Aviation Accident Summaries

Aviation Accident Summary SEA02FA146

Idaho Falls, ID, USA

Aircraft #1

N82Z

Beech BE-35

Analysis

After takeoff, the instructional flight entered a right closed VFR pattern for multiple touch-and-go landings. During the fourth pattern, just as the aircraft reached the location where the occupants were going to turn base, the tower advised them to make a left 360 degree turn and report reestablished on the downwind. One of the pilots advised the tower that they were just about to turn base, but because the tower needed the spacing to allow an IFR aircraft to depart, the controller repeated the instructions. One of the pilots read back the instructions, and then the aircraft entered a left 360 degree turn. Just about the time the aircraft was becoming reestablished on the downwind, the flying pilot allowed the airspeed to decrease below Vs (stalling speed), and the aircraft entered a spin.

Factual Information

HISTORY OF FLIGHT On August 5, 2002, at 1359 mountain daylight time, a Beech BE-35, N82Z, impacted the terrain about 1 mile northwest of Idaho Falls Regional Airport, Idaho Falls, Idaho. The private pilot in the left seat, along with an instructor pilot in the right seat and a passenger in the back, all received fatal injuries. The aircraft, which was operated by Eagle Vision, Inc., a flying club, was destroyed. The 14 CFR Part 91 commercial maneuvers instructional flight, which had been in the VFR traffic pattern for about 30 minutes, was being operated in visual meteorological conditions. No flight plan had been filed. The ELT, which was activated by the accident sequence, was turned off at the scene. According to the logbook of the pilot receiving instruction, on the day of the accident he completed two other flights in Beech N82Z. The first flight was five-tenths of an hour long, and the second lasted for one and eight-tenths of an hour. Both flights were instructional in nature, and the same individual who was providing instruction during the accident flight provided instruction during these first two flights. Both of the flights began and terminated at Idaho Falls Regional Airport. Aero-Mark fueling personnel and fueling records indicate the aircraft’s main tanks were topped off with 100LL aviation fuel (10.8 gallon) prior to the first flight of the morning. According to the tower controller, after takeoff for the third flight, the pilot of N82Z remained in the VFR pattern for right traffic to runway 20. The pilot then executed three touch-and-go landings prior to entering a right downwind for the fourth time. According to the controller, except for the fact that the patterns may have been slightly more extended than most, nothing seemed unusual or out of the ordinary. While on downwind of the fourth traffic pattern, the tower instructed the pilot of N82Z to make a left 360, and report reestablished. To these instructions, which were given in order for the tower to clear an Instrument Flight Rules-released aircraft for takeoff, the pilot of N82Z responded "Eight Two Zulu just ready to turn base." The tower controller then repeated the instructions (November Eight Two Zulu, make left 360 and report reestablished). To this repeated instruction, the pilot responded, "Roger, left 360, report reestablished." Immediately following that transmission, the controller saw the aircraft enter a left turn, but then looked away in order to continue activities related to the takeoff of the IFR-released aircraft. According to at least two witnesses, the aircraft made one full circle, and soon thereafter "spiraled" straight down. Other witnesses did not see the aircraft make the turn, but noticed it just before it "rolled" and started "diving," "spinning," or "spiraling" toward the ground. All agreed that the aircraft was heading in a generally north direction prior to what appeared to be a rapid uncontrolled descent. All also agreed that the aircraft was much lower at the initiation of the descent than they were used to seeing at that point in the landing pattern. Only one person who provided a written statement mentioned anything about the sound of the engine. That person, who was working inside a shop building near the accident site, said that he first became aware of the aircraft when he heard "a loud engine sound" that lasted for about one or two seconds. According to this individual, the engine sound then ended, and then about one to two seconds later he heard a "loud thud." The tower controller, who had temporarily diverted his attention to other required activities, saw the aircraft in a rotating descent only briefly before it impacted the ground. There was no radio transmission from the aircraft after the pilot repeated the instructions the tower gave him and initiated the left turn. PERSONNEL INFORMATION The private pilot, who was flying from the left seat, earned his private pilots license on March 22, 2002, which was a little over five months prior to the accident. He earned his instrument rating on May 28, 2002. According to his logbook, he had about 183 hours total flying time and 15.2 hours in the BE-35. All of the BE-35 hours were accumulated during instructional flights while in the company of the flight instructor present during the accident flight. His first flight in a Beech BE-35 aircraft was on 2/22/02 (15 days prior to the accident). He had not yet received a complex aircraft or high-performance aircraft endorsement. The flight instructor, who was sitting in the right seat, earned his private pilots license on July 26, 2001, just over one year prior to the accident. He earned his single engine aircraft flight instructor rating about eight months later, on April 1, 2002. He was endorsed to operate complex aircraft, as per FAR 61.31 (e), on December 6, 2001, but was not endorsed to fly high-performance aircraft, as per FAR 61.31(f), until July 22, 2002 (approximately two weeks prior to the accident). On July 22, 2002, this pilot made four fights in N82Z. The first flight (which was the first time he logged time at the controls of a Beech-35) lasted one hour. This flight was intended to be a combination high-performance endorsement check, and a required flying club/insurance checkout (although it was ultimately determined that the aircraft was not insured). The following three flights on that same day (1.2, 1.4 and .7 hours respectively) were logged as flight instruction given by this individual. In the remainder of the two weeks prior to the accident, the instructor logged 21 instructional flights totaling 41.6 hours in N82Z. On the four days from July 30 to August 2, he put entries in his logbook that indicated he made 15 additional