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).
Connecting rod failures in Kestrel engines, detailing tests to simulate oil pressure loss during aircraft rolls.
| Identifier | ExFiles\Box 179b\3\ img083 | |
| Date | 31th January 1933 | |
| ORIGINAL To R.{Sir Henry Royce} from He/Yng. c. Sg.{Arthur F. Sidgreaves - MD} Nor. c. Ry. Rg.{Mr Rowledge} c. Lt. Lp.{Mr Lappin} c. Mr. Jaques. c. F.P. He/Yng. 4/KT. 31.1.33. x417 x296= CONNECTING ROD FAILURES ON KESTREL ENGINES. REPORT ON TESTS CARRIED OUT ON K.II. M.S.23. ON BEARINGS TO SIMULATE CONDITIONS OF A ROLL. Introduction. Failures of Nos.1, 2, or 3 blade connecting rods have been experienced principally on engines in aircraft. Collectively the evidence showed that the failure had been caused initially by the whitemetal of the big end bearing running out. All the failures in the air had been confined to fully supercharged engines, and for this reason it was suspected that the operational conditions of the aircraft were possibly responsible for the trouble. Interrogation of pilots revealed that during certain manoeuvres oil pressure was lost due to the oil feed pipe being clear of the oil. The most important of these manoeuvres were the rolling and inverted flying. Tests made in the air on a Hawker Fury aircraft gave results as follows - memo ref. Lp.{Mr Lappin}1/LWM.16.1.33. - Oil pressure is lost for 43 secs. when rolling (CRS) with engine on at 2000 R.P.M. Time of roll 7 seconds. Oil pressure is lost for 30 secs. when rolling without engine. Time of roll 10 secs. In order to simulate the conditions of a roll, a special oil system was rigged up as follows :- An aircraft oil tank to specification No.1 sheet 16 section 4 of the A.R. Data Folio was mounted so that the oil level in the tank was at the same height as the oil pump inlet when approx. 3 1/4 galls. of oil was in | ||