N26837

Substantial
Fatal

GULFSTREAM AMERICAN CORP AA-5AS/N: AA5A0755

Accident Details

Date
Friday, May 25, 2012
NTSB Number
WPR12FA237
Location
Lakeview, OR
Event ID
20120531X10928
Coordinates
42.526111, -119.739440
Aircraft Damage
Substantial
Highest Injury
Fatal
Fatalities
1
Serious Injuries
0
Minor Injuries
0
Uninjured
0
Total Aboard
1

Probable Cause and Findings

The pilot’s decision to take off in known adverse weather conditions and his subsequent failure to maintain sufficient airspeed while maneuvering in mountainous terrain and an area of low ceilings, snow, and fog, which resulted in a loss of airplane control.

Aircraft Information

Registration
N26837
Make
GULFSTREAM AMERICAN CORP
Serial Number
AA5A0755
Engine Type
Turbo-jet
Year Built
1978
Model / ICAO
AA-5AG150
Aircraft Type
Fixed Wing Multi Engine
No. of Engines
2

Registered Owner (Historical)

Name
REGISTRATION PENDING
Address
466 E RIVERSIDE DR
Status
Deregistered
City
BURNS
State / Zip Code
OR 97720-1654
Country
United States

Analysis

HISTORY OF FLIGHT

On May 24, 2012, about 1722 Pacific daylight time, a Gulfstream American AA-5A, N26837, impacted the terrain about 40 miles northeast of Lakeview, Oregon. The private pilot, who was the sole occupant, was fatally injured, and the airplane, which was owned and operated by the pilot, sustained substantial damage. The 14 Code of Federal Regulations Part 91 personal cross country flight, which departed Lakeview County Airport, Lakeview, Oregon, about 27 minutes prior to the accident, was being operated in an area where instrument meteorological conditions were reported. The pilot's intended destination was a private airstrip near Hubler, Idaho, which would normally have been about a 2 hour flight. No flight plan had been filed. When the pilot did not arrive at his destination he was reported missing, and a search was initiated. On Wednesday, May 30, the airplane's wreckage was found near the 6,500 foot level of the steep western slope of Hart Mountain, in the Hart Mountain National Antelope Refuge.

According to search and rescue personnel, about 2 hours prior to the time he landed at Lakeview, the pilot departed the private airstrip near Hubler, with the intention of flying direct to Lakeview, dropping off two passengers, and then returning to Hubler. According to witnesses on the ground at Lakeview County Airport, the pilot landed there, deplaned two passengers, used the restroom, and then departed again. Recorded global positioning system (GPS) data shows that after his departure from Lakeview, he initially followed a ground track on nearly a direct line between Lakeview, Oregon, and Hubler, Idaho. Then, when he reached a point about 30 miles northeast of Lakeview Airport, near the east shoreline of Plush Lake, he made a 90 degree left turn, flew out toward the middle of the lake, and then turned about 75 degrees back to the right. From there he flew along the west side of the face of the steep mountain ridge that defines the west boundary of the Hart Mountain Antelope Refuge. Then, about five minutes after he had passed over Plush Lake, the pilot initiated a turn to the left. At the time that he initiated the turn, he was flying at a groundspeed of about 95 knots. The GPS data shows that the turn continued for about 180 degrees, so that the plane was then heading almost directly back in the direction from which it had come. The data also showed that just after rolling out of the turn, the airplane’s groundspeed increased to about 158 knots, and then over a period of about 10 seconds, rapidly decreased to about 45 knots. Almost immediately thereafter, the airplane made a nearly 90 degree turn to the left, followed almost immediately by nearly a 90 degree turn back to the right. The last recorded GPS data point was recorded about 3 seconds after the last turn to the right, with the last groundspeed recorded being 21 knots.

PESONNELL INFORMATION

The pilot was a 48 year-old male, who possessed an FAA private pilot certificate, with an airplane single engine land rating. He did not possess an instrument rating. His last FAA airman’s medical, a class 3 with no limitations or waivers, was signed off on March 7, 2012. His last annotated flight review was signed off in his pilot log on May 12, 2010, and although his last flight time total of 467 hours appears in his pilot log in 2010, he reported at the time of his last medical that his total flight time was 600 hours.

AIRCRAFT INFORMATION

The airplane was a 1978 Gulfstream American AA-5A, serial number AA5A0755, with a Lycoming O-320E2G engine, and a model 1C172BTM-7359 fixed-pitch McCauley Propeller. Its last annual inspection was signed off on 10 July, 2011, at which time the airframe had accumulated 2,535.88 hours total time. As of February 15, 2011, the engine had accumulated 645.95 hours since a major overhaul. At the time of the accident, the airplane had accumulated about 2,556 hours total time.

