What was found
FLT#1173,JFK-BNA. (AIRCRAFT PERFORMED AN AIR TURN BACK TO JFK). ' HYD 1 CAS LOW QTY 12% DOWN TO 10% AMBER IN FLIGHT AT FL340 ; REF LP 4209983-2 (REF LP 4209988-1 (REPLACED HYD LINE SECTION VIA PERMASWAGE REPAIR REF GMP BD500-A-J20-40-00-06AAA-913A-A. REF LP 4209988-2 FOR LEAK CHECK.) FOR PERMA SWAGE REPAIR. REF LP 4209988-2 (PERFORMED OPERATIONAL TEST OF HYD SYS #1 IAW AMP J29-11-00-01AAA-320A-A. NO LEAKS NOTED NEAR PERMASWAGE REPAIR, A/C OK FOR SVC) FOR LEAK CHK OF PERMAWAGE REPAIR. HYD SYS #1 OPERATIONAL NORMAL. NO LEAKS NOTED A/C OK FOR SVC.) FOR RESOLUTION OF HYD LEAKING FROM VERT STAB PERMSWAGE PRESSURE LINE ALL OPS NORMAL NO FURTHER LEAKS NOTED AT THIS TIME A/C OK FOR CONT SVC.'