What the future for Concorde and passenger travel could have been like today
Some of the details on this page are thanks to Gordon Roxburgh of Concordesst
The Concorde production sadly ended with airframe number 216 (G-BOAF).
This is particularly frustrating as the Concorde ‘B’ model was already designed and the engines were available for incorporation into the next airframe number 217.
This was the aircraft the airlines really needed and the aircraft the manufacturers wanted to build. Unfortunately political pressure intervened and the will to proceed with it simply evaporated.
The new engine (the Olympus 610 +25%) had, as its name suggests, more thrust and eliminated noisy, fuel-guzzling afterburners.
The wing was redesigned, had leading edge ‘droop’ and carried more fuel. With better lift/drag, specific fuel consumption and more fuel the range of the Concorde Model ‘B’ increased over the original Concorde ‘A’ Model.
Just four months after Concorde began her scheduled services in 1976, a Concorde ‘B’ model was first discussed and designed with slightly larger fuel capacity and slightly larger wings with leading edge slats to improve aerodynamic performance at all speeds.
It featured more powerful engines with sound deadening and without the fuel-hungry and noisy reheat. It was speculated that it was reasonably possible to create an engine with up to 25% gain in efficiency over the Rolls-Royce/Snecma Olympus 593.This would have given 500 mi (805 km) additional range even with greater payload, and would have made new commercial routes possible. This was cancelled due in part to poor sales of Concorde, but also to the rising cost of aviation fuel in the 1970s.
During 1976 Jacques Mitterrand, the Chairman and Managing Director of Aerospatiale, submitted a proposal to investigate an improved version of Concorde – the “Version B” to Mr. Cavaille, French Secretary of State to Transport a similar letter was submitted to the British government at that time.
The letter that he sent elaborated on the quality of the work which had been carried out and the know-how that had now been acquired by the four French and British engineering companies (Aerospatiale, BAe, Rolls Royce and SNECMA). In this letter he also stressed the importance of the role that the manufacturers of Concorde could have in the development of a second-generation supersonic aircraft, that would be foreseeable during the 1990’s, could lead to probably in some form of a collaboration between Europe and the United States.
An exploratory study was actually already underway during this time, looking into upgrading the capabilities of the current Concorde design for the early 1980’s. The letter submitted also gave the official go ahead for this exploratory study and proposed a full feasibility study for a Concorde ‘B’ design.
Due to the manufactures having great difficulty selling the remaining five Concorde airframes that were built during the initial production run, Concorde 216 (G-BOAF) was to be the last Concorde ‘A’ built, and 217 was planned to be a Concorde ‘B’ version. Had Concorde ‘B’ been built, what type of future would we be living in now? If the additional range and performance had been available then many more airlines might have purchased Concorde and passenger air travel as we know it today might have been completely different.
She was planned to have a range approaching and even exceeding 5000 miles. But it is easy to imagine the potential range of Concorde ‘B’ design, when you consider that the Concorde “A” model used by British Airways had a design specification range of 3690 miles, had to regularly fly 4250 miles on a route between London Heathrow and Barbados. This was made possible due to operational improvements that pushed the range of Concorde ‘A’ to nearly 4500 miles. The improvements have included small changes to the aerodynamics of the original model’s specifications. One interesting fact is that the take-off weight was made very low and close to the figures estimated for the Concorde ‘B’ design.
The Concorde ‘B’ design would of also benefited from increased subsonic performance and reduced noise emissions.
The cost of the Concorde Project was massive and with the poor sales of Concorde, and cancelled options from airlines, adding to that the rising cost of aviation fuel during the 1970s, the development of the Model ‘B’ version was considered too expensive and cancelled. Although the study carried out was a pretty comprehensive one and could of given Concorde a real future in during the years to come right into the 1990s and even on into the 2000s, after this time it was generally expected that a new generation SST with a new type of variable cycle engines would enter into service (BAe AST3 or Aerospatiale Alliance)
Exploratory and feasibility study for a Concorde ‘B’ design.
The study into a Concorde ‘B’ design had two aims:
1. To ensure the expansion and future demand for supersonic transport (SST), where the Anglo-French group was now and into the future as the main and only player,
2. To maintain the high knowledge level gained by the manufacturers in Britain and France, and to provide a solid position for the participation in a future program of a second-generation SST.
This feasibility study, was planned to last 9 months and was estimated to cost 9 million French francs, it was to comprise three areas:
2. Development costs
If this exploratory and feasibility study was to confirmed an economic interest for the manufacturers, and then led to the decision of the launch of an improved version of Concorde, such an improved version (allowing for a 5 year development programme) could be ready by spring 1982 for the 17th production Concorde 217
Civil aviation history shows that almost all new aircraft constituted a base point for the start of improved versions (The Boeing 747-100 evolved into today’s 747-400) and at this stage this was the plan for the Concorde program.
The interest in this development process would have been beneficial to both the airlines and the manufacturers of Concorde:
1. For the airlines, it would have offered performance improvements (lower direct operation costs, extension of the operating range, and reduction of environmental effects) while conserving the existing investments in crew training, maintenance procedures, etc.
