Seven (10) F-35s cleared to resume test flights
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Seven F-35s cleared to resume test flights - Monday, Mar. 14, 2011 Tony Carpaccio Bloomberg news
http://www.star-telegram.com/2011/03/14 ... esume.html
"WASHINGTON -- The Pentagon on Monday cleared seven of 10 F-35 joint strike fighter test planes to resume test flights after an incident that resulted in the grounding of all the planes.
The grounding was ordered after one plane experienced an in-flight failure of two electrical generators and an oil leak Wednesday.
The suspension was lifted on seven aircraft with older-model generators. The three using a newer version remained grounded, said Joe DellaVedova, spokesman for the F-35 program office.
An analysis of incident data showed that the problem was with the newer design.
Also Monday, the Navy detailed its plans to buy 680 F-35s, half suited for aircraft carrier landings and half short-takeoff and vertical-landing versions for the Marines.
Navy Secretary Ray Mabus; Adm. Gary Roughead, naval operations chief; and Gen. James Amos, the Marine Corps commandant, updated a 2002 agreement between the services.
It outlines the number of Marine fighter squadrons to operate off Navy carriers, steps to improve training, and production schedules.
The update reaffirms the number of planes and for the first time specifies that the Navy will buy 340 of the more complex F-35B short-takeoff, vertical-landing model for the Marines.
Defense Secretary Robert Gates has put the F-35B version on "probation," giving contractor Lockheed Martin and the Marines two years to fix development problems and show that the aircraft can complete testing and meet performance and reliability specifications.
If the F-35B can't be fixed during the probation period, he said, it should be canceled.
The F-35 is the Pentagon's most expensive weapons program. It was launched in October 2001 with a goal of producing 2,866 aircraft for the Air Force, Navy and Marines for a little more than $200 billion, or around $50 million per aircraft.
But the Pentagon's cost estimates have soared, because of technical and production problems, cost growth and schedule delays, to an estimated $382 billion for 2,457 aircraft, and more than $100 million per aircraft.
Lockheed is assembling the aircraft and managing the program at its west Fort Worth plant and has about half its 14,000-person workforce on the program.
An aircraft subcommittee of the House Armed Services Committee has a hearing today to review the F-35 budget for fiscal 2012. Vice Adm. David Venlet, the program manager, is scheduled to give his first congressional testimony since taking over the program in February 2010.
Staff writer Bob Cox contributed to this report."
http://www.star-telegram.com/2011/03/14 ... esume.html
"WASHINGTON -- The Pentagon on Monday cleared seven of 10 F-35 joint strike fighter test planes to resume test flights after an incident that resulted in the grounding of all the planes.
The grounding was ordered after one plane experienced an in-flight failure of two electrical generators and an oil leak Wednesday.
The suspension was lifted on seven aircraft with older-model generators. The three using a newer version remained grounded, said Joe DellaVedova, spokesman for the F-35 program office.
An analysis of incident data showed that the problem was with the newer design.
Also Monday, the Navy detailed its plans to buy 680 F-35s, half suited for aircraft carrier landings and half short-takeoff and vertical-landing versions for the Marines.
Navy Secretary Ray Mabus; Adm. Gary Roughead, naval operations chief; and Gen. James Amos, the Marine Corps commandant, updated a 2002 agreement between the services.
It outlines the number of Marine fighter squadrons to operate off Navy carriers, steps to improve training, and production schedules.
The update reaffirms the number of planes and for the first time specifies that the Navy will buy 340 of the more complex F-35B short-takeoff, vertical-landing model for the Marines.
Defense Secretary Robert Gates has put the F-35B version on "probation," giving contractor Lockheed Martin and the Marines two years to fix development problems and show that the aircraft can complete testing and meet performance and reliability specifications.
If the F-35B can't be fixed during the probation period, he said, it should be canceled.
The F-35 is the Pentagon's most expensive weapons program. It was launched in October 2001 with a goal of producing 2,866 aircraft for the Air Force, Navy and Marines for a little more than $200 billion, or around $50 million per aircraft.
But the Pentagon's cost estimates have soared, because of technical and production problems, cost growth and schedule delays, to an estimated $382 billion for 2,457 aircraft, and more than $100 million per aircraft.
Lockheed is assembling the aircraft and managing the program at its west Fort Worth plant and has about half its 14,000-person workforce on the program.
An aircraft subcommittee of the House Armed Services Committee has a hearing today to review the F-35 budget for fiscal 2012. Vice Adm. David Venlet, the program manager, is scheduled to give his first congressional testimony since taking over the program in February 2010.
