Pentagon Testing Chief’s Testifies on F-35 Program
(Source: compiled by; posted April 15, 2015)
PARIS --- The Tactical Air and Land Forces Subcommittee of the House Armed Service Committee on April 14 held a hearing on “Update on the F-35 Joint Strike Fighter Program & the Fiscal Year 2016 Budget Request.”

In his statement to the subcommittee, the Pentagon’s Director of Operational Test and Evaluation, J. Michael Gilmore, made some interesting points regarding the program, and revealed several points which had not previously been made public.

We reproduce below some excerpts from Gilmore’s statement, which is available on the committee website (23 PDF pages). Subtitles and emphasis in bold typeface below are ours.

Moving testing goalposts

As of the end January 2015, the program had redesignated 160 of the 350 remaining baseline test points as no longer required, and an additional 150 points as “highly desirable,” but to be completed only if the program is able to do so consistent with other priorities.

Operational limitations on test aircraft

Although five of the six F-35A OT&E aircraft assigned to the Edwards Air Force Base test squadron have been partially converted to the Block 2B configuration (i.e., full modification has not been completed) and are being flown with Block 2B software, the aircraft are still under operational limitations that restrict their utility.

For example, these aircraft are currently restricted to maneuvers not exceeding 3 g’s due to the limitation imposed on the fleet from the engine failure in June 2014. (Fully capable F-35A aircraft are to be able to maneuver at up to 9 g’s.) The aircraft are also restricted from steep dives (greater than 50,000 feet per minute) due to fuel tank pressurization limitations. Additional restrictions include the prohibitions of: operating the weapon bay doors in flight, using the night vision camera display in the helmet, and night flying in instrument meteorological conditions.

These limitations prevent the use of realistic combat tactics, which would have been necessary for conducting the OUE.

Second, the mission data loads previously planned for release in mid-2015 will not complete the planned lab and flight testing until early 2016. The mission data loads enable the aircraft’s sensors to search for, identify, and locate threat radio frequency emissions, a capability critical to the aircraft’s combat effectiveness. The loads are being produced by a government laboratory, the U.S. Reprogramming Lab (USRL), which, it now is certain, is not adequately equipped for the task for Block 2B, Block 3F or beyond.

Video by U.S. House Armed Services Committee

Deficiencies in the Reprogramming Lab

I need to emphasize problems caused by the deficiencies in the USRL, which I referred to in my annual report. Early in the program, a decision was made jointly by the contractor and the government to outfit the USRL facilities by simply replicating the planned mission systems development lab at Lockheed Martin, in Fort Worth, Texas. Apparently, between 2002 and 2008, the assumption was that the mission data file generation and mission data load testing capability needed by the USRL was essentially equivalent to, or perhaps a subset of, that needed for mission systems software integration.

I reported my concerns to USD (AT&L) regarding significant shortfalls in the two laboratories’ capabilities two years ago, and the program now recognizes significant shortfalls do indeed exist. In particular, the program now agrees that the USRL, as delivered by the contractor, has neither adequate hardware nor software for mission data load development and generation.

For example, in addition to significant shortfalls in needed hardware, the software tools for generating mission data files were delivered with severe “bugs” that cannot be quickly remedied, which are preventing engineers from generating the mission data loads needed to quickly detect and accurately identify radiofrequency emissions.

It is essential to act quickly to correct these shortfalls, as I have recently recommended to the USD (AT&L), to assure effective mission data loads for Block 3F, fully-combat-capable aircraft can be generated.

My understanding is that the program believes funding constraints are an obstacle to making the necessary corrections. In my view, it would be a serious mistake to underfund and/or delay the needed corrections, as they are critical to the success of the F-35 in combat.

Combat capability constraints

Block 2B aircraft are limited to internal carriage of two short-range air-to-surface bombs of the same type and two medium-range air-to-air missiles; external weapons, mixed loads of weapons, gun employment, stand-off air-to-surface weapons, and more air-to-air missile capability are planned for Block 3F.

Weapons integration testing has provided valuable information about system deficiencies that must be corrected in Block 3F in order to provide the F-35 autonomous targeting capability. Weapons delivery events in developmental testing to date have been characterized by significant involvement of the test control team to assist in target acquisition and identification and monitoring of sensor performance, such as radar search volume and target track stability. Fusion of own-ship and flight-member information continues to be problematic.

