G-BOAF moved to North Pen

After G-BOAF had been rolled out of the Majors Dock at Heathrow, she was moved into the Minors bay known as "North Pen" in BA's Tech Block A. The aircraft had weeks of system checks to complete before she could fly in a "make or break" test flight, or verification flight as it was to be known. All the aircraft's electrical and hydraulic systems required to be powered up and fully tested before she could take to the air, or even taxi under her own power. As many areas of the aircraft had been disturbed that had never been disturbed before, systems in these particular areas would also be fully ground tested.

During this time engineers also fitted extensive temperature measurement devices into the fuel tanks to confirm that the liners would not effect the way fuel is used for cooling purposes on board the aircraft. In Concorde the fuel circulates to cool the aircraft by acting as a heat sink, it also helps out with cooling for the air-conditioning. Engineers at Airbus UK also needed to determine if the aircraft's structure would be effected if the ability of the fuel to cool the aircraft was impaired in anyway.

Strain gauges and temperature sensors were fitted to tanks1, 5 and 6. These were connected to a recording station situated in the rear cabin, in place of seats 26A and B. As well as recording the data on the verification flight, it would be sample information for up to 50 flights, to confirm there was no adverse trends and that the modification continuted not to effect the aircraft's systems.

G-BOAD towed out of engine test bay

A verification test flight date had been tentatively scheduled for the middle of July, but a lot of work was required to be completed before then, including the all important engine runs. For several months British Airways had been using the Concorde engine test bay to store unmodified aircraft. This provided some cover from the elements as BA did not have enough hanger space, to store the entire fleet, with demise of Tech Block B a couple of year previously. Concorde G-BOAD was towed out of the test bay on July 3rd 2001 to allow Alpha-Foxtrot's engine runs to begin.

After several days of engine and system check BA announced to the media that Concorde would carried out the first of 2 taxi tests around Heathrow on July 9th. This test would be a key stage to the test flight and would enable a final check of the systems to confirm that the aircraft was flight worthy. Many systems had been unused for nearly a year, such as the steering, brakes and navigational equipment. The test also gave engineers the first data in a live environment on how the Kevlar tank liners and the aircrafts complex fuel systems would behave when the aircraft was filled with fuel, and moving under its own power.

It had been decided that Alpha foxtrot would also be fitted with the specification Michelin tyres from the outset after the ground tests proved they they would deliver the near anti-burst characteristics. The Istres flight-testing successfully ensured that these tyres could be fitted to and perform to spec on Concorde. The NZG Michelins were fitted to Concorde's main landing gear wheels at Heathrow. BA Concorde's kept their Dunlop tyres for the front nose gear wheels, while Air France would keep they Goodyears.

Alpha-Foxtrot's first taxi test at Heathrow (Discovery Channel)

The 5 mile long, 35MPH taxi around the inner taxiway at Heathrow allowed tyres fuel systems and other key checks to be completed. BA's Mike Bannister and CAA test pilot Jock Reid were in the cockpit along with a few of the engineers in a test that went out Live on the UK's TV news channels, showing that Concorde was still a big news story whatever went on.

The taxi test had went well but the engineers had found a glitch in one of the aircraft 4 Rolls-Royce Olympus engines. With the importance of the verification flight and the need for it to be a success BA decided that it would be wise to swap out the engine for a recently serviced engine to ensure the aircraft would perform flawlessly during the verification flight.

A final taxi test was carried out on July 13th where the aircraft departed from her V14 stand at Heathrow's Terminal 4. Unlike the first test where the aircraft had been given a low fuel load, this time the aircraft would be uploaded with a high fuel load to further check the liners and fuel system performance under departure and fight conditions.

With the taxi tests final checks successfully completed, British Airways announced on July 14th that they had scheduled the verification flight for the afternoon of Wednesday July 17th. They said that: "British Airways Concorde G-BOAF, would fly out of Heathrow for a 3hr 20 min test flight on Tuesday 17th of July, at around 14:20. The flight will terminate at RAF Brize Norton."

Mike Bannister waves from the cockpit before the flight

The flight would be crewed by British Airways chief Concorde Pilot Mike Bannister along with the UK Civil Aviation Authorities chief test pilot Captain Jock Reid. The flight will take place under CAA 'B' conditions for an aircraft that presently does not have a Certificate of Airworthiness. The verification flight had to be flown under the auspices of the manufactures, in this case Airbus UK (a joint company formed by the original manufacturers BAE systems and EADS) and not the airline as they can't technically fly the aircraft without its C of A.

