General Discussion

...being honest.

The issues experienced when trying to develop this stealth fighter were myriad. And even now there is along list of issues.
On the physical side:
- Stealth Coating: The stealth coating is fragile and can detach during sustained supersonic flight, requiring specialized hangars for maintenance.
- Supersonic Limitations: Structural issues in the tail section have forced limitations on how long the aircraft can fly at supersonic speeds.
- Gun Accuracy: The 25mm gun installed on the F-35A variant is structurally inaccurate.
- Environmental Sensitivity: The F-35 is sensitive to extreme temperatures, with batteries struggling in cold climates (e.g., Alaska) and engines facing wear issues.
- Pilot Safety: Early pilots reported extreme sinus pain due to cockpit pressure regulation issues and erratic handling during extreme maneuvers.

On the software side:
The program's software development, particularly the "Technology Refresh-3" (TR-3) hardware and software upgrade required for Block 4 capabilities, has faced severe delays.
- Delivery Backlog: Delays in TR-3 testing forced the Pentagon to pause deliveries of completed aircraft in 2023, creating a backlog.
- Functional Limitations: Recently delivered jets have been equipped with "truncated" or ballast versions of upgrades because the full software package is not yet ready.
- Reboot Issues: Test pilots have reported needing to reboot systems mid-flight due to TR-3 instability.
https://www.defenseone.com/technology/2025/02/f-35-programs-software-development-isnt-getting-any-better-pentagon-report-finds/402725/
and
https://simpleflying.com/why-lockheed-martin-f-35-still-shortsfalls-despite-record-year-deliveries/

The DoD Inspector General released a report just last December that was pretty scathing:

The full report is here: https://media.defense.gov/2025/Dec/23/2003848755/-1/-1/1/DODIG-2026-039_FINAL%20SECURE.PDF

We do have the F-22 Raptor, but it is rarely used in combat because it was designed specifically for high-end air-to-air superiority against sophisticated adversaries--not the kind of conflict we are in now.

So, despite being first developed in the 1960s, we are still building newer variants of the F-15 which is far cheaper to operate and faster to deliver than stealth alternatives--and it is still a very capable airframe that can carry up to 29,500 lbs. of ordnance versus the 5,700 pounds of ordnance the F-35 can carry internally to maintain stealth.

The F-35 Lightning II has a maximum total payload of approximately 18,000 to 22,000 pounds, but that is in "Beast Mode" using external hardpoints--so you lose much of the stealth capabilities. Once you lose that why would you fly a much less reliable and much more expensive airframe into battle that may require the pilot to reboot the computer mid-flight when the software it relies on to stay in the air becomes unstable?

Sometimes you just need to hop on the old reliable tractor and leave the shiny new one in the barn I suppose....