72-19-04 NICKEL-CADMIUM BATTERY: Amendment 39-1521 as amended by Amendment 39-1598 and 39-1723 is further amended by Amendment 39-1782. Applies to all aircraft having a primary electrical system that includes a nickel-cadmium battery that is capable of being used to start the aircraft's engine or APU, except those aircraft that have the charging rate of such a battery automatically controlled so as to prevent battery overheating, or that have a battery temperature sensing and over-temperature warning system with means and operating procedures for disconnecting the battery from its charging source in the event of an over-temperature condition, or that have a battery failure sensing and warning system with means and operating procedures for disconnecting the battery from its charging source in the event of a battery failure, and except Learjet Models 23, 24, and 25 airplanes.
Compliance is required as indicated.
To prevent a possible battery fire that may result from overheating caused by an undetected battery failure, accomplish the following:
(a) For any battery rated at less than 50 amp-hours, containing any polystyrene cell cases, that is installed on a turbine engine powered aircraft, within the next 10 hours' time in service after the effective date of Amendment 39-1521, either -
(1) Replace each cell having a polystyrene cell case with an equivalent cell having a polyamide cell case; or
(2) Replace any battery containing any polystyrene cell cases with a battery containing all polyamide cell cases that is approved by the Chief, Engineering and Manufacturing Branch of an FAA Region (or in the case of the Western Region, the Chief, Aircraft Engineering Division).
(b) For all batteries, within the next 10 hours' time in service after the effective date of Amendment 39-1521 unless already accomplished within the last 50 hours' time in service, and thereafter within the next seven days or 30 hours' time in service, whichever is later, following use of the battery for an engine or APU start or attempted start, visually inspect the battery, including the cell links and tops, for evidence of heat damage, or accomplish a procedure that is found by the Chief, Engineering and Manufacturing Branch of an FAA Region (or in the case of the Western Region, the Chief, Aircraft Engineering Division), to provide evidence of heat damage that is equivalent to that provided by physical inspection of the battery.
(c) If a battery is found to have evidence of heat damage during an inspection or procedure required by paragraph (b), before further flight either -
(1) Replace the battery with an equivalent serviceable battery; or
(2) On aircraft approved for operation without the affected battery being operational, mechanically disconnect the battery at the battery terminal.
(d) Upon request of the operator, an FAA maintenance/avionics inspector may adjust the repetitive inspection intervals specified in thisAD to permit compliance at an established inspection period of the operator if the request contains substantiating data that show that:
(1) The aircraft is being maintained and inspected in accordance with a continuous airworthiness maintenance program under Parts 121 or 127, or is being inspected in accordance with a continuous inspection program under Subpart D of Part 91, or Part 123, or Part 135; and
(2) The battery system has been maintained for at least the past year in accordance with the operators' maintenance program, and battery service on the aircraft has been free of heat associated problems during that time.
(3) The substantiating data required by paragraphs (d)(1) and (2) must include at least the battery inspection and reconditioning frequency, the name and address of the facility/operator maintaining the battery, and a log book or other records showing the number of battery removals and reasons for removal.
(e) Report evidence of battery heat damage found during inspections or procedures required by this AD, in writing, within 10 days of the inspection, to the Chief, Engineering and Manufacturing Division, Attention: AFS-130, Federal Aviation Administration, 800 Independence Ave., S.W., Washington, D.C. 20591. Each report must include the aircraft model, serial, and registration numbers, the battery make and model numbers, battery hours' time in service, and a description of the heat damage. (Reporting approved by the Bureau of the Budget under BOB No. 04-R0174).
Note: A pre-addressed Malfunction or Defect Report, FAA Form 8330-2 (available at any General Aviation District Office) may be used for a report required by this AD, if reference to the AD is made on the form.
(f) Except as provided in paragraph (h), before February 1, 1974, accomplish at least one of the following:
(1) Install a battery charging rate control system, approved by an FAA maintenance/avionics inspector, or by the Chief, Engineering and Manufacturing Branch of an FAA Region (or in the case of the Western Region, the Chief, Aircraft Engineering Division).
(2) Install a battery temperature sensing and over-temperature warning system and provide a means and an operating procedure for disconnecting the battery from the charging source in the event of battery over-temperature warning, that are approved by an FAA maintenance/avionics inspector, or by the Chief, Engineering and Manufacturing Branch of an FAA Region (or in the case of the Western Region, the Chief, Aircraft Engineering Division).
(3) Install a battery failure sensing and warning system and provide a means and an operating procedure for disconnecting the battery from the charging source in the event of battery failure, that are approved by an FAA maintenance/avionics inspector, or by the Chief, Engineering and Manufacturing Branch of an FAA Region (or in the case of the Western Region, the Chief, Aircraft Engineering Division).
(g) The inspections or procedures required by paragraphs (b), and (h) as applicable, may be discontinued after compliance with paragraph (f) of this AD.
(h) Upon request of the operator, an FAA Maintenance/Avionics Inspector may, if the request contains a satisfactory program for compliance with paragraph (f), extend the time for compliance with paragraph (f) to permit an aircraft to be operated in accordance with operating and maintenance limitations established by the inspector as necessary for safety, pending modification in accordance with such program, for any period of time -
(1) Between February 1, 1974, and March 1, 1974; and
(2) After March 1, 1974, to a date no later than April 1, 1974, in accordance with the following additional limitations:
(i) A battery may be used no more than twice to start or attempt to start an engine or APU.
(ii) After the first use of the battery to start or attempt to start an engine or APU, before any further such use of the battery,at the next station having qualified maintenance personnel, inspect the battery for indications of an overheat condition. If evidence that an overheat condition has existed is found during such an inspection, before further flight replace the affected battery with an equivalent serviceable battery and within the next 24 hours following the inspection report the condition to the inspector.
(iii) After the second use of the battery to start or attempt to start an engine or APU, at the next station having qualified maintenance personnel, replace the battery with an equivalent serviceable battery and comply with the inspection and reporting requirements specified in subparagraph (2)(ii) of this paragraph.
(iv) For a battery removed from an aircraft in accordance with subparagraph (2)(iii) of this paragraph, that is otherwise serviceable, before installing such a battery in any aircraft deep cycle the battery in accordance with an FAA-approved procedure.
Amendment 39-1521 superseded Amendment 39-1302 (36 F.R. 19075), AD 71-21-05, as amended by Amendment 39-1333 (36 F.R. 21581).
Amendment 39-1521 became effective September 20, 1972.
Amendment 39-1598 became effective March 6, 1973.
Amendment 39-1723 became effective September 19, 1973.
This Amendment 39-1782 becomes effective February 1, 1974.