# NTSB SEA96FA134: Cessna 150B, N1236Y, Hailey, ID, June 21, 1996 - Type: NTSB accident investigation - Classification: Accident · Fatal · Field investigation · Final report - Date: June 21, 1996, 09:05 local (15:05 UTC) - Place: Hailey, ID - Coordinates: 43.569412, -114.209327 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=43.5694&lon=-114.2093&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 2 fatal - Status: Completed, report July 28, 1997 - Report: Approved by Office Director - NTSB case key (mKey): 42278 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA96FA134 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42278/pdf - Page: https://openairdocs.org/ntsb/SEA96FA134 ## Probable cause the pilot's improper planning/decision, and his failure to maintain adequate airspeed during a climb over rising terrain, which resulted in a stall and collision with terrain. Factors relating to the accident were: failure of the pilot to ensure the airplane was within its weight and balance limitations, high density altitude, and the rising/mountainous terrain. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, climb - planning/decision - improper, pilot in command (cause) - aircraft weight and balance - improper, pilot in command (contributing factor) - weather condition - high density altitude (contributing factor) - terrain condition - rising (contributing factor) - airspeed - not maintained, pilot in command (cause) - stall - inadvertent, pilot in command (cause) - In flight collision with terrain/water, descent - uncontrolled - terrain condition - mountainous/hilly ## Analysis The pilot performed a preflight inspection of the airplane and had it fully serviced with fuel before taking off. Postaccident calculations indicated that the airplane was about 50 pounds over its maximum gross weight limit, and its center-of-gravity was behind the aft limit. The airport elevation was 5,315 feet; density altitude at the airport was about 5,840 feet. Immediately after departure in VFR conditions, the pilot flew the airplane toward rising terrain, despite the control tower's advisement to initiate a left turn over lower, level terrain. The controller asked the pilot for his position, and the pilot replied, 'I'm heading up the valley . . . east of the airport . . . I'm just about to come out of the valley at the east end.' No distress call was received from the airplane. Subsequently, the airplane crashed at an elevation of about 6,700 feet, below a saddle in mountainous terrain. There was evidence that the airplane had stalled; it came to rest in a steep nose-down attitude with the nose imbedded in the ground and crushing damage to the leading edges of the wings. ## Factual narrative HISTORY OF FLIGHT On June 21, 1996, about 0905 mountain daylight time, N1236Y, a Cessna 150B, operated by the owner/pilot, collided with rising terrain while maneuvering and was destroyed near Hailey, Idaho. The private pilot and his passenger were fatally injured. Visual meteorological conditions prevailed and no flight plan had been filed. The personal flight was conducted under 14 CFR 91. The flight departed from Hailey at 0852 and was destined for Manila, Utah. According to witnesses (interviews attached), the pilot and his brother-in-law arrived at the Friedman Memorial Airport in Hailey about 1600, one day prior to the accident, after flying in from Kelso, Washington. The pilot had 12 gallons of fuel placed in his airplane, and he spent the night at a friend's home in Hailey. According to the friend, the pilot intended on flying to Manila the next day to fly fish. The pilot told his friend that the airplane "flew great," and that he (the pilot) "felt fine." The pilot ate dinner with the friend about 1800 on the evening prior to the accident, and the pilot subsequently went to sleep about 2130. The next morning, on the day of the accident, the pilot awoke about 0600. The pilot, passenger, and the pilot's friend then went to the airport. The pilot had the airplane "topped off" with about one gallon of fuel, because he wanted to ensure the airplane had the maximum amount of fuel it could carry for endurance purposes. An examination of the airport's fuel receipts and quality control checks (attached) revealed no evidence of fuel contamination. The pilot also performed a preflight; no anomalies with the airplane were reported to the pilot's friend or airport personnel. According to personnel at the air traffic control tower in Hailey, and tower transcripts (attached), the accident airplane departed from runway 31 and was advised to "make a left downwind departure." The pilot acknowledged. About two minutes later, the pilot was then advised to "make a slight right turn and proceed on the east side of the valley until you get the altitude for your left turn." Again, the pilot acknowledged, but never initiated the left downwind turn. About three minutes later, the controller asked the pilot for his position. This occurred after the airplane had turned right and disappeared from the controller's view behind a hill to the north of the airport known as Red Devil Hill (area map attached). The pilot responded: "I'm heading up the valley, heading east of the airport out of Hailey." After another query by the controller, the pilot responded: "I'm just about to come out of the valley at the east end." This was the pilot's last recorded transmission. No distress calls from the pilot were received. The airplane impacted rising mountainous terrain about 6 nautical miles northeast of Hailey at an elevation of about 6,700 feet above mean sea level (msl). The Idaho State Division of Aeronautics stated that an emergency locator transmitter signal was received by the U.S. Air Force about 1236 on the day of the accident. The wreckage was later spotted about 1700. The accident occurred during the hours of daylight at the following coordinates: 42 degrees, 33.77 minutes North; 114 degrees, 10.68 minutes West. AIRCRAFT INFORMATION The accident airplane, a 1962 Cessna model 150B, had been owned and operated by the pilot since May 4, 1995. The