Let us assume that today's flight is the BA 193 to New York: departure time, 11.15 am. It is now 10.15 and the crew are beginning their checks. The inertial navigation systems need to be started up and told where they are, maps and charts have to be selected, the speeds for the take-off worked out, and the departure procedure studied. Each of the three crew check a part of the instrument panels and set them up for flight. They do this part of the preparation not from a checklist but from a memorized scanning sequence. Gradually the systems come to life.

Heads are down, arms reaching out, gongs ringing, lights flashing as the warnings are checked.

The cabin crew, six of them, have had their own briefing and know, among other things, which passengers have requested particular seats, who has asked for special meals, and whether there are any children or elderly passengers booked. They have probably recognized the names of regular travellers, some of whom may be important businessmen or women, government ministers, diplomats or stars of the entertainment and sporting world. They will also know if any passengers have connections to make, and if anyone has been what is euphemistically known as 'mishandled'. (This usually means that their baggage has been sent to the wrong destination on some previous flight – not necessarily, or even probably, on Concorde. But the story canbe much worse. When the airline system breaks down it can do so in a big way.) The cabin crews are adept at giving special attention to those who need it. Even very distinguished figurescan be nervous on an aeroplane; patience and charm help a great deal to restore their confidence.

While doing their own preparation, the cabin crew will usually find time to deliver some tea or coffee to the flight deck where by now, about half an hour before departure, the captain will be briefing the crew for the take-off. An extraordinary ritual, this, one might think: two grown men listening intently to a recital by the third of the whole of the take-off and climb-out they are about to perform. 'The co-pilot will call, "Speed building, 100 knots, V1, rotate and V2." At 100 knots we shall require at least three afterburners operative. The engineer will call, "Power checked" or "'Engine failure" ...' And so on, covering every moment of the departure. As well as serving the practical purposes of rehearsing the activities to come and of bringing out any unusual features which might apply on a particular day, the take-off briefing serves to re-establish the common ground between the individual crewmen - their training and accumulated knowledge of the aircraft and the airfield.

Twenty minutes before departure, the fuelling is complete and the passengers are boarding, their coats having preceded them, on wheeled racks, to be put away in cupboards. The loadsheet arrives and is checked carefully. This document, printed out computer, is the final summary of the weight and balance of the aircraft. By now the exact number of passengers and the weight of baggage is known, as is their distribution. The computation ensures that the total weight of the aeroplane (up to 185 tons) is within limits for take-off, and that the weight on landing will also be suitable. The centre of gravity is checked. The total fuel on board is confirmed, and the captain signs the loadsheet. The passengers now on board, the ramp coordinator makes his final report to the cockpit and leaves the aircraft, closing the door behind him.

'ASI bugs and pitch index ...'

'Checked.'

Movable white markers on the air-speed indicators have been set to the take-off speeds, and pitch angle indices in the attitude instruments (controlled by thumbwheels on the control columns) have been positioned at the calculated angle for the climb-out.

'Clock, engine and TLA bugs ...'

'Checked.'

There will be a power reduction at a predetermined time after the start of the take-off roll, to a calculated power setting. The clock-timer and throttle lever angle markers are set up. During the take-off a monitoring system will watch the engine power. The minimum acceptable settings for this take-off are dialled into the instruments.

'Start clearance...'

The co-pilot calls air traffic control for permission to start the engines.

'London Ground, Speedbird Concorde 193 on stand Juliet Two for start-up?'

'Speedbird Concorde 193, clear to start. Call on 121.9 for pushback.'

A few final items of the before-start checklist are gone through, and then number three engine starts to wind up. Stretch in the seat a little, here. It is three minutes to the scheduled departure time, a glance down the aisle shows that the passengers are seated (some already have their morning papers open), and we will shortly be under our own power. As for the crew, we have re-entered that private world where decisions are reasonably clear-cut, problems are known and understood - where we need rely only on ourselves. It is a marvelous feeling, this sense of independence. The awesome responsibility makes flying of this kind no light-hearted business, but the atmosphere on the flight deck is exhilarating, backed as it is by a respectful confidence in one's own and one's crew's abilities.

