Wilkes-Barre, PA, USA
N6872P
Piper PA24
The pilot, who was an airframe and powerplant mechanic, and the flight instructor both reported that, after turning onto the base leg at the end of the instructional flight, the pilot extended the landing gear in preparation to land; however, the gear did not fully extend, and the engine stopped producing power. The pilots made a forced landing to a soccer field short of the runway, during which the airplane struck a ditch and sustained substantial damage to the airframe. A postaccident examination of the airplane and engine revealed no obvious preimpact mechanical anomalies with the landing gear system or the engine. However, the pilot later stated that he had opened the engine cowling after the forced landing and saw the mixture cable was caught in the nose gear assembly. The pilot said he then unsnagged the cable, so it was not immediately obvious to investigators. He said that the mixture cable had gotten caught on the nosewheel assembly when it was trying to extend, which had caused the mixture control arm on the carburetor to move to the lean position. The pilot had performed maintenance on the landing gear a few weeks before the accident. He used plastic tie-wraps to ensure the throttle/mixture/carburetor heat cables were positioned away from the nose gear, which does not have a protected well on this make/model airplane. He then flew the airplane and placed it back in his hangar until the accident flight. The pilot said there were a lot of mice in his hangar, and he thought a mouse got up in the engine and chewed off the plastic tie-wraps, which allowed the mixture cable to come loose. However, there was no evidence to support this theory. A review of the airplane's Illustrated Parts Catalogue showed the mixture, throttle, and carburetor heat cables routed and secured away from the nose landing gear via metal clamps. Additional research of the Federal Aviation Administration Service Difficulty Reports (SDRs) revealed only one reported instance in which the mixture control cable got caught in the nose landing gear on this make/model airplane. The December 2003 report stated that, due to the mixture control cable not being properly secured or routed, it encountered the nose gear assembly during extension and fuel to the engine was shut off. The mechanic who submitted the SDR corrected the situation by properly routing and securing the mixture control cable. Given the available evidence, the mixture control cable in the accident airplane was not properly installed/secured. As a result, the cable caught on the nose landing gear assembly when the landing gear were extended and subsequently pulled the mixture control arm on the carburetor, thus shutting off fuel to the engine.
On January 3, 2019, at 1600 eastern standard time, a Piper PA-24-250, N6872P, sustained substantial damage during a forced landing to a field while on approach to the Wilkes-Barre Wyoming Valley Airport (WBW), Wilkes-Barre, Pennsylvania. The commercial pilot and the flight instructor were not injured. The airplane was registered to and operated by the pilot as a Title 14 Code of Federal Regulations Part 91 instructional flight. Visual meteorological conditions prevailed, and no flight plan was filed for the flight that departed Bradford County Airport (N27), Towanda, Pennsylvania, about 1540. The pilot stated that he had to extend the downwind leg of the traffic pattern due to a departing aircraft. He turned on to the base leg at an altitude of 1,000 ft above ground level (agl) and extended the landing gear, but the gear did not fully extend, and the gear-handle was "stuck." The pilot removed the access door for the emergency landing gear extension handle, but he could not get it to release. At this point, the flight instructor said, "You better put power in", but there was no response from the engine and the tachometer read "0." The airplane was unable to reach the runway and the pilot made a forced landing to a soccer field. The airplane struck a ditch, resulting in substantial damage to the airframe. All three propeller blades were also damaged. The flight instructor stated the pilot extended the landing gear on the base leg of the traffic pattern, but it extended mid-way and stopped. The pilot then said, "the engine quit." The flight instructor told the pilot to retract the gear, but the gear would not retract. The pilot tried the emergency landing gear extension handle but the handle would not move. The flight instructor also noted that the mixture control was "jammed up sideways" in the full rich position and could not be moved. Due to their low altitude (500 ft above ground level), they were unable to land at the airport and made a forced landing to a soccer field. The flight instructor said the landing was smooth until the airplane struck a drainage ditch. A postaccident examination of the airplane and engine revealed no obvious pre mishap mechanical issues with the landing gear system or the engine; however, the pilot subsequently admitted that after the examination was completed that he knew what caused the simultaneous loss of engine power and the landing gear malfunction. He said the mixture cable got caught on the nose wheel assembly when it was trying to extend, which caused the mixture control on the carburetor to move to the lean position. The pilot said that after the forced landing, and against the advice of his flight instructor, he opened the engine cowling and saw the mixture cable caught in the nose gear structure and unsnagged the cable so it was not immediately obvious to investigators. The pilot, who was also an airframe and powerplant mechanic, performed maintenance on the landing gear a few weeks before the accident. He retracted the gear 10-12 times and it worked "flawlessly." The pilot said he used plastic tie-wraps to make sure the throttle/mixture/carburetor heat cables were positioned away from the nose-gear, which does not have a protected well on this make/model airplane. He last flew the airplane on December 27, 2018. After he landed, he placed the airplane in his hangar and did not install covers over the landing gear to prevent mice from getting into the engine compartment. The pilot said there were a lot of mice in his hangar and he thought a mouse got up in the engine and chewed off the plastic tie wraps allowing the mixture cable to come loose. Prior to the flight he did not check inside the engine compartment for any rodent damage. A review of the Piper PA-24-250 Illustrated Parts Catalogue, pages 2G13-2G15, show the mixture, throttle and carburetor heat cables routed and secured away from the nose landing gear via metal clamps. Additional research of the Federal Aviation Administration (FAA) Service Difficulty Reports (SDRs), revealed only one reported instance where the mixture control cable got caught in the nose landing gear on this make/model airplane. The report was made in December 2003 and stated, "Mixture control cable secured and/or routed incorrectly when mixture control cable was replaced and/or lubed. when the cable came in contact with nose gear extension during final approach to runway. The nose gear assembly caught the mixture control cable somewhere between the firewall and carburetor pulling the mixture control cable down, shutting off the mixture at the carburetor with enough force to break the stop on the mixture control arm of the carburetor. Corrected by routing mixture control cable correctly and performing gear retraction checking operation." At 1554, the weather conditions reported at Wilkes-Barre/Scranton International Airport (AVP), Wilkes-Barre, Pennsylvania, located about 6 miles southeast of the accident site, was wind from 010° at 3 knots, visibility 10 miles, overcast clouds 3,600 ft, temperature 2°C, dew point -3°, and an altimeter setting of 29.94 inches of mercury.
The pilot/mechanic's improper installation and securing of the mixture control cable, which led to a simultaneous loss of total engine power and failure of the nose landing gear to fully extend when the cable caught on the nose landing gear assembly.
Source: NTSB Aviation Accident Database
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