We ran a Jet Ranger, Long Ranger, and three MD-500 E's on #1 Clear Diesel for years without any problems what so ever.
What am I missing here? For the B407 (and I assume other FAA certified acft), approved fuels appear in the Limitations section of the RFM and are all aircraft jet fuels (no diesel, kerosene, Irish whiskey, etc). The use of ANYTHING else would seem to raise multiple serious questions unless the Limitations are amended accordingly. Perhaps different with other aviation authorities outside the U.S.
No doubt these turbine engines will run on other types of fuels but the use of such fuels would seem to violate regulations, void warranties, create liabilities, etc. (Civil acft only - military make their own rules)