While the flight engineer starts the second engine, the captain makes an announcement to the passengers, outlining, for the benefit of those who have not flown on the aircraft before, what will happen on take-off. This is necessary because the extraordinary power makes the whole of the take-off a rather more sporting affair than usual - pleasant if expected, but possibly a little alarming if not.

The aeroplane is pushed backwards by a tug into the centre of the tarmac, where the remaining two engines are started. All aircraft have to do this in certain parts of Heathrow, to keep the noise to tolerable levels for the ground crews. Hydraulic power is now available from the engine-driven pumps, so the flying controls are checked. Another sequence of calls and responses from the checklist prepares the aircraft for taxying. When all four engines are running, the ground engineer removes his intercom plug and disconnects the tug. Before the aircraft moves away, the nose and visor are lowered to the 5-degree position. There is a 'clunk' as the uplocks release, and another as the mechanism locks the nose down.

Taxying

Sitting on the flight deck as the aircraft taxies, no one could mistake the motion for anything but Concorde's. The long, narrow fuselage produces a springiness which can be felt as far back as the first few rows of cabin seats. From the rear of the cabin, looking forward, the effect is quite obvious: you can see the fuselage flex as the nosewheel runs over bumps. This flexibility is not weakness - an aircraft's structural strength depends partly on its ability to take up shocks in this way.

No more than idle power is needed to keep it moving. In fact, it has to be braked occasionally to prevent it from gathering speed. Steering is effected through a small handle on the side panel. The pilot is 38 feet ahead of the nosewheel and 97 feet in front of the main wheels, so keeping it to the centre of a taxiway at a junction can sometimes involve the cockpit travelling over the grass for part of the turn.

During the taxi, another 30 checks are made, most by the flight engineer, on the aircraft systems. Fuel is pumped forward from the rear trim tank for use before take-off, and passengers may hear the whine of the electrical pumps running. They may also notice the reverse thrust being tested briefly.

Departure clearance is received. Take-off is on runway 28R the northern of the two parallel ruunways whose take-off direction is 277 degrees Magnetic. The route will be a Standard Instrument Departure (SID) towards Brecon, the 'Brecon One Foxtrot'. This means a climb-out straight ahead, until picking up a track of 263 degrees from a radio beacon just north of the airfield, then flying that track until seven miles from the same beacon, where a right turn is required on to a track of 275 degrees to Woodley, near Reading. Woodley must be crossed at or above 4000 feet altitude, and clearance to climb is restricted to 6000 feet for the time being. Speed must be no more than 250 knots (290 mph), and a radio frequency of 132.8 mHz will be used by the departure controller after take-off. We shall be superimposing on this our anti-noise procedure, which will involve cutting back the power at one minute and eleven seconds after the start of the roll, and re-applying it gradually between 5000 and 8000 feet on the climb.

`We have now arrived at the holding point, where we await our to go. This is an opportunity for a quick review of the situation. All the checks, except the final ones, which will be as we move on to the runway, are now complete. The plane is properly balanced, the flight engineer has moved his seat forward, having set his systems up to take care of themselves, and the cabin service officer has reported that the cabin is prepared for take-off. When cleared, we taxi onto the runway and line up, checking the sky ahead for aircraft and weather-radar on, if necessary. We are ready to go as soon as the control tower gives the word.

‘Speedbird Concorde 193, cleared for take-off.'

‘193 rolling.'

The Take-off

"Three, two, one, now’

The two pilots' clock-timers, which will count down to zero at cut-back, are started as the throttles go fully forward. There is almost immediate push in the back as we set off down the runway.

'Airspeed building -'

The co-pilot has checked both indicators. The afterburners begin to come in, speeding up the acceleration. Out of the corner of the eye, the green lights are seen to come on as the engines get enough air to develop full power and the after- burners light up.

'100 knots.'

'Power checked.'

