Post Secrets . . . Technical Training

Chapter Four

Back in the Customer training Centre we four were joined by eight pilots, two each, as we began the type technical course in earnest. It was to be long as type conversions go, seven weeks long in fact, just for class work, and conducted at a pace – not quite the pace of the secrets course but one that allowed no space for respite. The instructors at British Aerospace Customer Training Centre were entirely focussed in what were clearly well rehearsed routines to impart only the essentials of this complex machine to their wide-eyed students. We weren’t to be told exactly how everything worked; we were to be told only what we needed to know in order to behave appropriately: a process known as Specific Behaviour Orientation, or SBO. Using the now familiar procedures of morning revision questions and Friday exam papers we were introduced to, given details of, and taught to use, the systems in order to operate the aeroplane in a safe manner. When challenged over short, somewhat unsatisfactory, explanations the instructors could always fall back on SBO, which worked for the pilots but we engineers knew that sometime, somewhere, we would need more comprehensive explanations. For now though SBO, and another fall back for phenomenon too complex to explain, BFM, Bloody Fucking Magic, would have to do.

The Flight Simulator, that cockpit on jacks in which to torture flight crews at least twice a year, was used extensively as a training aid. As one would expect space was limited in there, so we were split into three groups of four and entered into a shift system of two lectures and one simulator period each day. For each of the systems – fuel, flying controls, electrics, hydraulics . . . we listened to the lectures, then sat in the simulator for hands on experience. In this way we consolidated the theory while becoming familiar with our new office.

I didn’t like it in there. It was cramped – the engineer’s station was jam packed with switches and dials leaving not one square inch of unused space on a panel so large the seat was fitted with a powerful electric motor in order to convey the occupant from end to end quickly regardless of the pitch attitude of the aircraft. Without the electric motor, we were told, it would be impossible to move forward when the aircraft was climbing steeply – a fact I could attest to because the Concorde cockpit had many of the features of the one in the Comet 4. In that old machine of the 1950s I found myself downhill at the rear of the cockpit unable to reach knobs and switches in urgent need of my attention on more than one occasion. I was in fact isolated back there with the radio equipment with my finger stuck in a hole in the panel while an engine fire was indicated further forward. I had to call to the pilot to reduce the attitude, decrease the slope, so I could move. It happened as we climbed, oh so quickly, out of Mombasa one morning warm enough to set off the ageing flames-witches in the engine bays. Those switches were there to warn us of a flame breakout from one of the Avon engines. In practise they lit up on hot days when we climbed steeply at full power. Leaving Mombasa with hearty breakfasts inside, and a hot runway and a glowing Elijah outside, could bring on the red overheat lights demanding we shut down the engine, but we didn’t want to do that. Better to reset the overheat warning before doing anything to slow our progress to the Nairobi golf courses. The reset buttons were at the rear of the cockpit and could be reached easily by unlocking the seat to fly downhill to the rear of the panel. In my enthusiasm I once pressed too hard on the reset button sending it into the panel and leaving my finger jammed in the hole. The overheat light didn’t go out so the pilots were worried. I knew the reset hadn’t operated, that there was no fire, but with my finger stuck in the panel and my seat jammed hard against the equipment rack I was lacking the credibility to assure the crew. It all ended well enough for the story to retold in bars from Bombay to Hong Kong with humour increasing on each occasion.

 

Comet Cockpit

 

Comet Engineer’s Station

The Concorde seat, which was to become the most regularly visited location for my posterior for the rest of my working life, was mounted on the aircraft centre line so the occupant could accurately read the engine primary instruments on the forward, centre, panel. The huge systems panel on the starboard side intruded to a point uncomfortably close. I’m a little myopic, so having dials close to my face actually helped; for my colleagues it was uncomfortable and for one man, who was a little older and needed glasses both for distance and reading, it was downright difficult. His bi-focal lenses induced him to tip his head up to see the close dials, and down for the more distant engine instruments. This head movement, which appeared opposite to the direction in which he focussed, confused the instructor into thinking he was not looking at the right instruments at the right time. There were some warmish exchanges.

I’ll pause here to criticise the manufactures who, in fairness, were trying to please everyone. The crew position at the system panel was called the 3CM, third crew member, because some airlines had no flight engineers so  would train a pilot to operate that station. It faced in from the starboard side with a pull out table and a kneehole for the operator’s legs when facing sideways.

For the more critical phases of flight the operator would turn the seat to face forward to operate engine controls, navigation equipment, and to orchestrate the checklists. In practise 3CM sat facing forward for the critical phases and turned through forty-five degrees to manage the fuel system through the rest of the flight because navigation, and monitoring of the Automatic Flight Control System on the forward panels, were an integral part of his purview. The side facing period never really existed because the table was only extended to accommodate the teapot when it, and the accompanying milk, sugar, and mugs, was deposited hurriedly by the always harassed operator of the forward galley. Besides, if 3CM sat facing sideways his, there were no female 3CMs, seat blocked the pilot’s access. So 3CM never put his feet under the table: instead he sat, bent knee, with his right foot awkwardly placed behind the co-pilot’s seat while his briefcase sat in the kneehole. It wasn’t comfortable, but the interval was short enough to make it tolerable. Before we leave the architecture of the 3CM station, and that is the last time I’ll use that expression because the only pilots who ever operated that station were Braniff employees, who never flew supersonic, I would mention that cockpit design was fundamentally flawed in the same way as the whole Concorde project. The side-facing panel may have worked well for slower, long range, machines that cruised for upwards of ten hours at a time but it worked less well for short range, three crew, operations as in the Hawker Siddeley Trident, and the Boeing 727. The Vickers Vanguard faired better by housing much of the systems equipment on large overhead panels. Concorde straddles two stools in that it is a long range machine, but the flight duration is short. Had the systems panel been divided into left, right, and overhead the cockpit might have been more ergonomically convenient, making for a pleasanter environment in which to work. Had the design concept been open to the waves of digital technology sweeping through the technical world in the 1980s the displays could have been made less intrusive.

