Thursday, January 1, 2009
Training: Accident Watch
On Sept. 21, 2008, at about 0538 CDT, the Robinson R44 II was destroyed when it impacted an occupied house and terrain near Kenosha, Wis. Instrument meteorological conditions prevailed at the time of the accident. No flight plan was on file. The private pilot and a passenger were fatally injured. The personal flight originated from the Horseshoe Casino Heliport near Whiting, Ind. about 0430, and was destined for the Kenosha Regional Airport near Kenosha, Wis. when the accident occurred.
"My family and I were asleep in our residence when I heard a loud bang like thunder. And then a cloud of debris came through our bedroom door. My wife and I were in the southeast bedroom. Our two sons were in the northeast bedroom and our daughter was in the bedroom over the garage. We got our kids and, with the help of our neighbors, made it down the stairs and outside. None of us were injured. I saw the flames across the street and one of our neighbors told me a helicopter hit our house." — Noel Wilson, Homeowner.
The main portion of the helicopter wreckage was found on a neighbor’s lawn across the street. A debris path started at the rear of the second floor above the house’s central staircase where the helicopter had come through the roof. The debris path was observed down those central stairs and through the front of the house. The path continued across the street and went to the resting helicopter.
A preliminary on-scene investigation did not show any indication of mechanical failure. However, at 0534 hrs the recorded weather at the local airport was wind 360 degrees at 3 kts and visibility ¾ statute mi in mist. Sky conditions were overcast at 100 ft, temperature 17 degrees C, and dew point 16 degrees C. Additionally, a state patrol trooper, who was outside a weigh facility about six miles south of the accident site, heard a helicopter heading north at a very low altitude and estimated it at 500 ft. He did not see the helicopter or its lights due to dense fog. He stated that the visibility there was about 300 to 500 ft.
Although the NTSB states this is a preliminary report and has not issued a probable cause, there are some things that stand out. The pilot had been flying for an hour, was close to his destination and was pushing weather. Nobody wants to land a few miles from their destination and since their home area is normally well known, pilots seem to take more risks to get there.
It is not just private pilots who can be affected by the desire to get home. On Dec. 10, 2006, about 1755 PST, a Bell 412SP impacted mountainous terrain near Hesperia, Calif. The commercial pilot and two medical crewmembers were killed and the helicopter was destroyed as a result of the post impact fire. Visual meteorological conditions predominately prevailed along the route of flight. The pilot had transported an injured patient from Phelan, Calif. to Loma Linda and was returning to his assigned base at the time of the accident. The pilot had traversed through the Cajon Pass in the area of the accident site five times previously on the date of the accident. The accident flight was the first flight of the pilot’s shift that was conducted during night conditions. After departing the Loma Linda University Medical Center heliport the flight proceeded toward the Cajon Pass. The Cajon Pass is one of the main avenues of transition between the San Bernardino/Riverside basin and the helicopter’s base in Victorville. The route along the highway is away from a well-lighted residential/industrial area having a well-defined horizon, and toward rising and dark terrain. Once at the top of the pass as the highway turns toward the northeast, the lights from the upper desert communities are once again visible.
At the beginning of the accident day the Victorville base received a mission request for a hospital transfer from Apple Valley, Calif. After checking the weather at 0753, the pilot declined the flight due to poor weather conditions in the Cajon Pass. The pilot then conducted three medical flights during the afternoon. The accident occurred during the positioning flight back to Victorville at the conclusion of the third mission. Weather conditions at the bottom of the pass were VFR and the upper desert at the destination airport was clear. However, the first fire department responders to the accident site reported that the area was covered by intermittent waves of fog, which made it difficult to locate the wreckage.
The NTSB determined the probable cause of this accident to be the pilot’s inadvertent encounter with instrument meteorological conditions and subsequent failure to maintain terrain clearance.
The similarities here are that both pilots were in familiar territory and trying to get home. Unfortunately, being familiar with an area can breed a false sense of security. Moreover, the desire to get home can be very strong making the option of turning around or landing very hard to do. However, that is the very time we must stop and seriously consider the risks.