US Department of Defense (DOD) documents obtained by US military journal Defense News have revealed a series of continued flaws and glitches in the F-35 Joint Strike Fighter fleet – with documents noting that 13 category 1 problems were identified for the F-35 program.
A category 1 problem is considered the most serious type of deficiency by the F-35 Joint Program Office, with the following criteria:
- Could cause death, severe injury or illness;
- Could cause loss or damage to the aircraft or its equipment;
- Critically restricts the operator's ability to be ready for combat;
- Prevents the jet from performing well enough to accomplish its primary or secondary missions;
- Results in a work stoppage at the production line; or
- Blocks mission-critical test points.
Some of the issues outlined in the reports from Defense News include concerns of cabin over-pressurisation, the handling of the JSF at supersonic speeds and sharp manoeuvring, as well as technical problems such as blown tires, brake lines and issues with the hydraulic systems.
F-35 original equipment manufacturer Lockheed Martin has hit back at the mounting concerns and growing list of flaws highlighted in US DOD reports and the subsequent coverage by Defense News.
Lockheed Martin's statement is below:
The F-35s today are meeting or exceeding performance specifications and delivering unprecedented capability and safety compared to legacy fighter aircraft. The feedback we receive from F-35 pilots is exceptional – and any pilot who has flown a legacy jet consistently relays back that if they are being sent in to harm’s way – they want the F-35, every time.
These issues are important to address, and each is well understood, already resolved or on a near-term path to resolution. We’ve worked collaboratively with our customers and we are fully confident in the F-35’s performance and the solutions in place to address each of the items identified.
ALIS Sovereign Data Management
ALIS meets data sovereignty requirements. Late last year, some customers requested that the F-35 enterprise develop additional capability to enable more data control.
We rolled out the additional Sovereign Data Management tool to international F-35 operators earlier this year, which allows them to manage aspects of their data that is sent to the F-35 Hybrid Production Support Integration (HPSI) team – and early feedback from the fleet is positive. It is also important to note that this has no impact to mission performance or safety of flight.
Part Inventory Data
This is a major focus at Lockheed Martin and we are implementing several actions including automation and enhanced supplier accountability processes that are delivering improved performance. Through automation, data is now vetted and validated automatically versus manually, improving speed and ensuring accurate EEL information is present before a part is delivered to the flight line.
With these new actions and related efforts, we've seen a 50 percent reduction in EEL and other action requests since 2017. We are confident this is on a path to resolution, which will reduce maintenance times and increase readiness rates. It is also important to note that this has no impact to mission performance or safety of flight.
The cabin pressure performance today meets the specified requirement. There have been no reported cases of barotrauma in the fleet and our joint government and industry analysis shows that risk of barotrauma is minimal and that there is no imminent safety issue.The enterprise is always reviewing pilot experience improvements and we have an update that performed successfully in lab testing and will now be flight tested for future integration, based on customer timing priorities.
Cold Weather Battery Performance
This was identified during extreme cold weather testing at negative 30 degrees or below at Eielson Air Force Base, Alaska in February 2018. The probability of the issue reoccurring on aircraft in the operational fleet is very low and with minimal impact to safety of flight or operational performance.
We have developed an update to the software and the battery’s heater control system to resolve this issue – and this updated software is available for users today to load on their aircraft in the event they will be conducting extreme cold weather operations. This will also cut into production in the 2021 timeframe. We are confident this is on a path to resolution.
F-35B and F-35C Horizontal Tail Durability at Sustained Supersonic Flight
The F-35B and C deliver on all performance requirements. The potential for tailboom or horizontal tail damage during prolonged supersonic speeds was found in the highest extremes of flight testing conditions that are unlikely replicated in operational scenarios. In fact, there have been no cases of this issue occurring in the operational fleet. Additionally, this is not identified as a safety of flight concern.
We implemented a change to the coatings on the horizontal tails and tail boom beginning in Lot 8 that increases durability and resolves this concern. This update allows the F-35B and C to deliver on all performance requirements with no tail boom or horizontal tail damage concerns.
F-35B and F-35C Angle of Attack (AOA)
We’ve implemented an update to the flight control system that is planned for integration in the third quarter of this year – and we expect this item to be resolved or downgraded.
Hydraulic Lines Ruptures Caused by Blown Tires
The F-35 has two redundant hydraulic lines and there has never been a case of both lines being impacted, which ensures safe operations. Brake control software updates and pilot training have alleviated this concern and resulted in a significant drop in blown tire events. Additionally, we made minor adjustments to the location placement of hydraulic lines on the F-35C that has resolved the potential for line breaks.
We believe the item is resolved and are standing by for additional customer feedback.
Helmet “Green Glow”
The U.S. Navy continues to fly with their current helmet, demonstrating their confidence in the system, and pilots with greater than 50 night landings operate with the current Gen II helmet at night. The improved Gen III helmet has already been designed, tested and is now being qualified for use. The first few of these new helmets have been delivered and we anticipate the upgraded helmets will resolve both the green glow and night vision conditions identified.
Additionally, as camera and OLED technology advances rapidly, we expect the F-35 helmet to continue to deliver unprecedented levels of situational awareness for pilots and only improve further over time.
Radar Sea Search
The F-35’s current radar sea search function meets the enterprises’ required specification. As we modernise the F-35, we are bringing enhanced search capabilities, which represent an increase from the original requirements, and we stand ready to integrate the upgrade in the future, based on customer priorities and direction.
Thrust limits on hot days
We are supporting the Joint Program Office and Pratt and Whitney, and they can best address questions related to the F-35’s engine, which is Government Furnished Equipment to Lockheed Martin.
Australia has committed to the purchase of 72 F-35A aircraft, at a cost of $17 billion, for three operational squadrons to be based at RAAF Base Williamtown and RAAF Base Tindal, as well as a training squadron at RAAF Base Williamtown.
The RAAF is also considering a fourth operational squadron for RAAF Base Amberley, which would see the amount of purchased F-35 JSF aircraft increased to 100.
The first F-35s were accepted into Australian service in 2018, with all 72 currently ordered aircraft to be fully operational by 2023.