Staff writer Bob Cox contributed to this report."
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Some F-35s Back Flying - JPO Update by Graham Warwick at 3/15/2011
http://www.aviationweek.com/aw/blogs/de ... d=blogDest
"A "design artifact" unique to a new electrical starter/generator configuration is the likely cause of the in-flight dual generator failure on F-35A test jet AF-4 on March 9, says the Joint Program Office.
The newer generator is installed on test jets AF-4, BF-5 and CF-1. The other aircraft - AF-1/2/3 and BF-1/2/3/4 - have the older generator configuration. As a result, the JPO has rescinded its stop-flying order for these aircraft, and flight testing has resumed.
The other SDD aircraft and the two low-rate initial production (LRIP) aircraft flying with the newer generator - AF-6 and -7 - remain on the ground as the investigation into the failure continues.
According to Lockheed Martin, the F-35 has two generators mounted to the engine gearbox and a third (Gen 3) on the integrated power package (IPP). Supplier Hamilton Sundstrand tells my colleague Bill Sweetman the dual configuration is actually a single line replaceable unit with two generators on it.
After the in-flight failure of both engine-driven generators, the aircraft reconfigured to run off of Gen 3 on the IPP and AF-4 returned safely, Lockheed tells Bill, adding that batteries were available to back up Gen 3, had they been needed."
http://www.aviationweek.com/aw/blogs/de ... d=blogDest
"A "design artifact" unique to a new electrical starter/generator configuration is the likely cause of the in-flight dual generator failure on F-35A test jet AF-4 on March 9, says the Joint Program Office.
The newer generator is installed on test jets AF-4, BF-5 and CF-1. The other aircraft - AF-1/2/3 and BF-1/2/3/4 - have the older generator configuration. As a result, the JPO has rescinded its stop-flying order for these aircraft, and flight testing has resumed.
The other SDD aircraft and the two low-rate initial production (LRIP) aircraft flying with the newer generator - AF-6 and -7 - remain on the ground as the investigation into the failure continues.
According to Lockheed Martin, the F-35 has two generators mounted to the engine gearbox and a third (Gen 3) on the integrated power package (IPP). Supplier Hamilton Sundstrand tells my colleague Bill Sweetman the dual configuration is actually a single line replaceable unit with two generators on it.
After the in-flight failure of both engine-driven generators, the aircraft reconfigured to run off of Gen 3 on the IPP and AF-4 returned safely, Lockheed tells Bill, adding that batteries were available to back up Gen 3, had they been needed."
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Power failure investigation continues for F-35 By Stephen Trimble DATE:17/Mar/11 SOURCE:Flight International
http://www.flightglobal.com/articles/20 ... -f-35.html
"US government officials cleared seven of 10 Lockheed Martin F-35 test aircraft to fly five days after a power outage and oil leak forced the AF-4 vehicle to land on 9 March.
But the full costs of the programme's most serious in-flight incident in nearly four years remain unclear. Six of the seven cleared test aircraft had returned to flight by 16 March. Three of the latest test aircraft to roll off Lockheed Martin's assembly line and both production aircraft delivered to date remain grounded indefinitely while the investigation of the incident continues.
The root cause of the generator malfunction remains under investigation within the programme, but officials decline to offer any clues of the failure or details about the difference between the older and newer generators.
It is also not clear if the AF-4 pilot was manoeuvring aggressively at the time of the power black-out. [???]
Since the F-35 design relies on electricity instead of hydraulics to power flight-control surfaces, a dual-generator failure is a critical safety issue. By design, the F-35's electric system has a third back-up - Honeywell's integrated power pack - which kicked in and allowed the pilot to land safely.
For the test fleet, the difference between airworthy and grounded depends on a vital component weighing only 56.7kg (125lb) and occupying a volume of 0.04m³ (1.69ft³), according to US Navy acquisition documents.
Airworthy aircraft are powered by an older version of the F-35's dual-redundant Hamilton Sundstrand electric starter-generators.
The grounded aircraft, which include the conventional take-off and landing AF-4, short take-off and landing BF-5, carrier-based CF-1 and production models AF-6 and AF-7, are powered by an updated version made by Hamilton Sundstrand called the alternate electric starter generators."
http://www.flightglobal.com/articles/20 ... -f-35.html
"US government officials cleared seven of 10 Lockheed Martin F-35 test aircraft to fly five days after a power outage and oil leak forced the AF-4 vehicle to land on 9 March.
