'SOFT AS SILK’ THROUGH THE SOUND BARRIER

Press, Volume CXV, Issue 33917, 9 August 1975, Page 11

'SOFT AS SILK’ THROUGH THE SOUND BARRIER

LONDON. My big surprise was to find that until told by one of the pilots that the airliner had gone through the sound barrier I had been unable to detect the transition from subsonic to supersonic flight.

There was no bumping against a “wall” or even a “feel” like changing gear in a motor car. 1 had to take a look at the Mach meter to assure myself the sound barrier had been crossed. The same thing happened when the aircraft achieved a speed of Mach 2. it was all so unbelievably smooth — nothing like the onetime stories we had read about the trials and difficulties of “crashing” through the sound barrier. Suddenly we were through it not once but twice, and the doubled operation was as smooth as silk. The take-off When I belted up and settled back in my chair for take-off on my first flight and power and reheat were turned on, I felt for a few seconds that I was being pushed back gently by a giant invisible hand during the climb out from the airport. The run before becoming airborne was surprisingly short. I noticed that there was less vibration and noise inside the cabin than in some of the subsonic jets flying over domestic routes; Restricted view When it reached cruising altitude there was the same internal quietness and serenity as in the latest subsonic Boeing jumbo

jets, the DCIO and the Lockheed Tri-Star. At cruise height, about 60,000 ft, the cabin pressure was the same as if I was standing on a mountain at 6000 ft. The view from my cabin window was restricted because the apertures are small to strengthen the airframe. Anyway, 60,000 ft up there is nothing much to see except the cloud formations below and, above, a great new vision of skyapproaching purple in colour. AH ages The passengers will be able to sit back unworried by the effect of supersonic flight on their bodies —

scientists have ruled out the fantastic stories about the risks of radiation, skin cancer and a dozen other frightening “risks” of 1300 mile-an-hour travel. Already on- their dozens of flights to the Americas, over Europe and to the Far East. Concordes have carried hundreds of passen-

gers ranging from royalty and heads of State to executives of big aviation companies and lesser lights. They have included septuagenarians and under-25s and none that I know of had to undergo any kind of a medical examination before they toof off. Passengers will notice

that there are the normal take-off checks by the flight crew, but there is one big difference — there are no slots, slats, flaps or spoilers to manipulate.

When the Concorde is lined up for take-off, the throttles are advanced fully, engine reheat is

switched on and that is when passengers feel the push-back into their seats.

“Know the feeling when you change your old car for the latest model? Well, in a nutshell, that is just what a pilot experiences when he switches from an everyday jetliner to the supersonic Concorde,” is how Captain M. Miles, in charge of Concorde operations for British Airways, describes supersonic airliner flight. Musical chairs When the airport procedures have been fulfilled, power is increased for the climb-away at the air speed

required by the authorities, say 300 knots, he said This gives optimum efficiency, but gets the aircraft up quickly to reduce any ground disturbance from engine noise. “The nose and visor are then raised, and the cock pit becomes a nice, quiet place to work in." Captain Miles said. In normal operation the autopilot is used most of the time, just as it is on subsonic jets. But that is not to say that it is needed as a primary control. Concorde pilots would sooner hand-fly it on a long sector than any other aircraft. Clearance for descent is usually given from 58,000 ft Captain Miles said. The throttles are then closed to decelerate and Concorde descends at a fast speed About 38,000 ft flight becomes subsonic and. from the on down to landing, the airliner behaves very much like a subsonic jet.

JACK PERCIVAL has already made three trips in the Concorde. In this article he tells what it is like to be a passenger “crashing” through the sound barrier.