[HN Gopher] In two incidents, F-16 aviators were rendered uncons...
___________________________________________________________________
In two incidents, F-16 aviators were rendered unconscious, but
saved by software
Author : prostoalex
Score : 195 points
Date : 2021-02-22 21:15 UTC (2 days ago)
(HTM) web link (www.popsci.com)
(TXT) w3m dump (www.popsci.com)
| hoseja wrote:
| "the system consists of a set of complex collision avoidance and
| autonomous decision making algorithms..."
|
| It's 50 nested ifs, isn't it.
| mattmaroon wrote:
| I wouldn't think it's really that complicated. The autopilot on
| a 182 would do the same thing. If the nose is pointed at the
| ground, pull back on the yoke. Etc. The nicer ones can even
| stop a spin and have a button you press that'll return you to
| straight and level flight. I guess a fighter is often
| purposefully in attitudes a regular plane normally isn't, but
| I'd bet it's a simple warning and override.
|
| But I don't fly fighters so I'm just guessing. Collision
| avoidance with other planes In a dogfight might be a lot more
| complex too.
| jki275 wrote:
| The F18 literally has a switch labeled "Spin Recover". One of
| the things it does is to take the computer out of the
| equation and allow the pilot to fully command the airplane
| rather than processing stick and rudder inputs.[1] General
| procedure though is take your hands and feet off the controls
| to start with. The full procedure is in the link a few pages
| in. Notably, it ends with "if passing 10,000ft AGL with no
| indication of recovery, eject.
|
| 1 - https://apps.dtic.mil/dtic/tr/fulltext/u2/a256522.pdf
| Animats wrote:
| Fighters sometimes fly close to the ground on purpose.
| Building a system that will allow extreme maneuvers near the
| ground without a false alarm trigger was hard. The Swedish
| air force was the first to use this system, and they
| routinely fly "close to the rock", through mountain passes.
| That's the hardest part of the problem, deciding when to
| initiate the recovery while not impeding what fighter pilots
| consider normal flight. The threshold is something like 0.3
| secs before it's too late to correct. That requires a very
| good trajectory predictor for figuring out when it's going to
| be too late.
|
| Next is getting the aircraft into a wings-level condition, no
| matter what direction it's pointing. For fighters, extreme
| attitudes are normal. Auto-GCAS will make violent maneuvers
| to do this. "At that instant, the Auto-GCAS commands some of
| the most aggressive, eye-watering maneuvers this ex-USAF
| flight test engineer and civil pilot has ever experienced. If
| inverted (bank angle greater than 90 deg.) and somewhat nose-
| down, a negative 1g push throws the pilot "up" into his
| shoulder straps and lap belt to get the aircraft's nose
| headed skyward. Immediately, a 180-deg./sec. roll is
| commanded, bringing the aircraft to wings-level, right-side-
| up."
|
| Only then can the system command a climb: "Somewhere after
| passing the 90-deg.-bank point, a 5g pull-up is initiated at
| an approximately 4g/sec. rate. The system commands a maximum
| angle-of-attack recovery, if flight conditions will not
| sustain a 5g pull-up."
| mhh__ wrote:
| Actually - I sort of want to work in defense for a few years to
| find out, that and the sheer amount of tech in a modern missile
| (the fact that they would likely be used is why I didn't apply)
| - I reckon most the algorithms here are basically finely tuned
| signal processing and other non-"AI" processes.
|
| There's a tendency to think that everything that isn't
| completely ab initio like machine learning is bad or inelegant
| - I often fall for this trap myself, but to just get the job
| done you can get a very long way with "dumb" algorithms and a
| practically infinite budget.
| noneeeed wrote:
| It pretty much is the case.
|
| Part of it is that predictability is a desirable feature in
| these systems, but also that problems like the one described
| in the article you don't really need things like ML. The
| majority of control problems like this are surprisingly
| straightforward. They might be complex, in the sense of
| having a lot of variables, but the physics involved is well
| understood and can be modelled using traditional techniques.
|
| The progress of self-driving cars is a good example of this.
| I can remember seeing expeimental self driving cars many
| years ago, but always going round mostly empty test tracks.
| Driving a car isn't that difficult for a computer system,
| what's hard is driving in highly complex urban environments
| with many other cars around that you need to predict.
|
| Planes, in contrast, have a rather simple environment. The
| number of objects they have to avoid is massively lower, and
| their freedom of movement is higher, with established rules
| for how to behave, there are no traffic signs to interpret.
| This means that all you are really doing is object detection
| with radar, and collision avoidance.
|
| In addition, modern combat planes are effectively flown by a
| computer all the time anyway, with the pilot providing the
| instructions. A number of fighter planes, especially the most
| modern, are essentially unflyable without computers due to
| their aerodynamics. Most are inherently unstable around at
| least one axis, which makes them more manouverable, but means
| they will not fly stably in the way a 747 will.