But the full costs of the programme's most serious in-flight incident in nearly four years remain unclear. Six of the seven cleared test aircraft had returned to flight by 16 March. Three of the latest test aircraft to roll off Lockheed Martin's assembly line and both production aircraft delivered to date remain grounded indefinitely while the investigation of the incident continues.
The root cause of the generator malfunction remains under investigation within the programme, but officials decline to offer any clues of the failure or details about the difference between the older and newer generators.
It is also not clear if the AF-4 pilot was manoeuvring aggressively at the time of the power black-out. [???]
Since the F-35 design relies on electricity instead of hydraulics to power flight-control surfaces, a dual-generator failure is a critical safety issue. By design, the F-35's electric system has a third back-up - Honeywell's integrated power pack - which kicked in and allowed the pilot to land safely.
For the test fleet, the difference between airworthy and grounded depends on a vital component weighing only 56.7kg (125lb) and occupying a volume of 0.04m³ (1.69ft³), according to US Navy acquisition documents.
Airworthy aircraft are powered by an older version of the F-35's dual-redundant Hamilton Sundstrand electric starter-generators.
The grounded aircraft, which include the conventional take-off and landing AF-4, short take-off and landing BF-5, carrier-based CF-1 and production models AF-6 and AF-7, are powered by an updated version made by Hamilton Sundstrand called the alternate electric starter generators."
So did they overfill the oil and are 12 of 12 flying? -
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Would be interesting to know, theoretically, how the B model would handle that type of power loss during a vertical landing. The reason I say that is that several additional steering control are then active, i.e. the control of the now vertical nozzle, lift fan and the role posts, and these needs to be snappy too, so now low consumption mode would be possible.
Former Flight Control Technican - We keep'em flying
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lamoey wrote:Would be interesting to know, theoretically, how the B model would handle that type of power loss during a vertical landing....
excellent question!
The batteries are online and charging for continuous backup
while the Honeywell spinsup and takes the load. Synching and phase loading without the computers blinking should have been a design challenge; and it must work for AA-1 and AF-4 didn't make a "smoking hole"! 
.... and yes, I did overfill the oil in my '57 chevy, once! 
It almost went that fast, but not as high! Last edited by neptune on 24 Mar 2011, 22:56, edited 1 time in total.
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It's Back....
F-35 Generator Failures - Too Much Oil, JPO Says by Graham Warwick at 3/25/2011
http://www.aviationweek.com/aw/blogs/de ... 1d7a3a38ea
"A maintenance procedure that left excess oil in the lubrication system caused the March 9 in-flight dual generator failure on F-35A test aircraft AF-4. Maintenance documents have been amended to improve servicing procedures and all aircraft fitted with the affected alternate engine starter/generator (AES/G) have been cleared to return to flight, says the Joint Program Office in a statement released a few minutes ago.
The statement says: "Previous maintenance procedures could allow a small amount of extra oil to remain within the generator following servicing. Under some conditions, the extra oil that is churning inside a narrow air gap within the AES/G could cause internal temperatures to increase. It was assessed that high temperatures led to the generator failures."
Soon after the incident it was determined that only those aircraft with the newer AES/G design were affected. Those with the earlier engine starter/generator (ES/G) - F-35A CTOL test jets AF-1/2/3 and F-35B STOVL test jets BF-1/2/3/4 - were returned to flight on March 14. This latest action clears those with the AES/G - AF-4, BF-5, F-35C CV test jet CF-1 and the first two low-rate initial production aircraft AF-6 and 7.
As for any effect on an already-delayed flight test program, the JPO says: "There was no significant impact to the System Development and Demonstration (SDD) program or production operations. Flight test schedules are built with a margin for precautionary safety stand-downs. The F-35 test programs at Edwards AFB, Calif. and Naval Air Station Patuxent River, MD remain ahead of their monthly flight test schedules."
___________________
Graham Warwick wrote:
If I can be permitted to comment on my own post...this will not be news to ardent JSF watchers who caught the story by Steve Trimble of Flightglobal which appeared - briefly - earlier this week.
When it did, my colleague Bill Sweetman made the very valid point that a single maintenance action resulting in the failure of both engine-driven generators must call into question the redundancy of the system, which mounts both generators on a single line-replaceable unit."
