FTW96GA365

During a night aerial application flight, the multiengine airplane impacted trees bordering a bayou/swamp area. The airplane was flown by a single pilot accompanied by a crew member to operate the spraying equipment. Company personnel stated that the crew member never flew the airplane. Two other pilots observed patchy fog forming along the ground and around the wooded bayou areas and returned to the airport. Local authorities stated that 'fog often forms up like a cloud out of the woods and spreads at tree height' during the night hours. The pilot's total flight time in the PA-23 airplane was 75 hrs (9.0 hrs in the previous 3 years). Marginal VFR weather with mist & thunderstorms was forecast. Airmet Sierra was valid for ceilings below 1,000 feet AGL with visibility below 3 miles with precipitation and mist. Area stations reported a temperature/dewpoint spread of one degree or less and the radiosonde data indicated a temperature/dewpoint spread of 4 degrees or less from the surface to 5,407 feet MSL. Terminal forecast winds were 5 knots or less. The average relative humidity was 90% with precipitable water at 139%.

History of flight:

On August 30, 1996, at 2323 central daylight time, a Piper PA-23-250, N14196, registered to and operated as a public use aircraft by the Jefferson Davis Parish Mosquito Abatement District No. 1, impacted trees while maneuvering near Jennings, Louisiana. The commercial pilot and another crew member were fatally injured and the airplane was destroyed. Dark night visual meteorological conditions prevailed for the local aerial application flight and a company VFR flight plan was filed. The flight originated at 2140.

During interviews, conducted by the investigator-in-charge, and on the enclosed statements, company pilots reported the following information. Rain showers occurred from 1800 through 2040 in the evening; however, at the time the flights departed the airport, the visibility was 10 to 15 miles with a ceiling at 1,400 feet AGL to 1,500 feet AGL. All of the flights operated with a single pilot except the multiengine airplane that had a "crew member as an observer to watch the area and to operate the spraying equipment while the pilot flew the airplane." The two single engine airplanes and the multiengine airplane (N14196) departed from runway 31 at the Jennings Airport and each airplane covered a designated area of the city. The pilot of N14196 sprayed his area with east to west swaths and once he had completed those areas, he was spraying the remainder of the load along the eastern edge of the Parish near the Bayou Nepzique.

During the flights, the two pilots of the single engine airplanes communicated via their aircraft radios; however, these pilots did not communicate with the pilot of N14196. One of the pilots reported that "at the end of my flight assignment there was some patchy fog around the wooded bayou areas." As this pilot returned to the airport for landing, he attempted to call N14196; however there was no reply even though he heard the base of operations radio repeater turn on. This single engine airplane landed at 2355. The second single engine airplane landed about 2410 and the pilot taxied the aircraft into the hangar as he "had begun to experience some patchy light ground fog forming in the area." N14196 did not return and the company pilots reported the airplane as missing. Search and rescue were initiated and the airplane was located at 1411 the following evening in the swamps adjacent to the Bayou Nepzique. Local authorities reported that the search was hampered by fog and that "fog often forms up like a cloud out of the woods and spreads at tree height" during the night hours. They further stated that the accident location was in a dark area of the swamps.

Bayou Nepzique marks the eastern boundary of the Jefferson Davis Parish and the western boundary of the Acadia Parish. The airplane was located in the swampy area along the east bank of the bayou inside the Acadia Parish. Interstate 10 (I-10) runs east and west across the bayou.

The driver of a vehicle, traveling west on I-10 at 2310 observed "the sky conditions to be high thin scattered clouds and at least 10 miles visibility in the area of Jennings." A witness, driving his vehicle east on I-10, reported observing an "airplane heading north and banked a little to the N-W [northwest] just over the Bayou Nezpique, and his running lights went out of sight, just over the trees [and] the time was between 11:15 & 11:30 PM [CDT]." Another witness who was riding in the vehicle recalled the driver saying "look at that plane it looks like it [is] going to land, there is no airport there." Then the witnesses "saw no[th]ing." A witness who lives in a residence at the approach end of runway 31 stated that she "noticed or heard that the engine or engines had a fluttering sound instead of the smooth sound that engine[s] produce." This witness further stated that the airplane "could have landed at the airport."

Personnel information:

The operator reported (NTSB Form 6120.1/2) the pilot's total time in this make and model (PA-23) airplane as 75 hours. Company records indicated that the pilot had flown the PA-23 for 3.7 hours in 1994, 1.9 hours in 1995, and 3.4 hours in 1996. Pilot logbooks were not made available to the Board. Company insurance records (copy enclosed) stated that the pilot had been involved in aerial application operations for 12+ years.

During interviews, conducted by the investigator-in-charge, company pilots stated the following information. The aircraft was certificated by the FAA for single pilot operations; however, the right seat person (Director of the Jefferson Davis Mosquito Abatement District) was considered a crew member by the company. The crew member would go along during the multiengine aerial application flights and operate the spraying equipment while the pilot flew the airplane. This crew member had flown an "estimated 1,000 hours during aerial application flights; however, he neither held nor was required to hold a pilot certificate and he never flew the airplane."

Aircraft information:

The Jefferson Davis Parish Mosquito Abatement District sent a letter dated March 1, 1988, to the FAA Flight Standards District Office at Baton Rouge, Louisiana, informing the FAA that the district would be operating N14196, Serial #27-4758, as a public aircraft. The standard airworthines certificate (FAA Form 8100.1) was returned to the FAA at that time.

The maintenance records were reviewed by the investigator-in-charge. Aircraft records indicated that an altimeter test as per FAR 91.411 was performed on January 18, 1991. Engine, serial #L-4027-48, was overhauled in February 1990 and reinstalled in the left position on N14196. Engine, serial #L-956-48, was disassembled, a crankcase crack repaired, tested, returned to service and installed in the right position on N14196 in May 1994. The last annual inspection was completed on May 20, 1996. Both propellers were overhauled, found airworthy, and returned to service on May 16, 1996.

Installed under the fuselage of the aircraft between station 91.50 and station 123.75 was a chemical resistant steel cage tank with an attached 8 foot spray boom. The chemical tank was held in place by 8 steel turn buckles each rated at 3,200 pounds. Installed in the center of the spray tank was a manually operated dump assembly with a cable running from the dump door through the inside of the aircraft to a handle positioned between the cockpit seats.

Meteorological information:

Weather reports were reviewed by the investigator-in-charge. The satellite photograph (enclosed) taken at 2303 indicated moisture covered portions of Southern Louisiana. The area forecast outlook for Louisiana included marginal VFR weather with mist and thunderstorms across the southern third of the state. Airmet Sierra was valid at the time of the accident for ceilings below 1,000 feet AGL with visibility below 3 miles with precipitation and mist developing over portions of the state.

The nearest local reporting stations to the Jennings Airport and the accident site (N 30 degrees 16 minutes 01.3 seconds; W 92 degrees 37 minutes 29.4 seconds) were Lake Charles, Louisiana, and Lafayette, Louisiana. Both stations reported a temperature/dewpoint spread of one degree or less throughout the time of the aerial application flight and the accident. Radiosonde (release time 2309) data indicated a temperature/dewpoint spread of 4 degrees or less from the surface to 5,407 feet MSL. Terminal forecast winds for Southern Louisiana were 5 knots or less.

The average relative humidity chart (surface to 500 millibars/hectoPascals; 18,000 feet MSL) indicated 90 percent across Southern Louisiana. The precipitable water panel indicated that 2.12 inches of precipitable water was present and that amount is 139 percent of normal (above normal) for any day during the month.

Wreckage and impact information:

The wreckage was distributed along a measured magnetic he