WPR11FA047

NTSB accident investigation · Beech C35 · Enterprise, OR · November 14, 2010

Accident · FatalField investigationFinal report
Date
November 14, 2010, 10:30 local (18:30 UTC)
Place
Enterprise, OR
Injuries
1 fatal
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N747MTBeech C35
Defining event
Maneuvering: Controlled flight into terr/obj (CFIT)
Weather
Visual (VMC) · Day
Status
Completed · report August 28, 2014
Report
Approved by Office Director
NTSB office
Western Pacific Region
Parties
FAA FSDO
FAA report
20101114050549A
Case key
77808

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 noninstrumented pilot’s inadequate weather planning, which resulted in his failure to maintain visual flight while maneuvering under low ceilings in rainy and foggy conditions and his subsequent failure to maintain clearance from mountainous terrain.

Findings · 5

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.

Planning/preparation: weather planningPersonnel issues › Task performance · PilotBeech C35: 1 caseAll aircraft: 156 casesProbable cause
Performance/control parameters: altitudeAircraft › Aircraft oper/perf/capability · Not attained/maintainedBeech C35: 2 casesAll aircraft: 1,310 casesProbable cause
Ceiling/visibility/precip: fogEnvironmental issues › Conditions/weather/phenomena · Contributed to outcomeBeech C35: 1 caseAll aircraft: 78 cases
Ceiling/visibility/precip: rainEnvironmental issues › Conditions/weather/phenomena · Contributed to outcomeBeech C35: 1 caseAll aircraft: 56 cases
Terrain: mountainous/hilly terrainEnvironmental issues › Physical environment · Contributed to outcomeBeech C35: 1 caseAll aircraft: 329 cases

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

The noninstrumented pilot was conducting a personal cross-country flight. Family members reported the airplane overdue, and it was located the next day in rough, mountainous terrain near the last radar target that matched the airplane's likely flightpath. The airplane initially impacted trees and then fragmented along the 80-yard-long wreckage distribution path. Instrument to marginal visual flight rules (VFR) conditions due to low ceilings prevailed around the accident site about the time of the accident. A tribal police officer who was patrolling in the area where the wreckage was located about the time of the accident reported that the weather conditions were windy, rainy, and foggy. The closest weather reporting station to the accident site reported a ceiling overcast about 400 feet above ground level. A series of airmen's meteorological informations were current for the region for instrument flight rules and mountain obscuration conditions. No evidence was found indicating that the pilot received any weather briefings before or during the accident flight; if a briefing from a flight service station had occurred, it likely would not have recommended VFR flight in the area. Data extracted from a handheld GPS onboard the accident airplane revealed that the airplane's flight track included numerous course changes, circles, and altitude changes consistent with a pilot attempting to maintain visual flight in marginal or instrument conditions. The pilot's toxicology report identified more than one benzodiazepine, including diazepam and nordiazepam, in the blood and liver; however, the levels were low. Therefore, the pilot was likely not impaired from the medication at the time of the accident.

