 360 degree pitch manoeuvre
at constant height, 90 degree alpha descents and full tail slides, all
without the engine missing a beat! Apparently, an F-16 pilot watching
was moved to shout "eject!" during the display.
Once More
into the Breach...
An
aeromodelling interlude featured John's own electrically powered 5
ft span Zephyr, which flew beautifully, and a B-52, powered by 8
miniature gas turbines each costing £2000, which crashed
spectacularly
with great realism, including the pall of dense black smoke which so
often accompanies full scale disasters. Fortunately the impact was
inside the airfield boundary and noone was hurt.
John then
explained his philosophy of safety and accidents. There are, said John,
no 'acts of God' because God does not design, build, maintain and
operate aircraft. Only people cause accidents; through pilot error,
technical error (maintenance, design, manufacture) and operational
error. Pilot error, the largest proportion of accidents, can be
minimised by selection, training and good design. Ultimately by
increasing automation the pilot can be eliminated!
A film of a
helicopter trying to rescue a boat in trouble by towing showed it
rotating on the towline straight into the sea, because the boat was
waterlogged.
Film of smart weapons and the AV-8B+ in the Gulf
War was followed by film of extreme engine testing. We saw fan blades
being deliberately blown off to demonstrate blade containment, bird
ingestion tests using 3 two-and-half pound birds at 160 kn for only a
3% loss of thrust, and rain ingestion testing with the engine
swallowing 15,000 gallons of water per hour! Airline passengers in the
audience felt much relieved.
VTOL history was represented by
film of the Higton RAE control rig (see Newsletter No.11) which led to
the specification for the Rolls-Royce TMR (Thrust Measuring Rig/Flying
Bedstead) really designed for control system research. Initially flown
by RR test pilot Capt. RT Shepherd, the bulk of the taxing and
dangerous RAE flying was by Sq Ldr RA Harvey.
John's final
selection covered the UK National Air Traffic Service (NATS) which
copes with 26,000 aircraft per week, one flight every 16 seconds or 1.2
million flights per year. It's good to know that we are in safe hands
when flying the airways.
During question time, when asked about
the Su 27's remarkable engine handling, John noted that the aircraft
had vortex generators on the nose pitot to nail the vortices so they
don't alternate from side to side, and a the long, carefully shaped
intake duct feeding a tolerant engine.
It would be an
understatement to say that the audience was delighted with the
substitute talk which had entertained, informed and given plenty of
food for thought.
