History of Flight
The pilot of the Remote Helicopters (NWT) Ltd. Bell 206B helicopter (registration C-GRHM, serial number 600) was performing water-bucketing operations to support forest-fire suppression approximately 23 nautical miles northeast of Wabasca, Alberta. At around 1600 mountain daylight time, the helicopter contacted trees adjacent to a shoreline, broke up, and came to rest inverted. The pilot, the sole occupant, was fatally injured.
Records indicated the helicopter was certified, equipped, and maintained per regulations and approved procedures, with no known deficiencies before the accident flight. The aircraft weight was estimated under the maximum gross weight limit, and the center of gravity was within limits. Sufficient fuel was on board.
Weather observations at Pelican airstrip, three nautical miles south of the accident site, recorded a temperature of 32°C and winds from the south-southwest at 5 gusting to 15 mph at 1430. At 1730, the temperature was 32°C with winds from the south-southwest at 8 gusting to 14 mph.
The pilot departed Wabasca at approximately 1030, arriving at Pelican aerodrome 20 minutes later. He then conducted forestry crew and equipment movements, accumulating 3.5 flight hours that day.
The pilot was observed suffering from allergy-like symptoms. At about 1400, he approached the camp medic for medication and was given a bottle of Reactine® (10 mg pills). He took two pills and returned the bottle, which contained a warning about possible drowsiness when operating vehicles. Another bottle of Reactine® 10 mg was found at the accident site with one pill remaining.
At approximately 1519, while C-GRHM was on the ground at Pelican, a request was made for water-bucket support for Fire 127. The pilot and two forestry officials prepared the aircraft and external load equipment. Connecting the longline/water bucket and removing the right-hand pilot door took 30 minutes, whereas industry standards consider 10 to 15 minutes ample. Door removal is common practice for longlining operations to facilitate external load monitoring.
The pilot departed Pelican at 1550 and proceeded to Fire 127. Water drops were directed by the fire operations officer in C-FALP, another Bell 206. The pilot had difficulty picking up the first water load. After the first drop, C-FALP escorted C-GRHM partway back to the water pickup lake.
At about 1608, C-FALP could not contact C-GRHM on any of three radio frequencies. The C-FALP crew located the accident helicopter on the ground along the western shore of the lake. The C-FALP pilot transmitted a MAYDAY and landed near the accident site, where the fire operations officer observed the pilot was deceased.
Wreckage and Impact Information
The wreckage was found at latitude 56°13′61′ N, longitude 113°18′191′ W, along the western shore of the lake used for water pickup. The helicopter was inverted on its left-hand side roof in the middle of a cutline, approximately 54 feet from the lake edge, oriented parallel to the shore (160°M).
A 50-foot longline attached to the bucket was loosely strung from the water-bucket clevis to the belly hook. The bucket clevis was detached from the longline hook, but no explanation was found. The hook functioned normally in tests on site and later by the manufacturer.
The water bucket was at the shoreline with its dump valve open. The bucket is 14 feet long when suspended; the dump valve normally closes automatically when suspended via a tensioned wire cable and only stays open when not suspended. The bucket functioned normally in post-accident testing.
Damage to trees was observed between the cutline and shoreline, with landing skid marks in tree bark on the lake side of trees bordering the cutline. One tree-top was broken from a bending load. Tail rotor blades struck some trees and bushes between the lake and cutline during the break-up sequence.
Ground scars and component indications showed the engine was developing high power at impact and continued to run briefly afterward.
Main rotor blade strike marks were found on the tail boom just aft of the horizontal stabilizer (severing the tail boom), on the right side of the cabin at the pilot door post, and in the ground immediately in front of the fuselage. The last mark held one blade horizontal and parallel to ground level, buried about eight inches. This blade was intact and attached to the main head and trunnion. The other blade was severely damaged, with indications of strikes at high power. The mast was sheared off just below the trunnion, with severe mast bumping by both sides of the trunnion droop stops.
Pilot Information
The pilot held a valid commercial helicopter licence with five aircraft type endorsements. His last medical examination was on 26 March 2006. He had accumulated 2000 total flight hours, 800 on the Bell 206. His last pilot proficiency check on the Bell 206 was on 31 March 2006 with a previous employer. An initial VFR flight check with Remote Helicopters (NWT) Ltd. was completed on 27 June 2006, and an external load exam was written.
According to his logbook, the pilot had approximately 100 hours of longline experience and 40 hours of sling load experience. He had neither been trained nor authorized to conduct water-bucketing operations by his previous or current employer. No indication existed of any water-bucketing experience.
Toxicology reports indicated the presence of an anabolic steroid, but its possible effect could not be determined. The medical examiner and Transport Canada stated that Reactine® is a newer type antihistamine that rarely causes drowsiness.
Transport Canada's Handbook for Civil Aviation Medical Examiners does not contain guidelines for specific antihistamines. However, the Defence Research and Development Canada Guidelines for Flight Surgeons indicate that Reactine® may produce drowsiness and central nervous system side effects and is not recommended for aircrew. A study by Nicholson and Turner (1998) found that cetirizine (Reactine®) was not free from central nervous system effects, with subjects reporting greater sleepiness, shorter sleep latency, and poorer tracking task performance at specific times. The study concluded that cetirizine should not be used by air personnel.
Section 404.06(1) of the Canadian Aviation Regulations states that no holder of a permit, licence, or rating shall exercise privileges if an illness, injury, disability, drug, or medical treatment could impair their ability to do so safely.
Operations
A contract between the Alberta Ministry of Sustainable Resource Development and Remote Helicopters (NWT) Ltd. provided helicopter services including monitoring forests and firefighting activities such as personnel transport, water bucketing, drip torching, and moving external loads.
Helicopter operations in a forest-fire environment are complex and stressful, with changing conditions and priorities.
Water bucketing is normally done with the bucket clevis attached directly to the belly hook. The bucket is rigged for a lateral cargo hook, as was the case for C-GRHM. Correct attachment requires the name plate on the bucket control head to face forward, aligning the ballast pouch forward. For this flight, the pilot attached a longline to the bucket, allowing the bucket to swivel in any direction, requiring higher skill when filling from a hover. This method is typically used when depositing water into a portable reservoir through trees.
This helicopter and pilot had been hired to transport the fire boss for assessment purposes. The pilot had received necessary training for that mission and had flown 6.1 hours on July 2, 7.5 hours on July 3, and 3.5 hours on the accident day. At the time of hire, there was no mention by the ministry that external load operations would be required. The casual contract lists mandatory equipment for rotor wing on fire operations, including many external load pieces. The ministry expects that both the helicopter and pilot be qualified to use the tools or advise the on-site supervisor if they cannot carry out the assigned mission.
Section 5.6.31 of the operator's operations manual addresses specialized training, requiring initial/recurrent flight and ground training before a pilot is assigned to duties involving specialized techniques like longline, water bucketing, or hover exit. The pilot had not completed this specialized training, nor were all required forms or exams completed. The operator had no system to ensure flight crews did not attempt missions or equipment for which they were not trained.
Investigation Findings
Investigation of the aircraft wreckage and components found no indication of any mechanical malfunction that may have initiated or contributed to the accident sequence. Weather was not considered a factor.
Although the initiating event could not be determined, it is most likely that the pilot was filling the water bucket near the edge of the lake and drifted toward the shoreline, where the left skid tubes contacted trees. This resulted in loss of control and a dynamic rollover condition. The damage patterns were consistent with this scenario.