Now we are really beginning to move, and a little work on the rudder pedals keeps us straight.

‘V1’

V1, the decision speed, is 165 knots today. Up to this point we would be able to stop on the runway if, say, an engine failed.

From here on, any failure will be taken into the air. The right hand moves from the throttles to the stick. The airspeed needle is approaching the next bug, set at 192 knots. 'Rotate.'

A fairly sharp initial backward movement of the stick gets the nose moving upwards. Eased off a little, this turns into a gentle rotation up to the preset pitch angle of 13˝ degrees. The rotation should take between five and six seconds. At an angle of l0 degrees and a speed of 205 knots the wheels leave the ground.

Reaching 13˝ degrees, the aircraft is held there while the speed builds up.

'V2 .'

221 knots - a safe flying speed, even with an engine failed.

'240 knots.'

Speed is rapidly building up towards the required 250 knots, so a gentle pitch up is started, to about 18 degrees, to contain it.

'Three, two, one, noise.'

Cut-back time. The afterburners are switched off, and the throttles brought crisply back to their new setting. Anticipating 250 knots, we are now climbing at about 1000 feet per minute as we pass over the houses closest to the airport. Our height is about 2000 feet.

With the nose and visor lowered, it is quite noisy on the flight deck. We intercept the 263 degrees track, then at 7 miles turn right again, looking for the 4000-foot altitude that will keep us

clear of light aircraft crossing below at Woodley.

As soon as that altitude is reached, and with clearance from the departure controller, we begin to speed up. From 5000 feet the power starts to go on. Further clearance is given to climb. By 8000 feet, a little to the west of Reading, we are at full power again and getting close to our proper climb-speed of 400 knots. The nose and visor have been raised, and we are climbing at about 3000 feet per minute, cleared now to 28,000 feet. The auto-pilot is engaged and instructed to take us to the cleared altitude at climb speed. The auto-throttles are primed, ready to take power off when we reach our cruise height. The INS is now in charge of navigation, taking us to the pre-programmed way- points: Lyneham in Wiltshire next, then to the acceleration point in the Bristol Channel.

This is always a pleasant point in the flight. Take-off is a period of pretty concentrated activity, making sure the anti-noise procedure and the SID are done correctly. The departure controller is on his toes, too. His job is to shepherd climbing aircraft through the pattern of those inbound, keeping them apart with instructions to turn (vectors), and with control of altitude. Getting settled in the climb is the first break in total concentration since the start of take-off. There is now time to think more generally. How are the passengers? Can we turn off the seat-belt sign? What is the weather like ahead? Is our oceanic clearance confirmed?

The Subsonic Cruise

At 28,000 feet we cruise at Mach .95 -just below the speed of sound. The interlude has been a short one because we are now approaching the acceleration point. Thee oceanic clearance has come through - to climb when ready and cruise between 50,000 and 60,000 feet on track Sierra November, the northernmost of the three fixed SST tracks across the North Atlantic. London Airways has given us clearance to climb under their radar control which, through remote stations, reaches well out to the south-west of Eire.

We may still be in cloud and there can be turbulence here, but the aeroplane rides it well - the wings, although narrow in span, have a large area. Compared with most jets, the wing loading is low, so gusts are well-cushioned. A short transonic checklist is carried out and the fuel transfer started - from the forward trim tanks to the rear - preparing for the change to supersonic flight. A brief explanation to the passengers lets them know what is coming. Many of them will want to see the figure 1 appear in the cabin Machmeters.

The Acceleration

The throttles are moved fully forward again, for full power. They will stay there until we decelerate on the other side of the ocean. The afterburners are re-lit, two at a time. They could all be switched on together, but the extra thrust coming on so suddenly would be uncomfortable. Selected in pairs, they produce two gentle nudges. The Mach number quickly increases through Mach 1. On the instrument panel, the precise moment at which the shock wave starts can be observed, as the altimeter and vertical speed indicator (both looking at pressure) go temporarily haywire. Once the wave has settled on the nose, only a few seconds later, they calm down. The aircraft is pitched up once more, to contain the speed, and it begins to climb. As it climbs, the Mach number continues to rise.

