Rolls-Royce and Snecma are battling to meet Airbus Military Company's (AMC) end-of-June deadline to come up with a joint powerplant proposal for the A400M transport aircraft.
The engine makers have already submitted separate bids to AMC but are under political pressure to come up with a "European solution", acceptable to the seven nations likely to acquire the aircraft. The key stumbling block is whether a joint proposal would be based on the core of the French company's M88 turbofan or the UK manufacturer's BR700.
Sources close to the talks say that although there is willingness on both sides to reach a deal, a compromise is proving elusive.
AMC needs to receive any joint engine proposal in the next couple of weeks to enable it to prepare for contractual negotiations with the customer nations later this year.
Although the Airbus military arm says it will make an engine selection independent of political considerations, industry sources say it is encouraging the engine makers to work together to avoid potential workshare disputes.
The consortium says it would accept a joint bid provided this does not push up overall programme costs or increase technical risk. AMC's commercial director Richard Thompson says: "We would not make a decision based on political issues as far as it will affect our commercial solution."
The UK has indicated that it wants R-R to have substantial participation in the powerplant as a condition to it placing a firm order for the aircraft.
R-R is proposing the BR700-TP, while Snecma is leading the Turboprop International (TPI) consortium, offering the M138. TPI partners the French company with Germany's MTU, ITP of Spain and Italy's FiatAvio.
The negotiations are focused on two options for integrating all five engine companies. The first is an M138-based solution for which Snecma would take responsibility for the high-pressure compressor (HPC), or a BR700-based one with R-R handling the HPC and possibly the combustor as well.
The M138 core is seen as offering better growth potential and could be derated for the A400M to improve durability. But it is considered riskier than the BR700-TP, the core of which is taken from the BR700 series and would not incorporate booster stages.
Source: Flight International
