Tuesday, March 31, 2015

Beechcraft H35 Bonanza, N112F, Skyler Aviation: Accident occurred March 30, 2015 at Tucson International Airport (KTUS), Arizona

The National Transportation Safety Board did not travel to the scene of this accident.

Additional Participating Entities: 

Federal Aviation Administration / Flight Standards District Office; Scottsdale, Arizona
Continental Motors; Mobile, Alabama

Aviation Accident Final Report - National Transportation Safety Board: https://app.ntsb.gov/pdf

Investigation Docket - National Transportation Safety Board: https://dms.ntsb.gov/pubdms

Aviation Accident Data Summary - National Transportation Safety Board: https://app.ntsb.gov/pdf

Skyler Aviation: http://registry.faa.gov/N112F 

NTSB Identification: WPR15LA139
14 CFR Part 91: General Aviation
Accident occurred Monday, March 30, 2015 in Tucson, AZ
Probable Cause Approval Date: 01/21/2016
Aircraft: BEECH H35, registration: N112F
Injuries: 3 Uninjured.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

The pilot reported that, after takeoff, the engine started to “sputter.” He adjusted the fuel mixture control lever but noticed no change in engine performance. He determined that insufficient runway was available to land, so he initiated a forced landing into desert terrain. During the landing roll, the airplane struck vegetation and sustained substantial damage.

Postaccident examination of the airplane, engine, and propeller revealed no evidence of preimpact mechanical anomalies that would have precluded normal operation, and the reason for the partial loss of power could not be determined. Review of the airplane manufacturer’s climb performance chart revealed that, at the time of the accident, the weather and environmental conditions were within the airplane’s takeoff performance limitations.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
A partial loss of engine power during initial takeoff climb for reasons that could not be determined because postaccident examination revealed no evidence of a mechanical anomaly that would have precluded normal operation. 


On March 30, 2015, about 1115 mountain standard time, a Beech H35, N112F was substantially damaged during a forced landing following a loss of engine power at Tucson International Airport (TUS), Tucson, Arizona. The private pilot and two passengers were not injured. The airplane sustained substantial damage to the forward fuselage and empennage. The airplane was registered to Skyler Aviation, and operated by the pilot, under the provisions of 14 Code of Federal Regulations (CFR) Part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan was filed. The cross-country flight was originating at the time.

In a written statement to the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), the pilot reported that prior to the flight he conducted a preflight check of the airplane, and noticed no abnormalities with the airplane. He taxied to runway 8 right, and proceeded to conduct his pre-takeoff check list, which included cycling the propeller and conducting an engine run up at 2,000 revolutions per minute (rpm). In addition, the pilot leaned the mixture until the engine hesitated, and advanced the mixture to maximize the cylinder head temperature. 

The pilot stated that during takeoff roll the airplane accelerated normally, and briefly became airborne at 80 knots. He said that he decided to keep the airplane on the ground until it was clear of the displaced threshold, and lifted off again. As the airplane ascended through about 50 feet above ground level, the engine "began sputtering." The pilot leaned and enriched the mixture, however, noticed no change in engine performance. He further stated that there was not enough runway left to land and he initiated a forced landing to an area of rough desert terrain. During the landing roll, the airplane struck vegetation and sustained substantial damage.


The four-seat, low-wing, retractable-gear airplane, serial number (S/N) D-5200, was powered by a Continental Motors IO-470-N14B engine, S/N 096504, rated at 260 horse power. It was equipped with a Beechcraft Bonanza P/N 278-100 two bladed, constant speed propeller.

Review of the airplane maintenance logbook revealed that the most recent annual inspection was completed on January 2, 2015, at the tachometer time of 1,903.8, and the total time of 2,026.18. 

The pilot stated that the maximum gross weight for the airplane was 2,900 pounds, and that the weight at the time of the accident was 2,700. However, the weight and balance revision in the flight manual supplement for N112F, dated December 11, 1975, indicated that the maximum gross weight for the airplane was 3,100 pounds. Using the empty weight of an airplane as determined by the weight and balance revision, the weight of the occupants, fuel, and baggage, the NTSB investigator-in-charge calculated that the gross weight at the time of departure was about 2,919 pounds. 

Using the manufacturer's Climb Performance chart, located in the Pilot's Operating Handbook, reported weather conditions and gross weight of the airplane at takeoff, the climb performance was calculated to be about 980 feet per minute.


At 1127, the Meteorological Terminal Aviation Routine Weather Report (METAR) for TUS reported wind calm, 10 miles visibility, no clouds, temperature 86 degrees Fahrenheit (F), dew point 28 degrees F, and altimeter setting of 30.11 inches of mercury (in Hg). Using the reported weather conditions and airport elevation, the calculated density altitude was about 4,802 feet mean sea level (msl), with a pressure altitude of about 2,469 feet msl.


Examination of the engine by the Federal Aviation Administration (FAA) inspector and a representative from Continental Motors was conducted at Air Transport facility, Phoenix, Arizona, on April 20, 2015. The engine remained partially attached to the engine mount structure through three of four engine mounts; the left rear engine mount was broken. All engine accessories remained attached to the engine via their respective mounts. All fuel and oil lines were intact and undamaged. The crankshaft was rotated by hand using a hand tool attached to the crankshaft propeller flange. Rotational continuity was established throughout the engine and valve train and thumb compression was obtained on all six cylinders. The complete engine examination report is appended to this accident in the public docket. 

The airplane was equipped with a JPI EDM-700 engine monitoring system. The EDM-700 is a panel mounted gauge that the operator can monitor and record up to 24 parameters related to engine operations. The EDM-700 was sent to the NTSB Vehicle Recorder Laboratory for data download and review. The unit contained about 15 hours of recorded data over 26 power cycles. The event flight was the last flight of the recording and its duration was approximately 13 minutes and 30 seconds. The parameters recorded were EGT, CHT, OAT, battery voltage, and oil temperature. Additionally, the calculated values of EGT differential and shock cooling rate were also included. No other parameters were recorded by the unit. The report indicated no abnormalities noted. The complete report and the raw data are part of the public docket for this accident prior to the engine failure.

Postaccident examination of the engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.

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