CHI98FA096A
CHI98FA096A

HISTORY OF FLIGHT

On February 22, 1998, at 1045 central standard time (cst), a Wasielak Sonerai II L, N38NL, operated by a private pilot, was destroyed when during cruise formation flight, it collided with a Stanek Sonerai II LTS, N43804, also operated by a private pilot. The two airplanes subsequently departed controlled flight and impacted the terrain. Visual meteorological conditions prevailed at the time of the accident. The personal flights were being conducted under 14 CFR Part 91. Neither pilot filed a flight plan. Both pilots were fatally injured. The local flight originated near Burlington, Illinois, at 1015 cst.

The manager of Olson Airport, Burlington, Illinois, confirmed that both pilot's were keeping their airplanes in an open air hangar on the airport. A witness at the airport said that he observed both pilot's pull their airplanes out of the hangar at 0945 cst. The witness said that both pilots took off together at approximately 1015 cst.

A pilot, who was in the air in the vicinity of Palentine, Illinois, said that he monitored a conversation between two pilots trying to find each other in the air, on a frequency of 122.7 megahertz (MHZ), between 1000 and 1030 cst. He said that one of the pilot's said that he was "near the dome," and at an altitude of 2,500 feet [mean sea level]." The other pilot said that his "GPS" [global positioning satellite receiver] was not working. The first pilot repeated, "Look south, I'm 2 miles from the dome." The pilot said that one of the two pilots may have mentioned the city of DeKalb, Illinois. He said that they sounded like men 40 to 50 years of age. The pilot said that one of the two pilots directed a radio frequency change to 122.75 MHZ.

A witness on the ground observed the two airplanes approaching his farm from the northeast. He said that the two airplanes were heading in a southwesterly direction. The witness said that the two airplanes were just about overhead when the airplane on the right [north], the one slightly aft of the other airplane, drifted into the other airplane. The witness said that he heard a "pop," and then watched the airplanes come down. One airplane flew off to the southwest while the other airplane came straight down. The witness lost sight of both airplanes as they went behind a line of trees running along the south side of his farmhouse. The witness said he heard both airplanes strike the ground. He ran into the house and contacted the DeKalb County, Illinois, Sheriff's Department.

AIRCRAFT INFORMATION

SONERAI II L, N38NL

The airplane was a homebuilt kit. The airplane was issued a special airworthiness certificate, experimental, amateur-built airplane, on June 20, 1987. According to the aircraft logbook, the airplane made its first flight on October 11, 1986. The airplane was purchased by the pilot on October 2, 1988. The airplane was first flown by the pilot on the same day. The airplane's last recorded condition inspection was performed on November 9, 1994, by an airframe and powerplant mechanic. No record of condition inspections performed in 1995, 1996, or 1997 were found in the aircraft logbook. The aircraft logbook indicated that as of February 15, 1998, the airplane had logged 533.8 hours.

SONERAI II LTS, N43804

The airplane was a homebuilt kit constructed the by pilot-owner. The airplane was issued a special airworthiness certificate, experimental, amateur-built airplane, on October 16, 1992. According to the aircraft logbook, the airplane made its first flight on November 28, 1992. The airplane's last recorded condition inspection was performed on April 20, 1997, by an airframe and powerplant mechanic. The aircraft logbook indicated that as of January 31, 1998, the airplane had logged 337.5 hours.

PERSONNEL INFORMATION

The pilot of the Sonerai II L, N38NL, held a private pilot certificate with a single-engine land airplane rating, issued on November 11, 1980.

According to his logbook, he had 932.7 total flight hours in single-engine land airplanes. The pilot had logged 483.8 hours in the Sonerai II L. The pilot's last recorded biennial flight review was on October 15, 1995.

The pilot of the Sonerai II LTS, N43804, held a private pilot certificate with a single-engine land airplane rating, issued on April 16, 1983.

According to his logbook, he had 716.7 total flight hours in single engine-land airplanes. The pilot had logged 337.5 hours in the Sonerai II LTS. The pilot's last recorded biennial flight review was on January 10, 1998.

WRECKAGE AND IMPACT INFORMATION

The NTSB on scene investigation began on February 22, 1998, at 1250 cst.

