New report sheds light on 2016 midair crash near Russian Mission that killed 5

A midair collision between two planes above a Yukon River village on a sunny morning in August 2016 left five people dead.

A new report released Monday by the National Transportation Safety Board states that the planes probably looked no bigger than a penny from a distance, but then suddenly expanded in size just seconds before the collision.

The planes came together about 6 miles northwest of Russian Mission and some 60 miles from the Southwest Alaska hub of Bethel.

The collision killed three people aboard the Ravn Connect Cessna 208 Caravan headed from Russian Mission to Marshall, and a pilot and hunting guide working for Renfro’s Alaskan Adventures who had left Bethel earlier that morning in a Piper PA-18 Super Cub en route to a remote site near Russian Mission. Ravn Alaska operates Hageland Aviation Services, along with two other air carriers.

The five people killed in the collision were Hageland Aviation pilot Harry Wrase, 48, of Wasilla; Hageland passengers Steven Paul Andrew, 32, of Kenai, and Aaron Jay Minock, 21, of Russian Mission; Renfro pilot Zach Justin Babat, 44, of Montana; and guide Jeff Thomas Burruss, 40, of Haines.

The report estimates that the pilots would likely have seen the other aircraft as “relatively small, slow moving objects,” about the diameter of a penny seen from 7 feet away, until just before impact.

About 10 seconds before the collision, the planes would have suddenly appeared to get bigger — a phenomenon known as the “blossom" effect for the sudden increase in size at a point when impact may be unavoidable.

A cockpit visibility study by investigators predicted that the cockpit structures of both planes would have allowed a clear view of the other aircraft from about two minutes before the collision, though the Cessna would have appeared close to the bottom of the Piper’s right wing and near the forward edge of its forward wing strut.

Hageland contests the prediction of how visible the planes were to each other, according to filings in the case docket. Hageland faults the NTSB finding for using “numerous assumptions and approximations” in the study, and says the agency used a “guesstimate” to determine the Piper’s position.

NTSB investigator Mike Hodges responded that a far greater uncertainty lies in the pilot’s eye position, a variable that Hageland didn’t challenge.

Renfro’s, however, lost the ability to participate in the investigation. That’s because, in a rare action taken by Alaska NTSB, the company is no longer a party to the case.

Renfro violated federal regulations that restrict the release of crash-related investigation information by sharing preliminary information with a technical expert, according to a Nov. 15 letter to the company from NTSB Alaska chief Clint Johnson.

Renfro’s attorney, Myron Angstman, said Thursday that Renfro’s owner Wade Renfro didn’t think NTSB instructions not to share supporting documents applied to Angstman.

Renfro’s faced a number of lawsuits after the collision, Angstman said. Two have been settled but more are pending. So Renfro shared the documents with him to help him respond to the court filings.

The charts, graphs and maps in the supporting documents included flight-path information crucial to the company’s legal strategy, he said.

A Ravn spokeswoman sent a statement: “The NTSB investigation has not yet concluded and no probable cause determination has been made by the Board. Since Hageland is an official party to this investigation, NTSB rules strictly preclude us from making any comment.”

Several National Transportation Safety Board investigators flew to the extensive crash site after the collision.

They found widely scattered wreckage, an impact crater from one of the planes, and one wing of each plane torn off: the left wing for the Cessna and the right for the Piper. The wreckage was separated by about 2,500 feet, though parts of the Cessna wing came to rest near the Piper, according to the report.

The report states that “no preimpact mechanical malfunctions or failures were noted for either airplane.”

The Piper was using an active radio frequency and a non-active secondary frequency that’s the common traffic advisory frequency used at Russian Mission and Marshall, both airports without air-traffic control towers, investigators found. The damage to the Cessna was too extensive to test its transceiver.

Generally, federal aviation rules require pilots to “see and avoid” other aircraft. But that strategy can have limited application, according to numerous agencies, including NTSB.

The agency published a safety alert called “Prevent Midair Collisions: Don’t Depend on Vision Alone” that encourages pilots to use cockpit technology that can warn them about other aircraft such as Automatic Dependent Surveillance–Broadcast (ADS-B). The device determines a plane’s position via satellite navigation and periodically broadcasts it, helping pilots maintain separation from other aircraft.

The Cessna was equipped with ADS-B Out, which broadcast the airplane’s GPS position and other data to ADS-B ground stations and to other aircraft, the NTSB found. The Piper was not, and so wouldn’t have been able to receive ADS-B messages. The technology is not required.

Neither plane carried cockpit displays of the ADS-B data.

Had the airplanes been equipped to display data, “the system could have aurally alerted the pilots to the presence of the other airplane and presented precise bearing, range, and altitude information about each target up to 39 seconds before the collision,” investigators found. "A ... display would have presented the relative positions of the two airplanes visually to each pilot as early as when the Cessna became airborne: about 2 minutes 39 seconds before the collision.”