The 'sound barrier' no longer exists. Going through Mach 1 produces no shudder, no bump, no noise. On the contrary, the aeroplane seems to like it. It slides through the speed of sound and on up to higher speeds as if it had been waiting to be let off the leash. At Mach 1.3 the air intakes begin to work noticeably. Needles on four small gauges at the forward end of the flight engineer's panel show that the ramps are moving down to control the incoming air: to slow it down and compress it before it reaches the engine face. The temperature of the outside air begins to be very interesting: the hotter it is, the slower the climb will be, and the more fuel will be used.

Since the temperature falls off with height, it would be impossible to say whether a particular temperature was 'hot' or 'cold' unless there was something to compare it with. Aircraft use the 'international standard atmosphere' for this purpose. It assumes a steady fall in temperature from 15°C at sea level to -56°C at 36,500 feet, and constant temperature above that height.

An instrument on the flight deck compares the actual air temperature with the ISA, and reads the difference. This 'temperature difference' (TD) is a very important figure.

We sometimes refer, then, to the outside air as being 'hot' when its temperature is -50°C.

This is not a sign of dementia, any more than is the apparently obvious statement that air at -70°C is 'cold' - it is just a convenient way of expressing relatively the nature of the air we are flying in.

Warm upper air is found fairly often during the climb between 40,000 and 50,000 feet, at about 10 degrees west longitude.

The climb route, slightly south of west in direction, passes about 45 miles from the coast of Eire at its closest point.

At longitude 12 degrees west, the track from Paris joins.

There is normally no conflict between the British and French schedules, but if there is, one aircraft will be held up a few minutes on the ground to allow a separation in time at this point of 15 minutes - about 340 miles. Some time before this point, the afterburners will have been switched off: above Mach 1.7 they are no longer required, and a slower climb is continued up to Mach 2, at 50,000 feet, the start of the cruise.

The Cruise

The true airspeed from now on will be between 1300 and 1350 mph: about 22 miles a minute, or a mile every 2.7 seconds. The actual groundspeed may differ from this by up to 100 mph each way - slower westbound against the wind, and faster east-bound with the wind behind.

But in the aeroplane, one might as well be stationary. Ten miles above the earth, and three to four miles above the nearest cloud, there is nothing to give the eye a sense of movement. It takes a conscious effort to persuade oneself that the speed is real. A look at the INS groundspeed read-out shows it, but rather more convincing, for some reason, are the miles ticking by in the distance-to-go display. They reduce, obviously, as one approaches the next waypoint. The rate is impressive. In the time it takes to read this sentence, two miles go by.

The flight is usually remarkably smooth, becoming more so as the cruise progresses and the aiircraft slowly climbs. Each of the fixed routes is used only by SSTs going in one direction, so the complete band of altitudes - between 50,000 and 60,000 feet - is available to them all. It is therefore possible to cruise in the most efficient way, at a fixed power, so that, as fuel is burned off and the weight decreases, the aircraft is allowed to climb. This technique, known as 'cruise climb', was used in the early jet era, when the subsonic airspace was also free. It had to be abandoned when the numbers of jet aircraft grew. For Concorde, which could also, if necessary, fly quite happily at fixed altitudes, it means a slight but worthwhile saving in fuel. On a North Atlantic crossing the aircraft will reach somewhere between 56,000 and 58,000 feet by the end of the cruise.

Lunch is being served. The long cabin, with its rather narrow central aisle, does not permit the flourishes that accompany first-class meals on subsonic aircraft. Nor is there time for the laying-up of individual place settings or the carving of joints of meat. But there has already been a cocktail service and there now follows a four-course meal: hors d'oeuvres, a choice of three entrees (one of them generally the much-demanded steak, with alternatives of fish and poultry), a dessert and cheese. Fine wines are served with the meal, and coffee and liqueurs follow.

The food is well-chosen and presented, and always of high quality.

