Airworthiness Directive · Amendment 39-16600 · Electrical power
The Cessna Aircraft Company Model 750 Airplanes
This AD applies to The Cessna Aircraft Company Model 750 airplanes, certificated in any category, having serial numbers -0222, and -0225 and subsequent.
We are adopting a new airworthiness directive (AD) for the products listed above. This AD requires an inspection to determine the serial numbers of the auxiliary power unit (APU) generator and the left and right engine direct current (DC) generators, and corrective actions if necessary. This AD also requires revising the airplane flight manual. This AD was prompted by a report of a DC generator overvoltage event which caused smoke in the cockpit and damage to numerous avionics and electrical components. We are issuing this AD to detect and correct an overvoltage condition on the DC electrical busses caused by exciter stator winding failures, and subsequent failure of the generator control unit (GCU) overvoltage protection circuitry, which could result in damage to critical electrical and avionics components.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
For airplanes having serial numbers -0222, -0225 through -0293 inclusive, -0295, -0296, and -0298: Within 6 months or 600 flight hours after the effective date of this AD, whichever occurs later, inspect to determine the serial number of the auxiliary power unit (APU) generator and the left and right engine 400 amp DC generators, in accordance with the Accomplishment Instructions of Cessna Service Letter SL750-24-08, dated August 13, 2009. For airplanes that have one or more generators having a serial number 060 through 297 inclusive without suffix “C,” before further flight, replace the affected generator(s) with a new or serviceable generator, in accordance with the Accomplishment Instructions of Cessna Service Letter SL750-24-08, dated August 13, 2009.
For airplanes having serial numbers -0222, and -0225 and subsequent: Within 30 days after the effective date of this AD, revise Section II, Operating Limitations, Generator Limitations, page 2-12, of the applicable airplane flight manual (AFM) to include the information in the applicable Cessna temporary change (TC) required by paragraph (h)(1), (h)(2), or (h)(3) of this AD. These TCs introduce procedures for resetting the APU generator. Operate the airplane according to the limitations and procedures in the TCs.
(1) For Model 750 Citation X airplanes (750-0173 and on and airplanes incorporating Cessna Service Bulletin SB750-71-10): Insert Cessna TC 75FMA TC-R01-46, dated April 23, 2009.
(2) For Model 750 Citation X airplanes (750-0173 and on and airplanes incorporating Cessna Service Bulletin SB750-71-10): Insert Cessna TC 75EUA TC-R01-35, dated May 8, 2009.
(3) For Model 750 Citation X airplanes (750-0173 and on and airplanes incorporating Cessna Service Bulletin SB750-71-10): Insert Cessna TC 75EUMA TC-R01-35, dated May 8, 2009.
Note 1: The AFM revisions required by paragraph (h) of this AD may be done by inserting copies of Cessna TCs 75FMA TC-R01-46, dated April 23, 2009; 75EUA TC-R01-35, dated May 8, 2009; or 75EUMA TC-R01-35, dated May 8, 2009; into the applicable AFM. When these TCs have been included in general revisions of the applicable AFM, the general revisions may be inserted into the applicable AFM, provided the relevant information in the general revision is identical to that in the applicable TC.
(i) As of the effective date of this AD, no person may install any Pacific Scientific generator having part number 92841-1 (9914752-1) that has serial numbers 060 through 297 without the suffix “C” on any airplane.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
