IUKA, MS, USA
N4AN
Maule M7-235C
According to the pilot, while landing on runway 18, the right rudder pedal went to the floor. The aircraft ground looped and received major structural damage to the fuselage where the right main gear attaches. Examination of the rudder by the FAA found that the rudder cable pulled loose from the nicopress fitting and sleeve. The aircraft tachometer showed 18.5 hours and the hobbs meter indicated 21.3 hours. The rudder cable and nicopress fitting were removed for further examination. During the examination of the rudder cable assembly a nicopress sleeve was found to be not adequately crimped and the sleeve was slightly larger than the gauge dimension. It was determined that one of the manufacturer's crimped tool was not set correctly to specification on the elevator and rudder cables.
On December 15,1999, at 1516 central standard time, a Maule M7-235, N4AN, ground looped during landing at the Iuka Airport in Iuka, Mississippi. The aircraft was operated by the private pilot under the provisions of Title 14, CFR Part 91, and visual flight rules. Visual meteorological conditions prevailed and no flight plan was filed for the pleasure flight. The pilot was not injured and the airplane sustained substantial damage. The flight originated in Decatur, Alabama, at 1400. According to the pilot, while landing on runway 18, the right rudder pedal went to the floor. The aircraft ground looped and received major structural damage to the fuselage where the right main gear attaches. Examination of the rudder by the FAA found that the rudder cable pulled loose from the nicopress fitting and sleeve. The aircraft tachometer showed 18.5 hours and the hobbs meter indicated 21.3 hours. The rudder cable and nicopress fitting were removed for further examination. The pilot held private pilot certificate No. 1918672 with single-engine land instrument airplane rating. His total flying time was 1310 hours, of which 15 hours in the Maule M7, and 110 hours of total instrument time. He held a current Third Class medical certificate that was issued on June 19, 1999. His last Biennial Flight Review was dated December 7, 1999. The Maule M7-235C, N4AN was owned and operated by the pilot in command. It was a high-wing tail wheel single engine aircraft powered by a 235 horse power Lycoming carburated engine. The total airframe time was 18.5 hours The weather conditions at Tupelo, located 50 miles south-west from the accident site, at 1553 at central daylight time as, visual meteorological conditions with scattered at 3000 with 10 mile visibility. The winds were from 270 degrees at 8 knots with gusts up to 17 knots. The altimeter setting was 30.01 Hg. During the examination of the rudder cable assembly a nicopress sleeve was found to be not adequately crimped and the sleeve was slightly larger than the gauge dimension. It was determined that one crimped tool was not set correctly to specification on the elevator and rudder cables. After load testing by the manufacturer several cables with oversize nicopress sleeves crimped by the same tool to over 1100 pounds., (required by AC 43. 13-1b for 1/8 cable) which resulted in the cables failing before the nicopress sleeves. Maul has manufactured approximately 2200 planes in the last 37 years with about 27 nicopress sleeves per plane (depending on model) which amounts to approximately 60,000 nicopress sleeves with no previous known problems. A service bulletin was issued by the manufacturer (Mandatory Service Bulletin N0. 20). It is recommended by the manufacturer to comply with the service bulletin before further flight for 1990 and later planes. For earlier planes it is recommended that the service bulletin be complied with at the next 100 annual inspection.
The separation of the nicopress fitting allowing a release of the rudder cable resulting in a loss of control during landing roll. A factor was the manufacturer's use of an improperly calibrated crimping tool.
Source: NTSB Aviation Accident Database
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