Read these two articles today on Boeing news.... found some new disturbing information in it. Looks like it may be awhile before I see F-35's in the friendly skies of NAS Lemoore...
'RED TEAM' RECOMMENDS POSSIBLE REDESIGN FOR F-35C NOSE GEAR
The Pentagon established a "red team" last September to investigate issues with the F-35C's nose gear and the team is recommending that if initial steps to fix the problem fail, the nose gear should be redesigned, Inside the Navy has learned.
Last August, Navy fleet aviators from Strike Fighter Squadron-101 (VFA-101) were able to evaluate the F-35C catapult shot for the first time during at-sea testing.
"During a catapult launch the nose landing gear strut is compressed as the catapult pulls on the nose landing gear, with the hold back bar restraining the aircraft from forward movement due to engine thrust," according to a Dec. 28 Navy information paper viewed by ITN. "Upon release of the hold back bar, the nose landing gear strut unloads and vertically oscillates as the aircraft accelerates towards take-off."
The motion is not only uncomfortable but the Helmet-Mounted Display and oxygen mask push back and up and down against the pilot's jaw. The jostling in the cockpit results in unreadable HMD during and immediately after launch, the paper reads.
"The Red Team believes multiple factors are contributing to the problem, including the pilot's seat restraint and hand-hold (grab bar) locations, the mass and center-of-gravity of the F-35 helmet and display unit, the physical characteristics of the nose landing gear strut (load vs. stroke, damping), and the length and release load of the repeatable-release hold-back bar (RRHB)," according to the paper.
Red team recommendations
The red team, composed of government and industry personnel, recommends a series of short-term, medium-term and long-term actions for the F-35C.
The short-term actions are slated to begin in early 2017 and will take about two to six months to complete, according to the paper. The actions include implementing improved and standardized restraint procedures for pilots and flight testing later this month on the effects of a reduced RRHB release load. VFA-101 will evaluate both the restraint procedures and a reduced RRHB load during its next carrier qualification period in the spring, the paper reads.
In late 2017, medium-term actions ranging from six to 12 months to complete will begin. These include HMD symbology, nose landing gear modifications and pilot motion modeling. Regarding symbology, "Options are being considered that would simplify the information displayed to the pilot during and immediately after catapult launch, to make it easier for the pilot to interpret flight-critical data," the paper notes. One of the problems here is the contractor doesn't think there is enough time in the system design and development phase to demonstrate this in simulation, according to the paper.
Long-term actions would not begin until 2019 and would take 12 to 36 months to complete. These include RRHB geometry that would reduce compression of the nose gear strut before launch. This course of action may require ship modifications, according to the red team.
Another long-term action is a nose landing gear redesign. A redesign is not being pursued because of highly constrained design space.
"A redesign could incorporate all the benefits of the advanced modeling efforts, but is expected to require a multiyear effort to re-qualify a major redesign," according to the paper.
Navy carrier qualification report
Further, Navy pilots determined the catapult launch for the Joint Strike Fighter is "not operationally suitable" after conducting extensive at-sea testing, according to a Navy carrier qualification report viewed by Inside Defense.
The F-35 joint program office is looking for fixes for the problems highlighted in the report, according to F-35 spokeswoman Brandi Schiff.
VFA-101 sent 12 pilots to the George Washington (CVN-73) for carrier qualification testing last August.
"Combined, the pilots have nearly 23,000 tactical flight hours and over 4,600 arrested landings in the F/A-18 Hornet and Super Hornet, and the F-14 Tomcat," according to the VFA-101 initial carrier qualification report. "Over the course of two days, each pilot accomplished two touch and go landings, 10 arrested landings, and the accompanying catapult shots for [carrier qualification]."
Documentation dating back to November 2014 reveals the developmental test community raised concerns about the F-35C catapult launch.
For example, a deficiency report issued in December 2015 that aggregated data from six previous reports acknowledged the catapult was suitable to continue developmental testing but would not be acceptable by fleet standards. VFA-101's at-sea testing last August was the first time fleet aviators could evaluate the catapult shot.
During a catapult shot, the pilot would experience extreme movement in the cockpit that poses a risk to his or her health, according to the deficiency report.
After each catapult operation pilots were asked to assess their pain level on a scale from 0 to 5. Out of a total of 105 catapult shots 74 of those caused pilots "moderate pain" or a three rating. Eighteen catapult shots caused pilots "severe pain" or a four rating. One catapult shot was deemed a five rating or "severe pain that persists" with the pilot suffering from neck pain and a headache, and 12 catapult shots scored a two rating or "mild pain." None of the 105 catapult shots received a one rating of "slight discomfort" or a zero rating of "no discomfort or pain," according to the Navy report.
