PORT TOWNSEND — There’s a tale of aeronautic intrigue behind those mysterious black trucks that were silently parked for a week in rented Hudson Point RV Park spaces.

The vehicles with satellite dishes and antennae and an unassuming trailer are owned by Bingen-based Insitu, which develops unmanned aircraft.

It was testing one near Port Townsend in Admiralty Inlet last week.

The company’s trademarked Umanned Aerial Vehicle aircraft is being developed for use as military aerial surveillance and reconnaissance planes during wartime missions in Iraq, and for private-sector commercial purposes.

“We do our yearly testing up on Puget Sound,” said Steve Nordlund, Insitu vice of business development, from his office on the Washington side of the Columbia River in Klickitat County.

“We were just up doing a flight operation test.”

Company employees come to Port Townsend perhaps twice a year, but they do not test aircraft inside Jefferson County or the city, he said.

The company works in partnership with Boeing, the state’s leading aircraft manufacturer, to produce in the latest ScanEagle UAV model.

Nordlund said the vehicles at Hudson Point were not involved in the testing other than to transport needed equipment.

The real testing, said Nordlund, was taking place out in Admiralty Inlet where Insitu employees were launching and test-flying the ScanEagle from a company vessel into Whidbey Island Naval Air Station airspace.

“Our aircraft is able to launch and recover on a ship and that’s very unique in our business,” said Nordlund.

Naval Air Station Whidbey Island is in the business of electronic warfare.

The air station is the base for squadrons of EA-6B Prowler electronic countermeasure jets, P-3C Orion patrol aircraft and EP-3E Aries II reconnaissance planes.

Nordlund said he could not go too deeply into the nature of the tests for homeland security reasons.

The company’s Web site at www.insitu.com shows specifications.