| 177tcca wrote:
| > the sheer amount of tech in a modern missile
|
| "Old", reliable tech is prevalent there, too.
|
| Sqlite in missiles is a good example.
| pjc50 wrote:
| The advantage of the "old" control systems approach is that
| it's not a black box; you can reason about its behavior
| across the state space and make assertions about its
| frequency response and stability conditions.
|
| (Is a neural network really different from a _very large_
| cascade of nonlinear filter elements?)
| BrianOnHN wrote:
| > Is a neural network really different from a very large
| cascade of nonlinear filter elements?
|
| It's different in theory, but not by much practically.
| Reverse engineering the former is a fool's errand, but so
| would be a sufficiently complex version of the latter.
|
| In terms of Kahneman's "Thinking Fast and Slow," ML, at
| least in its current stage, is like the fast thinking
| system. It's essential but is exponentially more valuable
| when combined with the slow system, which is still elusive
| in AI practice.
| mhh__ wrote:
| Indeed. I'm just kind of fascinated by military technology
| e.g. The F/A-18's cockpit HMDs and Hud were light-years
| ahead of anything in star wars with the exception of
| holograms even in 1983.
| nonameiguess wrote:
| Algorithms that don't use machine learning aren't dumb. The
| point of machine learning is you need to implement some
| function, can't derive it directly from first principles, but
| have lots of examples of correct inputs and outputs and can
| use that build a function estimator instead. But in a whole
| lot of quite sophisticated and intelligent applications, you
| can derive the functions from first principles. Not easily.
| One of the projects I spent the first few years of my career
| working on was the common image formation processing for spy
| satellite collections, and you need to take into account
| special relativity, orbital mechanics, curvature and velocity
| both of earth and of the arrays, midnight crossover in time
| keeping, temperature calibration and the impact on reported
| voltage detection of each sensor cell, parallax effects of
| rapid altitude changes, polarization of light. There's a ton
| that goes into it, but we know the physics and don't have to
| use statistics to make educated guesses. We can compute
| "given voltage levels x1, x2, ..., xn on sensor cells y1, y2,
| ..., yn at times t1, t2, ..., tn, that is what we were
| looking at" exactly.
|
| Mind you, I'm talking basic level 1 transformation of raw
| data streams to human-intelligible images. Once you get into
| automated object recognition, that's when we start to use
| machine learning, but the algorithms upstream of that are
| still plenty smart.
| ip26 wrote:
| GPS is a good example. Heavy math. Lots of physics. Not
| dumb at all, and you'd never get sub-1m accuracy with ML-
| GPS.
|
| Once you get it right (& get a lock) it works _every_ time,
| instead of occasionally deciding you are in Nome.
| mhh__ wrote:
| As a theoretical physics student who can actually write
| good code, this is the kind of thing I want to work on -
| unfortunately where I live you basically have a choice of
| making _things_ and making _money_
| nvoid wrote:
| > who can actually write good code
|
| If you're going to make this statement, you need some
| skin in the game by putting your GH in your bio.
|
| I don't have the balls to boast about my code so there is
| no GitHub link in mine :). There wouldn't be much to see
| anyway.
| mhh__ wrote:
| I work for the D language foundation, and they seem to
| trust me (god help them!)
| nonameiguess wrote:
| Actually, when I was on this team, I think I was the only
| person with a CS background. Almost everyone else was
| physicists and electrical engineers.
| koonsolo wrote:
| Coming from a game development background, the easy part is
| to make the perfect opponent. The hardest part is to let the
| opponent feel human.
|
| I'm guessing pointing a missile to the right direction has
| more to do with fast feedback loops and less about training
| neural networks.
| mhh__ wrote:
| With a missile the actual signal processing and acquisition
| is what interests me rather than the control theory e.g.
| you send radar pulses out, you get Doppler shifted pulses
| back absolutely littered with ECM - now turn that signal
| into a target to aim at.
|
| Laser codes on A2G missiles are a similar thing that
| interests me.
| [deleted]
| NoOneNew wrote:
| I dont really see a problem with that. While ugly as hell
| visually, it's stupid simple to find out what went wrong and
| fix it. Over abstraction and fancy technique doesn't
| automatically equate to reliability and performance. Why over
| complicate something just to inflate your own ego and be a show
| off to people who are not the end user putting their life in
| the hands of the software?
| tablespoon wrote:
| >> "the system consists of a set of complex collision avoidance
| and autonomous decision making algorithms..."
|
| > It's 50 nested ifs, isn't it.
|
| If that's the case, I don't see an issue if they're spread out
| among a reasonable number of functions.
|
| I wouldn't want some sexy ML system that will sometime go off
| the rails because the clouds are in the wrong place to be
| within 100 feet of an aircraft control system.