Of the six cabin staff, two work principally in the galleys, preparing and serving the food and drinks, while the other four attend to the passengers. Naturally, the business of getting as many as a hundred meals served demands a high degree of organization, and the cabin crew must be prepared to stop at any time to deal with the individual needs of a passenger, so they work hard during the flight. The job is physically taxing, too - because of the steep climb angle, getting loaded trolleys out of the rear galley is literally uphill work. Concorde needs, and seems to get, highly motivated people to work in its cabin. The cabin crews enjoy their job because they are able to do it well

and because of the response they get from the passengers.

After all, apart from Concorde, there are very few aircraft in the world that can fly at Mach 2 (and those are all military), probably none that can do so for two and a half hours without refuelling, and certainly none that can do all this while a hundred passengers are served with champagne, lobster and roast grouse.

On the flight deck, the crew is settled into the cruise. The autopilot is engaged, in the MAX CRUISE mode. At these heights the two limiting parameters are Mach number and skin emperature. If the outside air temperature is much above -50°C (ISA+6° - on the hot side), we will be watching the nose temperature rise close to 127°C, expecting the autopilot to reduce the Mach number when it is reached.

This is a time of lessened workload, even though we are moving so fast. The waypoints are spaced at 10-degree intervals of longitude, so there are reasonable time-intervals between them. At each one, however, a very thorough check has to be made. Is the next waypoint correct? Is the computer-defined track correct? Is the computer right about the distance between the two points? Do we need to enter any new points? What is the fuel remaining, and, with the fuel subtracted for the remain-ing flight, will the reserves be those calculated? When satisfied that all is as expected, the co-pilot sends a position report. Up to 30 degrees west longitude, the report goes to 'Shanwick' (a combination of Shannon and Prestwick), the Anglo-Irish control service for the eastern Atlantic area. Beyond 30 degrees west, control transfers to Gander.

The flight engineer, between checks of his systems, tunes in and copies down the weather broadcasts: Shannon (in case of return); Gander and Halifax in the Maritime provinces of Canada; Bangor, Maine; Hartford, Connecticut; Boston; New York; Newark; Baltimore; Philadelphia; and Washington. All these are places which we can reach and which are in some way prepared for a Concorde transit should the weather deteriorate at our destination. There are many other airfields which could accept us, but if a diversion is necessary, it helps to go somewhere where spares are held and where, if possible, the staff have had some experience of handling the aircraft.

Throughout the cruise, gentle activity is going on, scanning the instruments, checking, cross-checking, re-checking. The crew eat, too - an abbreviated version of the meal served to the passengers (without the wines, of course). There is a rule, followed by all airlines, that captains and co-pilots should always choose different dishes when they eat in the air, to guard against the remote possibility of food poisoning. We follow the rule on Concorde, too. It doesn't in the least diminish the pleasure of eating in the fastest restaurant in the world, with the best view.

The meal doesn't last long, though, It is soon time to start preparing for descent. Look for Newfoundland on the radar, selecting the 300-mile scale, tune in a DME station to provide the tightening-up for the navigation computers, get out the charts for the approach and landing, select the radio frequency for the message from our company which will tell us what the actual conditions are at New York.

We are running down past the Maritimes at 55.000 feet altitude, now, and the co-pilot is in contact with Moncton centre on VHF. It looks as if we shall end the cruise at about 56,000 feet today, and we check our descent distance. We shall need to be at 39,000 feet below Mach 1 at least 50 miles before Hyannis - 30 miles before we cross the coast at Cape Cod.

Allowing for a 50 mph headwind, we shall have to reduce power 132 miles before we want to reach Mach I, 182 miles before Hyannis. Now follows a conference similar to that which occurred before startup at Heathrow, only this time the briefing is for the approach and landing at John F. Kennedy Airport, New York. The descent, the expected arrival route and runway, the type of approach, landing technique and the procedure for go-around are covered. This review complete, and descent clearance received from Boston centre, the captain tells the passengers that we are about to slow down. They will, most likely, still be drinking their coffee.

