History of Flight
On August 8, 2015, about 1652 central daylight time, a Cessna 172G, N5800R, sustained substantial damage when it impacted a field after a partial loss of power during the initial climb from a private airstrip near Hartington, Nebraska. The pilot and one passenger received serious injuries. The airplane was registered to and operated by the pilot under 14 CFR Part 91 as a personal flight. Visual meteorological conditions prevailed and no flight plan was filed. The flight departed from a private grass airstrip about 1650, en route to Hartington Municipal Airport (0B4).
The pilot reported that the airplane had undergone an annual maintenance inspection at a facility located at 0B4. The first flight after the inspection was on the day of the accident. He completed the preflight, departed 0B4, flew to Chan Gurney Municipal Airport (YKN) in Yankton, South Dakota, where he performed one touch and go landing, then flew to the private airstrip for a full stop landing. About 15 minutes later, the pilot departed on the southwest runway, about 1,750 ft long by 30 ft wide, with alfalfa cut to about 2.5 inches.
In his written statement, the pilot reported initiating takeoff with flaps set at 30 degrees (in phone interviews, he stated he used full flaps, 40 degrees). The airplane became airborne about 1/2 to 2/3 down the runway. About 50 ft agl, as he reached to raise the flaps 10 degrees, the engine lost partial power. The yoke abruptly came back toward him, the nose shot up, and the stall warning horn sounded. He pushed the yoke forward with both hands and trimmed nose wheel down, but the trim wheel was hard to turn. He reached over and "bumped" the flap handle to 10 degrees. The left wing dropped and the airplane impacted the ground.
A witness who owned the airstrip reported watching the airplane depart. He stated the airplane became airborne about 1,000 ft down the runway, had the right pitch for climb but wasn't climbing, reaching about 20 ft agl over the runway. It cleared a "hump" in the road and continued southwest where terrain sloped lower. The engine sounded like cruising speed. The airplane kept the same pitch for 5–10 seconds, then the nose went up, left wing dropped, and it went straight down.
Another witness observed the airplane flying north to south on the west side of a small hill at about 80 ft agl. He reported power lines about 100 ft high running east and west along a gravel road in the flight path. The airplane "nosed up to climb" but did not have enough power; the nose went up, turned left, and nosed in. In a statement, he said the "plane sounded like it was losing power" and that the pilot told EMTs the plane lost power.
Personnel Information
The 64-year-old pilot held a private pilot certificate with single-engine land rating, about 250 total flight hours, 148 hours in make and model, 2.5 hours in the last 90 days, and received his biennial flight review on May 21, 2015. His logbook showed that prior to May 2015, his last logged flight was on July 18, 2004. He held a third-class medical certificate issued in April 2015.
Aircraft Information
The airplane was a single-engine Cessna 172G manufactured in 1966, seating four, with a 2,300 lb maximum gross weight, powered by a 145-horsepower Continental O-300-D engine. The pilot purchased the airplane in May 2015. An annual inspection had been completed on May 10, 2015, with total time 4,996.8 hours. After that flight, the pilot determined the engine was not operating properly and had another annual inspection performed on July 2, 2015, with total time 4,990 hours. The engine logbook entry dated 7-2-15 indicated all six cylinders were serviced with new rings, seals, and gaskets, a cylinder compression check was accomplished, and a ground and flight check was performed.
Examination of logbooks revealed the airplane had flown 1–3 hours between annual inspections for the last 10 years. Total engine time was 5,002.9 hours, time since major overhaul was 1,615.9 hours. Continental Motors SIL-98-9C recommends overhaul at 1,800 hours or 12 years.
Meteorological Information
At 1655, surface weather at YKN, about 8 nm north of the accident site, was: wind 120 degrees at 5 knots, sky clear, 10 miles visibility, temperature 27°C, dew point 21°C, altimeter 29.84 inches of mercury.
Wreckage and Impact Information
The airplane impacted a corn field about 912 ft from the end of the private airstrip. It was found nose down with the engine compartment crushed and buckled aft and upward. Wings and empennage remained attached. The left wing exhibited aft crushing along its leading edge, and the outboard section was buckled and twisted upward and aft. About 4 ft of the right wing's outboard section had aft crushing of the leading edge. All flight controls remained attached; control cable continuity was confirmed.
The wreckage was moved to a hangar for inspection. The flap actuator was found in the 10-degree position. The elevator trim actuator was measured at 5 degrees tab up (nose down trim). The fuel selector was in the BOTH position. The fuel strainer screen and bowl were clean, and fuel was found in the strainer. Fuel caps were attached with pliable seals.
The engine was examined at an overhaul facility. It rotated with all six cylinders producing compression and drive train continuity. Crankshaft, camshaft, valve tappets, push rods, rocker arms, and valves showed no anomalies. Engine timing was correct. Both magnetos bench tested with no anomalies. Spark plugs had no anomalies. Carburetor inspection showed a small amount of fuel, clean screen, and no anomalies. Air induction system was clear. Alternator, starter, and vacuum pump had no anomalies. About 1–2 inches of oil sludge was in the bottom of the engine case, but no abnormal foreign material or debris.
Visual examination of the propeller revealed "S" bending of the blades, leading edge polishing, and chordwise scratching.
Additional Information
The 1966 Cessna 172 Owner's Manual states regarding wing flap settings: normal and obstacle clearance takeoffs are performed with flaps up. Use of 10 degrees of flaps shortens ground run about 10 percent, but this advantage is lost in climb to a 50-foot obstacle. Flap settings of 30 to 40 degrees are not recommended at any time for takeoff.
The FAA's Airplane Flying Handbook (FAA-H-8083-3A) describes ground effect on takeoff: as the airplane lifts off and climbs out of ground effect, it requires an increase in angle of attack for the same lift coefficient, experiences increased induced drag and thrust required, and a pitch-up tendency with less elevator travel. With insufficient airspeed leaving ground effect, initial climb performance may be marginal due to increased drag. The only alternative to compensate is to lower pitch attitude to gain airspeed, resulting in altitude loss.