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Ken Martin - Memory of a flight.

In late November 1967 I joined the British Aircraft Corporation at Filton in Bristol as a Grade 8 Systems Engineer, a very small cog in the Concorde Design and Development team.

Located in No.8 Design Office, I was junior to a Senior Design Engineer, one Norman Handley. Norman was a good boss, teacher and mentor and someone I still have the greatest respect for. A stickler for detail, very strict on protocol and correct procedure, he was an avionics design engineer through to the core and taught me as much by example, as by instruction.

Over the next nine years I fell in love with my first aircraft, a typical avionics engineer phenomena, and a job that was, as far as I was concerned, the best in the world.

Starting with the development of the prototype aircraft, moving through pre-production and eventually Concorde production aircraft, I developed my skills and took on increasing responsibility.

By the beginning of 1975 my responsibility included the specification, development and systems installation requirements on the production aircraft for :-

1. The primary engine instrumentation, N1, N2, TBT/EGT, P7 and AJ, located in the flight deck central panel. Each set of instruments monitored the health one of the four RR 593/602 Olympus engines.

2. The Master Warning system, monitoring 106 aircraft systems and displaying warnings in the flight deck overhead panel via 37 Red, or Amber illuminated captions.

3. The Audio Warning system, which presented the crew with a range of audio tones, each drawing attention to a specific problem. The warning tones included, Low Altitude, Gear Not Down, Cell Call, Engine Fire and the Master Warning,

Some of the wiring inside Concorde

Concorde production line

G-BOAC on the production line

Concorde production line

All commercial aircraft use a common and internationally agreed set of audio warnings, but Concorde was the first aircraft to require an over-speed audio warning.

When the air speeds approached M2.00 the leading edges temperature of the aircraft increased to the point where the material became stressed. Repeated excursions beyond M2.00 would dramatically reduce the life of the aircraft and therefore an over-speed limit of about 2.04 was imposed.

Should the aircraft exceed this condition an audio warning would sound, alerting the crew to the over-speed condition.

Because supersonic aircraft was seen as an inevitable part of future aircraft development, an internationally recognised “over speed” warning tone was required. The U.K. Civil Airworthiness Authority (CAA) took on the responsibility to agree and accept, on behalf of all international authorities, an audio tone, which would be standard across the commercial aircraft industry.

Ten distinctive tones were generated in the BAC Filton labs, short listed to four, were selected by CAA and BAC aircrew, during a series of evaluations on the ground.

All participants agreed that the final selection could only be made under dynamic and realistic conditions of a flight-deck experiencing in an over-speed condition.

A full flight test plan was therefore required.

Concorde flight test time was very expensive and flight testing was limited to specific exercises, but only when all ground testing had been exhausted.

Every flight had a specific flight test programme, where the aircraft was flown into to a pre-defined flight condition and each test associated with that condition allocated a specific time slot.

The aircraft allocated for the audio warning evaluation was registration G-BOAC, an early production aircraft. Because this was a production aircraft any system modification necessary to implement the test was kept to an absolute minimum.

The audio warning evaluation plan was to transfer the four favoured tones from the large reel-to-reel machine used on the ground, to what was at the time, a new and novel small compact cassette recorder.

This portable machine and would be taken aboard the aircraft and at the commencement of the test, connected to the audio warning system via an auxiliary phono plug. With the aircraft in the appropriate over-speed condition the audio tone sequence would then be activated. A post the flight a meeting of BAC and CAA aircrew would then make the final selection.

Because CAA aircrew availability was limited, provision was made for a second flight test slot to be available on the same aircraft. This would be used only if a second evaluation was required.

The flight plan was agreed with the airworthiness authority and the two flight test time slots authorised.

With very sort lead-times in place, I had no choice, but take the reel-to-reel machine and compact cassette recorder home and transfer the tones to the cassette, out of office hours.

