# NTSB FTW98LA118: Cessna 172M, N13711, Bulverde, TX, February 4, 1998 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: February 3, 1998, 19:45 local (Feb 4, 1998, 01:45 UTC) - Place: Bulverde, TX - Coordinates: 29.800415, -98.729042 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=29.8004&lon=-98.7290&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report February 15, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 20531 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW98LA118 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/20531/pdf - Page: https://openairdocs.org/ntsb/FTW98LA118 ## Probable cause 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. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, approach - vfr pattern - downwind - electrical system,voltage regulator - inoperative (cause) - In flight collision with object, approach - vfr pattern - final approach - object - tree(s) (contributing factor) - proper glidepath - not maintained, pilot in command (cause) - lack of total experience in type operation, pilot in command (contributing factor) - light condition - dark night (contributing factor) - In flight collision with terrain/water, descent - uncontrolled ## Analysis 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. ## Factual narrative 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. ## Aircraft - Registration: [N13711](https://openairdocs.org/deregistered/N13711-2011-02-24), registration cancelled 2011-02-24, S/N 17262958 (OpenAirDocs) - Reported make and model: Cessna 172M - Registry model: [Cessna 172M](https://openairdocs.org/model/cessna-172m) (registry code 2072418) (OpenAirDocs) - Category: Airplane - Serial number: 17262758 - Airframe hours: 2822 - Engines: Lycoming O-320-E2D 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Gregg R. Gandy - Registered owner: Arnold J. Sivek, Jr - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, March 21, 1997 - Departed: 5C1, BOERNE, TX - Destination: 11XS - Airport: 11XS, Bulverde, runway 34, 3,200 × 75 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 40; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 118 total, 75 in this make and model, 50 as pilot in command, 20 in the last 90 days, 10 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Night/dark - Wind: 330° at 2 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 55 °F, dew point 36 °F ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19980203007289A](https://openairdocs.org/incident/19980203007289A), Feb 3, 1998: Cessna 172M, Bulverde, TX, Substantial damage. Total electric failure. Struck trees on night landing. Came to rest 100 ft short of runway in 100 ft tall trees. (.4)on ferurary 3, 1998, at 1945 central… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.