Forum: General F-35 Forum

http://www.flightglobal.com/blogs/the-dewline/

BREAKING: F-35 flight tests may resume next week

By Stephen Trimble on August 9, 2011 10:46 AM

A valve malfunction caused the F-35 grounding order last week. The Honeywell integrated power package (IPP) pulls in outside air to start-up, then switches to engine bleed air after the propulsion system comes online. The valve that switches the flow from inducted to bleed air didn't work, forcing highly compressed air to build up behind the valve until it essentially backfired. Ground tests may resume as early as tomorrow and flight tests could start again next week.

That information comes from Australian journalists who were briefed yesterday in Canberra by Lockheed Martin vice president Tom Burbage. Their news articles have not been posted yet, so there are no links to share.

As of yesterday, the joint programme office in Arlington, Virginia, remained in communications black-out mode.

F-16.net Sponsor

Partial Return to JSF Testing

http://www.aviationweek.com/aw/blogs/de ... d=blogDest

Partial Return to JSF Testing

Posted by Amy Butler at 8/10/2011 3:26 PM CDT

The F-35 Joint Program Office has authorized a return to ground testing for the developmental test aircraft Aug. 10.

This comes after a weeklong grounding of the test force owing to a mishap with a test jet. Aug. 2, AF-4, a conventional-takeoff-and-landing version, experienced a failure of its integrated power package (IPP). This led to a fire that was extinguished by onboard fire suppression systems. The IPP provides power to start the engine and provides cooling for the aircraft.

"Preliminary root cause indicates that a control valve did not function properly, which led to the IPP failure," according to Joe Dellavedova, JPO spokesman. "Monitoring this value is the mitigating action to allow developmental test ground operations." The test team is revising its ground monitoring procedures accordingly, he adds.

Reviews are continuing before the 20 F-35s in flying status can return to operations.

Dellavedova notes that margin was built into the schedule during the last restructuring to allow for incidents that occur in development.
Smile

Ground Operations Resume for developmental test aircraft

http://www.f35.com/news-events/top-issues.aspx

Ground Operations Resume for developmental test aircraft

UPDATE: August 10, 2011 - The F-35 Joint Program Office authorized a return to ground operations for the F-35 developmental test (DT) aircraft today. This is the first step in returning the F-35 fleet to full flight operations. A precautionary suspension of both ground and flight operations for the program was issued Aug. 3.

An Air Force Safety Investigation Board convened Aug. 4 and is reviewing the circumstances that led to the failure of the Integrated Power Package (IPP) aboard AF-4, an F-35A conventional takeoff and landing variant, assigned to Edwards AFB, Calif. The F-35's IPP is a turbo-machine that provides power to start the engine and generates cooling for the aircraft.

While the investigation continues, government and contractor engineering teams, after reviewing initial data, determined the fleet could safely resume DT ground operations. Preliminary root cause indicates that a control valve did not function properly which led to the IPP failure. Monitoring of this valve is the mitigating action to allow DT ground operations. The F-35 team is revising ground monitoring procedures to ensure testing involving the IPP takes place safely.

While initiating DT ground operations is a major step for the F-35 fleet returning to flight, further reviews are required prior to lifting the suspension of flight operations for the 20 F-35s currently in flying status. These aircraft are part of the System Development and Demonstration (SDD) and Low Rate Initial Production fleet.

The determinations of root cause and potential mitigating actions have the highest priority of the F-35 Team. The impact to SDD execution and production operations is being assessed. The program has built margin into the test schedule to accommodate these kinds of incidents that occur in the development effort. Periodic updates concerning this situation will be released as warranted.

No Fly Zone by Bill Sweetman at 8/17/2011 [Possible 'good news' F-35 last sentence]

http://www.aviationweek.com/aw/blogs/de ... d=blogDest

"The grounding of the Lockheed Martin Joint Strike Fighter force is entering its third week. The F-22 grounding is well into its fourth month, and the investigation of possible problems with its onboard oxygen generation system (OBOGS) will continue into the fall, according to a new USAF release.

There is no specific word on when a return to flight could take place, although the USAF's Scientific Advisory Board will be releasing interim reports as the investigation continues.

"The zero-risk solution is not to fly, and that's not a long-term option; it's an inherently dangerous business to fly and fight wars," according to Lt Col Matthew Zuber, SAB executive director. "We want to make sure we mitigate risks to a level that's appropriate for the urgency of the mission." The F-22 force has not been flying to its full envelope since January, when a 25,000-foot altitude limit was imposed.

However, so far, the investigation has not determined whether it is a lack of oxygen, the presence of contaminants such as carbon monoxide, or other factors that is causing F-22 pilots to experience hypoxia-like symptoms at three times the rate of pilots on other aircraft. Zuber says that no possibilities have been eliminated.

The F-35 remains grounded, but officials have expressed hope that test aircraft, at least, will be able to return to flight before the USAF Safety Investigation Board completes its report."

Back in the Air Very Happy

No Fly Zone -- Update

Posted by Bill Sweetman at 8/18/2011 9:45 AM CDT

http://www.aviationweek.com/aw/blogs/de ... d=blogDest

Update: The grounding of the F-35 test force has been lifted. A procedure for monitoring the valve in the integrated powerpack (IPP) has been approved, allowing test aircraft to continue flying before the USAF Safety Investigation Board completes its report. ...........

......On the F-35: Production aircraft remain grounded and restricted from IPP and engine running on the ground until a permanent fix is found. This will affect pre-delivery testing at Fort Worth as well as the two aircraft already delivered to Eglin AFB. It is understood that the fix is likely to involve both hardware and software and there is no firm date for implementation as yet.

Air Force Lifts Flight Ban on Lockheed F-35 Fighter Jet By David Lerman - Aug 19, 2011

http://www.bloomberg.com/news/2011-08-1 ... et-1-.html

"The U.S. Air Force today lifted a two-week-old flight ban that had grounded Lockheed Martin Corp. (LMT)’s F-35 Joint Strike Fighter, following a power problem on a plane at Edwards Air Force Base in California.

An investigation found there was a defective valve in the plane’s Integrated Power Package, a turbo machine that provides power to start the engine, according to an Air Force statement.

While the probe continues, engineers determined that it is safe to resume test flights, said Joe DellaVedova, a spokesman for the Joint Strike Fighter Program Office. The F-35 is the Pentagon’s biggest procurement program at a planned $382 billion to buy 2,457 of the stealth F-35 jets in different versions for the Navy, Air Force and Marine Corps.

Flights will resume for 18 of the 20 fighters that the Air Force has been flying, DellaVedova said. Two planes based at Eglin Air Force Base in Florida will remain grounded because they lack the monitoring systems used in developmental test aircraft that can detect any problems in flight, he said.

Flight operations will resume for the rest of the planes, which are based at Edwards and at the Patuxent River Naval Air Station in Maryland...."

Fanboy pressure in Russia was just too much .. a lot of pride riding on the PAK-FA.. plus big $$$ of course - they need to keep the Indians motivated.