| Abstract | An extensive survey of certain J85-CAN-15 performance variables at MILITARY power setting was undertaken to establish the functioning of the T2 Speed Cutback system. A total of 990 engine datasets were recorded prior to 500 take-offs of 61 different CF-5 aircraft at CFB Cold Lake and CFB Bagotville.
Because of uncommonly mild winter temperatures, insufficient low temperature data were obtained to allow meaningful assessment of T2 Speed Cutback system operation on a fleet-wide basis. However, one aircraft was dispatched to Yellowknife where a number of datasets were recorded during a four-day period. Analysis of these special data showed the T2 Speed Cutback systems on engine S/N 8560 (RH) functioned at inlet temperatures down to -38°C. The T2 Cutback system on engine S/N 8874 (LH) seemed to function at times, but not always.
The data collected in the fleet survey were utilized in a limited statistical analysis of certain engine operational parameters. It was found that, at MILITARY power setting, only 55% of all recorded speeds were within Installed Limits. The biased turbine outlet temperatures (T5B) were generally high, and about 20% of the readings indicated temperatures above the upper Limit. The VEN openings ranged from 12 to 26%, with the average value from CFB Cold Lake being approximately 3% smaller than that from CFB Bagotville. The fuel flowrate data displayed very wide scatter, with values differing by as much as 650 lbm /hr at the same inlet conditions.
Further investigations into the causes and implications of several of these observed phenomena have been recommended. |
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