Airbus UK did not now have any Concorde rated pilots so Capt Reid was to be a member of the crew representing Airbus UK. Jock Reid was the CAA's regular Concorde pilot through his work in taking part in the normal C of A checks at set intervals during normal operating conditions, and with his regular flights with British Airways he was the natural choice for this role. Also in the flight crew would be Captain Les Brodie (BA Concorde Flight Training manager) and Senior Engineering officer Trevor Northcot

"Up to a maximum 4 flights will be conducted with G-BOAF at this stage; with the main purpose being to validate the tank liner modification and what effect it has on the aircraft, if any effect at all." A BA spokesman announced.

Alpha Foxtrot parked in front of 3 of her sister ships

Never short of missing a PR opportunity, BA decided that the aircraft would depart from the apron in front of Tech Block A's East Pen, which just happened to be in front of three other BA Concordes, who's fate would rest on the verification flight that Alpha Foxtrot was about to carry out.

By 8am the UK's media was gathered in the adjoining car park to hype up the verification flight and its importance. Throughout the morning they would interview key people from Concorde's recent history, who would all stress the significance of the flight, to ensure that Concorde would be around for a lot longer yet.

The flight would depart from Heathrow's South Runway (09R), with a slot time scheduled for around 14:20. The planned flight profile would have the aircraft going supersonic (Mach 1 / 720mph) south east of Swansea and will then continue to climb, first to 45,000ft and then to on to 60,000ft which is nearly twice the normal cruising altitude of subsonic aircraft.

Final preperations (Reuters)

The aircraft would route out on the normal SM supersonic track until reaching 15W where she would then route up to the warmer atmospheric conditions around Iceland, to help simulate the temperatures that would be encountered on a transatlantic flight.

After turning just south west of Iceland, Concorde would then fly southbound to re-intercept its normal inbound flight path from New York to London, where it would decelerate to subsonic speed approximately 70 miles west of the coast of Devon, before being handed over to military air traffic control for its final approach to RAF Brize Norton.

After the final flight crew and test team briefings, in an office at the engineering base had been completed, the crew boarded Alpha Foxtrot on the ramp outside East pen to begin the final preparations for the flight. Ouside the aircraft, the ground crews checked and re-checked the aircraft before hooking up the tow truck.

Just after 13:00 Alpha-Foxtrot departed, under tow, from the British Airways engineering base at Heathrow. Followed by a convoy of engineering and support vehicles. The aircraft would be towed to Block 41 on the main airport apron, where final checks and engine start up could be completed before she could taxi off to the head of Runway 09L.

Alpha Foxtrot is towed from the ramp outside the engineering base (Reuters)	Final checks and start up were completed on the main airport apron (Paul Dopson)

With permission for start-up had been granted, the aircraft's 4 Rolls-Royce Olympus turbojet engines roared to life and provided power to the aircraft's hydraulic systems. After a through test of the flight control surfaces, Concorde drooped her nose down to the 5 degree take off position, and taxied off to line up for departure.

G-BOAF taxis past the spectator balcony (Robert Holbach )

Massive crowds had gathered on every conceivable vantage point at Heathrow, with many workers at the airport stopping what they were doing to come and see Concorde depart once again.

Shortly before 14:15, after a Virgin Atlantic Boeing 747 departed, Heathrow airports runway inspection vehicle " Checker" performed an unprecedented full length daytime check on the Heathrow runway. Alpha Foxtrot was cleared for take off by tower for probably the most important flight in her time with the airline.

At 14:18 the 4 Rolls-Royce engines were throttled to full re-heated power and Alpha Foxtrot, as BA9180e, came hurtling down the runway and took off into a very gloomy overcast sky, before disappearing into the clouds during her right hand turn.

Alpha-Foxtrot's Gear retracts shortly after take off (Paul Dopson)	Concorde powers out of Heathrow (Paul Dopson)

Now the important work would start; would the modification work, would there be any problems associated with liners interfering with the aircraft's clever use of fuel, such as fuel cooling, heat distribution in the fuel, fuel flow between tanks, the aircraft's centre of gravity, not to mention fuel flow into the engines themselves.