Until these problems are resolved, it will be difficult for F-35 aircraft to operate either autonomously or with other aircraft systems to build situation awareness and simultaneously engage multiple air and surface targets, which is the requirement.

Little use for Close Air Support

Because of the limited combat capability being provided in Block 2B, if the F-35 will be used in combat it will need the support of a command and control system that will direct target acquisition and control weapons employment for the limited weapons carriage available. If opposed, the F-35 Block 2B aircraft would need to avoid threat engagements and require augmentation by other friendly forces.

In a Close Air Support (CAS) mission, for example, F-35B aircraft will need to operate under the direct control of a forward air controller, using voice communications to receive target information and clearance to attack. This is because of the combined effects of digital communications deficiencies, lack of infrared pointer capability, limited ability to detect infrared pointer indications by a controller, and inability to confirm coordinates loaded to GPS-aided weapons.

If F-35 aircraft are employed at night for combat, pilots will have no night vision capability available due to the restriction on using the current night vision camera, which is planned to be subsequently upgraded after aircraft are retrofitted with Block 3i, using the Generation III helmet.

In general, using Block 2B F-35 aircraft, pilots would operate much like early fourth generation aircraft using cockpit panel displays, with the distributed aperture system providing limited situational awareness of the horizon, and heads-up display symbology produced on the helmet.

An F-35B, assuming, a 250-nautical mile ingress to a CAS area contact point would have approximately 20-30 minutes to organize with the controller and execute an attack using its two air-to-surface weapons. This would have to be above or outside of threat engagement zones.

By comparison, an Air Force A-10 would have approximately one and one half hours of time in the CAS area under the same conditions, but would be able to autonomously acquire and identify targets, while using datalink to receive and/or pass target and situation awareness information. An A-10 would also be able to employ at least four air-to-surface weapons, including the ability to carry a mixed load of ordnance and employ its internal gun, which provides very useful flexibility in the CAS role.

Although F-35 loiter time can be extended by air refueling, operational planners would have to provide sufficient tankers to make this happen. The F-35 fuel burn rate is very high compared to legacy strike fighters, at least 60 percent higher than the F-16C and 180 percent higher than the A-10. This creates a burden on the air refueling resources if used to increase F-35 loiter time.


Finally, though the Block 2B fleet release is planned to result in limited 5.5 g maneuver capability for the F-35B, and 7 g for the F-35A, current operating limitations are much more restrictive for F-35s that are not flight test aircraft. The restrictions on non-test aircraft (i.e. fielded, operational and training aircraft) due to the engine failure which occurred in June 2014 may be relaxed from the current 3 g limitation if the production aircraft are modified with pre-trenched stators or a “rub-in” flight procedure is completed.

Additional restrictions due to a fuel siphon tank overpressure problem discovered last year may limit maneuverability by restricting g-load as a function of fuel weight as well.

The details of the restrictions for fleet aircraft are still be determined by the Program Office and the operational impact is not known.

There are also operating limitations associated with carriage of weapons, both air-to-air and air-to-surface, which persist until the weapons are expended; these limitations, which have been imposed in part based on results of the ongoing test program, affect self-defense and target attack capabilities.

The fact that these problems exist notwithstanding the Program Office’s best efforts is, in my view, not surprising given the decision early in the last decade to begin producing F-35 aircraft prior to testing.

Block 2B flight testing seriously late

To meet contract specification requirements, the program structures flight testing to provide data for the purpose of closing individual success criteria.

As of January 21, there are 263 success criteria remaining to be closed that are aligned with the Block 2B fleet release, which is planned by the program to occur by July 2015.

This number is only slightly less than the 288 success criteria that were closed in the last three years, since February 2012, and is an indication of the challenges that remain to successfully complete Block 2B fielding.

Generation III Helmet-Mounted Display System

The second iteration of Block 3i software, 3iR4, included the capability to test the new Generation III Helmet-Mounted Display System (Gen III HMDS). The Edwards Air Force Base test center flew four test missions with 3iR4 on AF-3 in September 2014, accomplishing regression test points and some initial test points from the Gen III HMD test plan. This was the first testing of the new HMDS on F-35 test aircraft.

The test team discovered deficiencies, particularly in the stability of the new display management computer – helmet (DMCH), and suspended further testing until software that fixes the deficiencies in the helmet system can be provided to the prime contractor and included in an updated load of mission systems software. (end of selected excerpts)

Other witness statements and biographies are available on the hearing home page.


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