NTSB Factual Report

HISTORY OF FLIGHT

On April 14, 1995, at 1425 central daylight time (cdt), a Cessna 150M, N45457, registered to the Vagabond Flying Service of Bartlett, Illinois, and piloted by a commercially certificated pilot, was involved in a midair collision with a Beech V35B, N1HK. N1HK was registered to Chudy Leasing, Incorporated, of Las Vegas, Nevada, and piloted by a private pilot. The midair collision occurred over the approach end of Runway 36 at the Wittman Regional Airport, Oshkosh, Wisconsin. Visual meteorological conditions prevailed at the time of the accident. Both airplanes were destroyed.

N45457 was operating as a personal flight under 14 CFR Part 91. It was not operating on a flight plan. The pilot and passenger were fatally injured. N45457 departed West Chicago, Illinois, exact time unknown. N1HK was operating as a personal flight under 14 CFR Part 91. It was not operating on a flight plan. The pilot and pilot-rated passenger were fatally injured. N1HK departed Delevan, Wisconsin, exact time unknown.

One witness, located about 800 feet east of runway 36's approach end, observed both airplanes on final approach to runway 36. He said the N45457 was about 75 feet above the runway threshold descending for a landing and that N1HK was behind N45457 at a higher altitude also descending. The witness said N1HK overtook N45457 about 1,500 feet beyond the runway threshold. He said N1HK was still descending and was about 10 feet above N45457 when N45457 made a "...violent right turn." He said N45457's right wing collided with the runway and the left wing struck N1HK's belly. The witness continued, "The forward flight stopped-- the V-35 [N1HK] pitched up and fell to the left, on top of [N45457]." He said he did not notice any increase or decrease in engine sound during this event.

A second witness said he had landed shortly before observing an airplane approach for a landing on runway 36. While taxiing southbound on Taxiway "C" the pilot said the airplane was approaching runway 36 at a steep descent angle. He said, "Suddenly, the airplane pitched up into a straight up attitude. The plane rolled to the left starting to inverted and went straight down into the field." This witness said it was difficult to see due to the sun being in his eyes.

FAA information showed N45457 12 miles southwest of the airport when its pilot contacted the tower at 1417:23 cdt. The tower controller instructed N45457 to turn onto a left base leg for runway 36 and to report when it was three miles southwest of the airport. N45457's pilot acknowledged the controller's instructions. At 1419:32 cdt, N1HK contacted the control tower and reported 18 DME nautical miles south of the airport. One of the pilots said they were inbound for landing. The tower controller instructed N1HK to proceed straight in for Runway 36 and issued the altimeter setting and surface wind conditions. One of the pilot's in N1HK's acknowledged the controller's transmission.

At 1422:54 the pilot of N45457 reported his airplane was 3 miles southwest of the airport. The controller advised the pilot his airplane was not in sight. He told the pilot his airplane was number two for landing due to another airplane being on short final for runway 36. The controller advised the pilot of N45457 that his airplane was in sight and cleared N45457 to land on runway 36. There were no other contacts made between the control tower and pilot of N1HK.

PERSONNEL INFORMATION

The pilot of N45457 obtained his private pilot's certificate on July 2, 1945. He obtained his commercial pilot's certificate on April 12, 1970, and his airplane flight instructor certificate on December 18, 1975. The FAA's Airman's Medical Branch records showed his last pilot medical certificate was issued on January 7, 1992. At the time of its issuance the pilot stated he had 2,255 hours. The pilot's logbook showed he had a total time of 2,315.4 hours as of January 9, 1994. According to this logbook, he satisfactorily completed a biennial flight review on May 13, 1992. N45457's pilot had flown the Cessna 150 model airplane 5.2 hours during March 1995, according to flying club records.

The pilot of N1HK possessed a private pilot's certificate issued on September 8, 1989. At the time of its issuance, the pilot stated he had a total flight time of 57 hours. FAA pilot records show he obtained his airplane instrument rating on September 24, 1990. At the time of its issuance the pilot stated he had accumulated a total flight time of 147 hours. His third class FAA pilot medical certificate was issued on November 11, 1994.

The last entry in the pilot's logbook showed he had flown a Cessna 172 for .7 of an hour during January 1, 1995. His logbook showed he flew a total of 12.9 hours during 1994. According to his logbook, he had accumulated 6.5 hours in a Beech model 35. His last logged flight in the Model 35 was on June 29, 1992. His logbook showed this flight was a 4.2 hour cross country flight. His pilot logbook showed he had accumulated a total time of 92.3 hours in a Beech Model A-36 Bonanza. His last logged flight in the Model A-36 was on August 18, 1993. This flight was a 1.4 hour cross country flight according to his logbook.

The pilot-rated passenger in N1HK obtained his multi-engine airline transport pilot's certificate on June 14, 1963. He obtained his airplane flight instructor certificate on May 22, 1964. At the time of this certificate's issuance he stated he had a total flight time of 2,970 hours. This pilot's logbook records were not located by family members.

