Narrative:Air South Flight 168 departed Atlanta at 21:07. At 21:13 the flight reported level at its assigned cruising altitude of 7,000 feet. The Beech had been cruising for eleven minutes when it attained a gradual nose down attitude due to a change in the longitudinal trim. The pilots noticed the change after about six seconds and initiated a recovery action. The horizontal stabilizer continued to move to a full nose down position. Excessive pulling force on the control column was necessary to recover from the high speed dive. The necessary stick forces for such an out-of-trim condition can exceed the capability of one pilot, and in
some cases two pilots, to control. The Beech continued to descend until both wings failed at high speed, just before the airplane crashed into the ground in a near vertical attitude.
Probable Cause:
PROBABLE CAUSE: "An unwanted change in longitudinal trim which resulted in a nosedown high-speed flight condition that was beyond the physical capability of the pilots to overcome. The initiating element in the accident sequence could not be specifically determined. However, the design of the aircraft flight control system was conducive to malfunctions which, if undetected by the crew, could lead to a loss of control."
Accident investigation:
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Investigating agency: | NTSB |
Status: | Investigation completed |
Duration: | 1 year and 2 months | Accident number: | NTSB/AAR-70-18 | Download report: | Final report
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Follow-up / safety actions
NTSB issued 1 Safety Recommendation
Issued: 26-AUG-1970 | To: | A-70-58 |
REQUIRE DIRECT PARTICIPATION OF FAA PERSONNEL IN THE CERTIFICATION OF ALL NEWLY DESIGNED AIRCRAFT COMPONENTS; REVIEW ITS AIRCRAFT CERTIFICATION SYSTEM FOR POSSIBLE PROCEDURAL CHANGES WHICH WOULD ENSURE THAT LESSONS LEARNED IN INVESTIGATION OF LARGE AIRCRAFT ACCIDENTS AND INCIDENTS WOULD BE APPLIED, WHEN APPROPRIATE, TO CERTIFICATION OF SMALL AIRCRAFT; BRING RECOMMENDATION (2) ABOVE, TO THE ATTENTION OF THOSE UNITS WITHIN THE FAA THAT ARE CHARGED WITH THE CERTIFICATION OF SMALL AIRCRAFT. (Closed - Acceptable Action) |
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Photos
Map
This map shows the airport of departure and the intended destination of the flight. The line between the airports does
not display the exact flight path.
Distance from Atlanta Municipal Airport, GA to Greenville-Spartanburg Airport, SC as the crow flies is 245 km (153 miles).
Accident location: Exact; as reported in the official accident report.
This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.