Aviation Accident Summaries

Aviation Accident Summary FTW99FA033

BACLIFF, TX, USA

Aircraft #1

N4908D

Cessna 172N

Analysis

While on a local VFR flight, the non-instrument rated private pilot encountered instrument meteorological conditions, and subsequently, the airplane collided with power lines and terrain. At the time of departure, the weather conditions at the airport were visibility 5 miles in mist and ceiling broken at 2,200 feet. About 7 minutes after the airplane's departure, the local controller noted that a fog bank was moving towards the airport from the southeast. About 17 minutes after departure, the airplane collided with 120-foot high power lines approximately 10 miles southeast of the airport. The collision severed the left wing, and the airplane then impacted on a road and slid into a ditch. Witnesses reported that it was 'very foggy' when the accident occurred. Examination of the airframe and engine revealed no evidence of any pre-impact mechanical discrepancies that would have prevented normal operation. The pilot had 124 hours total flight time, of which 2.3 hours were under simulated instrument conditions.

Factual Information

HISTORY OF FLIGHT On November 24, 1998, at 1101 central standard time, a Cessna 172N airplane, N4908D, was destroyed when it impacted power lines during cruise flight near Bacliff, Texas. The airplane was registered to a private individual and operated by Lentz Flying Service of Houston, Texas. The non-instrument rated private pilot and his passenger received fatal injuries. A flight plan was not filed for the 14 Code of Federal Regulations Part 91 personal local flight that originated from Houston's Ellington Field Airport at 1044. The FAA had no record of the pilot receiving a telephone weather briefing for the flight. According to witnesses, instrument meteorological conditions prevailed at the accident site. Immediately prior to the accident flight, another pilot and a flight instructor flew the airplane on an instrument instructional flight. The flight instructor reported that there were no discrepancies with the airplane during the 45-minute flight, which departed Ellington Field on an instrument flight rules (IFR) flight plan. The flight terminated with an instrument landing system (ILS) approach back to Ellington Field. The flight instructor gave the keys of the airplane to the accident pilot, who was scheduled to rent the airplane from 1000 to 1200. Review of a voice tape provided by the FAA, which contained the communications between the Ellington Field control tower and the airplane, revealed that when requesting taxi clearance, the pilot reported that he had listened to automatic terminal information system (ATIS) broadcast "Hotel." ATIS "Hotel" included the 1025 Ellington Field weather observation, which reported visibility 5 miles in mist and ceiling broken at 2,200 feet. (For the entire 1025 weather observation, see the Meteorological Information section of this report.) The pilot requested a southeast departure, and the airplane was cleared for takeoff on runway 17R and given a left turn out of the traffic pattern. Approximately 7 minutes after the airplane departed, during a transmission to another aircraft, the local controller stated that there was "a fog bank moving in from the southeast." Examination of radar data recorded by Houston Terminal Radar Approach Control revealed that after takeoff, the airplane turned left to an easterly heading and climbed to an altitude of 800 feet msl. Approximately 1049, the airplane turned right to a south-southeast heading and continued to climb until it reached an altitude of 1,200 feet msl at 1054:34. The airplane continued to head south-southeast for about 1 minute, until it reached a point approximately 15 nautical miles southeast of Ellington Field. The airplane then made a 180-degree right turn, followed immediately by a 45-degree left turn, which placed it on a northwesterly heading. Between 1057:34 and 1059:34, the airplane descended from 1,100 to 400 feet msl, then climbed to 900 feet msl. During this time period, the airplane's heading gradually changed from northwest to northeast. The airplane remained at 900 feet msl for about 30 seconds, then again began to descend. The last radar return with an associated altitude, recorded at 1100:48, placed the airplane at 300 feet msl, approximately 10 nautical miles southeast of Ellington Field and approximately 1/4 mile southwest of the accident site. A witness, who was driving northbound on Highway 146, stated that he observed the airplane "hit the power lines" that paralleled the west side of the highway. The airplane then impacted the road "right in front" of his vehicle and "slid off into the ditch" running along the east side of the highway. Another witness, who was also driving northbound on Highway 146, stated that the airplane "crashed on the road closely behind [her vehicle]." Both witnesses reported that it was "very foggy" when the accident occurred. AIRCRAFT INFORMATION Examination of the airplane's maintenance records by the NTSB investigator-in-charge (IIC) revealed that the 1979 model Cessna 172N, S/N 17272393, received its most recent annual inspection on September 10, 1998. A 100-hour inspection was completed on October 29, 1998, at an airframe total time of 3,525 hours. As of this date, the engine had accumulated 1,675 hours since major overhaul. When the accident occurred, the airplane and engine had accumulated 35 hours since the 100-hour inspection. Review of the maintenance records revealed no evidence of any uncorrected maintenance discrepancies. PERSONNEL INFORMATION The pilot held a private pilot certificate with a single engine land airplane rating. He held a third class medical certificate dated July 14, 1997, with the limitation: must wear corrective lenses. The pilot's logbook, which was recovered