AIRCRAFT INFORMATION

The airframe and powerplant logbooks for N1HK were essentially destroyed by the post-impact fire. Fragments of these records were found and showed N1HK had about six FAA STC's added to its airframe during its service life. The maintenance facility that did the annual on N1HK said it was done during the early part of April 1994. A representative of that facility said the inspection sheet related to the airplane's annual inspection showed it had an airframe total time of 2,638.06 hours. He said it recalled that the airplane was scheduled for its next annual during the last week of April 1995.

N45457's maintenance records showed it had an annual inspection on April 1, 1994. According to its airframe logbook, N45457 had 5,827.9 hours total operating time. The last entry in its airframe logbook was on February 23, 1995. It showed a total airframe time of 6,019.7 hours.

METEOROLOGICAL INFORMATION

Weather conditions at the time of the accident were clear skies with 20 miles visibility. The sun's azimuth position relative to Wittman Regional Airport was 216 degrees, 50 minutes, and its position above the horizon was 50 degrees, 17 minutes according to an astronomer from the Adler Planetarium, Chicago, Illinois.

AERODROME INFORMATION

At the time of the accident, Wittman Regional Airport, Oshkosh, Wisconsin, was classified as a Level One airport by the FAA. According to the FAA, this type airport control tower is required to have a minimum of one controller in the tower cab. Runway 36 had an operating Precision Approach Path indicator (PAPI) operating at the time of the accident.

The airport control tower was not equipped with a DBRITE Scope, a radar screen repeater. A representative from the FAA said this type of equipment had not been installed at the airport due to its incompatibility with the FAA's Chicago Air Route Traffic Control Center radar system.

He said that the closest terminal radar site was at Green Bay, Wisconsin's, Austin-Straubel Airport's Air Traffic Control Tower. The representative said that due to the distance between Green Bay, Wisconsin, and Oshkosh, Wisconsin, the radar presentation near Oshkosh is not suitable to make a DBRITE usable to controllers at the Wittman Regional Airport's control tower.

WRECKAGE AND IMPACT INFORMATION

The wreckage of N45457 and N1HK was in the process of being separated and removed from the site when the IIC arrived on- scene. Local authorities told the IIC the separation and removal was being done to extract the accident victums from the wreckage. Their action was stopped so the IIC could examine the wreckage. N1HK's and N45457's wreckage had been located on the west side of runway 36's centerline, and about 1,000 feet from its approach end. According to police photographs' both airplanes were entangled with each other.

About 60 percent of N1HK's structure had been destroyed by fire. About 75 percent of N45457's structure had been destroyed by fire. The wreckage of N1HK was laying on top on N45457's remains. Small pieces of white and white and light green colored sheet metal were located about 250 feet and 600 feet north of the runway's approach end. These pieces varied in size between 1/4 inch square to a ragged shape about 1 inch across in any direction.

Parallel cut marks in the runway surface, about 6 inches long and oriented in a north south direction, were found about 900 feet north of the runway's threshold. The concrete associated with these cut marks was discolored by what appeared to be engine oil. The engine oil had a fanned shape that was approximately 10 feet long and oriented in a north-south fashion.

N1HK's right main landing gear was imbedded into N45457's right horizontal stabilizer. N45457's left horizontal stabilizer's leading edge corner was crushed aft about 2 inches just inside its composite tip. N45457's vertical stabilizer had about 60 percent of its area burnt away. The rudder had its skin cut and bent to its left side at the midspan location.

N45457's left wingtip had scrape marks over about 50 percent of its chord from the trailing edge forward. The inboard section of this wing, from the aileron-flap junction to the wing's root, was destroyed by fire. The landing flap for this wing assembly was found on the runway's west edge, about 300 feet south of the main wreckage site. The flap's leading edge center section had torn and twisted metal between its extension tracks around its top and bottom surface. A cut parallel to the flap's leading edge was observed next to the inboard flap extension track on the unit's top side.

One propeller blade of N45457 was curled afterward starting about 9 inches in from the blades tip. The outside surface of the curl had scar marks at 45 degrees to the blade's span axis. The other blade was twisted along the span from the span's midpoint outward. The end of this blade exhibited fire damage. N1HK's propeller was located about 75 feet from the main wreckage.

N1HK's propeller's spinner was crushed aft and still attached to the propeller. A substance, similar to white and blue paint, were found around the spinner's surface. The same white colored material was observed on the face of one propeller blade and the front surface of a second blade. A third blade also had chordwise scar marks on about 50 percent of its front span. The center of this blade had deep spanwise scarring that was parallel to its chord. Two of the three blades were bent aft about 20 degrees at the hub.

The remains of N1HK's wing consisted of its left wingtip fuel tank and about 50 percent of it structure inboard of the fuel tank. The inboard half of this wing section had been destroyed by fire. The fuselage had been destroyed by fire aft of the firewall. The forward and lower section of the cowl was all that remained of the airframe forward of the firewall. The fuselage cabin section, tail cone, and empennage were destroyed by fire.