METEOROLOGICAL INFORMATION

The May 24, 2012, 1715 recorded aviation weather surface observation (METAR) for Lakeview Airport indicated a wind of 250 degrees at 10 knots, a visibility of 10 miles, few clouds at 5,000 feet, broken clouds at 7,000 feet, overcast clouds at 8,500 feet, a temperature of 05 degrees C, a dew point of 02 degrees C, and an altimeter setting of 29.72 inches of Mercury.

The METAR taken one hour later at the same location indicated a wind from 020 degrees at 14 knots, gusting to 22 knots, a visibility of 10 miles, few clouds at 2,200 feet, broken clouds at 3,300 feet, overcast clouds at 5,000 feet, a temperature of 03 degrees C, a dew point of 01 degrees C, and an altimeter setting of 29.71 inches of Mercury.

According to a NTSB Staff Meteorologist, there was an unofficial weather station located about 4 miles west of the accident site at an elevation of 5,650 feet. That station indicated that there had been a significant increase in relative humidity, from 61% to 98%, during the hour prior to the accident. This increase, according to the meteorologist, would suggest cloudy conditions in the general area of the accident site near the time of the accident. The site records also show that during the hour prior to the accident the temperature dropped below freezing, and that about two hours prior to the accident, there was a measured peak wind gust of 33 knots. There was also an AIRMET (Airmen’s Meteorological Information) in effect for the area around the accident site for moderate turbulence. In addition, there were several non-aviation National Weather Service products in effect for the area at the time of the accident, including a Winter Weather Advisory that advised winter conditions, to include snow, terrain obstruction, and gusty west winds up to 30 mile per hour.

According to a representative of the Lake County Sheriff’s Office, there was a small group of people who were near the area of the accident site about the time that the airplane impacted the terrain. Although they did not see or hear the airplane, they were able to describe the general weather conditions around that time. According to those individuals, the wind was blowing at a speed estimated to be above 20 mph, with periods of stronger gusts up to about 30 mph. They also stated that the top of the mountain ridge was covered in solid clouds, that it was snowing around much of the area, and that there were some areas of light patchy fog below the clouds.

About the same time that the accident pilot was flying toward Lakeview from the north, another pilot, who was flying a Mooney 201 en route from Chandler, Arizona, to Hillsboro, Oregon, was approaching Lakeview from the south. As with the accident pilot, the Mooney pilot was flying by visual flight rules, and in his specific case, was basically trying to follow the Victor airways. When interviewed by the NTSB Investigator-In-charge (IIC), he stated that at first the weather had been mostly okay along his route, with only a few scattered rain showers. But as he reached a point about half way between Reno, Nevada, and Lakeview, in the area just northeast of Susanville, California, the ceilings started to lower, and the areas of precipitation increased. When he reached the Lakeview area, the weather became significantly worse. The ceilings near Lakeview Airport were about 6,500 mean sea level (msl), which was about 1,800 feet above ground level (agl), which ultimately was determined to be within 100 feet of the altitude of the accident site. He also reported that the ceilings were occasionally lower, and that about the same time, he also began encountering a mix of rain showers and snow showers. He reported that the snow was moderate at times, and that as he proceeded north of Lakeview, ice started to accumulate on the airplane’s wings. As he proceeded further north, he was in and out of snow and rain showers, which were interspersed with clear areas underneath the overcast ceilings where he could see up to 20 miles. But the further he proceeded to the north, the open areas occurred less and less, and when he was in the snow showers he could only see the ground directly below him, with no ability to see anything horizontally out in front of him. He reiterated that visibility in the snow showers was "very bad." As he flew up the west side of the valley north of Lakeview, he was under a 1,000 foot agl solid overcast ceiling, and he could see that the tops of the ridges on all sides were in the clouds. As he got about 30 miles north of Lakeview, near Paisley State Airport, he could see that the weather was closing in on him and getting worse in every direction. He therefore made the decision to turn back to Lakeview, with the hope of getting a rental car to finish his journey. After he landed at Lakeview he checked the weather to see if it was going to improve, which it was not, and then arranged for a rental car. As he was driving away from the airport, which was about an hour after he had landed, he saw the AA-5A enter the pattern for landing. At that time there were a number of localized snow showers in the area, and he said that his thought at that time was that he had been foolish to push it as far as he had, and that the pilot that was then entering the pattern in the AA-5A had to be even more foolish than he had been. Within a mile of leaving the airport to the west in the rental car, he entered another snow shower. He estimated that once he was within the snow shower, the visibility was less than one mile. He did not see the AA-5A actually land, as he was driving away from the airport at that time, and he therefore did not know if that airplane was also encountering any of the local snow showers during the landing sequence. He said that during the hour he had been on the ground at Lakeview the weather did not change significantly. It was not getting much worse, but it did not get any better. It just kind of stayed the same, with constant low ceilings and some occasional localized snow showers.

As p...

Data Source

Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# WPR12FA237