Man Hit By Aircraft During Arctic Nuclear Sub Exercise

Man Hit By Aircraft During Arctic Nuclear Sub Exercise (UPDATED 19 Dec 2019)

Often headlines disappoint.  Well this story is exactly what the headline says.

On 20 March 2018, de Havilland Canada (now Viking Air) DHC-6 Twin Otter N716JP struck an individual during take-off from a remote sea ice airstrip (‘Ice Camp Skate’), about 140 miles north of Deadhorse, Alaska (the flight’s destination).  The US National Transportation Safety Board (NTSB) report that the casualty suffered serious head and neck injuries and the aircraft received substantial damage to the left wing and left aileron.

Damaged Wing Tip of Bald Mountain DHC-6 Twin Otter N716JP (Credit: NTSB)

Damaged Wing Tip of Bald Mountain DHC-6 Twin Otter N716JP (Credit: NTSB)

The Part 135  VFR flight was operated by Bald Mountain Air Service as part of a contract for logistical support of ICEX 2018, a 5 week exercise with three US Navy and Royal Navy nuclear submarines (USS Connecticut, USS Hartford and HMS Trenchant) operating beneath the frozen Arctic Ocean.

The Accident Flight

The aircraft commander reported clear skies with ice pack haze.  The airstrip was lined with snow berms on both sides.

Arctic Airstrip (Credit: via NTSB)

Arctic Airstrip (Credit: via NTSB)

The take-off was to the North at 19:45 LT and he noted that:

…the sun was low on the horizon, resulting in shadows on the airstrip, and that flat light conditions made it difficult to discern topographical features.

The injured person, an employee of the Arctic Submarine Laboratory, who operated the site, made a statement that he had informed the aircraft commander that he would position himself alongside the runway to photograph the departure, behind the 3-4 ft tall snow berm.   The aircraft commander reported that…

…just before the takeoff roll, he and the first officer saw a pedestrian standing near the left side of the departure end of the airstrip.

DHC-6 Twin Otter of Bald Mountain Air Services Taking Off From an Ice Runway (Credit: BMAS)

DHC-6 Twin Otter of Bald Mountain Air Services Taking Off From an Ice Runway (Credit: BMAS – stock photo)

The aircraft commander stated that…

As the takeoff roll continued, the airplane became airborne, so the captain lowered the nose to remain within ground effect and gain airspeed before initiating a climb. The captain added that, as the airspeed increased, he started to climb the airplane and then initiated a left turn. Both pilots reported that, during the turn, they heard a loud thump, which was immediately followed by an aileron control anomaly. The captain initiated a left turn back toward the airstrip and subsequently made an emergency landing. After landing, both pilots saw the pedestrian lying near a snow berm on the left side of the airstrip. The captain reported that he did not remember if it had been prearranged to have the pedestrian stand near the departure end of the airstrip during the departure.

The pedestrian reported that…as the airplane’s takeoff progressed, it did not climb as quickly as it had during previous departures and that the last thing he remembered before the collision was seeing the left wing getting lower to the ground as the airplane began a left turn and flew toward him while continuing to accelerate.

A security video camera recorded the accident sequence, and the recording supported the pedestrian’s account of the sequence of events. Although the captain reported that he climbed the airplane before initiating a left turn, the review of the video revealed that the flight crew operated the airplane at a low altitude and along a flightpath that placed it in dangerous proximity to the pedestrian (which was inconsistent with federal regulations) and left no margin to avoid the collision with him.

The next thing the injured person remembered was waking up in the medevac helicopter.

The aircraft was equipped with a CVR but “the CVR failed to capture the events of the accident” for reasons the NTSB do not elaborate.

Damaged Wing Tip of Bald Mountain DHC-6 Twin Otter N716JP (Credit: NTSB)

Damaged Wing Tip of Bald Mountain DHC-6 Twin Otter N716JP (Credit: NTSB)

A security video camera recorded the accident sequence, and the recording supported the pedestrian’s account of the sequence of events. Although the captain reported that he climbed the airplane before initiating a left turn, the review of the video revealed that the flight crew operated the airplane at a low altitude and along a flightpath that placed it in dangerous proximity to the pedestrian (which was inconsistent with federal regulations) and left no margin to avoid the collision with him.

NTSB Probable Cause

The flight crew’s improper decision to deliberately operate the airplane at low altitude and along a flightpath that resulted in a collision with a pedestrian after takeoff. Contributing to the accident was the pedestrian’s proximity to the runway.

Background

Video: ICEX 2018

The temporary ice camp, on a moving ice flow, had been established to support the exercise.

Video: ICEX: Choosing An Ice Floe

The 2,500 ft long by 75 ft wide airstrip included one runway oriented north/south and an intersecting runway oriented east/west.  The site was cleared once the exercise was over.

Arctic Airstrip (Credit: via NTSB)

Arctic Airstrip (Credit: via NTSB)

It is reported a US Army Chinook helicopter may need to be used to recover the aircraft.

Video: Submarines Surface Under Arctic Ice • ICEX 2018

Video: ICEX 2018 Begins

NTSB Probable Cause

The flight crew’s improper decision to deliberately operate the airplane at low altitude and along a flightpath that resulted in a collision with a pedestrian after takeoff. Contributing to the accident was the pedestrian’s proximity to the runway.


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USN Seawolf-class nuclear submarine USS Connecticut (SSN 22) after surfacing through the ice during the multinational exercise ICEX 2018 in the Arctic Circle. (Credit: US Navy – Chief Darryl I. Wood)