from the airplane and examined by the NTSB IIC, indicated that the pilot had accumulated a total of 124 hours of flight time, all in Cessna 172 airplanes. According to the logbook, the pilot had flown a total of 2.3 hours under simulated instrument conditions. METEOROLOGICAL INFORMATION At 1025, the reported weather conditions at Ellington Field were wind from 120 degrees at 6 knots, visibility 5 statute miles, mist, scattered clouds at 400 feet, ceiling broken at 2,200 feet, temperature 22 degrees C, dewpoint 21 degrees C, and altimeter setting 30.21 inches of mercury. The remarks section of the 1025 weather observation stated that the visibility to the south was 3 statute miles. At 1055, the reported weather conditions at Ellington Field were wind from 130 degrees at 7 knots, visibility 5 statute miles, mist, scattered clouds at 400 feet and 1,600 feet, ceiling broken at 5,000 feet, temperature 22 degrees C, dewpoint 20 degrees C, and altimeter setting 30.20 inches of mercury. The remarks section of the 1055 weather observation stated that visibility to the south was 2 statute miles. At 1052, the reported weather conditions at Scholes Field in Galveston, Texas, located 15 nautical miles south of the accident site, were wind from 080 degrees at 9 knots, visibility 5 statute miles, mist, ceiling overcast at 100 feet, temperature and dewpoint 21 degrees C, and altimeter setting 30.20 inches of mercury. WRECKAGE AND IMPACT INFORMATION According to FAA inspectors, who responded to the site, the accident occurred approximately 10 nautical miles southeast of Ellington Field at the intersection of Highway 146 and Jasper Road. A handheld global positioning satellite (GPS) receiver located the site at 29 degrees 30.930 minutes north latitude and 95 degrees 00.925 minutes west longitude. Four power lines, each supported by towers which the inspectors estimated to be 120 to 130 feet tall, paralleled the west side of Highway 146. The static wire (top wire) on the power line closest to the highway was severed. The outboard two-thirds of the airplane's left wing was found on the west side of Highway 146 near the base of one of the power line towers. The majority of the airplane came to rest inverted in a ditch on the east side of Highway 146 immediately south of Jasper Road. The inspectors noted a "strong fuel odor" at the accident site. Following their on scene examination, the FAA inspectors arranged for the recovery of the wreckage, which was transported to the U.S. Coast Guard facility at Ellington Field. On November 25, 1998, the wreckage was examined at the Coast Guard facility under the supervision of the NTSB IIC. The fuselage between the firewall and the forward doorposts was bent up and to the right, and the left forward section of the cabin was crushed inward. The right wing and empennage remained intact and attached to the fuselage. The top portion of the vertical fin and rudder were crushed and bent to the right. Control continuity was established from the control surfaces to the cockpit for the elevators, elevator trim tab, and rudder. Aileron control continuity could not be established due to separation of the left wing. The flap actuator was not extended, which corresponds to a retracted flap position. The left wing separated along a jagged surface extending diagonally from a point on the leading edge approximately 12-feet, 8-inches inboard of the tip to a point on the trailing edge approximately 8-feet, 8-inches inboard of the tip. The left aileron remained attached to the separated section of the wing. The left wing lift strut was severed approximately 2 feet below the wing attach point. At the separation point, the leading edge of the strut displayed a semi-circular indentation oriented approximately parallel to the wing leading edge. Abrasion marks were present on the leading edge of the strut from the separation point to the wing attach point. Abrasion marks were also noted on the front of the strut attach fitting and on the bottom of the forward wing spar inboard of the strut attach point. From the strut attach point outboard for about 3 feet, the underside of the wing leading edge was crushed upward and displayed dull gray metal transfers. The 160-horsepower Lycoming O-320-H2AD engine was partially separated from the airframe. Severe impact damage was noted on the left side of the engine in the area of the #2 cylinder. The aluminum head of the #2 cylinder was fractured into pieces, and the steel barrel was bent. After removal of the #2 cylinder by investigators, the crankshaft was manually rotated and continuity was established to the valve train and accessory drive gears. During rotation, thumb compression was obtained on cylinders #1, #3, and #4, and the dual magneto sparked at all terminals. The vacuum pump drive coupling was intact, and the pump turned freely when the crankshaft was rotated. The McCauley fixed pitch propeller remained attached to the crankshaft. One blade displayed leading edge gouges, chordwise scratches, and "S" bending. The other blade displayed chordwise scratches and was twisted. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy of the pilot was performed at the Galveston County Medical Examiner's Office in Texas City, Texas. Toxicological tests performed by the FAA's Toxicology and Accident Research Laboratory were negative for carbon monoxide, cyanide, ethanol, and drugs. ADDITIONAL INFORMATION The airplane was released to a representative of the owner on January 11, 1999.

Probable Cause and Findings

The pilot's inadvertent VFR flight into instrument meteorological conditions and his inability to maintain adequate altitude/clearance from the wire. Contributing to the accident were the fog, low ceilings and his lack of instrument time.

 

Source: NTSB Aviation Accident Database

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