WAUKEGAN, IL, USA
N225BA
CESSNA 340A
The pilot was being vectored for an ILS approach when he activated the runway edge lighting. He said he saw the lights as he was being vectored to the final approach course. While on final approach he extended the landing gear and illuminated the landing lights. The lights caused a cockpit glare and he turned them off. As the airplane was passing through 500 feet above ground, he turned the landing lights on a second time. He said he saw a big glow and turned the lights off a second time. After he did this he said he saw nothing. The airplane collided with the ground and MASLR light stand. It was found about 1 hour and 15 minutes after the ground collision. A searcher said the visibility was about 400 feet. The pilot said he was aware of a NOTAM about the inoperative VASI, REIL, and Medium Intensity Approach Lighting System and Runway Alignment Indicator (MASLR). An FAA CAMI optometrist was told the circumstance's surrounding the accident. He said what the pilot experienced was a '...classic case of flash blindness.' Information he provided showed the pilot would have a blind gap in his visual field under circumstances he encountered.
HISTORY OF FLIGHT On May 8, 1996, at 0509 central daylight time (cdt), a Cessna 340A, N225BA, piloted by an airline transport rated pilot, was substantially damaged when it collided with the ground during an ILS approach to runway 23 at the Waukegan Regional Airport, Waukegan, Illinois. The 14 CFR Part 91 flight was operating on an IFR flight plan. Instrument meteorological conditions prevailed at the time of the accident. The pilot was seriously injured. The flight departed West Chicago, Illinois, at 0442 cdt. Before departing the pilot was advised by the control tower that "...O'Hare's got 1800 RVR,... if you still want to go he can give you the heading, but our visibility is decreasing down now to a mile and a half." The pilot responded, "Yeah, I'm going to go because Milwaukee is still better and it's right on the lake front... so we'll take a look at it if we can't we'll come back here." N225BA was cleared for takeoff shortly after this conversation. The flight was radar vectored toward the destination airport. The pilot was vectored onto Waukegan Regional Airport's runway 23 localizer course and cleared for the runway 23 ILS approach. He was given the altimeter setting for O'Hare International Airport, Chicago, Illinois, and repeated it back to the approach controller. At 0504:27 N225BA was at the outer marker and was told that radar service was terminated. About 5 minutes later the approach controller called N225BA's pilot and did not get a response. According to the pilot's NTSB Form 6120.1/2, he activated the airport's pilot controlled lighting while being vectored for the instrument approach. After establishing his airplane on the glideslope the pilot said he turned on the airplane's landing lights. He said he turned the lights off when he experienced cockpit-glare. The pilot said he saw the runway edge lighting when the airplane was at 1,200 feet mean sea level (msl). He said, "At approximately 1000 [feet] MSL I again turned on [the] landing lights to illuminate the runway. When this occurred, runway lights started to fade out. I switched off the landing lights, and saw nothing." During an interview the pilot said he activated the runway edge lighting when the airplane was west of the airport. He said he could see the runway lights clearly as the airplane was vectored toward the final approach course. He added that he was aware of the Notices To Airmen about the inoperative Visual Approach Slope Indicator, Runway End Identification Lights, and Medium Intensity Approach Lighting System and Runway Alignment Indicator (MASLR) system. The pilot was asked to describe what occurred when he turned the airplane's landing lights on a second time. He said all he saw was a big glow when he turned on the landing lights. When he turned the landing lights off, he said he saw nothing afterwards. The airplane was found about 1 hour and 15 minutes after it collided with the ground. One searcher said the pilot told him he had "...lost his bearings [with the ground] when [the] lights went off." According to the searcher the ground visibility was about "...400 feet or less..." when N225BA was found. OTHER DAMAGE N225BA collided with the first MALSR lighting tower associated with the runway 23 instrument approach after sliding on the ground for about 100 feet. Shortly before coming to a stop, N225BA struck a taxiway edge