SONERAI II L, N38NL

The Sonerai II L airplane's main wreckage was found resting inverted in a plowed field, approximately 2,660 feet south of Trombley Road, an east-west running gravel road, 1/2 mile north- northeast of the village of Malta, Illinois. The main wreckage consisted of the airplane's fuselage, empennage, wings, main landing gear, engine, and partial propeller.

The wreckage rested in a single crater, 46-inches long, 30-inches wide and 27-inches deep. The crater was oriented on a 270-degree magnetic heading. Impressions in the dirt, 8-feet long and 10- inches wide, just forward of where the airplane's left and right wings were located, spanned outward north and south of the crater. Numerous paint chips were found along the west edge of the impressions. Small pieces of paint, fiberglass, metal, personal effects, and smoked plexiglass were scattered westward from the crater for a distance of 54 feet within in a 165 degree arc. The engine, partial propeller, fuel tank, and forward instrument panel were located in the crater. The remainder of the airplane rested inverted on top of the crater. The airplane wreckage was oriented on a 270-degree magnetic heading.

The fuselage was bent downward and broken at the forward cockpit.

The cockpit floor was crushed upward and bent aft. The pilot's seat was bent aft and down. The metal frame, which made up the cockpit walls, was compressed downward and broken. The fabric covering the metal frame was buckled outward and shredded. The canopy frame was broken out at the hinges. The frame was broken into two pieces which were twisted and crushed. The plexiglass bubble windscreen was broken out and shattered. Several pieces of the canopy plexiglass showed parallel-running white paint rubs and scratches. The instrument panel was crushed aft and broken. All of the flight and engine instruments were destroyed. The fuel tank was crushed aft into the backside of the instrument panel. It had broken open along the left side and was compressed. The smell of fuel was prevalent at the site. Fuel was also found pooled at the bottom of the impact crater.

The fuselage frame, from a point aft of the cockpit, to just forward of the empennage, was bent downward. The fabric covering along the bottom right side of the aft fuselage was torn open. The covering along the left side of the aft fuselage was buckled outward and shredded. The elevator push-pull tubes were bent downward and broken at the empennage, and just aft of the cockpit. The aft fuselage frame, just forward of the empennage, was bent upward approximately 40 degrees. The fabric covering in this area was buckled outward and wrinkled. The vertical stabilizer, rudder, horizontal stabilizers, and elevator showed no damage. There was no damage to the airplane's tailwheel. Elevator and rudder control continuity was confirmed.

The airplane's left wing remained attached to the fuselage frame at the main spar and trailing edge mounting bolts. The wing was crushed aft along the entire span, to approximately mid-chord. The crush angle measured from the leading edge across the upper wing skin was approximately 73-degrees. From mid-chord aft to the aileron, the wing was buckled outward. The upper wing skin was broken open longitudinally at mid-span, along the rivet line.

The wingtip was broken off at mid-chord and along the rivet line. The forward half of the left wingtip was broken into numerous small pieces. The aft half of the left wingtip was broken longitudinally along the top rivet line aft to the aileron. The left aileron remained attached to the wing at the three hinges. The aileron was bent upward 20-degrees at mid- span. Left aileron control continuity was confirmed.

The airplane's right wing remained attached to the fuselage frame at the main spar and trailing edge mounting bolts. The wing was crushed along the entire span, approximately one-third aft. The crush angle measured from the leading edge across the upper wing skin was approximately 70-degrees. From the one-third aft point, aft to the aileron, the wing was buckled outward. The upper wing skin was broken open longitudinally at mid-span, along the rivet line. The right wing tip was broken off along the rivet line, and broken into numerous small pieces. The right aileron remained attached to the wing at the outboard hinge. The middle and inboard hinges were torn out of the aft wing spar. The right aileron was buckled in numerous places along its entire span. The right aileron was bent downward at the inboard corner of the trailing edge. Right aileron control continuity was confirmed

The airplane's main landing gear was bent aft under the fuselage. The landing gear legs sustained minor damage. The tires and wheelbrakes were undamaged. The firewall was crushed forward and bent around the rear of the engine. The back of the single magneto had punched a 4-inch wide hole through the firewall metal. The front of the airplane's lower cowling was crushed aft between the engine and the spinner. The remaining part of the lower cowling was broken out and shredded. The airplane's upper cowling was separated and broken into numerous pieces. The engine, propeller, and spinner were buried in the crater. Three of the four engine mounts were broken. A 6-inch long crack was observed in the top side of the number three cylinder running perpendicular to the crankshaft. Engine control continuity was confirmed. The wood propeller blades were broken off, just outboard of the spinner. One blade had broken aft and splintered in a counter-clockwise direction approximately 6-inches outboard of the hub. The blade showed chordwise scratches on the front surface. The other propeller blade was broken aft at the spinner. The spinner was crushed aft and twisted counter- clockwise. The rear spinner plate was crushed aft so as to conform to the shape of the propeller hub. Numerous small pieces of the propeller blades were found in the crater, embedded in the engine and engine cowling, and scattered around the accident site.

