By Geoff Fein

The Navy yesterday grounded 39 of its fleet of P-3C Orion aircraft due to structural fatigue concerns discovered during an ongoing evaluation of the aircraft, according to the service.

“This is a proactive effort based on the study,” a Naval Air Systems Command (NAVAIR) spokesman told Defense Daily yesterday.

The Navy has a total of 161 Lockheed Martin [LMT] P-3Cs, 82 of which are in operation. Of those 82, 20 are to be grounded due to structural fatigue, a source said.

Of the 20 grounded yesterday, 10 are currently deployed, the source noted.

The Navy is still working on a plan for operational impact, the service said.

The remaining 19 aircraft grounded are in long-term maintenance, the source added.

“The grounding is due to analysis which projects wing fatigue cracks exceeding previously defined thresholds of acceptable risk,” the source said. “Analysis is supported by observation of cracks in inspected aircraft. There is a risk of catastrophic structural failure if these aircraft are not grounded.”

The number of aircraft grounded, however, could potentially grow beyond 39, the NAVAIR spokesman said.

“This is an ongoing analysis. It’s possible we may ground more [aircraft], if necessary,” he said.

Although the P-3C Orion’s mission is primarily hunting submarines, it is also used to conduct intelligence, surveillance and reconnaissance work, both over land and sea, the source said.

Program officials determined that these aircraft are beyond known structural limits on the lower section of the P-3C wing, according to a NAVAIR statement.

“Analysis and corrective measures are expected to take between 18 to 24 months per aircraft to complete,” according to the statement.

However, the source noted that the work on fixing the wings won’t begin until material and the industrial capacity are in place to do it.

“It’s going to take a while to get that 18 to 24 month clock to start,” the source said.

The cost to repair the aircraft will be based on the material condition of each Orion, the NAVAIR spokesman added.

The Navy has yet to determine where the repairs will take place, he added.

“These aircraft will either return to safe operations after replacement of critical structural components or they will be removed from service,” the source said.

The Navy is in the process of individually tracking down the remaining 29 aircraft, the NAVAIR spokesman said.

“They are located everywhere we have P-3Cs,” he said.

Lockheed Martin, which builds the P-3C, said it will do everything it can to help the U.S. Navy find a solution to this challenge with their P-3 fleet.

“As the original equipment manufacturer, we are uniquely qualified to offer our assistance; besides the Navy, nobody knows this airplane better than Lockheed Martin,” Rob Gross, P-3 communications official, told Defense Daily.

In addition to the Navy, about 15 international customers fly the Orions and expect to operate them for decades to come (Defense Daily, April 14, 2006).

According to the source, Lockheed Martin is notifying the international operators.

Among the countries flying the P-3C Orion are: Australia, Brazil, Canada, Germany, Iran, Japan, Korea, Norway, Pakistan and Spain. The United States is also in the process of selling the aircraft to Taiwan, the source said.

“The impact to foreign users is not anticipated to be as immediate because of the age and hours flown,” the source said. “The U.S. Navy aircraft are older and flown harder than the Foreign Military Sales customers.”

There are also several domestic operators of the P-3C including the U.S. Customs and Border Patrol, the National Oceanic and Atmospheric Administration, and California-based aerospace firm Aero Union.

Along with the 161 P-3Cs, the Navy has 16 EP-3s, none of which were impacted by the structural fatigue issue, and 12 P-3 non updates (NUDS), largely used for testing.

The P-3C Orion will eventually be replaced by Boeing‘s [BA] P-8A Multi-mission Maritime Aircraft (MMA). The P-8A is scheduled to enter into initial operational capability in 2013 and full operational capability in 2018, according to the Navy.

The Navy’s program of record for the P-8A calls for a total of 108 aircraft.

The first aircraft will be delivered for flight test in 2009 (Defense Daily, Oct. 29).

According to the NAVAIR spokesman, the P-3C will continue in service until 2019.