History of Flight
On June 4, 2013, about 1531 Alaska daylight time, a float-equipped de Havilland DHC-2 (Beaver) airplane, registration N616W, sustained substantial damage when it collided with mountainous, tree-covered terrain about 14 miles east of Petersburg, Alaska. The airplane was operated by Pacific Wings LLC as a visual flight rules (VFR) sightseeing flight under 14 CFR Part 135. Of the seven people aboard, the pilot and three passengers sustained minor injuries, two passengers sustained serious injuries, and one passenger was fatally injured. Visual meteorological conditions prevailed, and company flight following procedures were in effect. The flight originated at the Lloyd R. Roundtree Seaplane Facility in Petersburg about 1519.
The flight was a sightseeing flight for cruise ship passengers whose ship was docked in Petersburg. As part of company flight following, Pacific Wings uses Spidertracks for real-time tracking. During an interview, the operator's director of operations reported that after returning from a flight, he was alerted that the flight track for the accident airplane had stopped transmitting along the anticipated route to LeConte Glacier. Unable to establish radio contact, he initiated a search. The standard tour flight was 45 minutes, but pilots could alter the route based on weather conditions.
About 1547, the US Coast Guard received a 406 MHz ELT signal from the accident airplane. At about 1614, after notification of an overdue airplane and reports of an ELT signal along the anticipated route, search and rescue personnel from USCG Air Station Sitka began a search. About 1816, a USCG HH-60 helicopter located the wreckage. A rescue swimmer discovered one occupant deceased and six survivors, who were hoisted and transported to Petersburg.
The pilot stated that the accident flight was his fourth of the day and third tour. He reported weather had deteriorated with a ceiling of about 2,000 feet, light rain, and fog along mountain ridges. He departed for LeConte Glacier via Horn Cliffs. While approaching a mountain pass, he initiated a climb by adding a little flap (about 1 pump of the flap handle actuator) without adjusting engine power from cruise. He noted 80 knots airspeed and a 200 feet per minute climb. He had difficulty seeing over the cowling due to the nose-high attitude and noticed trees in his flight path. He initiated an immediate left turn; the airplane stalled and began to drop, impacting the terrain. The pilot stated there were no preaccident mechanical anomalies.
A passenger recalled receiving a preflight safety briefing. After departure, the airplane made a left turn, stalled, then a sharp left turn before impact. He reported low clouds but good visibility, and they did not enter clouds. The engine speed seemed to increase significantly just before impact.
Personnel Information
The pilot, age 39, held an airline transport pilot certificate with multi-engine land rating and commercial privileges for single-engine land and sea. He also held a Hawker Siddeley HS-125 type rating. His most recent first-class medical certificate was issued April 24, 2013, with a limitation not valid after October 24, 2013. According to the operator's report, his total aeronautical experience was about 4,841 hours, with about 1,465 hours in same make and model. In the preceding 90 and 30 days, he flew 114.1 and 45.7 hours. His most recent Part 135 check ride was on February 5, 2013, administered in an amphibious Cessna 185.
Aircraft Information
The airplane was a 1958 de Havilland DHC-2 MK1 (Beaver) with a total time in service of 34,909.3 flight hours. The most recent annual inspection of airframe and engine was on January 22, 2013, 76.1 hours before the accident. The engine was a Pratt and Whitney R-985 radial rated at 450 horsepower, overhauled 1,015.6 hours before the accident. The airplane was equipped with Edo 4930 floats. According to the FAA-approved flight manual, the stall speed for a DHC-2 with flaps up at an estimated gross weight of 5,057 pounds ranges from 60 to 105 miles per hour, depending on bank angle.
Meteorological Information
The closest weather reporting facility was Petersburg Airport, about 14 miles west. At 1536, a METAR reported calm wind, visibility 2.5 statute miles with light rain and mist, scattered clouds at 500 feet, broken clouds at 1,300 feet, overcast at 1,800 feet, temperature 52°F, dewpoint 48°F, altimeter 30.03 inHg.
Wreckage and Impact Information
On June 5, the NTSB investigator-in-charge, assisted by the US Coast Guard and two volunteers from Juneau Mountain Rescue, reached the accident site with an Alaska State Trooper. The on-scene examination revealed the airplane impacted in a near vertical attitude on a tree-covered 37-degree slope at an elevation of about 912 feet mean sea level. The nose was on approximately a 30-degree magnetic heading, uphill. Trees surrounding the site exceeded 200 feet tall. All major components were at the main wreckage site. An initial impact point was marked by a broken treetop about 80 feet from the main site, with about 4 feet of the outboard right wing found at its base.
The right wing separated into three sections; the largest remained attached to the aft wing attach point but separated from the forward attach point. Extensive spanwise leading edge aft crushing was present. Flight control surfaces separated from their attach points. The left wing was severed and suspended in trees above the main site, exhibiting spanwise leading edge aft crushing with multiple elliptical impact areas. Its control surfaces remained attached; the left wing lift strut separated at the fuselage. The airplane impacted on its nose and float tips; both float tips showed impact damage and the float support structure collapsed.
Extensive impact damage was evident to the firewall and right cockpit area. The forward right-hand door remained attached but the door post and forward fuselage exhibited crushing. The empennage was bent to the right about 90 degrees just forward of the horizontal stabilizer. The left horizontal stabilizer showed leading edge aft crushing with two elliptical impact areas; the right was relatively undamaged. The left elevator separated at the outboard attach point; the right remained attached. The cowling was crushed upwards and aft. The engine assembly separated from the firewall and had impact damage to the front and underside. The exhaust tube had malleable bending and folding with sharp creases not cracked or broken. The propeller and hub remained attached to the crankshaft; two blades had extensive bending and torsional S-twisting; the third had leading edge gouges, torsional S-twisting, and chordwise scratching. Control continuity could not be established due to impact damage. Examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.