70-10-04 SPRAGUE ENGINEERING: Amdt. 39-988. Applies to all civil aircraft certificated in all categories including, but not limited to the Boeing Models 707/720/737 aircraft and Convair Model 22 aircraft with the Sprague Engineering Accumulator Assemblies, P/N A-200-25 and A-200-50 installed. \n\n\tCompliance required within the next 3000 hours time in service after the effective date of this AD, unless already accomplished. \n\n\tTo prevent hydraulic accumulator end cap failure due to cyclic fatigue and subsequent explosive hazard to personnel, structure and surrounding equipment, as well as loss of hydraulic system fluid and pressure, accomplish the following: \n\n\tReplace the aluminum end caps on Sprague Accumulator Assemblies, P/N A-200-25 and -50, with steel end caps, Sprague P/N 60257-2 (oil end cap) and P/N 60257-3 (air end cap), in accordance with the instructions of Sprague Engineering Modification Bulletin No. 2, dated March 28, 1969, or later FAA approved revisions and Sprague Overhaul Instructions with Parts Breakdown, Accumulator Assembly, A-200 Series, dated September, 1967, or an equivalent installation and replacement approved by the Chief, Aircraft Engineering Division, FAA Western Region. \n\n\tThis amendment becomes effective May 16, 1970.