Friday, September 25, 2015

Is the de Havilland Otter a dangerous plane?

As news broke earlier this month of a floatplane crash of near Iliamna that killed three passengers and injured seven others, some observers turned their attention to the plane.

The Sept. 15 crash involved a single-engine de Havilland Otter DHC3, a model that's seen a series of high-profile crashes in recent years.

In 2010, an Otter crashed into a mountain north of Dillingham, killing former Sen. Ted Stevens and four of the eight other people aboard.

In 2013, all 10 people aboard another Otter died when that plane crashed on takeoff at the Soldotna airport, the deadliest Alaska aviation accident in decades.

Earlier this year, an Otter flying cruise passengers on a flightseeing trip in Misty Fjords National Monument outside Ketchikan crashed, killing the pilot and eight passengers.

And now comes the Iliamna crash -- and with it growing suspicion that the Otter is not only partly to blame for these tragedies, but perhaps even among the most dangerous aircraft in Alaska.

Nothing could be further from the truth.

A survey of the National Transportation Safety Board's aviation accident database between Jan. 1, 1995, and Sept. 15, 2015, yields 21 accidents involving de Havilland DHC3 Otters. Six of those resulted in fatalities, causing the deaths of 26 pilots and passengers.

In the same 20-year period, twin-engine Piper Navajos, a common plane in rural Alaska, were involved in 49 accidents, which together resulted in 16 fatalities. Meanwhile, Cessna 185s were involved in a whopping 168 accidents, resulting in 28 deaths. And the most familiar aircraft of Alaska Bush flying, the Piper Super Cub, was involved in at least 335* accidents, resulting in 36 total fatalities.

What these numbers show isn't so much that one or another plane is more dangerous, but that big, high-profile accidents can powerfully shape our perceptions of risk.

Depending on the seat-to-cargo configuration, an Otter can carry as many as ten passengers, plus a crew of one or two pilots. So while Otters crash far less frequently than other typical Bush planes, when they do, more lives are at risk.

A Super Cub, on the other hand, usually only carries one pilot and one passenger. (There is a modification that can be made allowing a second passenger in the baggage compartment, but it's rare.) So in a fatal Super Cub crash -- there have been eight since 2010 -- only two people at most are killed.

Any fatal plane crash is a tragedy, but these are less likely than larger, deadlier Otter crashes to make headlines -- especially outside Alaska.

Moreover, each of these aircraft is used in different ways, making  direct comparisons impossible. Navajos are typically used by air taxi and commuter operators flying in and out of established airports and airstrips. The Cessna 185s and Super Cubs (the latter are by far the most popular aircraft to own and operate in Alaska) are largely general aviation aircraft, used by guides or private pilots for hunting, fishing and other recreation-oriented travel -- often at off-airport locations such as gravel bars.

The de Havilland Otter has been known for decades as a venerable Bush workhorse in the U.S. and Canada. Dating back to 1951, it became particularly popular on floats for use traveling to hunting and fishing lodges in British Columbia and Alaska. In many ways, the Otter (along with its predecessor, the smaller de Havilland Beaver), is an iconic aircraft and enduring symbol of Last Frontier flying.

A string of high-profile crashes might make it an easy target for those seeking to understand Alaska aviation’s perpetually high accident and fatality records. But the answers to that problem are far more complicated than a single aircraft. Every plane crash in Alaska happens for a specific set of reasons that are unique to that flight. But a glance at the de Havilland Otter DHC3’s accident record shows that the plane is often the least significant aspect of the accidents in which it is involved.

*Because of the NTSB databases’s design, the Super Cub must be searched in multiple ways (such as a PA18, PA 18 and PA-18). Some of those searches turn up overlapping records, while others do not. Based on these conflicting records, at least 335 Super Cub accidents, and possibly as many as 385, occurred during this period. In contrast, the other aircraft with lower accident numbers were easy to verify exactly.

Original article can be found here:  https://www.adn.com

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