euler_angles

We made our XMLs with, horror of horrors, a Visual Basic script that ran in Excel and digested several input documents to generate a map template that we could then tweak by hand and turn into an XML through another VB script.

Fixed

Oh, thanks for the spot. Not sure why it's doing that...

All of this was done as a work up to a carrier deployment. In software terms, trying the arrestments on land is deploying to test, doing them on a carrier is production. There were three separate developmental test deployments to carriers for the F-35C. Each deployment sought to expand the understood envelope and and handling procedures. The hook redesign happened before the first deployment. The hard landing story in the post happened during the work up to the third and final deployment.

That's what the flight testing was for. I am not aware of a way to all-up test something as dynamic as an arrestment without actually building a jet and trying to catch a wire.

The F-18 tailhook geometry is far different than the F-35 tailhook geometry. F-18 hooks are much farther back from the main landing gear, and are also much longer.

I have other threads on Twitter discussing the F-35

> https://twitter.com/the_engi_nerd/status/1758633498464952414 Labeling everything I could see in the cockpit > https://twitter.com/the_engi_nerd/status/1757243336941871159 a discussion of my primary job in flight test, aircraft instrumentation. > https://twitter.com/the_engi_nerd/status/1747803565987381495 riffing along with chapter one of "F35: From Concept to Cockpit", a compilation of papers written by Lockheed-Martin employees at the conclusion of F-35 system design/development.

Quarto made that really easy. Very cool.

Done!

Yes, there are pendants that are supposed to keep the wire above the deck, but the short space between the F-35C main landing gear and the tail hook point means that there's not enough time for the pendants to raise the wire above the deck in the manner that the original (erroneous) wire dynamics model would have suggested.

I am but a grunt who mostly programs radar models, I didn't know Quarto blogs could do that until just now. Yeah, sure, I'll add it.

There was a lot of static load testing done, and things like a drop test [0] of a full scale article. But to my knowledge, the only way to test the dynamics of a carrier arrestment is to actually do an arrestment. We do them on land; NAS Patuxent River and NAS Lakehurst (among others) have a full set of Mark 7 arresting gear like you would find on a Nimitz class. Lakehurst also has the advanced arresting gear present on the Ford class.

[0] https://www.youtube.com/watch?v=lGPseVNfZO0

The whole purpose of this series of tests was to try to exercise the arresting gear in the most punishing ways. One way that's usually done is to try to arrest far off the centerline (where the arresting force will be applied far more intensely to one side) and also to try to have the arresting hook grab the wire while the jet is still wheels above deck (this slams the aircraft down, HARD)

After this incident it was determined that we had fulfilled the intent of the test plan.

Also, instrumented aircraft capable of doing arrestments were in short supply: the program only had two of them, and we pushed one to its very limit.

Author here. Did not expect to see this on HN at all. Just an engineering war story I shared.

What the other person replying to you said. They even use this terminology in official documents. So I do, too, for laughs.

The missile clearly fuses, it had a warcranium. Where are you and others getting the idea that the missile had no warcranium?

Yeah that missile fused. It was a normal AIM-9X. Missile war cranium detonations are underwhelming (there's not that many pounds of explosives involved) because they are trying to kill aircraft via shrapnel of some kind. Two common designs are a continuous rod that expands in a circle around the detonation, or a hashed metal casing that produces hundreds of small fragments.

> The balloon was brought down with a missile that had the primary explosive removed

The missile fused and was a normal AIM-9X.

You can see result of the war cranium detonation in the videos as a cloud of black smoke. It's just that things are happening so fast that it looks like the missile just sails right on through.

> This being the F-22's first air-to-air kill after nearly 2 decades in service, it's not like these missiles are a precious resource to be conserved.

The first clause of your sentence here is not logically related to the second clause. These acquisitions programs are separate. While missile purchase quantities are adjusted based on projected needs, it is not as if there is a quantity in inventory earmarked specifically for the F-22 only.

> It is possible that the F-22 simply could not get up high enough to engage with guns even if that was desirable

It wasn't desirable, based on the experience the Royal Canadian Air Force had trying to shoot down a wayward weather balloon in 1988. https://apnews.com/article/268893fddde785d029d5a51b136951eb

Over 1000 rounds fired without bringing the balloon down.

Nations in foreign military sales programs are briefed prior to purchase. The contents of those briefings are usually classified.

The problem with being an expert on the F-35 is, you can't talk about most of the things you know. So internet hot takes dominate and you can't refute them without revealing things that you shouldn't reveal.

The F-22 was that advanced. The avionics suite of the F-35 is significantly more advanced than the F-22. The F-22 hasn't been produced in over a decade and is going to be phased out in the early 2030s.

Even if there weren't a law still on the books banning the F-22's export, we don't have production and no one would buy one when they could have a still-in-production F-35.

In the present time, there is an air defense network around Washington DC. It uses the NASAMs system. Anything that is determined to be a threat can be engaged with surface launched AIM-120C missiles.

https://www.kongsberg.com/kda/what-we-do/defence-and-securit...

I've literally been that engineer, manning that computer, in that room at White Sands, for that instrument on SDO. I was the telemetry/power systems engineer for one of their launches to do underflight calibration on the EVE instrument. It was an absolute nightmare of a job.

The PCs were Dolch lunchbox style single board computers. I had to scrounge the one together for the mission I worked in 2013 by assembling it from a couple of others that were broken. Then I got the joy of installing DOS, to run good old TDP502.exe to handle the telemetry stream coming in. Every fifteen seconds I had to hit "Print Screen" to make the tractor feed printer attached to the machine do a print out of my screen. Kind of insane given that the ground station was making a Chapter 10 format recording of the same data, but NASA allowed no deviation from the way they had always done things.

Worst job I ever had.

You're right about the tone of those statements. But just how much dystopian bureaucracy can one take before expressing displeasure at the dystopian bureaucracy?

There are definitely organizations within the US government developing software that need to be convinced.

When I worked for an aerospace company that is now, thankfully, defunct, our HR department gave us all a miniature Twix candy bar and a company ink pen.

The candy bar I received was melted and the ink pen did not work.

This was a couple of days after I learned that I would not receive a bonus that almost every other employee received.

The latest release of nbdev has fully embraced Quarto! It's very awesome, check it out.

Had a great experience with black. Only thing I did was change its default line length limit to 120 characters (I was regularly dealing with signal names from source data that were about 90 chars).

I used to (2012 - 2014) work on that Sounding Rocket program the article talks about. I never saw a monochrome screen, but the computers handling the telemetry monitoring during launches were old Dolch lunchbox style cases holding a single board PC with a really cruddy LCD panel. The computers were either 386s or 486s (depending on which one you got) running DOS 6 and a program written for telemetry monitoring in 1989 called 'tdp502.exe'. This was written in Borland Turbo C++ and was rather flaky.

Coming off a program with 2000s era equipment for telemetry and monitoring, going to this was a big shock and the pain of using such antiquated equipment made everything very difficult.

Just submitted my application. I use PyCharm and Jupyter on a daily basis.