The Air Force has agreed to a family's plea that the Pentagon renew the search for the body of Major Troy Gilbert, whose F-16 fighter jet crashed in Iraq in 2006 as he came to the rescue of troops pinned down by enemy fire. His full remains were never recovered.

Gilbert's remains were shown on an insurgent video taken at the crash site, but when American troops arrived at the wreckage they did not find his body.

A small amount of tissue found on the plane's canopy was positively identified through DNA testing as belonging to Gilbert and was enough to classify him as "killed in action."

It was that small set of remains that was interred at Arlington National Cemetery and  in the years since Gilbert's family has held out hope that the search would continue for the rest of his remains.

When the last of the American troops left Iraq last December, the family was shocked to learn that no searches were being conducted for the rest of Gilbert's remains because he is listed as killed in action, "body accounted for."

Frustrated with that news, Gilbert's family went public last week requesting that the Air Force change Gilbert's status to "unaccounted for" so that the Pentagon could reopen the search for his remains.

Gilbert's mother, Kaye, told WFAA-TV, the ABC affiliate in Dallas, Texas, "since my son is partially in the ground in Arlington, one or two inches maybe, but 99 percent is still in the ground over there, please, please help us get him home."

An  Air Force official said Thursday that Air Force Secretary Michael Donley agreed with the family that the search for the rest of Gilbert's remains should resume.

According to the official, Donley sent a letter to the Under Secretary of Defense for Policy requesting an "exception to policy" so that the Defense Prisoner of War/Missing Personnel Office (DPMO) could "assume a proactive pursuit of Major Gilbert's remains and to bring the fullest possible accounting of his remains."

Donley's  request must still be approved by the Under Secretary.

In a statement, Donley said the Air Force will work with the Defense Department and DPMO "to keep his case active and pursue information leading to the recovery of his subsequent remains."

Donley added, "We honor the ultimate sacrifice Major Gilbert made for our nation. His family deserves nothing less than our best effort to recover his remains and return them to his loved ones."

Gilbert's family was notified of Donley's action on Thursday and was overjoyed at the development.

"Our family is ecstatic!" Rhonda Jimmerson, Gilbert's sister, told ABC News. "Mountains have moved and we're very very happy that the military has agreed to continue the search for Troy."

Jimmerson said "they're not changing his status but they're going to be very proactive and they're going to move forward in continuing his search."

She said the goal had been for DPMO to continue the search for her brother's remains and Donley's letter addresses that request.

According to Jimmerson, the family hopes to get more details at a meeting with DPMO officials next Friday that the family had scheduled before today's announcement.

The family wants to hear that the letter guarantees the search will be active for however long it takes to find Gilbert's remains.

Jimmerson said "everyone has informed me that this is moving mountains for them to act so quickly."

She attributed the quick action to the support of Americans who wrote their congressmen and got others active in the effort to correct what the family saw as a mistake by the military.

She called the news of Donley's letter a "step forward …in the correct direction."  "I know that this is incredible and wonderful and it is momentum going into that direction," she said.

"Do we still have questions? Absolutely.  Absolutely as a family we still have questions, "said Jimmerson. "But it's definitely the military, the Air Force especially, has done a wonderful job here and we're very happy with the direction we're moving in."

Jimmerson praised previous recovery efforts conducted by American military troops at great personal risk.

When his plane crashed in November,2006, Gilbert was coming to the rescue of American special operations forces down by Iraqi insurgents.

During his strafing runs, he flew his aircraft extremely low to the ground in an effort to avoid injuring  civilians who were nearby.   On his second pass the  plane crashed after the tail end of his plane hit the ground.

For his heroic act, Gilbert was  posthumously awarded the Distinguished Flying Cross, the nation's second highest award for valor.