The ones registered as "DC-3C-R-1830-90C" are a bit of a giveway (R-1830 is the military designation of the Twin Wasp) and were formerly C-47Bs
Are you absolutely certain of their provenance
Dave? The reason I ask is of the following (FAA TCDS),
Optional Engines DC-3C
Interchangeable with the S1C3G engines. Ratings are same as S1C3G. 100 min. grade fuel must be used unless carburetor setting is revised to permit use of 91 grade fuel. All must have 16:9 reduction gearing:
R-1830-49, R-1830-57, R-1830-82, R-1830-96, R-1830-92
Interchangeable with the S4C4G engine at identical ratings. Ignition timing must be modified to 20° for 91 grade fuel. All must have 16:9 reduction gearing:
S3C4G, R-1830-90C, R-1830-65, R-1830-43, R-1830-90D, R-1830-67, R-1830-43A
So the engine designation would not necessarily point to the aircrafts ancestry. Of course the British may do things differently, and is the reason for asking
Dave.
I have no idea of the British requirements, but the FAA required,
Upon completion of the conversion to certificated status, the manufacturer's nameplate on the aircraft should be altered to include the date of conversion and the new commercial model designation. In case the original nameplate is not sufficiently large to include this additional information, a similar plate should be installed near the original plate. Under no circumstances should the original or any succeeding nameplate be removed from the aircraft.
The nameplate would make it the unambiguous reference.
In Australia all the airline aircraft I saw and rode in were Wright powered. Many were ex C-47 that had the P&W removed, in fact don't know if any were "real DC-3's". RAAF aircraft were P&W.
For readers you may find the FAA TCDS of interest.
P&W powered
http://rgl.faa.gov/Regulatory_and_Gu...20Rev%2032.pdf
Wright powered
http://rgl.faa.gov/Regulatory_and_Gu...20Rev%2023.pdf
Many thanks too
Dave for listing all the TCDS, thought I'd include the links to a couple.