BULVERDE, TX, USA
N13711
Cessna 172M
During the dark night landing approach for runway 34, following a total electrical system failure, the airplane struck trees. The pilot was on a lower glidepath and a higher airspeed than when using flaps (electric). The pilot planned the descent to touch down just beyond the threshold lights to allow as much runway as possible for a faster than normal landing. The pilot had 4.4 hours of night flight time. An examination of the electrical system revealed that the voltage regulator was not operating properly. Maintenance history for the electrical system components is unknown.
On February 3, 1998, at 1945 central standard time, a Cessna 172M, airplane, N13711, struck trees during the landing approach near Bulverde, Texas, after experiencing a total electrical system failure. The airplane was operated by one of the co-owners under Title 14 CFR Part 91. The private pilot, sole occupant, was not injured, and the airplane sustained substantial damage. Visual meteorological conditions prevailed for the cross country flight and a flight plan was not filed. The flight departed Boerne, Texas, approximately 15 minutes prior to the accident. During a personal telephone interview, conducted by the investigator-in-charge (IIC), and on the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), the pilot reported that the flight departed the Boerne Stage Field Airport for the return flight to Bulverde Airpark Airport. En route, the pilot obtained weather information by listening to the ATIS for San Antonio, Texas. At Bulverde, the pilot executed a downwind entry for runway 16 and activated the pilot controlled runway lights. During the completion of the landing checklist, the pilot selected the flaps; however, the flaps did not extend. Subsequently, the pilot checked the electrical system by trying the landing lights; however, the landing lights did not operate. During the base to final turn, the cockpit panel lights began to dim, and the radio stopped operating. The pilot attempted to get the wheels on the runway; however, the final approach speed was high and the airplane bounced back into the air. The pilot initiated a go-around and entered the pattern for a landing on runway 34. The pilot used a flashlight for monitoring the cockpit instruments. When the airplane was on short final for runway 34, the pilot "put one hand on the throttle. I was on a flatter approach that I otherwise would have been if I had flaps, and was descending to touch down just beyond the threshold lights to allow as much runway possible for a faster than normal landing. Approximately 75-100 yards short of the end of the runway, the shadow of a tree came into view just above the glare shield immediately in front of the airplane." The airplane struck the tree and descended to the ground. The pilot and the FAA inspectors who examined the site reported that the trees along the wreckage distribution path were 70 to 100 feet tall. The airplane came to rest approximately 100 yards short of the runway. Structural damage occurred to the propeller, engine mounts, firewall, wings, and empennage. The alternator circuit breaker was found "popped." On February 13, 1998, at Alamo Accessories, San Antonio, Texas, the alternator, alternator circuit breaker, and the voltage regulator were examined under the surveillance of the FAA inspector. The FAA inspector reported that the alternator "worked fine", but the voltage regulator did not work. The "voltage regulator finally came on line, but after running for a while the voltage and amperage would drop off gradually to '0' settings." Maintenance history for the electrical system components is unknown. The pilot's flight records were reviewed by the IIC. The pilot had logged 4.4 hours of night flight time.
The pilot's failure to maintain the proper glidepath following a total electrical failure resulting from an inoperative voltage regulator. Factors were the dark night conditions, the pilot's lack of experience in night flying, and the trees.
Source: NTSB Aviation Accident Database
Aviation Accidents App
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