NTSB · Safety Recommendation
Safety Recommendation A-72-117
Recommendation
TO THE FEDERAL AVIATION ADMINISTRATION: REQUIRE COMPLIANCE WITH PARAGRAPHS (E)(3) OR (E)(4) OF THE AD, REGARDLESS OF THE CELL CASE MATERIAL USED IN THE BATTERY.
Safety Issue and Context
THE NATIONAL TRANSPORTATION SAFETY BOARD HAS INVESTIGATED SEVERAL ACCIDENTS AND INCIDENTS INVOLVING NICKEL-CADMIUM BATTERY FIRES SINCE YOUR ISSUANCE OF ADVISORY CIRCULAR AC-00-33 AND AIRWORTHINESS DIRECTIVE AD 71-21-5. THE SAFETY BOARD IS CONCERNED OVER THE NEAR- CATASTROPHIC CIRCUMSTANCES OF SOME OF THESE OCCURRENCES. THE BOARD BELIEVES THAT ALTHOUGH THE AD WAS RESPONSIVE TO THE PROBLEM AS IT WAS KNOWN AT THE TIME, THE FACTS REVEALED IN OUR RECENT INVESTIGATIONS INDICATE A NEED FOR FURTHER CORRECTIVE ACTION.
Response History
September 10, 1973 · NTSB Correspondence · FAA
Closed--acceptable action.
August 10, 1972 · Recipient Response · FAA
The proposal for a new ad has been discussed with representatives of air transport association, national business aircraft association, general aviation manufacturers association, and six airlines to assure that the ad as issued will be effective and practical. We are now processing ad action, applicable to all aircraft having nickel-cadmium batteries, regardless of cell construction and aircraft engine type. The ad will require repetitive battery inspection. Concurrently with this ad we plan to request comments regarding installation of temperature warning, battery disconnect, and other means of battery protection. This request is being issued in
the form of a notice of proposed rulemaking rather than an adopted rule, to permit industry development of improved methods of combatting the problem. We believe our actions to be fully responsive to the problems covered in your safety recommendations a-72-116 and a-72-117.