The Descent

Very, very gently, the throttles are brought back to a mid-position. While the autopilot holds the aircraft at the last cruise altitude, the Mach number drops quite rapidly. Suddenly we are reminded of what has kept us going so fast. At Mach 2, balanced, as it were, in the middle of the equation of thrust and drag, we were hardly aware of the four Olympus engines. Only now, by its absence, is their power demonstrated.

At Mach !.6 the throttles are brought further back and the aircraft is pitched down to begin the descent, which is carried out at a constant indicated airspeed of 350 knots. Indicated air-speed (the speed shown on the pilots' instruments) is measured by comparing dynamic pressure, which depends on speed, with static pressure - that is, the pressure of the local air. Since pressure changes (reduces) with height, this is the only useful aero-dynamic measure of speed, but it bears little relation to the actual, or true, airspeed once the aeroplane is substantially away from the earth's surface. At this point in the descent, for instance, the true airspeed is still around 1000 miles an hour.

During the descent the true airspeed and the Mach number continue to reduce. The distinctive hooked shape of Cape Cod stands out clearly on the radar. Progress along the descent slope is checked. This can be done from tables, but there is a useful rule-of-thumb which gives a quick answer: the figures behind the decimal point of the Mach number are roughly equal to the miles to go to Mach 1. Thus, at Mach !.47, say, it will take about 47 miles for the Mach number to reduce to 1.

The descent rate will be around 5000 feet per minute, and so the autopilot will begin to capture the selected cruise altitude (usually 39,000 feet) early - some 2000 to 3000 feet above. A gentle pitch up starts, and the aircraft settles at its required height. Mach 1 is seen for the last time on the flight, the auto-throttles are engaged, and once more the aeroplane is cruising at Mach .95. From now on, although cruising some 15 per cent faster, we are back in the world of the subsonic jets, and will conform to all the same procedures.

The most attractive part of the flight is over: the stratospheric calm is behind us and the tempo is increasing. As we head from Hyannis on Cape Cod to Hampton on Long Island, we are transferred from Boston air traffic control centre to New York.

Although this is a quiet time of day at Kennedy (it is now 9.30am Eastern Standard Time), an airport which handles some 1300 aircraft movements a day is never dull. Radio communications become busy. We listen to the terminal information broadcast, and are likely to find the runway has been changed (a computer at Kennedy airport allocates landing and take-off runways in order to vary the noise patterns around the airport, and 9am seems to be one of its favourite times to make a

change).

Further descent clearance comes now, in steps, as we are handed over from controller to controller. At 10,000 feet we slow to 250 knots, lowering the visor and nose. The angle of attack is about 6 degrees, and we begin to feel the vortex lift acting on the wing.

'Speedbird 193 heavy, you have crossing traffic at eleven o'clock, slow moving, north-west bound, altitude unknown.'

'Speedbird 193, looking.'

The controller has on his radar picture a 'blip' showing an aircraft flying, in visual conditions, quite legally across our path. He has judged its speed, and it is probably a light aircraft at low altitude, but three pairs of eyes will spend a good proportion of their time looking out for it. Unless it clears our path we may have to ask the controller to vector us around it.

To the European mind, accustomed to various forms of restriction, the freedom of the American skies can seem alarming. Put simply, the airspace below 10,000 feet in the US is largely open to all aircraft as long as there is good enough visibility to see and be seen. Radar controllers provide information to those aircraft under their control (principally airliners), but cannot necessarily communicate with the smaller aircraft. The burden of avoidance seems to fall rather heavily, therefore, on the larger, faster aircraft.

One must remember, however, that the airspace over the USA is much less cluttered with military areas, and that in general the centres of dense traffic are further apart. Navigation aids and

radar coverage are more advanced than they are in Europe as a whole, and the system clearly works. Statistically, the USA is still the safest part of the world in which to fly. The airliners, with very effective help from the controllers, can cope, and the light aircraft are as unrestricted as is reasonably possible.

