Mechanics, you may remember the days of quick engine cleanings. Today, engine care has become more sophisticated. WP 0324 of TM 1-2840-248-23&P (Oct 19) now specifies cleaning intervals and adjustments to those intervals based on environmental conditions.
In certain operating environments (such as cold weather, salt water, desert or sandy), multiple wash and rinse cycles are necessary and recommended by engineers to facilitate cleaner compressors, longer on-wing time and reduced critical wear. Also, hot section cleanings are recommended to remove clogged cooling passages and reduce elevated engine operating temperatures, which if not done, can result in premature component failures.
WP 0324 also provides guidance on approved cleaners. A note in this work package states that B&B 3100 (MIL-PRF-85704, Type I) is the primary cleaner for Army turbine engines, approved for locales where environmental restrictions permit. Where they don’t permit, engine cleaners that conform to MIL-PRF-85704, Type II and Type IIA, are acceptable. Comply with the existing washing procedure. Both types of cleaners are less effective than Type I; as a result, you may have to wash the engine more often for better results. Note that Type IIA cleaners do not require dilution with water.
TM 1-2840-248-23&P has very little work to perform at PMI on the T700 engine. Maintainers should therefore consider other maintenance tasks that’ll enhance performance between PMI intervals. One example is conducting off-wing hot section engine cleanings when operating in dirty environments (WP 0325). Performing off-wing hot section cleanings removes any accumulation of particles that may impede cooling airflow through hot section parts, which in turn, may cause material fatigue, decreased parts clearances and corrosion.