WPR09LA343

NTSB accident investigation · Cessna U206G · Yellow Pine, ID · July 14, 2009

Accident · Serious injuriesLimited investigationFinal report
Date
July 14, 2009, 10:10 local (16:10 UTC)
Place
Yellow Pine, ID
Injuries
1 serious, 1 minor
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N71BSCessna U206G
Defining event
Initial climb: Collision during takeoff/land
Weather
Visual (VMC) · Day
Status
Completed · report March 3, 2010
Report
Approved by Office Director
NTSB office
Western Pacific Region
Parties
Federal Aviation Administration
FAA report
20090714011649A
Case key
74277

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

The pilot's failure to maintain clearance from the trees while taking off in a high-density altitude. Contributing to the accident were the pilot's failure to perform pre-takeoff performance calculations, his positioning of the elevator trim in a nose-down position, and the discrepancy between the airplane's flap positioning lever and the actual position of the flaps.

Findings · 6

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Flight control system: elevator tab control systemAircraft › Aircraft systems · Incorrect use/operationCessna U206G: 1 caseAll aircraft: 37 casesProbable cause
Object/animal/substance: tree(s)Environmental issues › Physical environment · Contributed to outcomeCessna U206G: 1 caseAll aircraft: 933 cases
Performance/control parameters: altitudeAircraft › Aircraft oper/perf/capability · Not attained/maintainedCessna U206G: 4 casesAll aircraft: 1,310 casesProbable cause
Temp/humidity/pressure: high density altitudeEnvironmental issues › Conditions/weather/phenomena · Effect on operationCessna U206G: 1 caseAll aircraft: 278 cases
Use of equip/info: aircraft controlPersonnel issues › Task performance · PilotCessna U206G: 13 casesAll aircraft: 9,295 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

During a biennial flight review, at the suggestion of the evaluating instructor pilot, the Pilot-In-Command elected to land at a remote back-country airstrip where he had not made prior plans to land. After landing at the 800- to 900-foot-long strip, the pilot took off in the high-density-altitude environment without having first completed an aircraft performance calculation or checking his airplane's outside air temperature gauge. Although the pilot reported that there did not seem to be any issues with the engine producing full power, soon after liftoff the airplane struck a number of pine trees and descended into the terrain. A postaccident inspection of the airplane did not find any evidence of powerplant anomalies, but did reveal that the elevator trim was set at a five degrees tap up (airplane nose down) position, and that the flaps were extended 25 degrees even though the cockpit indicator indicated that they were at 20 degrees.

Factual narrative

On July 14, 2009, about 1010 mountain daylight time, a Cessna U206G, N71BS, collided with trees just after taking off from a remote airstrip near, Yellow Pine, Idaho. The private pilot received minor injuries; his instructor pilot received serious injuries, and the airplane, which was owned by the private pilot, sustained substantial damage. The Title 14 Code of Federal Regulations, Part 91 Flight Review evaluation flight, was being conducted in visual meteorological conditions. The flight initially departed Hailey, Idaho, at 0750, and had landed at three other back-county airstrips prior to the accident. No flight plan had been filed. According to the private pilot, who was acting as pilot-in-command (PIC), the purpose of the flight was for him to receive a signoff for a biennial flight review. Prior to landing at the strip where the accident took place, he and his instructor landed at three other "back-county" airstrips. Then as they flew near Yellow Pine, the instructor suggested to the PIC that they land at the Simonds Airstrip. Although the PIC had not planned to go into the 800 to 900 foot-long airstrip, had not been in there before, and had not familiarized himself with it prior to the flight, he elected to make the landing anyway. He said that he made that decision because one of the other airstrips he already landed at that day was about the same length. The landing, which the PIC described as "routine," was made on the sloping rough surface of the runway, with the airplane coming to a stop near its uphill end. The two occupants then spent about four minutes discussing the landing and the upcoming takeoff and departure. The PIC then turned back onto the runway, adding power during the turn, and headed downhill for the takeoff. According to the PIC, everything seemed normal until just after the airplane became airborne. At that point the amount of aft pressure he needed to apply to the control yoke to get the airplane to climb seemed to increase substantially. Then, no more than two seconds after passing the end of the runway, at about 50 feet above ground level (AGL), the airplane began to impact the tops of a group of dead standing pines, each of which had diameters of between six to ten inches. Soon thereafter the airplane descended rapidly into the terrain. During a post-accident phone interview, the pilot said that the temperature at the time of the accident was between 50 and 60 degrees Fahrenheit, and the field elevation was 5,243 feet mean sea level (MSL). These ambient conditions resulted in a density altitude of about 6,300 feet (based upon 55 degrees). When asked if he had done any performance calculations prior to either the landing or takeoff, he stated that he had not. When asked if he had checked his airplane's Outside Air Temperature (OAT) gauge prior to the takeoff, he said that he had not. During the same interview, the pilot said that he had landed at many of the back-country airstrips in the area over a period of manyyears, but would not have gone into this one except for the fact that the instructor suggested it. During further discussions the PIC said that from the time he added power for the takeoff, until the plane started impacting the trees, he did not detect anything unusual about the engine, and that there had not been any missing, coughing sputtering, or rpm changes. A post-accident inspection of the engine found fuel in the fuel pump, fuel distribution valve, and the fuel injector lines. Spark was produced at all spark leads by both of the magnetos. There was no evidence of engine anomalies or malfunctions that would have affected the performance of the airplane. A post-accident inspection of the airframe found two issues of interest. The first was that the elevator trim had been set at the five degrees tab up (airplane nose down) position. The second was that although the flap position lever in the cockpit was in the 20 degrees extended position, the flap position jackscrew was determined to be extended 4.6 inches, which equates to a flap position of 25 degrees. According to Cessna Aircraft Company, both of these conditions may have contributed to the need for the pilot to apply more backpressure on the yoke just after liftoff than he had expected. In further discussions with Cessna Aircraft Company it was determined that the discrepancy between the cockpit flap position indicator and the flap jackscrew was most likely from either 30 years of wear in the system since the airplane was manufactured in 1979, or as a result of adjustments made when the Supplemental Type Certificate (STC) which added the Short Takeoff and Landing (STOL) kit onto the airplane was performed. In the pilot report that he submitted to the NTSB, the PIC stated, "For my airplane, this runway leaves too little margin for the unexpected." In addition, he stated that, "…it would have been helpful if the departure end trees were removed or shortened."

Aircraft

Registration
N71BS
Reported as
Cessna U206G
Category
Airplane
Serial number
U20605307
Airframe hours
2,958
Engine
Cont Motor IO 520 SERIES, 285 horsepower, reciprocating
Damage
Substantial damage
Flight
Instructional · Part 91
Operator
Swanson Blake J
Registered owner
Swanson Blake J
Airworthiness certificate
Standard, Normal
Last inspection
Annual · April 28, 2009
Departed
Yellow Pine, ID
Destination
KMYL · McCall, ID
Airport
Simonds Airstrip

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
50
Injuries
Minor
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, With waivers/limitations
Last flight review
July 17, 2007
Seat
Left
Flight hours
1,944 total · 1,400 in this make and model · 1,944 as pilot in command · 15 in the last 90 days · 6 in the last 30 days · 2 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 statute miles
Lowest ceiling
None
Temperature
55 °F

Docket · 5

The files NTSB released with the investigation on November 20, 2009, on NTSB’s docket system: statements, records, photos and specialists’ reports. 995 KB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.