ATL99FA132

See narrative for ATL-99-FA-132A.

N38099 was flying southbound at 150 ft. agl spraying herbicides. N9010T had just taken off from a flatbed truck heading north behind a gathering of trees 100 ft. tall. N9010T climb over the trees to an altitude of 150 ft. at a speed of 35 mph. He then turned east into the sun, directly into the flight path of N38099. Within seconds, N9010T collided with N38099, impacting it on its lower right side. Immediately after impacting, both helicopters descended to the ground and came to rest 100 yards apart.

See narrative for ATL-99-FA-132A.

History of flight

On September 16, 1999, about 0730 central daylight time, a Continental Copters, Inc. Tomcat MK5A, N9010T, and a Texas Helicopters Corp. OH-13E/M74, N38099, collided in flight over a field in Heflin, Alabama. Both helicopters were registered to Gulf Helicopters, Inc., and operated by the commercial pilots under the provisions of Title 14 CFR Part 137, and visual flight rules. Visual meteorological conditions prevailed and no flight plans were filed. The pilots of both helicopters received fatal injuries, and both helicopters were destroyed. N9010T departed Heflin, Alabama, at 0725.

According to witnesses, N38099 was flying southbound about 150 feet above ground level (agl) spraying herbicides. N9010T had just taken off from a flatbed truck heading north behind a gathering of trees about 100 feet tall. A witness standing near the truck observed N9010T climb over the trees to an altitude of about 150 feet at a speed of 35 mph. He then turned east into the sun, directly into the flight path of N30899. Within seconds, N9010T had collided with N38099 on its lower right side. Immediately after the collision, both helicopters descended to the ground. Witnesses stated that they did not observe either helicopter take any evasive action prior to impacting.

According to several employees of Gulf Helicopters, Inc., who witnessed the accident, the pilots were used to working alone and did not normally work together in such close proximity. Despite the fact that both helicopters were equipped with radios, one witness stated that the two pilots were not in communication with each other at the time the accident occurred.

Personnel information

The pilot of N9010T was born on August 31, 1946. He held commercial pilot certificate 424588654, dated June 1, 1984, with airplane single/multiengine land and helicopter ratings. His certificate was issued with a limitation for carrying passengers for hire at night and on cross country flights of more than 50 nautical miles. He also held a DC-3 type rating, with a limitation for VFR flight only. In addition, he possessed a second class airman medical certificate, dated June 30, 1999, with the restriction, "Must wear corrective lenses." According to information the pilot provided on his most recent medical application, he had a total of 26,000 hours at the time of the examination.

The pilot of N38099 was born on May 25, 1970. He held commercial pilot certificate 418238172, dated December 17, 1998, with airplane single/multiengine land, instrument and helicopter ratings. His airplane multiengine land rating was issued with a limitation for VFR flight only. He also held a Flight Instructor certificate with airplane single engine land and instrument ratings. In addition, he possessed a second class airman medical certificate, dated April 30, 1999, with no restrictions or limitations. According to information he provided on his most recent medical application, he had accumulated a total of 2,500 hours at the time of his last examination.

Aircraft information

N9010T (s/n CCI-74-3), a Continental Copters Inc. Tomkat MK5A, was manufactured in 1974. It was equipped with a Lycoming VO-435-A1F (s/n L-618-31) engine, rated at 250 horsepower. It had a maximum gross weight of 2,350 lbs., and was a restricted category aircraft used for the purpose of agricultural and pest control. The last annual inspections on the engine and airframe were performed on November 23, 1998, at a tachometer time of 424 hours. At that time, the aircraft total time was 1941 hours, and the engine had accrued 361.4 hours since the last major overhaul.

N38099 (s/n 77-006), a Texas Helicopters Corp. OH-13E/M74, was manufactured in 1977. It was also equipped with a Lycoming VO-435-A1F (s/n L-1723-52) engine, rated at 250 horsepower. It had a maximum gross weight of 1,500 lbs., and was a restricted category helicopter also used for agricultural and pest control. The engine was installed in the aircraft on July 19, 1999, at a tachometer time of 636.6 hours. At that time, it had accrued 310.5 hours since the last major overhaul. The last annual inspections on the engine and airframe were performed on July 20, 1999. Both helicopters were equipped with herbicide tanks.

Meteorological information

At 0753, weather conditions in Anniston, Alabama, located 16 miles to the west, were clear skies, visibility 10 statute miles, winds from 140 at 8 knots, temperature 19 degrees C. (66 degrees F.), dew point 6 degrees C. (43 degrees F.), and an altimeter setting of 29.96 Hg.

Wreckage and impact information

After colliding, both helicopters impacted the ground and came to rest approximately 100 yards apart. N9010T's tail rotor was found 100 feet aft of the main wreckage. The tail boom and the skids were also separated from the fuselage. The main rotor was separated from the hub, and the engine and transmission were partial separated. N30899's tail rotor was intact, however the tail boom and tail rotor drive shaft were partially separated at the tail boom's midway point. The engine and transmission assembly remained attached to the main fuselage. The main rotor blades were separated at the blade's midway point. There were no pre or post impact fires.

Medical and pathological information

Autopsies on both pilots were performed by Dr. Stephen Pustilnik, MD, with the Alabama Department of Forensic Sciences in Birmingham, Alabama, on September 16, 1999. Toxicological protocols were also performed by the Alabama Department of Forensic Sciences. Results for ethanol, carboxyhemoglobin and drugs were all negative on each pilot.

Additional information

FAR Part 137 (Agricultural Aircraft Operations) does not address mandatory training, coordination or communication requirements for multi aircraft agricultural operations.

Other than the Federal Aviation Administration, there were no additional parties to the investigation.

Both helicopters were released to the operator, Gulf Helicopters, Inc., on September 16, 1999.