Factual narrative

An extensively damaged handheld GPS unit was located in the wreckage. A National Transportation Safety Board specialist extracted data from the device's non-volatile memory using NTSB hardware and software. The specialist's report is part of the public docket for this accident. The NTSB investigator-in-charge (IIC) converted all time to Pacific standard time. The data for November 14, 2010, began at 0939:30 over the airport at Walla Walla at a recorded altitude of 1,221 feet. The track initially went south-southwest, and climbed to over 5,000 feet. It then turned west in a climb, followed by a turn to the east; it made several course changes as it went to the east. The maximum altitude recorded was 7,196 feet at 1016.32, and then the airplane began descending. The track made a right turn through approximately 270 degrees, and made a meandering track in a northerly direction. The track indicated a left 180-degree turn that lasted 24 seconds until the data stopped, and the airplane lost about 1,000 feet of altitude during the turn. The last contact was at 1024:29 at a recorded altitude of 5,546 feet; the coordinates were 45.41079 degrees north latitude 118.526 degrees west longitude. The IIC converted the radar coordinates, family provided GPS coordinates, and coordinates from the GPS on board the airplane to common units. The last radar contact and on-board GPS coordinates were about 0.2 nautical miles (nm) apart. The on-board GPS coordinates were 1.37 nm from the family's coordinates for the main wreckage. The airplane was a Beech C35, serial number D-3092. No logbooks were located for the airplane, but a mechanic who did the last annual inspection provided information. He stated that it had an annual inspection on November 12, 2009. The tachometer read 1,246 hours, and total time on the airframe was 4,266 hours. The engine was a Continental Motors, Inc., E-225-8-20, serial number 36362-D-73-8-R. Time since major overhaul was 1,110 hours. On November 14, 2010, about 1030 Pacific standard time, a Beech C35, N747MT, collided with terrain near Enterprise, Oregon. The pilot/owner was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The private pilot sustained fatal injuries; the airplane was substantially damaged. The personal cross-country flight departed Walla Walla, Washington, about 0930. Visual meteorological conditions prevailed, and no flight plan had been filed. The family reported that the airplane was overdue, and the family and Civil Air Patrol (CAP) began a search. The CAP located the airplane on November 15 in rough mountainous terrain in the Johnson Ridge Area of the Umatilla Indian Reservation. The wreckage was near the last radar target that matched the suspected flight path for the airplane. The radar coordinates at 1024:29 were 45 degrees 24.5102 minutes north latitude 118 degrees 31.7564 minutes west longitude at a Mode C reported altitude of 5,400 feet. The Umatilla County Coronercompleted an autopsy, and determined that the cause of death was multiple fractures and internal injuries. The FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicological testing of specimens of the pilot. Analysis of the specimens contained no findings for carbon monoxide, cyanide, or volatiles. The report contained the following findings for tested drugs: 0.112 (ug/ml, ug/g) diazepam detected in liver, 0.072 (ug/ml, ug/g) diazepam detected in blood; 0.27 (ug/ml, ug/g) nordiazepam detected in liver, 0.099 (ug/ml, ug/g) nordiazepam detected in blood, oxazepam not detected in blood, oxazepam detected in liver. A tribal police officer reported that he was patrolling in the area where the wreckage was located about the time of the accident. He stated that the conditions were windy, rainy, and foggy. An NTSB staff meteorologist provided the following information. The closest official weather observation station was La Grande, Oregon (KLGD), which was 14 nautical miles (nm) northeast of the accident site at an elevation of 2,717 feet mean sea level (msl). An aviation routine weather report (METAR) for KLGD issued at 1035 PDT stated: wind from 170 degrees at 3 knots; visibility 10 miles; sky 2,100 feet overcast; temperature 7/45 degrees Celsius/Fahrenheit; dew point 4/39 degrees Celsius/Fahrenheit; altimeter 30.13 inches of mercury; relative humidity 81 percent. Raw METARs for the vicinity and time period of the accident indicated ceilings ranging from 1,900 to 2,700 feet. Light precipitation was recorded prior to the accident, and a few clouds were as low as 500 feet agl. GOES-11 infrared imagery depicted a band of low clouds over the accident site with cloud top temperatures corresponding to 14,000 feet. Also evident in the imagery were several north-to-south oriented cloud bands, which were perpendicular to the wind flow. This suggested transverse banding; this is also common with orographic type clouds and mountain wave activity. The National Weather Service Boise sounding for 0400 PST depicted a moist sounding with a relative humidity greater than 80 percent from the surface through 14,000 feet; the freezing level was about 6,000 feet. The wind and temperature profile supported mountain wave development with a predominant wave at 7,000 feet and 10,000 feet with moderate and greater turbulence potential. In summary, the weather conditions in the vicinity of the accident site indicated instrument flight rules to marginal visual flight rules conditions due to low ceilings. A review of Federal Aviation Administration (FAA) airman records revealed that the 50-year-old pilot held a private pilot certificate with a rating for airplane single-engine land. The pilot held a third-class medical certificate issued on August 20, 2010; it had no limitations or waivers. The FAA inspector reported that the pilot had a total flight time of 790 hours with 30 hours in the last 90 days. He had an estimated 30 hours in this makeand model airplane. An FAA inspector examined the wreckage at the accident scene. The first identified point of contact (FIPC) was a scar about 25 feet up on the trunk of a conifer tree that was about 15 inches in diameter at that point. The airplane fragmented; the debris path was about 80 yards long and 60 yards wide on a northwesterly path, and roughly parallel to a downward drainage. The family recovered the wreckage. They reported that the coordinates where the main wreckage came to rest were 45 degrees 23.712 minutes north latitude 118 degrees 30.130 minutes west longitude. The initial impact was approximately 250 feet southeast from a tree that was sheared off, and a 10-foot section of that tree was carried along with the wreckage. The engine continued on, and stopped 150 feet northwest of the fuselage. The wings were about 50 feet either side of the impact path, and about halfway between the first impact and the fuselage position.

Aircraft

Registration
N747MT
Reported as
Beech C35
Category
Airplane
Serial number
D-3092
Airframe hours
4,266
Engine
Teledyne Continental Motors E-225-8-20, 225 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Operator
Bruce Cummings
Registered owner
Bruce Cummings
Airworthiness certificate
Standard, Normal
Last inspection
Annual · November 12, 2009
Departed
ALW · Walla Walla, WA
Destination
8S4 · Enterprise, OR

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
Fatal
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, Without waivers/limitations
Seat
Left
Toxicology
Performed
Flight hours
790 total · 30 in this make and model · 30 in the last 90 days

Weather

Conditions
Visual (VMC) · Day
Wind
170° at 3 knots
Visibility
10 statute miles
Lowest ceiling
2,100 ft overcast
Temperature
45 °F, dew point 39 °F
Altimeter
30.12 inHg
Observed at
KLDG, 17 nm away

Docket · 14

The files NTSB released with the investigation on August 13, 2014, on NTSB’s docket system: statements, records, photos and specialists’ reports. 6.8 MB 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.