The next morning ground trials were run to ensure the test sequence was understood and operable. The test was then authorised for inclusion in the 18th April afternoon flight of G-BOAC.

Opportunities for the design office staff to participate in an in-flight test were few and therefore considered as something special to be grabbed with both hands.

As the design engineer responsible for the audio warning system and the principle author of the test plan, I put my own name forward as the flight test-observing engineer.

Unfortunately, two days before I was due to fly, my boss Norman drew me aside and said “Sorry Ken, rank has it’s privileges. I will be the observing engineer. You will have to wait for the next opportunity.”

I wasn’t very pleased with Norman pulling rank, but that was the name of the game. I had no choice but just get on with the job. Given the same circumstances I would have probably done the same. A M2.00 flight was every Filton design engineers dream.

I took Norman through the process, including how to pre-set the tape output on the ground and when required, how to connect it to the audio warning system prior to the triggering the test sequence.


On the afternoon of the 18th the aircraft took off, with Norman aboard and the flight test schedule was started.

Now the Concorde flight deck is cramped, with the three aircrew, Captain, Co-pilot and Flight Engineer, taking up most of the very limited space.

For this flight, John Cochrane, BACs chief test pilot, took the Captains seat, the CAA representative took the co-pilots seat with the flight engineer immediately behind them.  The only position available to an observer was a fold down “Dickey Seat” immediately behind the Captain and to the left of the flight engineer. It was an uncomfortable seat with limited arm and leg room.

The aircraft took off from Fairford, flew down the English Channel and out into the Atlantic. In full re-heat it became supersonic and climbed to a high cruising height in readiness for the programmed of flight tests. When his turn came, Norman was invited to the flight deck to take up his observer’s position in the dickey seat. Norman was quite a tall man and when squeezing past the flight engineer’s seat, knocked the cassette recorder against it causing the tape cartridge to be ejected. He recovered the cartridge and knowing that start position was undisturbed dropped it back into the machine and closed the lid.


Once seated he plugged the cassette output into the audio warning test point and gave John Cochrane the thumbs up. John edged the throttles forward, took the aircraft up to M2.04 and signalled to Norman to initiate the test.

Norman pressed the play button and everyone waited in anticipation. Unfortunately for Norman, what everyone heard was not the expected audio tones, but a small ten year old voice singing with full gusto, “If I could teach the world to sing in perfect harmony.” A very popular Coca-Cola TV advert of the time.

Amongst hilarious laughter from the aircrew and total confusion, Norman tried and failed to recover the situation. The Flight Test Manager called the test “out of time” and drew a halt to the proceedings. Norman grossly embarrassed, vacated his seat and the next flight test sequence was initiated.

The next morning, unaware of the test failure, I was quietly taken aside by Norman and asked what the hell I thought I was doing, making the design office the subject of total derision by those upstarts of the flight test engineering organisation.

Almost immediately I knew what had happened, so with extreme difficulty, I suppressed a smile and explained what probably had happened.

I had taken the cassette recorder home and prepared the test cassette tape for flight. However, this was a new and novel machine and fascinating to all, including one certain young and imaginative mind eager to exploit new technology.

Press play to hear the Coke advert


Once my primary task was complete, I had set up the recorder, so that Steve, my ten year old son, could demonstrate his prowess at mimicking the popular ITV advert. I had used the A side of the cassette for the audio tones and the B side for his home based audition. Unfortunately I had failed to erase his voice after he had gone to bed.


When it came to the flight test, I knew the tones were on the A side and the cassette was in the machine A side up and therefore nothing could go wrong. Unfortunately for Norman, he was unaware that there was an A and a B side. When he returned the cartridge to the machine after the unexpected ejection on the flight deck, it was B side up and not A.

Norman listened to my explanation with a stony face. When I had finished, I was subjected to thirty seconds of authorative lecture, before he could no longer keep a straight face and we both burst into laughter.