two-seat aircraft was powered by a single 100-horsepower Continental engine. An examination of the airplane's maintenance records did not reveal any unresolved discrepancies. The airplane underwent an annual inspection on August 4, 1995, and had flown about 46 hours from the time of the inspection to the time of the accident According to aircraft delivery documents from the Cessna Aircraft Company, the empty weight of the airplane was 1,002 pounds. The Safety Board computed the weight and balance of the airplane for the accident flight with weight data collected for the aircraft occupants, fueling, and baggage. The computations (attached) revealed that the airplane was over its published gross weight by about 50 pounds, and it was also beyond its published aft center of gravity at the time of the accident. According to 1962 Cessna 150B Owner's Manual, the aerodynamic stall speed at gross weight and with flaps up is 54 miles per hour. The maximum rate of climb at maximum published gross weight, 5,000 feet above mean sea level (msl), and 41 degrees F is 550 feet per minute. This rate of climb figure does not take updrafts and downdrafts into account. PERSONNEL INFORMATION According to FAA records, the pilot, age 43, was issued an FAA private pilot certificate with ratings for single engine land airplanes in 1977. He was also issued an FAA Third Class Medical Certificate on May 29, 1996, with the limitation that he "must wear corrective lenses." A review of the pilot's personal flight log book revealed that he had logged a total of 220 hours of flight time, including 14 hours in type during the 30 days preceding the accident. According to witnesses, the pilot was not familiar with the Friedman Memorial Airport in Hailey, nor the surrounding area and departure procedures. METEOROLOGICAL INFORMATION According to a meteorological surface observation taken at the Friedman Memorial Airport in Hailey about the time of the accident, the following conditions prevailed: scattered clouds at 5,000 feet above the ground level (agl), broken cloud ceiling 8,000 feet (agl), temperature 48 degrees F, visibility 30 statute miles, wind speed at 12 knots from 360 degrees magnetic, altimeter pressure setting of 29.92 inches of mercury. Safety Board computations revealed that the density altitude at the airport at the time of this observation was 5,840 feet. The airport sits at a standard sea level elevation of 5,315 feet msl. The standard sea level elevation of the accident site is about 6,700 feet. WRECKAGE AND IMPACT INFORMATION The airplane wreckage was examined at the accident site one day after the accident on June 22, 1996, and again on June 23, 1996. The airplane came to rest in the crevice of a steep ravine below a saddle in mountainous terrain. The wreckage was distributed along a magnetic bearing of 210 degrees along downsloping terrain. The wreckage path was measured to be about 50 feet in length. No evidence of fire, explosion, or in-flight structural failure was found. All primary and secondary flight control surfaces were accounted for at the accident site. The wing flaps were found in the retracted position. The tailcone was completely separated from the cabin area. Both wings were resting, leading edge down, on opposite slopes of the ravine; their leading edges displayed evidence of "accordion" crush damage. The nose of the airplane was imbedded into the ground in a near vertical attitude. Flight control cable continuity was verified for all flight controls, except the right rudder cable. While applying vigorous manual tension on the cable from the separated cabin area, the cable became loose and was pulled out of the cabin floor. An examination of the separated end cable revealed that it was corroded. The corroded area of the cable occurred at a location where the cable passes underneath the forward portion of the cabin near the forward door post. Pulleys for the rudder cable are mounted in the front doorpost bulkhead assembly. An examination of the area did not reveal any evidence of corrosion or mechanical deficiency. A section of both ends of the cable were extracted and sent to the Safety Board's metallurgical laboratory for further analysis. An examination of the cockpit revealed that the fuel mixture control was in the full forward position. The throttle control was pulled aft about two inches and jammed. The oil temperature gage was pointing to the bottom of the green arc. The e ## Aircraft - Registration: [N1236Y](https://openairdocs.org/deregistered/N1236Y-1997-03-24), registration cancelled 1997-03-24, S/N 15059636 (OpenAirDocs) - Reported make and model: Cessna 150B - Registry model: [Cessna 150B](https://openairdocs.org/model/cessna-150b) (registry code 2071806) (OpenAirDocs) - Category: Airplane - Serial number: 15059636 - Airframe hours: 4896 - Engines: Continental O-200-A 100 horsepower reciprocating - Damage: Destroyed - Flight: Personal, Part 91 - Registered owner: Mckean, Mark L. - Airworthiness certificate: Standard, Utility; Standard, Normal - Last inspection: Annual, August 4, 1995, 46 hours before - Departed: SUN, ID - Destination: 40U, MANILA, UT ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 43; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 220 total, 180 as pilot in command, 28 in the last 90 days, 16 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 360° at 12 knots - Visibility: 30 statute miles - Lowest ceiling: 8,000 ft broken - Temperature: 48 °F, dew point 28 °F - Altimeter: 29.00 inHg - Observed at: SUN, 6 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19960621015069A](https://openairdocs.org/incident/19960621015069A), Jun 21, 1996: Cessna 150B, Hailey, ID, Destroyed, 2 fatal. Over gross and aft of gg struck mountainside en route. Factors failed rudder cable. Density altitude downdrafts. ## Other investigations on N1236Y (1) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB SEA67F0187](https://openairdocs.org/ntsb/SEA67F0187), Aug 31, 1966: Cessna 150 (N1236Y), Eugene, OR, substantial damage From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.