Wednesday, September 2, 2015

PRELIM REPORT: 2 killed on August 19, 2015, after a Cessna 172P, N62731, collided with mountainous terrain during low altitude flight near Helena, Montana.

NTSB Identification: WPR15FA247

14 CFR Part 91: General Aviation
Accident occurred Wednesday, August 19, 2015 in Helena, MT
Aircraft: CESSNA 172P, registration: N62731
Injuries: 2 Fatal.


This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed. NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report. 


On August 19, 2015, about 2230 mountain daylight time, a Cessna 172P, N62731, collided with mountainous terrain during low altitude flight near Helena, Montana. The private pilot and passenger were fatally injured. The airplane sustained substantial damage to the wings, fuselage, and empennage. The airplane was registered to and operated by the pilot as a 14 Code of Federal Regulations Part 91 personal flight. Night visual meteorological conditions prevailed about the time of the accident, and a flight plan was not filed for the local flight. The flight originated from the Helena Regional Airport (HLN) at 2215 and was destined for White Sulphur Springs Airport (7S6), White Sulphur Springs, Montana.

According to local law enforcement, the pilot contacted his wife about 2207 and subsequently departed for 7S6, with a family member onboard. The following morning Salt Lake Center recorded an electronic locator transmitter signal near Bozeman, Montana that was also picked up by a low flying aircraft. The pilot's flight instructor then initiated an aerial search and located the airplane about 0830 the day after the accident.

The airplane impacted an area of rising mountainous terrain in a valley between two ridges at a terrain elevation of 5,046 feet. The initial impacted point (IIP) was identified by a green marking that resembled an aircraft position light located below an aluminum material transfer mark that spanned about 13 feet in length on a vertical rock face. The outboard section of the right wing was located at the base of the rock face about 30 feet from the IIP. Multiple sections of right wing were located in a tree that sat on a hillside about 30 feet beyond the IIP and surrounded by portions of the right wing and propeller at the base of the tree. Both the engine and left wing were located in the energy path about 20 feet from the tree, but before the main wreckage which was located about 20 feet beyond the engine at a lower elevation.

An onsite examination of the airplane by the National Transportation Safety Board investigator-in-charge revealed that the airplane impacted right wing first and subsequently came to rest on the downhill slope about 70 feet from the IIP. The rudder, trim and elevator cables were traced from the cockpit to their respective control surfaces. Both the elevator trim tab actuator and aft chain were intact and in their original position within the horizontal stabilizer. The flap bell crank and jackscrew assembly had separated from the right wing and were found in the energy path about 30 feet from the main wreckage. The flap jackscrew measured 2.9", consistent with a 10 degree flap position, which corroborated the flap indicator position. Both propeller blades were accounted for at the accident site and exhibited chordwise scratches, leading edge nicks, and bending.

The 2153 recorded weather observation at HLN, located approximately 18 nautical miles west of the accident site, included winds from 250 degrees at 5 knots, visibility 5 statute miles, haze, an overcast cloud layer at 4,800 feet, temperature 22 degrees C, dew point 4 degrees C, and an altimeter setting of 29.86 inches of mercury.

The density altitude at the time of the accident from the National Oceanic and Atmospheric Administration was 7,192.1 feet.

The pilot, age 59, held a private pilot certificate with a rating for airplane single engine land that was issued on September 30, 2014. A review of the logbook revealed that the pilot had accumulated a total of 280.4 flight hours; 276.9 of which were in the accident airplane make and model, and 3.8 were at night. The pilot accumulated a total of 0.8 night flight hours in the preceding 8 months.