UH-1 Tailboom Motion Detection System
On September 16, 2013, about 1535 Pacific daylight time, a Garlick UH-1B, N204UH, experienced a tailboom separation while logging in heavily wooded terrain about 3 miles east of Detroit, Oregon. The pilot, who was the sole occupant on board, was fatally injured. The helicopter sustained substantial damage to the tailboom, main rotor system, and fuselage.
Witnesses reported that when the helicopter was just above the trees, they either observed or heard the load of logs release early and impact the ground hard. After looking up, they observed the helicopter's fuselage separate from the tailboom; both descending through the trees. The fuselage impacted the ground inverted and the tailboom came to rest about 140 feet away.¹
At the memorial service for the pilot, Bart Colantuono, UH-1 operators and mechanics in attendance sat down at table and discussed the accident, causes and possible solutions to alleviate losing any more aircraft or pilots in the same type of accident. Many UH-1 operators are already aware that the tailboom fittings in UH-1 helicopters can be fractured after years of service and those in attendance immediately focused on this as the cause.
As far as a solution, the idea of a tail boom motion detector was proposed during the impromptu gathering. Aircraft Structural Repair’s president, Dustin Wood, from Stevensville, Montana worked with operators of UH-1’s and developed a working tail boom motion detection system, called the BART system, to initially install into UH-1B helicopters with a tailboom plug. Currently three of the systems have been installed and approved through the Federal Aviation Administration (FAA) 337 Major Repair and Alteration. Installations for UH-1H's are also available.
“It is nice to see operators and mechanics working together to come up with solutions that can save lives,” said Dustin Wood “Being proactive about finding a life saving solution so Bart did not die in vain was important to us all”
The system was put to the test on February 14, 2015. A logging pilot in the Northwest was performing 133, external load operation in an UH-1B helicopter with the BART tailboom motion detection system installed. While flying a load of logs the pilot heard a loud bang and immediately noticed the master caution light was on and the caution panel was illuminated with the “TAILBOOM” light.
The pilot immediately removed all left pedal input, released the load, and landed with as minimal left pedal as possible – without incident.
Upon inspection, the upper LH tailboom fitting was found cracked as well as the sheet metal former on the upper LH tailboom bulkhead. Two pilots who flew this helicopter and checked the fitting closely prior to this flight with flashlights did not see any visible cracking or rivets smoking that would have indicated a problem.
The broken fitting was examined and determined the length of time the fitting was cracked was minimal. According to the pilot it was evident by this incident that a full break in the tailboom fitting could have become catastrophic immediately.
Aircraft Structural Repair of Stevensville Montana is now offering the BART tailboom motion detection system for UH-1’s for installation through the FAA 337 field approval process. This includes the installation of a Tailboom Motion Detection System to alert the pilot of a cracked upper LH tail boom fitting, longeron or attach bolt. The system consists of a rod incased in tubing to the interior of the tail boom and extending forward into the fuselage where a micro switch is attached to the airframe. Upon failure of an upper LH tail boom fitting, longeron or attach bolt the switch will illuminate the master caution panel indicating TAILBOOM. In most cases the BART system can be installed in 12 hours or less.
“Since the BART Motion detection system was introduced at the HAI Huey Forum in Orlando in March 2015 interest has been steady from operators contacting me.” according to Dustin Wood “We would like to get more of them installed, save more lives and make the UH-1 fleet that much safer.” Dustin Wood at Aircraft Structural Repair, Inc. can be contacted by email at email@example.com or by phone at 406-531-7297.
¹ Extracted from National Transportation Safety Board Report WPR13FA411