F135 Hold Lifted?

F-35 Joint Strike Fighter prime contractor Lockheed Martin told InsideDefense.com today that the suspension on the delivery of Pratt & Whitney F135 engines has been removed. The F-35 office overseeing the program did not confirm whether it has lifted the suspension.

The comment comes one day after the F-35 joint program office said F135 engine deliveries were suspended until the root cause of a June 30 engine fire could be determined.

InsideDefense.com asked Lockheed whether the suspension could affect F-35 aircraft production and if the company maintains a surplus inventory of F135s to mitigate against disruptions to supply -- as reported earlier this week.

In a Sept. 3 email, Lockheed spokesman Michael Rein said: "There has been no appreciable impact to the F-35 production aircraft delivery schedule as a result of the F135 delivery suspension," adding:

Lockheed Martin maintains an inventory of engines with adequate schedule margin to account for any unforeseen minor delays in engine deliveries. Since the engine delivery suspension has been lifted, Lockheed Martin received additional F135 engines. No impact to F-35 production aircraft delivery schedule is anticipated.

When asked how Lockheed is working with the JSF joint program office to ensure its decision to hold back F135 deliveries does not impact the production schedule, Rein replied:

Lockheed Martin, Pratt &Whitney, and the JSF joint program office hold weekly production coordination meetings to plan both near-term and long-term F135 propulsion system deliveries. These meetings allow us to minimize any impacts to F-35 production due to an engine delivery delay.

JPO spokesman Joe DellaVedova was unable to say whether the suspension has been lifted and a further response has not been provided.

Earlier this week, InsideDefense.com reported that engine deliveries to Lockheed had been on hold since May. P&W initially suspended deliveries after the company discovered that a parts supplier had been using suspect titanium. The joint program office kept the hold in place following an engine fire at Eglin Air Force Base in Florida on June 30. InsideDefense.com further reported:

Regarding F135 delivery delays, DellaVedova said the decision to keep them on hold was related to the engine fire. The June 30 mishap involved an Air Force jet and resulted in the temporary grounding of all three F-35 variants. The aircraft returned to flight on July 15 under a restricted flight envelope that remains in place.

Continued disruption to the supply of engines could lead to aircraft production delays, which might affect the Marine Corps' F-35B initial operational capability date of July 2015.

Bates said engine production continues but without materials supplied by A&P Alloys. "Due to the unrelated Eglin engine incident, the JPO continued to suspend engine deliveries until further notice," Bates said. "We are delivering engines ahead of need for Lockheed Martin."

According to DellaVedova, holding back on deliveries will allow for corrective actions on the engines once the root cause of the F-35A engine fire is determined.

Pratt believes it has found a technical solution to rectify the fault that caused the fire. The company plans to run a series of tests over the next month to determine a way forward.

According to Pentagon officials, early analysis indicates the fire was an isolated incident caused by excessive rubbing of the fan blades in the cold section of the engine.