On July 30, 2000, approximately 1700 Pacific daylight time, a Short Brothers SD3-30 200 airplane, N179Z, registered to and operated by the U.S. Forest Service on a public-use firefighting mission, was substantially damaged when the parachute of a cargo box being dropped from the aircraft became entangled in the aircraft's horizontal stabilizer. Following the entanglement, the cargo box (which contained chain saws and water for a smokejumper crew which the aircraft had just dropped) broke free of its parachute and fell away from the aircraft, and the aircraft subsequently returned to its departure base of Missoula, Montana, and landed without further incident. There were no injuries to the airline transport pilot-in-command, copilot, or two spotters aboard the aircraft, nor were there any reports of injuries to persons on the ground. The accident occurred near Frog Lake, in the Selway-Bitterroot Wilderness of the Clearwater National Forest, on the Idaho side of the Idaho/Montana border approximately 60 miles northeast of Elk City, Idaho. Visual meteorological conditions prevailed at the time of the accident, and the aircraft was on an agency visual flight rules (VFR) flight plan. The pilot reported: ...We dropped 8 smoke jumpers and three cargo passes without incident. The fourth pass was a chainsaw box and water cubie. The next cargo pass was performed at 200ft. with an airspeed of 105-110 knots, air was stable. The command to "kick" was given and within a second the aircraft pitched down. Back pressure and power were applied. Several other up and down pitches occurred. Both the box breaking away and the chute blowing out caused the aircraft to return to flying in a normal manner....The aircraft was flown back to [Missoula], an emergency declared, landing performed without further incident. The pilot indicated on his NTSB accident report that no aircraft mechanical malfunction or failure was involved in the accident. A letter attached to the pilot's NTSB accident report, signed by the Director of Recreation, Minerals, Lands, Heritage, and Wilderness of the U.S. Forest Service's Northern Region, Missoula, Montana, stated that the mishap consisted of "the cargo and parachute exiting the aircraft improperly, thus becoming entangled in the horizontal stabilizer" (according to an FAA inspector from the Helena, Montana, Flight Standards District Office [FSDO], the cargo deployed over the top of the horizontal stabilizer and the parachute deployed under the horizontal stabilizer.) The Forest Service director's letter went on to state that the mishap "was caused by external events involving either paracargo packing, handling, or deployment." The pilot's NTSB accident report stated that in response to the accident, "The Smokejumpers have...rerigged their chainsaw boxes to allow for normal deployment", and that "Drop procedures have been changed for better monitoring of cargo chute & static line."