NTSB · Safety Recommendation
Safety Recommendation A-67-023
Recommendation
WE RECOMMEND THAT FAA CONDUCT TESTS, EITHER SINGLY OR IN CONJUNCTION WITH NASA TO: 1. DETERMINE THE AIRPLANE CONFIGURATION AND PILOT INPUT REQUIRED TO PRECIPITATE THE FLAT-SPIN MODE. 2. DETERMINE IF ADEQUATE RECOVERY CONTROL IS AVAILABLE TO CHECK AN INADVERTENT ENTRY AND ANY SPECIALIZED PROCEDURE NECESSARY TO EFFECT RECOVERY. DEPENDING ON THE TEST RESULTS AND ULTIMATE RESOLUTION OF THE PROBLEM, CONSIDERATION SHOULD BE GIVEN TOWARD PLACARDING THE AIRPLANE TO PREVENT INADVERTENT FLAT-SPIN ENTRIES AND TO A DISCUSSION OF THE REQUIRED RECOVERY TECHNIQUES IN THE AIRPLANE FLIGHT MANUAL.
Safety Issue and Context
DURING THE PAST SEVERAL YEARS THE PIPER PA-30 TWIN COMMANCHE HAS BEEN INVOLVED IN THIRTEEN SPIN-TYPE ACCIDENTS THAT HAVE RESULTED IN THIRTY FATALITIES. INVESTIGATION DISCLOSED THAT A NUMBER OF THE AIRPLANES INVOLVED SPUN AND IMPACTED IN AN UNUSUALLY FLAT ATTITUDE. THIS TOGETHER WITH THE RELATIVELY HIGH EXPERIENCE AND/OR PROFICIENCY LEVEL OF A NUMBER OF THE PILOTS INVOLVED SHARPENS OUR CONCERN OVER THESE ACCIDENTS.
Response History
October 2, 1967 · Recipient Response · FAA
DURING THE INTERIM PERIOD, WHILE A SOLUTION IS BEING INVESTIGATED, WE HAVE ISSUED AN ALERT TO ALL OF OUR INSPECTORS REGARDING STALLS AND ENGINE-OUT MANEUVERS ON THESE AND RELATED TYPE AIRCRAFT. THEY ARE REQUESTED TO CONVEY THE ALERT MESSAGE TO ALL INSTRUCTOR PERSONNEL IN THEIR AREAS OF JURISDICTION. WE ARE ALSO PUBLISHING AN ADVISORY CIRCULAR TO CAUTION ALL PILOTS, INSTRUCTORS, AND OPERATORS AGAINST HIGH POWER STALLS, ENGINE-OUT STALLS, AND EMPHASIZING THE USE OF PROPER TECHNIQUES IN THE DEMONSTRATION OF MINIMUM CONTROL SPEEDS IN ACCORDANCE WITH RECOMMENDED PRACTICES.
IN ADDITION, THE AGENCY IS CONDUCTING A THOROUGH REVIEW OF ALL AVAILABLE PA-30 ACCIDENT STATISTICS TO DETERMINE FLIGHT CONDITIONS, POWER AND CONTROL SETTING PRIOR TO SPIN ENTRY, AND PILOT HISTORY AND EXPERIENCE OF THOSE INVOLVED. THIS WILL INCLUDE AN ANALYSIS AND EVALUATION OF THE KINDS OF OPERATION IN WHICH THE GENERAL AVIATION COMMUNITY IS UTILIZING THE AIRCRAFT.