Here’s why those military helicopters were flying low over Bellevue

Military helicopters buzzed southeast Bellevue and Issaquah Tuesday evening, into the early hours of Wednesday.

FlightRadar24 showed they were Boeing MH-47G Chinook helicopters belonging to the army, based at Joint Base Lewis-McChord (JBLM).

Gary Dangerfield, external communications chief for the base, confirmed that and said special operations teams were conducting training flights on July 15 and 16.

“These activities are not in response to any current event, and every effort is made to limit disruptions to the community,” said Dangerfield.

He added that local law enforcement and government entities had been notified and that the Army takes special safety precautions when flying over highly populated areas.

Bellevue residents spot helicopters

Residents spotted the three heavy lift transport helicopters flying in a “v”-formation as early 7:30 p.m. They reported them flying so low that the air from the rotors shook the tops of trees, and the sound drowned out a dinner party conversation.

“Military helicopters comply with FAA guidelines regarding routing and altitude. In some training scenarios, aircraft may fly at lower altitudes to meet mission-specific training objectives. These flights are conducted within approved safety parameters,” Dangerfield said.

Radar tracked the helicopters flying north across Bellevue, then south and east to the southern tip of Lake Sammamish at about 1,200 feet until they disappeared from radar. That can happen when aircraft fly too low or behind a mountain, or if a transponder is turned off.

Video appears to show the aircraft making passes across the eastside as late as 12:05 a.m.

“Night flying is authorized and is a necessary part of aviation training. It allows pilots and crews to gain the skills required to operate safely in low-light environments. Flights at night, including those reported over the Bellevue and Lakemont areas, are conducted to support this critical training requirement,” Dangerfield explained.

Residents can report any concerns they have by email or a special hotline.

Over 130 aircraft based at JBLM

More than 130 aircraft and more than 400 pilots are based at JBLM. They all have mandatory training hours to complete.

Chinook helicopters are not small aircraft. According to Boeing, the H-47 series has a maximum weight of 54,000 pounds. The length is more than 50 feet with the rotors folded. The rotors themselves have a diameter of 60 feet.

The MH-47G is considered the top of their line. According to Military.com, they can conduct low-level flights in bad weather with low visibility and cover long distances. They are used to carry troops and cargo.