lighting post. PERSONNEL INFORMATION The pilot has an airline transport rating. His NTSB Form 6120.1/2 showed a total time of 21,925 hours. He possesses type ratings in the following airplanes: Dassault DA-20 and DA-50, the Grumman G-159 and 1159, the Hawker Siddeley HS-125, and North American NA-265. According to the pilot's NTSB Form 6120.1/2, he has a total time of 822.1 hours in the Cessna 340 and 2,597 hours of instrument flight time. His most recent instrument flight time was 1.3 hours in a Dassault 990 on May 7, 1996. AIRCRAFT INFORMATION N225BA's last annual inspection was on March 8, 1996, when it had a total airframe time of 6,279.3 hours. The airplane's pitot-static system and transponder check as required by 14 CFR Part 91.413 was completed on February 26, 1996. The pilot's altimeter calibration report sheet showed a scale error of +20 feet at 500 feet, +10 feet at 1,000 feet, and +20 feet at 1,500 feet. The co-pilot's altimeter also passed the pitot- static test. There were no error parameters given for its test. METEOROLOGICAL INFORMATION A Federal Aviation Administration (FAA) Airways Facility employee was among the first persons to arrive at the accident scene. He said fog was on the surface of the airport and that the ground visibility was 400 feet or less. Weather information for the accident airport was not available when the accident occurred. AIDS TO NAVIGATION The airport's runway 23 ILS system was examined by the FAA. The system's components were certified within the tolerances allowed, and "...found to be normal." The approaches examination paperwork is appended to this report. WRECKAGE AND IMPACT INFORMATION N225BA's final resting position was about 25 feet southeast, and 150 feet south of the runway 23's parallel taxiway end. The airplane's heading was about 220 degrees. The left wingtip fuel tank was about 150 feet southeast of the airplane. The main and nose landing gear assemblies were found along the wreckage trail. N225BA collided with the ground about 100 feet northeast of the first MALSR light tower. The ground scar preceding the MALSR tower strike was oriented on a heading of 180 degrees. Propeller blade tip scar marks were found among the ground scar marks made by the landing gear, cowl's, and fuselage. Ground scar marks made by the airplane continued from its first ground collision point its final resting position. The cockpit examination revealed that all electrical and magneto switches were in the "OFF" position. Both throttles were found in the mid-range position. The propeller and mixture controls were found in the full forward position. ADDITIONAL INFORMATION The pilot said there were no mechanical or electrical problems with the airplane during the flight. The pilot said his final approach speed was about 100 to 105 knots as best he could recall. 14 CFR Part 91.175c, Operation below DH or MDA, the pilot cannot descend below "...authorized DH unless.... at least one of the following visual references for the intended runway is distinctly visible and identifiable to the pilot: The threshold lights., The runway lights., [etc.]." According to an FAA experimental optometrist, the pilot's inability to see the runway lights after the second illumination and turning off the landing lights was a classic case of flash blindness. He said as a person's age increases the recovery from a flash blindness event will take longer. The optometrist provided the following from his references on flash blindness, or photostress: "Photostress with an intense flash of light alters retinal adaptation and produces a dense after-image which is manifested as scotoma." According to the 14th edition of Taboer's Cyclopedic Medical Dictionary, "Scotoma" is an "Islandlike blind gap in the visual field." The information continues, "The mean duration for recovery in patients under [age] 40 was 51.10 [to] 50.91 seconds. In patients over 40 the mean duration of recovery [was] 57.34 [to] 59.3 seconds... ." The optometrist said he wouldn't doubt that the pilot encountered flash blindness event and experienced temporary visual incapacitation.
the pilot's inability to maintain visual contact with the runway environment due to 'flash blindness' when he turned on the airplane's landing light, and his subsequent inability to regain control of the airplane after turning off the landing light due to his loss of night vision. A factor was the bright light condition encountered by the pilot.
Source: NTSB Aviation Accident Database
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