That is not to take anything away from the brilliant engineers who designed and developed her. Hampered as they were by muddled thinking in government she is a testament to both their knowledge and skills. Instead of a project of pride, of no-holds-barred thrusting at the forward edge of aviation technology, she was a compromise: a half hearted attempt to appease the bean counters while slipping through committee after committee without diminishing the bright twinkling in the eyes of the inspired. While I bitch at the compromises incorporated in that cockpit, in those elderly engines, in the materials used, I, too, nod in acknowledgement of an exceptional achievement by engineers with one hand side behind their backs.

 

Fuel System

It is, perhaps, appropriate to start talking of the fuel system because it is complex, and its management involves more than keeping the engines adequately supplied throughout the flight range. The designers adopted the ‘Total Energy’ concept when building Concorde so heat – energy by any other name – was not to be wasted. Where it became excessive, in the engine oil, the cabin air, and the hydraulic fluid, it was transferred to the fuel where it could be stored for use in the engines. The fuel was also used to balance the aircraft, as it was on the SV10, only not just for light passenger loads on short hops across the channel: Concorde fuel was in constant use for trim purposes because the lifting force shifted considerably throughout the speed range and would, if not balanced out, take the aircraft to a point where it becomes uncontrollable. So incorporated into the systems panel, amid the selectors and indicators for the thirteen fuel tanks, twenty-two inlet valves, and thirty-two pumps, was a control and display unit for the aircraft’s centre of gravity.

The fuel panel with the centre of gravity display in the yellow box

Each engine had its own Collector Tank and each of those had three booster pumps to support its veracious appetite. These collectors, as they were known, conceptually became the engines because the fuel was used so quickly: The flight engineer thought not of feeding the engine, but of feeding the tanks that feed the engines.

In the fuselage were three, large, tanks collectively known as the trim, or transfer, tanks, because they were the most effective in trim management. In practice all the tanks served a role in the trim system, so we needed to be aware of each tank’s position in regard to the aircraft’s centre of gravity in order to understand the schedule of use of the fuel within them. If the need arose to change the trim quickly, as in an emergency descent, the transfer tanks, with their mighty hydraulically powered pumps capable of moving two thousand kilograms of fuel a minute, were the guys to call upon. In normal operations the fuselage tanks were managed in concert with the wing tanks but, when the chips were down, as in a double engine failure . . .

 

Hydraulic System

That first glance at the Concorde hydraulic system sent me back, way back beyond the man in the check cap drawing a line on the floor of the BAC SVC10 assembly shop. It took me back to the hangars of East African Airways in Nairobi where we maintained the Comet 4s. The Comet flying controls were powered by three hydraulic systems labelled Blue, Green, and Yellow with pressure and contents gauges on the systems panel, and control selectors on the overhead panel and, what-do-you-know, here they were again on the Concorde systems panel and on the Concorde overhead panel. There were major differences in that the selectors on the Comet connected to the flying control servodynes via steel cables running through the fuselage, whereas the Concorde selectors were mechanical only in their relationship to each other. The actual signalling to the flying controls and hydraulic services was electrical, but the similarity of concept was clear: from the colour coding to the positioning of the controls and indications it was abundantly clear that some of the same design team were involved.

As we dug deeper the myriad of differences between the two aircraft hydraulic systems, from the operating pressures, capacities, and service interactions to fluid used and the safety measures incorporated, emerged. In an emergency, when all else fails, a windmill driving an electrical generator and hydraulic pump could be lowered into the airstream to provide just enough control to land the Concorde. The Comet had no such system – instead there was an electrically powered, red, hydraulic pump to provide minimum services and to guarantee supply to the wheel brakes. This, red, pump was located in the electrics bay, under the forward cabin floor, where banks of batteries, lead/acid accumulators, capable of producing hydrogen in considerable quantities, were also housed. During the landing sequence the red pump would be switched on to ensure adequate brake pressure but only if the electrical bay was free of mist or smoke. Very early in my career, flying with two WWII veteran pilots, I asked that the red pump not be used because a warning light said there was mist in the bay.

“What does that mean?” asked the pilot with his finger on the switch.

“It could be smoke, from an electric fire, but more likely it’s hydrogen mist, from an overheating battery,” I warned.

“So I only have limited braking?”

I agreed.

“Or,” he continued, “I risk blowing the aeroplane in half.”

Again I agreed.

“I’ll risk blowing the aeroplane in half,” he declared and switched the pump on.

 

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