Each Merlin was costing the Air Force $6,000 in royalty payments. It was they who opted for the Allison, which had problems because it was not fitted with backfire screens, so limiting power produced. The Secretary of Defence James Forrestal forbade modification of the engine to have screens, even though NA had demonstrated the modified engine. The Allison -82 had very poor serviceability, requiring 33 hours maintenance per flight hour, mostly due to engine issues. During 1949 serviceability was less than 50%. The troubles with the Allison increased program costs from $35 million to $50 million and the aircraft was a year late getting to service. Might have been cheaper to stick with the Merlin, but as Ed Schmued commented, "Īt was a great airplane and it was ruined by personal interests. It was pathetic. It was really pathetic to see a good design ruined by politics and the lack of cooperation by the Allison people in building a good engine".
All the Allison airframes were completed by 30 Apr '48, but non availability of Allison engines didn't see the last aircraft delivered until 12 Apr '49. Non availability of spares from Allison contributed to the poor serviceability noted above.
Last edited by megan; 2nd Feb 2019 at 00:52.