F-35 Generator Failures - Too Much Oil, JPO Says by Graham Warwick at 3/25/2011
http://www.aviationweek.com/aw/blogs/de ... 1d7a3a38ea
"A maintenance procedure that left excess oil in the lubrication system caused the March 9 in-flight dual generator failure on F-35A test aircraft AF-4. Maintenance documents have been amended to improve servicing procedures and all aircraft fitted with the affected alternate engine starter/generator (AES/G) have been cleared to return to flight, says the Joint Program Office in a statement released a few minutes ago.
The statement says: "Previous maintenance procedures could allow a small amount of extra oil to remain within the generator following servicing. Under some conditions, the extra oil that is churning inside a narrow air gap within the AES/G could cause internal temperatures to increase. It was assessed that high temperatures led to the generator failures."
Soon after the incident it was determined that only those aircraft with the newer AES/G design were affected. Those with the earlier engine starter/generator (ES/G) - F-35A CTOL test jets AF-1/2/3 and F-35B STOVL test jets BF-1/2/3/4 - were returned to flight on March 14. This latest action clears those with the AES/G - AF-4, BF-5, F-35C CV test jet CF-1 and the first two low-rate initial production aircraft AF-6 and 7.
As for any effect on an already-delayed flight test program, the JPO says: "There was no significant impact to the System Development and Demonstration (SDD) program or production operations. Flight test schedules are built with a margin for precautionary safety stand-downs. The F-35 test programs at Edwards AFB, Calif. and Naval Air Station Patuxent River, MD remain ahead of their monthly flight test schedules."
___________________
Graham Warwick wrote:
If I can be permitted to comment on my own post...this will not be news to ardent JSF watchers who caught the story by Steve Trimble of Flightglobal which appeared - briefly - earlier this week.
When it did, my colleague Bill Sweetman made the very valid point that a single maintenance action resulting in the failure of both engine-driven generators must call into question the redundancy of the system, which mounts both generators on a single line-replaceable unit."
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Simple fix … make servicing the CSD/GEN an IPI item or add the task to the control roster? I wonder how this electronic wonder jet is going to fair when the ambient temps increase to “fry eggs on sidewalk hot” 
All the best
All the best
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Pay real close attention when the JSF is being debated Sunday, March 27, 2011
http://snafu-solomon.blogspot.com/2011/ ... sf-is.html
Does Soloman have the correct situation described here about the generators? "But the redundancy of the system isn't in the dual generators...its in the back up to those generators...."
SNAFU also refers to this F-16.net news item: http://www.f-16.net/news_article4312.html
It seems to me that there is confusion between 'generators' and 'actuators'? But I don't know enough about this situation. Anyone? Buehler? Anyone? Thanks for any info about this situation to clarify competing views.
http://snafu-solomon.blogspot.com/2011/ ... sf-is.html
Does Soloman have the correct situation described here about the generators? "But the redundancy of the system isn't in the dual generators...its in the back up to those generators...."
SNAFU also refers to this F-16.net news item: http://www.f-16.net/news_article4312.html
It seems to me that there is confusion between 'generators' and 'actuators'? But I don't know enough about this situation. Anyone? Buehler? Anyone?
Thanks for any info about this situation to clarify competing views.- Elite 1K
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[quote="spazsinbad"]Pay real close attention when the JSF is being debated Sunday, March 27, 2011
http://snafu-solomon.blogspot.com/2011/ ... sf-is.html
Does Soloman have the correct situation described here about the generators? "But the redundancy of the system isn't in the dual generators...its in the back up to those generators...."
SNAFU also refers to this F-16.net news item: http://www.f-16.net/news_article4312.html
It seems to me that there is confusion between 'generators' and 'actuators'? But I don't know enough about this situation. Anyone? Buehler? Anyone? Thanks for any info about this situation to clarify competing views.[/quote
??? ...????????????????????????????????????
???...?????????????
Hope this helps!
http://snafu-solomon.blogspot.com/2011/ ... sf-is.html
Does Soloman have the correct situation described here about the generators? "But the redundancy of the system isn't in the dual generators...its in the back up to those generators...."
SNAFU also refers to this F-16.net news item: http://www.f-16.net/news_article4312.html
It seems to me that there is confusion between 'generators' and 'actuators'? But I don't know enough about this situation. Anyone? Buehler? Anyone?
Thanks for any info about this situation to clarify competing views.[/quote
??? ...????????????????????????????????????
???...?????????????
Hope this helps!
My eyes have seen the glory of the Lord and the esthetics of the Flightline
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That clears things up. Thanks.
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