Thomas Marovich died on July 21, 2009 when he fell while performing routine helicopter rappelling proficiency training while assigned to the Backbone fire near Willow Creek, California. On October 2, 2009 the Occupational Safety and Health Administration (OSHA) issued “serious” and “willful” violation notices to the U. S. Forest Service for the incident.
The USFS has just released their Preliminary Aircraft Accident Investigation Report which was completed on October 19, 2009, and a Safety Action Plan dated February 1, 2010. The report is 63 pages long, but I will mention a few of the key points.
A proficiency rappel is required every 14 days to maintain technical competency. Marovich was in his first season rappelling and was about to make his 11th rappel.
Before the rappelling training, Marovich noticed that the Kong clip on his Tri-link was broken. The Kong Clip is used to center the “J” hook at the forward corner of the Tri-link. It is a nice piece of equipment to have, but is not essential. Kong clips are prone to breaking and are not popular. He sought assistance from a spotter trainee who replaced the Kong clip with an “O” ring, which was an authorized substitution. If I interpreted the report correctly, the “O” ring was installed incorrectly.
Here are some photos from the report showing for illustration purposes examples of a correct and then an incorrect installation of an “O” ring on a Tri-link.
"J" hook, Tri-link, and an "O" Ring, correctly installed. USFS photo.
"J" hook, Tri-link, and an "O" Ring, incorrectly installed. USFS photo.
Three different equipment rigging set ups. The top set up is rigged correctly using a Kong clip. The middle set up is rigged correctly using an O-ring. The bottom set up is rigged improperly using an O-ring. USFS photo.
Before the rappelling attempt, four people looked at or inspected Marovich’s rappelling gear: the spotter trainee who installed the “O” ring, Marovich, and in the helicopter a spotter, and another helitack crewperson who did a “buddy check”.
This photo was taken seconds before Marovich fell, unarrested. He is on the left side.
Marovich fell, unarrested, shortly after stepping out onto the helicopter skid. He was pronounced deceased about 30 minutes later.
The Human Factors section of the report, beginning on page 33, is particularly interesting. Written by Jim Saveland and Ivan Pupulidy, it discusses, along with other issues, the concept of not seeing elements in our visual field, or “blindness”.
Below are some excerpts from that section:
