From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Circular letter detailing the standard procedure for using and testing sparking plugs during engine type tests.
Identifier | ExFiles\Box 33\3\ Scan262 | |
Date | 8th December 1925 | |
COPY. Aeronautical Inspection Directorate. Air Ministry. London. W.C.2. Dec. 8th. 1925. 59906/25/I.E.I.b. Inspector-in-Charge, A.I.D. Messrs Rolls Royce Ltd., Derby. CIRCULAR LETTER NO. 63. Sparking Plugs used on Engine Type Test. There appears to be a difference in the methods adopted at the various engine contractors with regard to the sparking plugs fitted on engines undergoing type test. In order that a uniform practice may be adopted throughout, the following instruction covering the standard approved procedure is issued for your information and action. 1. A set of new sparking plugs will be fitted in the engine prior to the commencement of the 100 hrs. endurance test. 2. At the termination of the first 10 hrs. run, the sparking plugs will be removed, examined, cleaned and adjusted, and this operation may be repeated at the termination of each 10 hrs. run. 3. Sparking plugs which prove defective during any one 10 hrs. run will be replaced by new ones at the completion of that 10 hrs. run, but such plugs must be put on one side, a label attached giving full particulars of failure and number of hrs. service and retained for examination and investigation at the conclusion of the type test. Generally as far as possible, but without detriment to the engine, it should be the endeavour to run the full 100 hrs. on one set of sparking plugs. 4. At the conclusion of the 100 hrs. endurance test and before commencing the high speed test a new set of sparking plugs may be fitted if desired, and such plugs used to complete the further tests required. Spd.I.E.I. | ||