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).
Acceptance test procedures and requirements for subsequent production sparking plugs.
| Identifier | ExFiles\Box 58\2\ Scan110 | |
| Date | 1st June 1934 guessed | |
| -6- (b) In addition, a half engine set of sparking plugs shall have completed satisfactorily 25 hours in a similar engine in flight during which the capability of the sparking plugs for coping with oiling-up and over-heating conditions shall be tested by repeated diving and climbing, and by throttling down and opening-up of the engine. The sparking plugs used for these tests must be in accordance with the letter of provisonal approval. The erosion of electrodes shall be measured and after any 25 hours flying period on the engine the increase in the gap between the electrodes shall not exceed .005". Section 4. Acceptance Tests for Subsequent Production Sparking Plugs. 21. Each sparking plug shall be submitted to the tests given in clauses 19(b) and (c) for a period of not less than 3 seconds and to the sparking test laid down in clause 19 (d). 22. Each sparking plug shall be submitted to a gass leakage test at a pressure of 100 lb. per sq.in. at atmospheric temperature and the gasleakage must not exceed 1.0 c.c. per minute when measured at atmospheric temperature and pressure. 23. As a check test not more than 0.5% of the sparking plugs submitted for acceptance may at the discretion of the authorised inspector by subjected to any of the tests given in clauses 17 to 19. 24. Any plug rendered unserviceable must be replaced by the maker. Should the whole of the 0.5% of the sparking plugs fail to pass the tests the whole of the batch may be rejected. Attached drawing No. E.{Mr Elliott - Chief Engineer}& I. 4176. | ||