Sunday, June 5, 2016

Air Force warns of sonic booms ahead of exercise

Kathryn's Report:

The Air Force will conduct another large-scale exercise in the massive Powder River Training Complex in the Northern Plains and is warning of potential sonic booms that can rattle the walls and windows of homes.

The training area covers nearly 35,000 square miles of airspace in the Dakotas, Montana and Wyoming — the largest military aircraft exercise space over the continental United States.

Officials at Ellsworth Air Force Base in South Dakota say multiple types of aircraft will take to the skies Tuesday through Thursday, June 7-9, and cautioned that some aircraft could cause loud noises, including sonic booms.

A sonic boom is a loud explosive noise caused by the shock wave from an aircraft traveling faster than the speed of sound.

The website HowStuffWorks compares an airplane's sonic boom to a wake produced by a speeding boat. Being on the ground and experiencing a window-rattling sonic boom produced by sound waves is much like being on a lake shore and being hit by a large wave from a boat's wake.

Supersonic flights in the Powder River Training Complex airspace are supposed to occur only during large-force exercises, such as the one scheduled this week. Those exercises are limited to once per quarter for up to three days, not to exceed a total of 10 days per year.

All B-1 supersonic flying is supposed to occur 20,000 feet above mean sea level to minimize the severity of sonic booms. All fighter-jet supersonic flying is supposed to stay 10,000 feet above ground level.

B-1s are allowed to fly supersonic in the airspace for about 30 seconds during 60 sorties throughout the year, or approximately 30 minutes per year. Fighters engage in an estimated 48 minutes of supersonic flight per year in the airspace.

Several landowners and ranchers in southeast Montana and northwest South Dakota contacted this week by the Journal said they have not experienced any sonic booms since the military airspace was expanded in September.

But some ranchers have complained that the training exercises disrupt their operations, and the South Dakota Stockgrowers Association in February petitioned Air Force officials to provide more information to ranchers. The Rapid City-based group is pleased with steps the military has taken to better inform ranchers, such as posting notices in local newspapers, said Executive Director Silvia Christen.

She said more work is needed to improve communication between the military and ranchers who experience problems from low-level flights, but added, "for the most part I think we're on the right track."

Northwestern South Dakota rancher Clark Blake said his ranch was inundated with as many as 10 to 12 loud, low-level B-1 bomber flights on some days after the airspace was expanded. After complaints arose, the flights seemed to stay higher, he said.

The Federal Aviation Administration approved quadrupling the size of the training airspace in March 2015. The expanded complex officially opened in September, with flying operations that included B-1 bombers from Ellsworth and B-52 bombers from Minot Air Force Base in North Dakota. The first large-scale exercise was in December, and the second was in March.

This week's exercise will include six types of aircraft, from fighter jets to refueling tankers, and involve several hundred personnel from multiple bases, according to Lt. Col. Lanny Anaya, assistant director of operations for the 28th Operations Support Squadron at Ellsworth.

"Honestly, it is a team effort," he said.

The Air Force cautions non-military aircraft pilots to review the FAA notice of the exercise and avoid areas and altitudes where military planes will be practicing.

Original article can be found here:

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