An E/A-18G Growler launches from the flight deck of the Navy's aircraft carrier, USS Ronald Reagan, on October 1. A canopy explosion on a Growler that injured two crewman triggered the Navy’s temporary grounding of its entire fleet of Growler and Super Hornet jets, according to an initial report. Photo by Nathan Burke/U.S. Navy/UPI | License Photo

WASHINGTON, Dec. 29 (UPI) -- The U.S. Navy temporarily grounded all Super Hornet and Growler squadrons because a canopy exploded off a jet earlier this month, according to a Naval Safety Center summary of the incident.

At the time the Navy said an "on-deck emergency" involved the aircraft's canopy but the military did not give details. The Growler's pilot and electronic warfare officer were hurt Dec. 16 as the Boeing E/A-18G Growler assigned to Electronic Attack Squadron 132 prepared for a training flight at Whidbey Island Naval Air Station in Washington state.


Several factors likely contributed to the incident, including a combination of frigid and soggy weather, and routine aircraft washing, according to the Navy.

The Navy suspended flight operations for the planes for three days as it investigated. Super Hornets and Growlers share certain common aircraft systems.

The Naval Safety Center classified the incident as a "Class A" mishap, its most serious type with at least $2 million in damage or a "permanent total disability" to a crew member.

The two onboard were taken to Harborview Medical Center for "severe" injuries. Lt. Cmdr. Jeanette D. Groeneveld, spokeswoman for Naval Air Forces, told The San Diego Union-Tribune on Thursday that both pilots remain hospitalized.

The Gowler did not catch fire from the explosion, Groeneveld said.

Naval Air Forces ordered changes throughout the F-18 fleet because they have similar component designs for the affected systems as the Growler incident, the Navy said in a statement.

Changes are for "aircraft water-wash procedures" and updates to the Navy's procedures for ground emergencies.