"The oscillations shake the pilot's head sufficiently to impair their ability to consistently read flight critical data, which poses a safety of flight risk," the report reads.
Pilots were also asked to rate HMD readability for each catapult operation on a scale of 0 to 4. After 51 catapult operations pilots rated readability a three or "difficult viewing anything in HMD." Nine catapult shots received a two rating or "able to view only critical HMD data" and seven received a four rating or "cannot view anything in HMD." None of the catapult operations received a zero rating of "easy to view all HMD data" or a one rating of "able to view most HMD data."
In order to compensate for the additional movement in the cockpit, most VFA-101 pilots locked down their harnesses.
This workaround poses a safety risk because it makes the ejection difficult to reach or the pilots would have to unlock their harnesses.
"In the current state, F-35C carrier operations must be performed under strict operational risk management with ideal environmental conditions and seasoned pilots are also required," according to the report.
F-35 Program Executive Officer Lt. Gen. Christopher Bogdan told reporters during a Dec. 19 round table at his office in Arlington, VA, "there's no doubt" his team has to find a solution to the nose gear.
However, he stressed, "the only time that is a problem with the C model is at very light gross weights. At medium weights and at heavy weights you don't see this problem at all."
Bogdan said his office is considering numerous short-term fixes, including changing the way pilots strap themselves into the aircraft and how they hold the straps.
"The long-term fix surely would be one that you would mechanically fix so that you don't have to make the pilots do any kind of special combinations," Bogdan said. "That fix is probably a couple of years off."
During night operations the oscillations caused by the catapult launch require ideal conditions in order to minimize pilot disorientation, the Navy report reads.
Another problem identified during the August at-sea testing was a high rate of tire wear. For example, VFA-101 required new main-mount tires after three field carrier landing practice sessions. -- Lee Hudson
F-35C DESIGN FIX TO SUPPORT AIM-9X MISSILE WEIGHT WILL COST TAXPAYER $8.8M
A design fix for the F-35C that strengthens the wing to support the weight of the AIM-9X air-to-air missile will cost about $8.8 million, Inside the Navy has learned.
The initial cost estimate assumes that flight testing the design fix this month will be successful, according to a Dec. 28 Navy information paper viewed by ITN.
Thirty-two F-35C jets will require the modification and the Pentagon anticipates the retrofits will be completed by the end of 2018, the paper reads.
"The aircraft required for the Initial Operational Test and Evaluation will be completed by Spring 2018 and the Initial Operating Capability aircraft will be completed by Fall 2018," according to the information paper.
F-35 Program Executive Officer Lt. Gen. Christopher Bogdan told reporters Dec. 19 during a media round table at his office in Arlington, VA, his team had an "inkling" during the program's modeling and simulation phase there was going to be a problem with the F-35C wing supporting the missile.
If the design fix to strengthen the jet's outer wing is a success during flight testing, it would be a simple modification for C models, according to Bogdan.
"The reason is because the outer wing on the C model comes off like a piece of Lego, it just comes off and you pop it back on," he said.
ITN previously reported flight testing the design fix would begin in November 2016 instead of January 2017. The flight tests will last for about six weeks at Naval Air Station Patuxent River, MD, according to F-35 spokesman Joe DellaVedova.
Last August, J. Michael Gilmore, the Pentagon's director of operational test and evaluation, sent a memo to DOD leadership titled "Achieving Full Combat Capability with the Joint Strike Fighter (JSF) is at Substantial Risk." One of the items referenced in the memo is that during flight testing of the AIM-9X, which is mounted externally on the outermost wing stations, the missile's weight exceeded load capacity during F-35C landings and up-and-away maneuvers caused buffeting.
All JSF variants are planned to be fielded with AIM-9X, but the F-35C is the only model that has weight issues with the weapon.
The load bearing on the F-35C outboard wing when carrying the AIM-9X must be strengthened, according to Gilmore's report.
The proposed design fix increases the outboard wing structure by modifying two structural components, DellaVedova told ITN in September.
"The updated design has been completed and flight test[ing] to verify performance of the updates will begin in November," DellaVedova wrote in a Sept. 13 statement. "That's why we test. We want to find issues now so the F-35 will be the most lethal multirole fighter the world has ever seen."
Further, in August 2016 the Navy completed its final at-sea developmental test of the F-35C that included the first-ever use of test pilots carrying external weapons on the jet.
Tom "Briggo" Briggs, the air vehicle engineering department head at Naval Air Systems Command, told reporters Aug. 15 aboard the aircraft carrier George Washington (CVN-73) the F-35C carried concrete bombs on three external pylons located on the jet's wings during testing. The concrete is molded to be similar in shape and size of the GBU-12 and AIM-9X. -- Lee Hudson
