N56897Piper PA-28-140 · 1973

On September 23, 2015, about 1328 Pacific daylight time, a Piper PA 28/140, N56897, collided with terrain shortly after takeoff from Elko Regional Airport, Elko, Nevada. The airplane was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91. The private pilot sustained minor injuries, the passenger sustained serious injuries, and the airplane was substantially damaged. The cross-country flight departed Elko about 1326, with a planned destination of Nampa Municipal Airport, Nampa, Idaho. Visual meteorological conditions prevailed, and no flight plan had been filed.

The pilot stated that he and the passenger had departed from their home field of Kidwell Airport, Cal-Nev-Ari, Nevada, about 0715 that morning. He intended to start the day early, due to the hot weather conditions en route. They stopped at Perkins Field Airport, Overton, Nevada, where they serviced the airplane to capacity with fuel, and then flew north towards Ely, Nevada. Having reached Ely and passed through Ruby Ridge Pass at an altitude of 8,800 ft mean sea level (msl), the engine began to run slightly "rough"; this had never happened before. The pilot adjusted the fuel mixture towards the lean position, the engine smoothed out, and an increase of 200 rpm was observed. He reported that he typically operated the engine at full rich fuel mixture during takeoff and cruise.

Having reached Elko, the pilot serviced the airplane with the addition of 15 gallons of fuel in the left tank, and 10 gallons in the right tank. He specifically did not want to fill the tanks to capacity as they were close to their destination, and he was concerned about performance degradation in the high temperature and elevations. The passenger was in the front right seat, and there were two bags in the back seats, both less than 10 pounds in weight.

He then started the engine about 1320, and the run-up was uneventful. The engine was operating normally and he began the takeoff roll on runway 12, as the other runway (6/24) was closed for construction. He had flown in and out of Elko before, and surmised that the length of runway 12 (3,012 ft), while adequate for takeoff, left him with minimal options should an emergency occur.

The airplane accelerated normally, and shortly after rotation, the controls began to feel "mushy"; He had experienced this before in hot weather conditions. He continued the initial climb, and gently applied control inputs, and anticipated that the airplane would regain a positive climb rate like it had in the past. However, the airplane would not climb more than 200 ft above ground level (agl). Having crossed the street at the end of the runway the airplane began to descend. As the descent continued he flew over warehouses, and he decided to retard the throttle and land straight ahead in a field. Just prior to impact he pulled the yoke aft to reduce airspeed and resultant energy forces. The airplane landed hard in the field, shearing off both main landing gear, and crumpling the fuselage just aft of the cabin.

The pilot reported that at no time did the engine make any coughing or sputtering sounds, and that it kept operating normally throughout.

Witnesses who observed the airplane takeoff all recounted similar observations, as it appeared to be flying slowly after rotation, and did not gain significant altitude. One witness stated that the nose of the airplane was unusually high as it began to descend out of view behind buildings. None of the witnesses observed smoke or vapors emitting from the airplane during flight.

At 1356, the automated surface weather facility at Elko Airport reported wind variable at 5 knots, gusting to 18 knots, 10 miles visibility, temperature at 27° C, dew point -6° C, and an altimeter setting at 30.13 inches of mercury.

The airplane was recovered, and examined by the NTSB Investigator-in-Charge, and representatives from the FAA and Piper Aircraft.

The examination revealed that the engine fuel mixture control was in the full-forward (full rich) position. The top spark plugs were removed and examined. All electrodes exhibited "normal", to "normal-worn" out wear signatures, indicative of normal service life when compared to the Champion Aviation AV-27 Check-a-Plug chart. Plugs 1, 3, and 4 exhibited dark grey discoloration and sooting, and plug 2 was coated in black soot consistent with "carbon fouled" when compared to the Champion chart.

No mechanical malfunctions or failures were observed during the examination. A full examination report is contained within the accident docket.

Airplane Performance

The airplane performance chart located in the Piper Pilot's Operating Manual, defined that at a gross weight of 1,950 pounds, with zero wind, flaps 0, on a paved level and dry runway, and a density altitude of 7,000 ft, the takeoff distance would be about 1,550 ft; with a distance to clear a 50 ft obstacle of about 3,300 ft. At the maximum gross weight of 2,150 pounds, the takeoff and clearance distances increased to 1,700 and 3,600 ft respectively. A notation on the chart stated, "EXTRAPOLATION OF CHART ABOVE 7,000 FT IS INVALID".

The "Operating Instructions/TAKEOFF" section of the operating manual was found in the airplane, and made the following recommendation,

"NOTE: Mixture full rich except a minimum amount of leaning is permitted for smooth engine operation when taking off at high elevation."

Lycoming Engines Service Instruction No. 1094D "Fuel Mixture Leaning Procedures", dated March 25, 1994, made the following recommendations,

"For 5,000 ft density altitude and above or high ambient temperatures, roughness or reduction of power may occur at full rich mixture. The mixture may be adjusted to obtain smooth engine operation. For fixed pitch propeller, lean to maximum RPM at full throttle prior to take-off where airports are 5,000 ft density altitude or higher. Limit operation at full throttle on the ground to a minimum."