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F-35 vertical landing  (Source: DefenseNews)
Jets have significant issues with engines and other componnets

The F-35 Lightning II program can't win for losing. The long running issues with the aircraft have been well documented and have led to delays in the program. Many of the flight issues with the F-35 have centered on the more mechanically complex F-35B STOVL version of the fighter aircraft. A new report has surfaced that highlights some previously unknown problems with the F-35 program.

According to a report compiled by the Pentagon Director of Operational Test and Evaluation, the F-35 aircraft all suffer from various problems with handling, avionics, afterburner, and the helmet-mounted display systems. The F-35A and F-35B variants are specifically said to suffer from "transonic wing roll-off, [and] greater than expected sideslip during medium angle-of-attack testing" according to the report. The report also notes that many of the components being used in the aircraft are not as reliable as expected.

The F-35B has had various issues with subcomponents in the past, specifically the ones that allow the door behind the cockpit to open so the aircraft can get the air needed for vertical landing. The F-35B has made successful vertical landings recently.

One key problem that is common on the aircraft is an issue described as afterburner "screech" reports Defense News. Apparently, the F-135 engine provided by Pratt and Whitney has a problem where airflow causes severe vibrations that prevent the engine from reaching maximum power.

The helmet-mounted display system in the aircraft is also having issues, but the report doesn't delve into this exact problems. The F-35 has no traditional heads-up display like other aircraft flying today - all pilot data is on a display inside the helmet.

Lockheed martin spokesman John Kent said, "The F-35 air system advances Helmet Mounted Display technology to capabilities not flying today on any other tactical platform. With this advancement in technology come challenges that the program is actively managing. The challenges are being worked with the supplier." Kent goes on to say, "While there are no current plans to change suppliers, options are being considered in parallel that mitigate the most stressing issues. Flight testing is proceeding with the HMD installed and used with no safety of flight concerns."

The report also mentions an issue with the aircraft’s onboard inert Gas Generation System that helps prevent oxygen from building up inside the fuel tanks where it becomes a fire hazard. The report recommends a redesign for the system. 



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If all this is true
By Amedean on 1/19/2011 4:46:50 PM , Rating: 2
If all of these modifications are true, we are looking at severe re-engineering that can be years away! It would be INSANE to expect a new engine fitted and tested in 2 years. Good lord all of the backwards engineering just to engineer and wrought the thousands of miles of wires and circuitry. Then after that doing tolerances to determine the thermo-dynamics at engine operating temperatures - good heavens no this is giving me a headache!




RE: If all this is true
By Makaveli on 1/19/2011 6:18:12 PM , Rating: 2
lol maybe they should just cancelled the whole program, make a few more raptors. Then use the rest of the money to pay off some of that god damn debt. It may be a few drops in the ocean but how big does the debt have to be for it to become a problem?


RE: If all this is true
By Smartless on 1/19/2011 6:24:40 PM , Rating: 2
Yeah. From a less educated standpoint, I wonder if that vent behind the cockpit that sucks air into the VTOL is a danger to the pilot if ejecting. Most likely not since the ejection force is so great but just the thought about how much suction that must generate...

As for testing and the retesting, a pity we don't know the whole story because then we could track where this all went wrong instead of speculating. What would truly be a shame is if we finally build it and only order a 100 since it sucks.


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