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Posted

That could well be exactly what it is - orange illumination just made it look like a localised patch of fire.

Yeah, that would tally with it just being illuminated smoke, as per HF's suggestion.

Go look at some day cats on Youtube or wherever, and you'll see the steam coming from the cat tracks on launches. I think its just the normal release lighted by the deck lights.

  • 3 weeks later...
Posted

New State Department directive: We only fight wars in regions with moderate temperatures.

Winning! Time for a war in the Caribbean? Or maybe Brazil - lets go take their coffee and hit women!

Posted

At first I thought it was something similar to the Harrier and specific to the B model, where it had to have water injected in order to increase performance and not overheat. But this is actually an avionics heat issue.

Posted

The Air Force already accepts this constraint with the RQ-4. Northrop has done well hiding the info, but here's a glimpse from the Block 10, still flown by the Navy.

These heat problems are caused by the UAV using the fuel (via heat exchanger) as a heat sink to cool the avionics. The aircraft flags an overheat condition if the fuel temperature exceeds 105 °F.

https://www.navfac.navy.mil/content/dam/navfac/Specialty%20Centers/Engineering%20and%20Expeditionary%20Warfare%20Center/PDFs/ci_tech_data_sheets/TDS-NAVFAC-EXWC-CI-1406.pdf

  • Upvote 1
Posted

The Air Force already accepts this constraint with the RQ-4. Northrop has done well hiding the info, but here's a glimpse from the Block 10, still flown by the Navy.

https://www.navfac.navy.mil/content/dam/navfac/Specialty%20Centers/Engineering%20and%20Expeditionary%20Warfare%20Center/PDFs/ci_tech_data_sheets/TDS-NAVFAC-EXWC-CI-1406.pdf

I kinda wondered how UAVs do it, they're basically flying avionics bays.

Posted

The Air Force already accepts this constraint with the RQ-4. Northrop has done well hiding the info, but here's a glimpse from the Block 10, still flown by the Navy.

https://www.navfac.navy.mil/content/dam/navfac/Specialty%20Centers/Engineering%20and%20Expeditionary%20Warfare%20Center/PDFs/ci_tech_data_sheets/TDS-NAVFAC-EXWC-CI-1406.pdf

A work around for this back in the day during hot day launches was to have a fire truck spray the wings. Fire truck behind following very slowly spraying the wings.

Day time desert launches were rare but when they had to happened this kept it cool enough to launch during the ground cycle which was kept as short as possible. Another technique was to cool the fuel truck for hours with a HUGE ac unit in a closed hangar prior to the daytime (desert) launch. Fuel the vehicle just a couple of hours prior to launch and hose it down on the way to the runway. Not elegant but worked to keep a Block 10 cool enough.

Posted

A work around for this back in the day during hot day launches was to have a fire truck spray the wings. Fire truck behind following very slowly spraying the wings.

Day time desert launches were rare but when they had to happened this kept it cool enough to launch during the ground cycle which was kept as short as possible. Another technique was to cool the fuel truck for hours with a HUGE ac unit in a closed hangar prior to the daytime (desert) launch. Fuel the vehicle just a couple of hours prior to launch and hose it down on the way to the runway. Not elegant but worked to keep a Block 10 cool enough.

i think the problem is not that we have to use work arounds, but more how does a company that is located in a desert, and designs, builds, and tests their planes in the desert, not fix this in the ground up design of the aircraft? its not like they are sukhoi located in the barren frozen waste land that is russia

Posted

i think the problem is not that we have to use work arounds, but more how does a company that is located in a desert, and designs, builds, and tests their planes in the desert, not fix this in the ground up design of the aircraft? its not like they are sukhoi located in the barren frozen waste land that is russia

True - but just relaying a semi-amusing anecdote. But we only paid $148 million a pop for the F-35A model, did we really think we could go so cheap and get a plane that operate in hot conditions?

Analyst: F-35C to Cost $337 Million Apiece in FY15
Posted

i think the problem is not that we have to use work arounds, but more how does a company that is located in a desert, and designs, builds, and tests their planes in the desert, not fix this in the ground up design of the aircraft? its not like they are sukhoi located in the barren frozen waste land that is russia

Chances are something changed late into the design process that would've involved a very expensive fix or further limitation in order to work-around, and it was determined that just finding ways to keep the fuel cool(er) in the truck was the best (cheapest) option. My guess for the "something" would be weight issues causing a downgrade of the ECS which in turn meant more reliance on the use of the fuel system as a heat sink than was originally intended.

FWIW if you read between the lines in the AF PA story, they've already been doing this at Edwards, so it's been a known issue for at least a little while. Hence why I'm fairly certain it's less a "whoops completely didn't think about operating in the desert" thing and more a "yeah we changed some stuff from the original design for various reasons and because of the changes we expected issues at high temps; we validated these concerns while flying DT at Edwards and have subsequently begun to push out the work-arounds developed there to the operational fleet."

But that doesn't make as good of a headline as "F-35 CAN'T USE WARM FUEL LOL"

Posted

I just can't believe these engineers designed a problem that didn't exist in prior aircraft. The assumptions made on fuel temp or BTU exchange requirement were obviously wrong by a long shot.

Posted

I just can't believe these engineers designed a problem that didn't exist in prior aircraft. The assumptions made on fuel temp or BTU exchange requirement were obviously wrong by a long shot.

BB i get what you are saying but Tree hits the nail on the head. When are we going to get pentagon wars 2 - the jet that ate the pentagon

Posted

https://breakingdefense.com/2014/12/the-tale-of-the-f-35-and-hot-jet-fuel/

Turns out the blogosphere may have been wrong. I know I've seen F-35s flying in Vegas in the middle of summer, and haven't seen any white fuel trucks that I remember. May be less of an aircraft shutting down issue and more of avionics overheating and slowing down to protect themselves issue but now I'm really pulling shit out of my ass.

That or the pilots are so bored they figured out to play pocket tanks on the MFD and it was too much for the computers to handle.

Posted

BB i get what you are saying but Tree hits the nail on the head. When are we going to get pentagon wars 2 - the jet that ate the pentagon

Not as good as the movie, The Pentagon Wars, but a step in that direction, The Jet that ate the Pentagon.

For all the relevant critiques of the trying to get a multi-service, multi-nation, multi-role fighter right this time, the worst flaw has been concurrency. Buy then fly then fix has left us and others committed to it no matter how many problems, technical or financial, come.

Concurrency’s Costs: An F-35 Example

Posted

https://www.jsf.mil/news/docs/20141211_F35MROUEUROANNOUNCED.pdf

In the European region, F-35 initial airframe MRO&U [Maintenance, Repair, Overhaul and Upgrade] capability will be provided by Italy by 2018. [...] In the European region, engine heavy maintenance will initially be provided by Turkey, also in 2018 [...] An announcement on the Asia-Pacific region workload assignments will be made at a later date.

This must be one of the worst written, poorly worded, wandering, repetitive press releases I have ever read. Seriously, did the editor even graduate elementary school? As a result, the writing style in the DOD release is only slightly better, because they still have to cite this trash.

https://www.defense.gov/news/newsarticle.aspx?id=123819

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