Bird Detecting Radar Reduces Strike Damage

Hafemeister Article IMG 07

LCDR Danny Cook, Training Air Wing Two safety officer, and Eddie Earwood, USDA bird aircraft strike hazard coordinator, examine the Merlin radar at NAS Kingsville. The radar is changing the way the Wing plans training, adjusting schedules to avoid flying during the periods of greatest bird strike hazards. (U.S. Navy Photo by Rod Hafemeister)


A student pilot is on final approach when he sees a flash of something feathered pass in front of him and then feels an explosion.

Bird strike! The single engine on his T-45 Goshawk jet trainer has failed, turning the aircraft into a 5-ton glider.

At Naval Air Station Kingsville, that scenario is more than a training exercise – it happened in 2005 and again in 2007, forcing the student and instructor to eject and destroying two $29 million aircraft.

Today, the air station and the flying training wing are using technology to better understand the threat of bird strikes and adjust flying hours to minimize it.

Based in South Texas near the Gulf Coast, NAS Kingsville is home to half of the Navy and Marine Corps strike pilot training. It’s ideally situated for such training, with large, uncongested training areas and more than 220 days of sunshine annually.

But the Coastal Bend area has another attribute: It’s the southern United States end of the Central Flyway, the largest migratory flyway in North America.

Every spring and fall, millions of birds pass through the area.

“In the fall, it’s the raptors – hawks and falcons,” said Eddie Earwood, a Department of Agriculture (USDA) biologist. “In the spring, the problem is especially birds that migrate in the evening, after the sun goes down.”

Earwood is stationed at NAS Kingsville as coordinator of the base’s Bird Aircraft Strike Hazard (BASH) program under an agreement between USDA and the Department of Navy.

He was brought in as a result of a Class A mishap that destroyed a T-45 in 2005. In 2007, a second bird strike led to ejections and the loss of a T-45. “The 2005 crash was a collision with a single turkey vulture,” he said. “In October 2007, it was a large group of migrating broad-winged hawks.

“We decided to see if radar could be used to identify birds before the planes find them. We wanted to identify large groups of birds, such as the migrating hawks, before they entered our critical or most used airspace.”

The focus was on the tower pattern, where dozens of sorties a day practice approaches and landings.

The answer was Merlin, a special bird-detection radar.

“As a direct result of those two bird strikes in the pattern, we got the Merlin radar,” said LCDR Danny Cook, safety officer for Training Air Wing Two.

The radar was put through tests in 2008 and 2009 and was leased for the first time in 2013.

It sits between the air stations runways, taking images in three axes.

“Our initial thought was that it would let us see large birds at a distance,” Earwood said.

Merlin can pick up large groups of large birds out to about four miles. But it turned out it also does a good job of picking up large groups of small birds at shorter distances – which has resulted in changes in how the system is used.

Before the radar, tower personnel would set a bird hazard condition and restrict flight operations based on what wildlife they could see from the tower. But adding bird radar was problematic because of manning and logistics.

“It was determined that the wing duty officers would be better suited to make the bird hazard decision, if they had good situational awareness to do so,” Earwood said.

“The radar became their eyes on the airfield. Combined with communications with the tower and wildlife detection and dispersal team observations, it gives them the information necessary to make that decision.”

Having pilots in the flying wing determine the bird hazard condition was a first, Earwood said.

The radar was set up to display in the wing duty office – and now can be streamed live to computer screens.

“Over the years, we’ve gotten a better program,” Cook said. “The wing duty officer can directly monitor bird activity. He’s able to set a BASH condition based on what he’s seeing in real time.”

The wing has established three levels of bird hazard condition: low, moderate and severe.

Severe means “no fly” – aircraft on the ground stay there and aircraft needing to land come in with a high-angle approach that minimizes the chance of a bird strike and maximizes the odds of landing safely if a bird strike happens.

“Since we’ve integrated the Merlin radar, we haven’t lost an aircraft to a bird strike,” Cook said. “We’ve had some damages, but no lost aircraft.”

Earwood and the wing also are using the Merlin radar to develop historical data of the patterns of BASH threats, including times of year, times of day and weather conditions.

“We have daily reports of the number of tracks, the amount of bird activity at different times,” Earwood said.

“The wing sees that real-time data in a scrolling graph that measures bird activity. A red line was implemented at 70 percent of the historic peaks to help standardize setting of bird hazard condition.

“Approaching the red line, the condition is moderately elevated, at or above is severely elevated.

“As of September 2015, anything above that red line is a full stop – which resulted in a more than 45 percent reduction in overall bird strikes for September, which historically has been the peak month for bird strikes at NAS Kingsville.

“The wing is participating in the BASH program in a real way – it’s a cultural change.”

While the fall raptor migrations are generally a daytime threat, the spring migrations include many small birds that take flight just after dark, avoiding predators and feasting on spring flying insects.

Spring 2016 marked the first time the BASH condition settings were fully used at night.

“This spring, we’ve hit ‘severe’ and ordered full stop on landings,” Cook said.

“Our plan is to study and adjust the condition thresholds annually; spring typically hits ‘severe’ almost every night for nearly a month.

“So now we’re looking at adjusting our training schedules to minimize evening operations here at NAS Kingsville during that period. We can be smart about it to continue our production of new pilots.”

The radar also has revealed the hot spots where birds are likely. That is helping greatly with habitat management to reduce the threat, Earwood said.

“This allows us to make recommendations on ways to mitigate the threat from wildlife without adversely affecting mission accomplishment,” Earwood said.

“At the end of the day, we’ve got to work together to train Navy and Marine Corps pilots safely.”

Cook said the radar is a great tool, but it’s not going to prevent every bird strike.

“Even with the radar, there’s going to be birds out there that don’t meet the ‘severe’ threshold,” he said.

“We’ve managed the threat – that’s all we can do.

“The only way to eliminate it is to not fly.”

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