flights, but he did not enter their duration, nature, or the aircraft in which they took place. It is estimated that his total flight time was approximately 450 hours. METEOROLOGICAL INFORMATION The aviation surface weather observation (METAR) taken at Idaho Falls Regional Airport at 1353, six minutes prior to the accident, indicated clear skies, winds from 340 degrees at three knots, visibility eight miles, temperature 74 degrees Fahrenheit, a dew point of 44 degrees, and a barometric pressure of 30.06 inches of mercury. WRECKAGE AND IMPACT INFORMATION The aircraft impacted the terrain in an open grassy field about 150 feet west of North 26th Road West. The geographic coordinates of the accident site were North 43 degrees, 31.92 minutes, West 112 degrees, 5.02 minutes. The aircraft came to rest with the nose pointing approximately 270 degrees magnetic, with the front part of the engine embedded in the ground at an angle of about 30 degrees nose down. There were no ground scars that would indicate any forward or rotational movement after the aircraft's initial contact with the ground. The entire leading edges of both wings were crushed almost directly aft into the forward spars. The top skin between the spars on both wings was buckled upwards, and both main landing gear struts had been forced through the top of the wings. All three landing gear mechanisms were in the down position, and the nose gear had been torn from the airframe. The flap actuation mechanism indicated that the flaps were in the up position. Both the left and right main fuel tank bladders had been forced forward through the leading edge of the wings, and the front portion of each had been torn open at several places. Both wing tip fuel tanks had burst open, and there was a clear impact ground scar directly below both tanks. Impact forces had partially wrapped the firewall around the engine, and the instrument panel, most all of which had been destroyed, had been forced forward on to the top of the engine. The empennage, which was essentially intact as a unit, had almost entirely separated from the rest of the fuselage just aft of the rear seat. Continuity was established between all flight control surfaces and the point where their respective control cables entered the cabin. Because of the extent of damage within the cabin, determination of unrestricted continuity within that area could not be established. The ruddervator trim tab was about 10 degrees down (nose-up trim). Both propeller blades had chord-wise polishing and scratching consistent with rotational impact with the soft soil, along the leading edge of their entire spans. The outboard two-thirds of one blade, which was still attached to the hub, was bent aft about 25 degrees. The outboard one-third of the other blade, which had separated from the hub, was bent back about 10 degrees. The center hub-attach shaft on the separated blade was bent about 20 degrees in a direction opposite engine/propeller rotation. Both blades showed about 10 degrees of longitudinal twisting. The altimeter read approximately 7,000 feet, and was set at 30.04. The airspeed indicator read 100 miles per hour. The horizontal situation indicator (HSI) showed a heading of 330 degrees, with the heading bug set on 200 degrees. The transponder was set at 1200, with altitude reporting function turned on. The digital navigation/communication radio was in the on position. No other instruments could be read. The engine was removed from the aircraft and taken to a maintenance facility for a teardown inspection. The crankcase had suffered severe impact damage, and was cracked/split in six places. The top portion of the case between the number five and number six cylinders had broken out, revealing the connecting rods and crankshaft. The accessory case was severely damaged and all the accessories had partially or completely separated from their mountings. Both magnetos were extensively damaged and could not be rotated. The damaged interiors of both magnetos were inspected, and there was no visual indication of shorting of the coils or unusual wear of the contact breaker points. The carburetor had been broken off of its mount, and was partially broken open. There was no evidence of pre-impact damage to the carburetor's interior parts, and no evidence of diaphragm tears or leakage. Except for a very small piece of fibrous lint, there was no contamination in the carburetor inlet filter screen. The exhaust had been crushed and broken by the impact, and the oil cooler and oil tank had been crushed down into the engine. The fuel pump and propeller governor had broken away from the engine. The fuel pump coupler was still intact and turned freely. Although the top of the pump had been broken off, there was still fuel present within its body. All of the cylinders were removed from the engine, and no anomalies were found in the valves, rocker arms, or valve spring assemblies. There was no abnormal scoring or scraping on the cylinder walls, and the pistons and piston rings appeared normal. There was no unusual wear on the piston wrist pins, and the deposits on the pistons domes were the normal light cream color. All of the connecting rods appeared normal and moved freely on the crankshaft journals. The crankshaft appeared to be intact. The spark plugs exhibited normal wear patterns, and did not display any abnormal or unusual deposits or contamination. The central electrode on most of the spark plugs had started to take on the erosion-produced football shape, but there was no indication of any shorting or malfunction. The inspection of the airframe, engine, and propeller did not reveal any evidence of pre-impact anomalies or malfunctions. ADDITIONAL DATA AND INFORMATION Western Pathology Associates performed autopsies on both of the aforementioned pilots. The cause of death for both was listed as extensive blunt force injuries and body fragmentation due to an airplane crash. The FAA's Toxicology and Accident Research Laboratory conducted toxicology exams on specimens from these same individuals, and both proved negative for ethanol and screened drugs. Carbon monoxide and cyanide tests were not performed. The aircraft remained in the custody of the Bonneville County Sheriff's office both prior to and during the on-scene investigation by the NTSB.

Probable Cause and Findings

The flying pilot's failure to maintain adequate airspeed resulting in a stall/spin. An additional cause was the flight instructor's inadequate supervision of the flight.

 

Source: NTSB Aviation Accident Database

Get all the details on your iPhone or iPad with:

Aviation Accidents App

In-Depth Access to Aviation Accident Reports