SONERAI II LTS, N43804

The Sonerai II LTS airplane's main wreckage was found resting inverted in a plowed field, approximately 1,500 feet south of Trombley Road, an east-west running gravel road, 3/4 mile north- northeast of the village of Malta, Illinois. The main wreckage consisted of the airplane's fuselage, empennage, canopy, wings, landing gear, engine, and partial propeller.

The wreckage rested in a single crater, 10-feet long, 4-feet at its widest point, and 14-inches deep. The crater was oriented on a 180-degree magnetic heading. A spray of dirt beginning at the northwest corner of the crater, fanned out toward the northwest in a 40-degree arc, for approximately 25 feet. Numerous pieces of clear plexiglass which made up the airplane's canopy, broken pieces of an emergency locator beacon, a transceiver and a hand- held GPS receiver, a chart, an airplane checklist, and some personal effects were found in the crater.

The airplane's upper cowling was crushed downward and slightly aft, from the propeller, aft to the cockpit area. The lower cowling was buckled outward and split longitudinally along the left side. A portion of the lower cowling on the left side was broken out. The right side of the lower cowling was twisted to the left and split longitudinally along the lower right side. The airplane's engine was bent downward approximately 20-degrees at the engine mounts. The upper portion of the firewall was bent aft and crushed downward. The forward fuel tank showed an 8-inch deep bend in the aft portion. The fuel cap was off. The smell of fuel was prevalent. The forward landing gear was bent forward and twisted to the right. The tire showed no damage. The wood propeller blades were broken off. One blade was broken aft and splintered in a counter-clockwise direction just outboard of the hub. The other propeller blade was broken aft and splintered counter-clockwise 12 inches outboard of the hub. The blade also showed several longitudinally-running splits in the wood. Chordwise scratches were observed on the blade's front surface. The spinner nose cone was crushed in and down. The spinner's aft plate was crushed aft around the top of the propeller hub and twisted counter-clockwise.

The canopy frame was broken inward and crushed. The left side of the canopy frame was bent outward and down. The clear plexiglass windscreen was broken out and shattered into numerous fragments. The forward instrument panel was bent rearward and down. Several of the flight and engine instruments were broken out. The front seat was pushed aft and crushed inward. The metal tubing, making up the front cockpit frame, was bent downward at the front seat. The remaining tubing was crushed downward. The exterior fabric making up the side walls of the airplane's cockpit, was buckled outward, wrinkled, and torn. The rear seat instrument panel was bent aft and crushed downward. The rear cockpit seat remained intact. The aft fuel tank, just behind the rear seat was bent aft at the top front, and bent inward at the top rear. The fuel cap was off. The smell of fuel was prevalent. The metal tubing making up the cockpit floor was intact. The fabric making up the airplane's bottom skin showed heavy wrinkles. The main landing gear legs, tires, and brakes were undamaged.

The airplane's left wing remained attached to the fuselage frame at the main spar and trailing edge mounting bolts. The wing showed numerous bends and heavy buckling along the entire span of the upper wing surface, from the leading edge, aft to the aileron hinge line. The wing's leading edge showed an inward crushline of 20-degrees from mid-span, outboard to the wingtip. The wing showed a chordwise bend of 10-degrees, 6-inches outboard of the mid-span rivet line. The bottom skin showed buckling from the leading edge, aft to approximately mid-chordline. Numerous buckles were observed beginning at the trailing edge mounting bolt, and running forward at 45-degrees to mid-chord, and outboard approximately 1/3 span from the root. Several longitudinal and inward-running scratches were observed along the lower outside edge of the left wingtip, approximately 30-degrees from the longitudinal line, and 12 to 16 inches aft of the leading edge. A 5-inch long, 5-inch wide hourglass-shaped fracture was observed in the outside edge of the wingtip, 18 inches aft of the leading edge. The fiberglass at the fracture was crushed upward and pushed outward.

