78-18-05 PIPER AEROSTAR: Amendment 39-3295. Applies to Piper Aerostar Model 600, 601 and 601P airplanes certificated in all categories, serial numbers 150 through 520. \n\n\tCompliance required as indicated. To prevent reversed readings of left and right wing tank fuel quantity accomplish the following: \n\n\t(a)\tWithin 10 hours time in service after the effective date of this AD, unless already accomplished, with LH and RH wing tanks at least 50% depleted from tank capacity: \n\n\t\t1)\tRead and record fuel quantity indication for LH and RH wing fuel tanks. \n\n\t\t2)\tAdd 10 gallons of fuel to one wing tank only. \n\n\t\t3)\tRead and record fuel quantity for each wing tank. \n\n\t\t4)\tDetermine that the added fuel registers on the correct wing tank fuel quantity indicator selector position. \n\n\t\t5)\tIf the correct wing tank fuel quantity selector position registers the added fuel, the system is normal and no further action is required under this AD. \n\n\t(b)\tIf the appropriate wing tank fuel indicator position does not correctly register the added fuel the system may be improperly wired or the selector may be improperly indexed. In this event, prior to further flight: \n\n\t\tCorrect the fuel quantity indicating system malfunction. Refer to figure 1 for details of proper switch installation. \n\n\t(c)\tWithin 10 hours time in service after the effective date of this AD, on those airplanes with the fuel quantity indicating selector switch relabelled as an interim solution under (B)(2) of the original message of July 7, 1978, correct the fuel quantity indicating system as in (b) of this AD and revert to standard switch labelling. \n\n\t(d)\tSpecial flight permits may be issued in accordance with FARs 21.197 and 21.199 to operate aircraft to a base for accomplishment of the repair required by paragraph (b) of this AD. \n\n\t(e)\tEquivalent inspections and repairs may be used when approved by the Chief, Aircraft Engineering Division, FAA Western Region. \n\n\tThis amendment becomes effective September 13, 1978.