Yes, the tailhook bay is very, very small. We had a primary disconnect in the bay for the instrumentation wiring for our tailhook sensors. Any time we had to get at that disconnect without having the tailhook trestle removed, we would call it "proctology".
As a guy who knows the F-35 and the program pretty well, I think the best Canadian minds on the F-35 are Richard Shimooka with the Macdonald-Laurier Institute, and former CAF and F-35 test pilot Billie Flynn.
I abhor war. I believe the only way to secure peace is to be very good at war. That's why I participated in flight testing the F-35, and why I work on electronic warfare simulations now.
I wish I lived in a world where there's no need for any of this, but as far as I know, war is as old as the species.
No offense taken. The observation of an instrumentation technician and an engineer (me) definitely counted for not much at all in the grand scheme of things. And we could have just as easily been proven wrong.
Since you're the author: can you remember any cases where the person with "common sense" thought "this crap ain't gonna work" but it worked anyway? Surely people only remember those cases when common sense won, and selectively forget those where it didn't?
> can you remember any cases where the person with "common sense" thought "this crap ain't gonna work" but it worked anyway
I have one! Totally different field though. Cruise ships (and roro ferries) look sooo ungainly in water that regular people frequently ask how do they not just roll over. The Icon of the Seas goes 9 meter underwater and 20 stories over the water. It does not feel or look right. Yet it is right, and keeps upright :), because it does not have uniform density. The engines and machinery, and tanks at the bottom of it keeps the center of gravity low enough to make it stable.
The funny twist is that vehicle carrier ships also look unstable the same way and there the intuition is more correct. There have been multiple accidents where such ships capsized. But the intuition there is still not correct about the reasons why they flip over. (It is not that they don’t have enough draft, but due to free surface effects and the cargo destabilising).
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.
We weren’t allowed to have any other real programming tools, and the telemetry “maps” we were trying to make were/are major/minor frame oriented. This maps nicely to a grid of data: a spreadsheet.
IRIG 106, Chapter 4 PCM telemetry covers what we were doing in this process, along with Chapter 9.
I feel your pain. I've written entire applications in Visual Basic in Excel onboard the CVN before. It was the only programming language I could get access to.
Wait, what? Why weren't you allowed to have real programming tools? I mean, I see a lot of FTEs using Excel, but I thought it was a matter of familiarity. I've also encountered some who are using Matlab, SAS, Python, R, etc.
US DoD heavily controls what can and can't be installed on their stuff. To make matters worse each branch and organization has their own approach to how they control what gets installed.
Sometimes it's just the path of least resistance to use what you already have.
I remember putting in a request to install Python. It took me 6 months to get a response of no. I had the opportunity to appeal with more information on the use case, but I just did it in VB for Excel at that point.
While that's true, FTEs (Flight Test Engineers) tend to have more leeway. As I said above, I've seen Army S6 give approvals for all sorts of programming environments. And the AFTCs seem to be a bit more lenient than that even when it comes to deploying in SCI environments.
Granted, I've also seen a piece of software denied because it has USB in the name (even though it had nothing to do with USB), so YMMV.
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 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.
(BTW, the twitter link on your blog is mistakenly going to twitter.com. I think you meant to link to your account: https://twitter.com/the_engi_nerd Cheers!)
> After this incident it was determined that we had fulfilled the intent of the test plan.
Ok, so it was considered good enough? (This quote made it seem like the testing had failed and they were giving up: "The program decides to officially stop trying to chase the off-center arrrestments and wire only arrestments.)
Also, I still don't understand what wire-only arrestments are. Aren't all arrestments wire only?
I think "wire only" means the hook catches while the wheels are still off the deck.
I suppose that hard landing might have, in some ways, replicated the hard slam-down this would produce. Author, is that the case? Was the hard landing judged to have been a decent proxy for the wire-only arrestment?
Seems unlikely. One is slamming due to a heavy glideslope. Two is slamming due to a serious yank on the rear section. The airframe stresses and flight dynamics will be different.
Absolutely. We had a whole carrier suitability team full of people who lived and breathed this stuff. It was just my responsibility to make sure the aircraft instrumentation system got them the data they needed, at a high enough quality, to empower their analyses and decision making process.
> Ok, so it was considered good enough? (This quote made it seem like the testing had failed and they were giving up: "The program decides to officially stop trying to chase the off-center arrrestments and wire only arrestments.)
Kind of both: it was too dangerous to test a wider range of parameters, and the testing was therefore "successful" because it was crystal clear that going beyond the point where they had the problem would not be safe. So in this case "giving up"/stopping and "determining the limits of the landing envelope, were reached at the same time.
No, aircraft land on carriers while applying full forward thrust and (I am 99% sure) no wheel brakes. The idea is that if the wire fails to catch they "bolter", i.e., do a touch-and-go, so they can come around for another landing attempt. (If they stopped or reversed thrust and the wire didn't catch, they'd end up in the drink.)
Based on other comments (or re-reading the authors comment carefully), it turns out that "wire only" mean that the wire catches before the wheels touch the ground. (This puts additional strain on the wire and airframe.)
You're correct, no wheel brakes and throttle to full as soon as the wheels touch.
If the cross-deck pendant snaps, the engines don't have time to throttle up before you go over the edge. And of course if you don't catch a wire you really don't want to be trying to stop.
There are brakes on the wheels (that can slow a plane moving at flying speed)? That's a lot of force. I assumed the wheels merely prevent friction between the plane body and the deck, and the engines and control surfaces, and the wire, did the braking.
"no wheel brakes" here means that the brakes aren't engaged, as stated so that if the aircraft misses the wires it can touch and go without drowning the pilot and destroying an $80m aircraft