A 3-inch long, 1/2-inch wide white rub mark and scratch was observed on the lower wing skin, 11 inches inboard from the wingtip edge, at mid-chord. The rub ran 32-degrees inboard from the lateral axis. The airplane's left aileron was bent upward 15-degrees at mid span. Left aileron control continuity was confirmed.

The airplane's right wing remained attached to the fuselage frame at the main spar and trailing edge mounting bolts. The wing's leading edge showed an inward crushline of 20-degrees beginning 5 feet outboard of the wingroot and spanning outboard to the wingtip. The wing showed numerous bends and heavy buckling along the entire upper skin surface, beginning at the leading edge, and running aft to the aileron hinge line. A bend was observed in the leading edge, 12 inches outboard of the wingroot. A 12- inch wide, 8-inch deep bend was observed in the wing's leading edge, just inboard of the wingtip rivet line. The bottom skin of the right wing showed lesser bends and buckles throughout the surface. The inboard 24 inches of the right aileron were bent downward approximately 20-degrees. Right aileron control continuity was confirmed.

The metal tubing, making up the frame of the fuselage, aft of the rear cockpit seat, was bent down and twisted left approximately 60 degrees from the vertical axis. The fabric skin in this area was twisted, torn, and shredded. Numerous paint chips were found on the ground beneath the aft fuselage.

The empennage was twisted clockwise 15 degrees from the vertical axis. The top 16 inches of the vertical stabilizer's leading edge was crushed inward and down, beginning at the top forward corner and running aft along the top of the stabilizer to the rudder hinge line. The elevator was intact and buckled outward slightly. Rudder control continuity was confirmed. The right horizontal stabilizer and right side of the elevator sustained no damage. The left horizontal stabilizer was intact. A 12-inch long, 12-inch wide, diamond-shaped tear was observed in the upper skin of the left horizontal stabilizer, near the tip. The left elevator showed no damage. Control continuity to the elevator was confirmed.

A rectangular-shaped canvas flight bag, containing the pilot and aircraft logbooks out of Sonerai II L, N38NL, was located in a neighboring field, 162 feet from the main wreckage of the Sonerai II LTS on a magnetic heading of 105-degrees. The flight bag was resting upside-down. The contents of the bag, with exception of a small flashlight, were undamaged. A 35 millimeter camera rested 10 feet west of the flight bag.

MEDICAL AND PATHOLOGICAL INFORMATION

The Autopsy of the pilot of N38NL was performed on February 24, 1998, at the DeKalb County Medical Examiner's Office, Sycamore, Illinois. The autopsy revealed no evidence of physical incapacitation or impairment. The results of FAA toxicology testing of specimens from the pilot were negative for all tests conducted.

The Autopsy of the pilot of N43804 was performed on February 24, 1998, at the DeKalb County Medical Examiner's Office, Sycamore, Illinois. The autopsy revealed no evidence of physical incapacitation or impairment. The results of FAA toxicology testing of specimens from the pilot were negative for all tests conducted.

TESTS AND RESEARCH

The vice president of the Experimental Aircraft Association (EAA), Chapter 153, Schaumburg, Illinois, said that he personally knew both pilots and that they had been active members in the chapter for several years. He said that both pilots had been friends for years and flew their airplanes almost every weekend. The EAA Chapter vice president said that he had observed them flying in formation together on arrival at various EAA functions. He described their flights together as a loose formation, approximately 30 to 50 yards apart. It was their custom that the pilot of N38NL flew as the lead airplane, with the pilot of N43804 flying to the right and slightly behind. This was because N43804 had a little better performance than N38NL.

The EAA Chapter vice president characterized both pilots as being "conservative. Neither was a risk taker, and both seemed to know their limitations as pilots." He said that though both of their airplanes were capable of aerobatics, he believed that neither pilot had "ever attempted as much as an aileron roll in their aircraft."

ADDITIONAL INFORMATION

There was one party to the investigation, the Federal Aviation Administration Flight Standards District Office, West Chicago, Illinois.

The Sonerai II L wreckage and the Sonerai II LTS wreckage were released and returned to Hendrickson Flying Service.

Use your browsers 'back' function to return to synopsis
Return to Query Page