Straight up / Flight Safety -
The CT7 is the civil version of the T700. The GE/Fiat T700-T6A equates to the CT7-6, and the -T6E to the CT7-8. The T700-T6A’s FADEC isn’t a true full authority digital engine control, but rather a supervisory DEC.
The -T6A does indeed power the Italian and Canadian versions of the EH101, together with a single civil aircraft, but the majority of EH101s are powered by the Rolls-Royce/Turbomeca RTM322. As Straight Up mentions, the RTM322 was developed for the EH101, but the new FADEC-equipped engine wasn’t the cause of the EH101’s protracted development - compared to the ‘commercial’ S-92, the EH101 was a substantially more complex mission system (i.e. airframe, avionics, weapons & ground support), with a much longer development & test program. Systems delays and the three crashes obviously did cause the development program to be longer than originally planned, but it was never going to equate to what Sikorsky has achieved with the S-92.
The first EH101 prototypes were flown with the older T700, with RTM322-powered prototypes joining the fleet in 1993. The RTM322 had already been trialled on the Sikorsky S-70C and SH-60 by this time, and was therefore considered something of a low-risk item. The EH101/RTM322 combination has now been selected by the RN, RAF, Danish AF and Portuguese AF, with more opportunities being campaigned. The RTM322 has so far secured 70% of EH101 orders, and has also been selected to power 70% of NH90s, the other application on which the RRTM engine competes against the GE/Fiat offering.
Offering substantially greater power growth than the T700 family, the RTM322 is a natural choice for future variants of the S-92, but then I’m biased...
GE/Fiat has an exclusivity agreement on initial sales of the Helibus, but I’ll have to leave Nick to comment on future engine options...
Cheers,
t/shaft