On board, in addition to the flight crew, were 5 engineers including two, George Robinson and Robin Morton, from the Manufacturer Airbus UK who had been involved in the flight certification of Concorde in the 1970s. Along with 3 engineers from British Airways they monitored all the aircraft systems and took the all important fuel temperature readings at regular intervals to confirm all was well.

Landing at RAF Brize Norton (Crown Copyright)

After over 3hrs 20mins in the air the aircraft came peering through the gloomy overcast sky at RAF Brize Norton in Oxfordshire. In a similar fashion to the scenes at Heathrow all the locals, media and the enthusiasts turned out to see the aircraft arrive, in what can only be described "trying" conditions.

After a textbook landing Bannister taxied the aircraft to a crowded stand, with everyone wanted to know how the tests had gone. As the aircraft came to a stop at the Brize Norton Terminal, Bannister saluted the onlookers with the traditional raising and lowering of the Concorde droop nose.

The crew disembark at a wet Brize Norton (Reuters)

On his departure from the aircraft Mike Bannister was delighted: "It was absolutely fantastic to get back behind the controls. I have been flying Concorde for 22 years but this was the best flight ever. "The initial reaction is that the aircraft performed brilliantly. I have great professional pride in being allowed to fly this wonderful plane." He told the waiting press and engineers keen to hear first hand if the aircraft's future had been secured.

BA chief executive Rod Eddington said: "After many hours of work by our engineering team it's good to have the aircraft flying again. This is an important day for everyone. "

With all the information gathered from the flight that they needed, the engineers sat down to analyse the data they had received from the test flight. Mike Bannister managed to take time out to call the engineering staff back at Heathrow to congratulate them on the job they had done to get G-BOAF back in the air, and with so little faults - not bad for such a complex aircraft that had been on the ground for over a year.

Mike Bannister in the cockpit after the flight (BA)

Later that week Captain Bannister told the Guardian newspaper "Early indications were that our calculations on the ground were rather conservative. The increase in the aircraft's weight was offset by the new interior and the new lighter tyres. There was no difference in the way the aircraft handles. In general terms, it performed brilliantly. It felt fantastic to be flying again. I first flew Concorde in 1977, but Tuesday was the highlight of my career."

The results from the initial tests were very positive none of the problems that the tank liner mod could have caused the aircraft, such as the afore mentioned fuel cooling, heat distribution in the fuel, fuel flow between tanks, fuel flow into the engines and the aircraft's centre of gravity, were not seen. Such was the success of the test the engineers knew very early that only one further test flight would be required to validate their data.

Alpha Foxtrot spent a couple of days at RAF Brize Norton, where the engineers checked out all her systems before again declaring her airworthy for the return flight to Heathrow. During this time on the ground the engines would be run up to allow the engineers to "run the tanks dry". With the figure known how much fuel was in the aircraft to begin with, this would allow them could calculate the level of un-usable fuel that would be left in the tanks but not reach the engines and understand what effect the liners would have on this figure. In any aircraft this figure is key as it is essentially the tank empty point for the engine to function, even though in theory these is fuel left according to the gauges.

Alpha-Foxtrot departs from RAF Brize Norton(Sky News)

Only 3 days after her first flight G-BOAF was ready to go home. The same flight and engineering test crew that were on board during the first flight would carry out the exact same tests during an identical return leg via the south of Iceland en-route to Heathrow.

The BA 9181e set off from RAF Brize Norton at 13:50. The take off was again covered extensively by the UK media and was covered live by the BBC and Sky News.

After an uneventful flight Alpha-Foxtot arrived back into Heathrow just after 5pm at 17:08. To many this was reminiscent of the normal New York service that would see the aircraft return to Heathrow just after 5pm. The only difference here was the rather than taxi to her stand at Terminal 4 to allow the passengers to depart the aircraft taxied directly to the BA engineering base.

Heathrow arrival after 2nd verification flight (Sky News)

Once back in the engineering base and safely shut down, G-BOAF was towed straight into the North Pen hanger at Tech Block A, where the Concorde engineering staff had gathered to meet the aircraft. The staff who had done the work wanted to hear first hand from the crew and collegues how the verification flights had gone, and if any other work would be required on the aircraft.

Staff morale, that had for so low for so long, after the Air France accident and subsequent grounding was on a high. There was still a lot of work to do but the first big steps on the way to re-certification had been made, but there would be a lot of work still ahead if the airlines wanted to put the aircraft back in revenue service.