2. For the manufacturers, it would have made it possible to carry out these improvements at a minimum capital cost. Indeed the development of the initial production version generally revealed aerodynamic areas where gains could be made along with structural margins, but these could not be exploited due to the time constraints in getting Concorde into passenger service successfully.
3. If the decision to build the B model would have been taken, the modifications would have been relatively inexpensive as they were just some minor changes to the existing production process, allowing the majority of the tooling to be maintained. The high level of knowledge that was gained during the certification of the current model would have greatly reduced time and costs during the certification of the B model.
These considerations should have applied particularly to the case of Concorde, considering the exceptional degree of innovation obtained and the great amount of technical knowledge accumulated during the twelve years of development of the initial production version.
The broad objectives of the Concorde ‘B’ version were to ensure the expansion of the network of routes that supersonic aircraft could use.
The following improvements were considered to be necessary:
The Reduction of harmful acoustic effects on the airport environment:
Although the level of noise produced by Concorde at takeoff and landing is equivalent to that of the first generation long haul aircraft in service (B 707, DC8), only the second generation of long haul aircraft (B747, DC10, L1011) equipped with high-bypass jet engines satisfied the new international noise rules. With the reaction of the United States, which had at the start of scheduled Concorde services not accepted the use of Concorde on their territory, it would be important to reduce the level of noise generated by the aircraft.
Operating range increases
The operating range of the initial version – primarily designed for the connection Paris London-New York – was to be increased to allow connections of the type:
Other European capital cities – East Coast of the US in one sector.
United States – Japan in two sectors.
Europe – Australia in three sectors.
Fuel consumption reductions
Concorde’s fuel consumption accounts for a third of the direct operating cost (DOC). A reduction in fuel consumption would mean an improvement in economics for the airlines using the aircraft, making it even more marketable by the manufacturers, and also enable the airlines to reduce ticket prices.
Airframe aerodynamic improvements
The objective of noise reduction implies an increase in the smoothness of flight during takeoff and landing, which also results in an improvement in all subsonic flight modes (climb, subsonic cruise, approach).
This would also help in the above objective of increasing the operating range.
This modification must respect two constraints: to preserve – if not improve – the supersonic smoothness of flight, and to limit the effects from modifications or additions on the central core structure of the wing, in order to re-use the majority of the tooling currently used in manufacture and assembly.
A moderate increase in the range could be obtained by aerodynamic tweaks to the current design. These included lengthening the wing tips and mounting droop slats on the leading edges of the wings. These tweaks would reduce the induced drag at supersonic speeds and increase the available lift at slower speeds.
The additional lift generated by the leading edge droops would permit the aircraft the fly at a lower angle of attack at slower speeds, therefore requiring less power to be generated by the powerplant, which in turn would reduce noise and increase fuel efficiency.
Optimisation of twist and camber of the wing, combined with the increase in the lift coefficient (Cz) along with the increased thrust offered by the supersonic engine also allows improvements of the smoothness of flight at Mach 2.
Detailed aerodynamic improvements, (reshaped trailing edge of the control surfaces and thinning of the lower lips of air intake) which were later applied to the current production models before they entered service, were also proposed to be continued on the Concorde ’B’
Modifications of the powerplant unit
The majority of the noise produced by Concorde during takeoff and landing comes from the areas of strong aerodynamic shearing, which are located at the edge of the exhaust system.
The powerplant, which is optimised for supersonic cruise rather than subsonic flight would be modified so that gains could be made throughout the whole speed range during flight, and Specific gains could then be made in the fuel consumption in the transonic region, thus then giving an increase in the operating range required.
Physically, the modifications would consist of replacing the low-pressure compressor with a compressor with a increased diameter, and the low pressure turbine assembly with a two-stage turbine.
Then the installation of a discharge system to increase the margin of air flow through the engine would result in an increase in air flow which reaches 25 % on takeoff and 35 % during approach. The thrust gains obtained at takeoff and at transonic speeds could also make it possible to remove the reheat (afterburner) system with its very heavy fuel consumption and significant addition to the noise generated by the powerplant.
Fuel tanks modifications
The increase of capacity obtained by the enlarging of the external wing and the tank at the front of the wing could be supplemented by the addition of a fuselage tank connected to the latter.
The maximum quantity of fuel that can be put on board increases from 95,254 kg to 99,790 kg.
Modifications of aircraft systems
Changes would have been incorporated in the autopilot system for the takeoff and approach stages, in order to automatically optimise the aircraft in these key stages of flight and to reduce the noise levels around the airports during takeoff and landing.
Airframe weight and performance
The additional wing area along with the modifications to the engines and intakes would add to the empty weight of the aircraft:
The reductions would have been obtained mainly by the use of carbon fibre in the construction of control surfaces, service doors, etc.
The increase in the empty weight and the fuel carrying capability also requires an increase in the various performance characteristics (a payload of 24,800lbs/11260kg is used).