Europe airspace, hampered as it is by the need for much more extensive military reservation, and the-fact that regulations vary from country to country, is a much less pleasant place for general aviation. In Britain in particular, getting from one place to another in a small aircraft can be something of an obstacle race.

'Cleared direct to Deer Park. Descend to 8000 feet. Leave Deer Park on the 221-degree radial for vectors to the three-one Left ILS. Change to Kennedy Approach . . ..'

From the main entry point, north-east of the airfield, we will fly the standard route, slightly out to sea, and turn right on to the instrument approach to the left hand of the two parallel runways whose landing direction is 310 degrees magnetic.

A series of clearances arrive, allowing us to descend to 2500 feet over the water. Soon after crossing the coast the airspeed is further reduced in stages, so that when turning on to the final approach we will be at 190 knots (220 mph). As we have slowed down, so has the angle of attack increased to produce the necessary lift. By now, level at 2500 feet, it is i I degrees. Already we have begun to adopt that predatory look.

The Final Approach

Lined up on the localizer, we see the runway ahead and watch for the bar which represents the glidepath to come down from the top of the instrument. As it does so, the wheels are selected down. Lights on the undercarriage indicator show that the doors have opened and that the up-locks have broken. A bump indicates that the nosewheel has come down. A green light confirms it is locked. Another for the tailwheel. Two more bumps for the main wheels. As one always arrives before the other, there is a slight sideways lurch in each direction - hard to feel in the cabin, but distinct on the flight deck. 'Four greens. Nose down.'

Now we need the nose fully drooped, to 12˝ degrees. It becomes invisible, leaving a completely clear view of the territory ahead. The rest of the landing check is completed and we fly down the glideslope. At this point, say six miles from thecrunway threshold, and on the correct glideslope, the runway looks odd to a new Concorde pilot. The aircraft seems too high.

It always seems amazing that the eye can judge an approach at 3 degrees to the surface, but I suppose it is no more odd than the ability to aim a flexible golf club at a small stationary ball, or a tennis racket at a larger but moving one.

Memory of what a runway should look like controls the mental process. There are some distortions. A long, narrow runway produces the impression that the aircraft is too high throughout the approach. A short, wide one has the opposite effect; but pilots learn to compensate for these variations.

The appearance of being high on approach in Concorde stems from another visual trick. Becausee of the large angle of attack (13 degrees on final approach), the pitch angle is some 10 degrees above the horizon, compared with 2 to 3 degrees on most aircraft. As a result the runway, despite being the right shape, is simply lower down in the pilot's field of vision - he is looking down his nose at it. Although the picture of the runway is as it should be, it looks wrong - at least to start with. But the human mind is very adaptive and it does not take long before a correct-

ive mechanism starts to work.

Apart from this odd visual feature, Concorde on the approach is very pleasant to fly. The good roll response, the light feel and the extraordinary stability make it east to manoeuvre and give it a satisfying tendency to stay where it is put. The pilot concentrates on keeping it 'in the slot', flying with one hand while the other rests on the throttle levers, following the movements caused by the autothrottle system into which the required airspeed has been set.

Because the engines are below the body and wing, changes of power cause pitch-changes. Power increase: pitch up. Power decrease: pitch down. Most aircraft behave to some extent like this, so there is nothing wholly new to learn. Gusts are easy to with - the autothrottle almost sees them coming, and the autostab systems keep the aircraft on its flight path when other aircraft would wander off.

Final approach speed on a typical landing is 155 to 160 knots - about 180 mph. At a noise-sensitive airfield like Kennedy (or Heathrow), in reasonable weather conditions, the speed is kept at 190 knots (220 mph) until 800 feet altitude - about 2˝ miles from the threshold. At the higher speed, less power is required to maintain the glideslope. In this case the speed is reduced, still under control of the autothrottle, between 800 and 500 feet. At 500 feet the speed is stable and the aircraft is about 1˝ miles from the runway, lined up and ready to land.

'400 feet - a hundred to go.’