MEDICAL AND PATHOLOGICAL INFORMATION

On July 7, 1994, the second pilot in N1HK was issued an FAA second class medical certificate. The FAA Designated Medical Examiner (DME) who issued the pilot his last medical certificate said the pilot had contacted him during April 1995. He said the pilot advised him that he had a heart bypass operation during October 1994. The pilot asked the DME to help him in getting his FAA pilots' medical certificate reinstated. Further investigation revealed the pilot had the bypass surgery on October 25, 1994.

The autopsies on the fatally injured pilots were conducted by Dr. Helen Cooper-Young, at the St. Vincent's Hospital in Green Bay, Wisconsin, on April 14, 1995. The autopsy report's for the pilot of N45457, and the two pilots in N1HK state the fatal injuries were a result of multiple trauma.

The FAA's Civil Medical Institute performed a toxicological examination on N45457's pilot and the pilot in N1HK who did not have the heart bypass operation. A toxicological examination of the pilot in N1HK who had the bypass operation was not made due to inadequate samples being available according to the Winnebago County Coroner.

According to the toxicological examination report for N45457's pilot, all results were negative. The toxicological report for the pilot of N1HK showed negative for carbon monoxide, cyanide and ethanol. However, an unspecified amount of quinine was detected in the urine sample and 99.600 (ug/ml) salicylate was detected in the urine sample. According to Taber's Cyclopedic Medical Dictionary, 14th edition, quinine is associated with analgesics, antipyretics, and antimalarial drugs. Salicylate is associated with oil of wintergreen, aspirin, and external treatment of certain skin conditions.

ADDITIONAL DATA/INFORMATION

The FAA's radar NTAP data showed the altitude and flight paths of both airplanes. N45457's pilot reported that his airplane was 3 miles southwest and starting his base leg. As N45457 entered its final approach, NTAP data showed N1HK was about 800 feet above, and slightly behind, N45457. N1HK was also on a final approach path for runway 36. Approximately 40 seconds before the conclusion of the NTAP data for both airplanes, N1HK had descended about 800 feet. During the same time frame, N45457 had descended about 100 feet. The NTAP data and illustration of that data is appended to this report.

The IIS observed one obstruction between the control tower cab and the approach end of Runway 36: A fire escape ladder that had a circular grating around it. This ladder was located next to the tower cab's south window's center frame. An on-sight examination of the tower cab revealed the ladder could be an obstruction to a person's line of sight vision with runway 36's approach path. However, the amount of obstruction to the runway's approach path would be dependent upon the controller's position on the north side of the tower cab.

An FAA controller employed at the control tower at Wittman Regional Airport between April 28, 1983, and April 22, 1995, stated, "Throughout my 12 year tenure at Oshkosh ATCT, [the tower cab window] glare was a hindrance that had to be overcome daily. In previous years the issue of glare has been the subject of verbal complaints and discussed frequently with facility management." The controller on duty at the time of the accident said that window glare had been a problem at the facility.The IIC also observed the reflective window glare in to tower cab.

About 15 minutes before the accident, one of the two FAA control tower controllers went on a scheduled break. The remaining controller was handling nine airplanes at the time of the accident. The controller on break was sitting in the tower cab facing North. The on-duty controller was also facing North handling other aircraft when the accident occurred.

During an interview with the on-duty controller it was revealed he observed N45457 heading eastbound toward a final approach course for Runway 36 shortly before the accident. He said he never saw N1HK during the time he was handling both airplanes. The off-duty controller said he wasn't looking for airplanes because he was on a break.

The on-duty controller said the accident date was his first day of work after having two days off. He said he had 8 hours of sleep the night before reporting for work on the accident date. He said he had been working his position for about 15 minutes before the accident took place. He was asked what the FAA prescribes as the minimum number of controllers to be in the tower cab of a level one tower facility such a

NTSB Probable Cause

INADEQUATE VISUAL LOOKOUT BY THE PILOT OF THE BEECH V35B, RESULTING IN HIS FAILURE TO SEE-AND-AVOID THE CESSNA 150, WHICH WAS AHEAD AND BELOW HIM ON FINAL APPROACH; AND FAILURE OF THE TOWER CONTROLLER TO PROVIDE ADEQUATE SERVICE (FLIGHT ADVISORIES AND LANDING SEQUENCE) TO THE PILOTS OF THE CESSNA 150 AND BEECH V35B. FACTORS RELATING TO THE ACCIDENT WERE: INADEQUATE AIR-TO-GROUND COMMUNICATION BY THE BEECH V35B PILOT, BY FAILING TO NOTIFY THE TOWER THAT HE WAS ON FINAL APPROACH, AND BY FAILING TO OBTAIN A CLEARANCE TO LAND; FAILURE OF THE TOWER CONTROLLER TO VISUALLY IDENTIFY THE BEECH V35B; EXCESSIVE WORKLOAD FOR THE TOWER CONTROLLER; AND POSSIBLE GLARE FROM THE WINDOWS OF THE TOWER CAB (OTHER LIGHT CONDITION).