Having seen the funny side of it and accepting that, in part, it was his own fault for not checking the tape cartridge, the lecture was forgotten and I would get my Concorde flight. However, it didn’t stop him from telling all, every time the incident was mentioned, that he had been deliberately set up by his junior engineer. In practice, the event and his explanation, served me well, because it did wonders to my street credibility with the rest of the young engineers.



In the late afternoon of the 22nd April 1975, I took up residence in the dickey seat and for the second test with the aircraft at 53,500 feet, John Cockrane edged the throttles forward to set up the over-speed condition.  Flying west into a rising sun, I pressed “play” and the four tones sound in sequence. After a good humoured cheer from all participants, John Cochrane made the comment that what they heard on the last test flight, was by far the best. After a few more laughs, serious discussion followed and after a repeat, one tone was officially accepted.

Because this had been an unexpected repeat test, it was the final of the days testing. On completion, John eased the lovely lady about and we began the gentle decent, flying east back into the dusk, the sun setting fast on our tail. With John’s permission and in spite of the cramped condition, I elected to remain in the dickey seat rather than return to the relative luxury of the main cabin. Although the view was limited through the raised visor, it was still spectacular. Northern France on our right, the English Channel in front and the south west of England coming up on our left.


It was then that John engaged the auto-pilot and elected to go aft for a coffee and the call of nature, leaving the CAA as captain. I moved out of the dickey seat and back into the main cabin so that John could get out of the flight deck. As he passed, and to my great delight, he asked me if I would like to go forward and take his seat for a while. 

A second invitation was unnecessary and a few seconds later I was sitting in the captains seat with England and France below me. The restricted view from the dickey seat had been spectacular, from the Captains seat it was out of this world. The day was still clear and sunny with only a few powder puff clouds casting elongated shadows across parts of Wales and the midlands. To my left, I could see the southern edge of Ireland and to my right, France down as far as La Rochelle. Forward was clear view up the Channel with the curvature of the earth as a dark, almost black division between earth and space. 

As the sun closed the horizon behind us, sunset below was a dark cloak passing slowly over the surface of the earth. Forward of the line, the earth was bathed in bright sunshine with long shadows of hills distorting the landscape. The transition from light to dark was a surprising thin with the dark side very black and apparently raised like a ramped step. In the darkness to the east, town lighting was visible like sparking star clusters shimmering through the thin atmosphere.

Although the aircraft was in auto-pilot it was a requirement that a pair of hands remained on the yoke at all times, just in case. The CAA pilot in the second seat, with his fingers gently touching the yoke, look across and asked if I would take control while he made some notes.

With a thumping heart I placed my hands around both yoke grips and eased my feet onto the rudder bars. I was told to hold her gently and not to apply any pressure to the yoke even when it moved.


My hands closed and I felt the slight vibration and gently movement produced by the autopilot. She was alive.


“You have control?” asked the CAA pilot looking across. “I have control” I replied and he raised both his hands to confirm that I had taken control.


While he made his notes, I was in control. I was flying my beloved Concorde. Perhaps a slight exaggeration of the truth, but justified under the circumstances. For the next few minutes I held her gently in my hands as she descended, on autopilot, slowly through 45,000 feet at just over M1.8 into a darkening star lit landscape.

How could life ever get any better?

After a few minutes I returned control to the CAA pilot, gave up my possession to John and return to my seat in the cabin for the approach and landing at Fairford.


A couple of weeks later I received my M2 blue tie and flight certificate, signed by Brian Trubshaw.

The certificate confirmed that I had flown on Production Concorde G-BOAC, on the 22nd April 1957. The maximum speed was M. 2.04 and maximum altitude 53,500 feet. My flight was timed at 3hours 30mins of which 1hour 3mins was supersonic. The tie I wore with pride and remembrance of when just once I had flown a lovely lady worthy of all my admiration.


There is no mention of my special few minutes on the certificate; that requires no paper proof, because the experience and the story behind it will remain locked in my memory for the rest of my life.


Ken Martin

September 1986

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