'300 feet - decision height.' (From this height a go-around

would be started if the runway was not in view.)

'Continuing.'

The runway has been in sight all along, but the crew are behaving exactly as they would if the cloud base were low – a typical example of airline flying- taking the opportunity to practise for the case that really matters, when the situation isn't so good. On another day we might fly a fully automatic approach, as if for landing in fog. In that case, the decision height would be fifteen feet, and the procedure would be the same - only the numbers would change.

The Landing

'200 feet.'

The flight engineer, who cannot see the runway since he is behind and a little below the pilots, is reading the radio altimeters which are bouncing signals off the groundto determine height to within a foot.

'100 feet ...

'50, 40, 30, 20, 15.'

At 40 feet the autothrottles are disconnected by pressing a small button on either side of the levers. A slight backward movement of the stick slows the rate of descent a little, pitching up perhaps a degree, from 10˝ to 11˝ degrees. The pilot's eye is still 75 feet above the runway (about the same height as a 747 pilot's) and he aims at a point about 2000 feet down the runway, knowing that the main wheels, trailing below and behind, will arrive well before that point.

From about 100-feet altitude we have been able to hear the 'ground effect' starting. A large wing, approaching the ground, begins at some point to squeeze the air between it and the surface, settling into a cushion of its own making. The large wing area and the high angle of attack make this effect more pronounced on Concorde than on conventional swept-wing aircraft, and seems to throw back some of the noise of air rushing into the engines. That is what it sounds like, at any rate.

At fifteen feet, the throttles are closed. The immediate effect is a tendency for the nose to drop. Landing is largely a matter of countering this tendency as the aeroplane settles into its ground effect. A slow backward movement of the stick keeps the nose where it is. The rate of movement depends on the strength of the pitch-down tendency. Good landings are simply a question of getting the balance right, so that the nose stays rock-steady against the far end of the runway.

Once on the ground there is a second landing to perform – the nosewheel is still a long way in the air. A nudge forward with the stick to get it on its way, followed by a backward movement to cushion its descent, and all the wheels have arrived.

As soon as the main wheels are on the ground, reverse thrust is engaged. Once the nosewheel is on, power is increased in reverse to kill the speed. At this point the stick is pushed fully forward to keep the nosewheel on the ground. With no lift from the now-level wings, the weight of the aircraft is borne on the wheels (principally the main ones) and the reverse thrust, acting above this new pivot point, tends to raise the nose.

The elevons are still effective, though, and the nosewheel is kept firmly on the runway as braking starts. The powerful carbon discs get to work, the speed reduces, and the runway, which on touchdown didn't seem as long as it should be, with the eye still 35 feet in the air, lengthens again to its proper shape.

' 100 knots.'

The two outboard throttles are pushed into reverse idle.

'75 knots.'

The inners follow.

'40 knots.'

All the engines are returned to forward idle power and the aeroplane is nearly ready to be turned off. It is easy, in any aeroplane, to think that the speed just after landing is lower than it really is, so a glance at the INS groundspeed is useful here.

Once we have turned off the runway, the nose is raised to the 5-degree position again, and the two inboard engines are shut down (at this weight, at the end of a flight, two engines provide quite enough power for taxying).

From runway 31 Left it is a longish taxi round to the British Airways terminal on the other side of the circle of airport buildings. As we approach it, the time is a few minutes after 3pm in London. Here, in New York, we are nearing our arrival time of 10.15 - apparently an hour before we left our gate at Heathrow. Just under four hours, gate to gate: an hour less than than it takes the earth to rotate through the angular distance separating London and New York. Three and a half hours' flight-time to cover three and a half thousand miles – an average speed of a thousand miles an hour.

Some of the disembarking passengers show signs of excitment - it has been their first supersonic flight, and it will be a while before they have sorted out the mixture of unreality and normality they have experienced. Others, the majority now, take it all for granted - they have probably used Concorde several times. And it has been normal. So it should be by now; but this normality had to be present from the first flight, in January 1976, and that took a little doing.