PRIVACY ACT MATERIAL REMGyE3 HEADQUARTERS . TASK GROUP 7,4, PROVISIONAL APO 187, c/o Postmaster San Francisco, California — ~~ 23 March 1954 Joint Task Force SEVEN APO 187 (HOW), c/o Postmaster San Francisco, California Dear Lt A fact clearly understood by all airmen is that aircmft which sit on the ground for extensive periods collect serious maintenance deficiencies with an increasing possibility of an abort on the next flight the longer the period the aircraft remain grounded, This well known pitinwips.e may not be quite so obvious to those unaccustomed to maintaining ana onerating aircraft. I will therefore explain that the reasons for this deteriora- tion in maintenance condition lie in such difficulties as drying up of various neoprene seals in numerous hydraulic lines, corrosion of metal surfaces which must move past one another with close tolerances, sticking valves caused hy precipitation of sediment in the valves or by lack of the lubricating action of the fluid which normally flows through the valve and seepage of moisture and/or corrosion into numerous electrical circuits and devices, Frequent flight eliminates the cause of these conditions since all of the various systems of the aircraft are overated, thereby expanding seals, lubricating the close tolerance surfaces and the valves, and heating the electrical circuits, thus preventing the accumulation of moisture, It is possible, by operating the aircraft on the ground, to~activate a considerable number of these systems but unfortunately, the remainder can be activated only in flight. As examples of these conditions, on our flights yesterday, when we exercised all of our aircraft, the landing gear would not retract on two B-34's and numerous F-84's had tip and pylon tanks which would not feed due to stuck valves. In order to counteract this serious deterioration of maintenance in this prolonged period of relative inactivity of our critical aircraft, I am taking the risk of flying our aircraft frequently. proc:ss is as follows: ae TAB NO. 16 > a Ww AY 3=3214-S ~ -—_—_ Specifically, ny