| tyingq wrote:
| Some more detailed info: https://sci-
| hub.se/https://doi.org/10.1109/DASC.2011.6096148
| mvh wrote:
| Google "ACAS X" if you're interested in what these algorithms
| are like. There are some good papers available online.
| tester34 wrote:
| >It's 50 nested ifs, isn't it.
|
| which can be complex ... algorithm, can't it?
| the_af wrote:
| Yes, in fact many static code analyzers and metrics will flag
| a piece of code as too complex if it has too many nested ifs.
|
| But it does sound a lot less glamorous, doesn't it?
| tester34 wrote:
| for marketers? maybe
|
| for me? if it works, then it's great - especially here,
| where it saved people's life & expensive af aircraft
| mikestew wrote:
| Well, "it works" in your desktop testing. That doesn't
| mean it works. How do you test the permutations of 50
| nested if statements such that you _know_ "it works"?
| Whoops, there's a bug reported from the field. Have fun
| debugging that corner case.
|
| Or IOW, why do you think the static analyser flagged it
| in the first place?
| akiselev wrote:
| It doesn't matter if it's 50 nested ifs or not if we're
| talking about a recent generation jet fighter - it's
| going to be hell to test no matter what. Even with
| provable control systems you're still at the mercy of
| cutting edge technology and the whole point of the jet is
| superiority over a yet unknown adversary with high tech
| capabilities so the system has be overengineered with
| that in mind.
| fma wrote:
| I have a _very_ rudimentary knowledge of ML. But decision
| trees basically is if else statements, isn 't it? The "ML"
| part is coming up with the tree.
| Nition wrote:
| Decision trees are old news. The new hotness is Utility AI.
| Super advanced. It's still just if statements, but they're
| _weighted_.
| jakub_g wrote:
| 2^50 meets the definition of "complex", if you ask me
| robocat wrote:
| Assuming there are only "if" and no "else", then there would
| be 51 code paths (Presuming other preconditions like: the
| condition is code or there is some code within each if; the
| code cannot throw exceptions; there is no return statement;
| etcetera).
|
| You could perhaps have only two code paths: the 50 ifs are
| true and something happens, or any one of the ifs are false
| and something doesn't happen... although that could be
| written as a single if statement with "and"s.
|
| The 2^50 case would be more code than we can store (unless
| using techniques that reduce the complexity i.e. not 2^50).
| Nition wrote:
| Funny how that sort of statement can sound promising to the
| general reader but scary to a programmer.
|
| I anything I'd put more trust in "We have a very simple
| collision avoidance system, you could probably write it
| yourself."
| imagine99 wrote:
| Might be just the one... if pilot.conscious = false then
| flyto(base);
| gnatman wrote:
| Sales guy here- turns out programming's easier than I
| thought!
| phkahler wrote:
| That's because they glossed over the part that actually
| determines weather "concious" is true or false. They also
| skipped the content of flyto(base). But those may just be
| composition of many more simple things.
|
| The art of programming is combining simple things to
| consisstently produce desired results during general usage.
| imagine99 wrote:
| That's just because the above code is in Pascal. You see,
| it would be much more complicated if written in C++ or
| distributed real-time Java.
| martin_a wrote:
| I was _so_ freaked out by that one equal sign.
|
| Pascal uses := for assignments, if I remember correctly?
| [deleted]
| imagine99 wrote:
| That is correct, but for boolean expressions, logical
| operators etc. it's just the one equal sign. E.g.
| if pilot.sleeping = true then alarm.playing := true;
|
| // This will check if the property "sleeping" of pilot is
| true and will then set the property "playing" of alarm to
| true as well. You could also do a "while" or "repeat ..
| until" there which would probably better to stop the
| alarm if the pilot wakes up again (... then alarm.playing
| := false).
|
| It could totally work this way if you programmed a simple
| flight simulator with Delphi, even today.
|
| BTW, one exception to := in assignments are initialized
| variables inside a var section: var
| announcement: string = 'Wake up!';
| leetcrew wrote:
| sad that this didn't catch on more broadly. I find that
| the difference between `=` and `==` is consistently
| confusing to beginners. it's actually worse when someone
| has a strong math background. that and the fact that `1/2
| * x` is zero in most languages...
| imagine99 wrote:
| Fully agree. This is why I still argue even today that
| (Object) Pascal aka. Delphi is a wonderful language and
| tool for beginners and casual programmers who want to get
| things done quickly and (somewhat) intuitively. Delphi
| unfortunately is not very en vogue at the moment due to
| misguided and community-destroying licensing policies by
| the company that owns it. But that's no fault of the
| language and the toolset. Both together make one the most
| mature, flexible and easily accessible environments for
| programming that I've ever encountered, from quick &
| simple UI-driven cross-platform apps to Web backends to
| hardware-oriented IoT stuff with a little Assembly
| sprinkled in.
|
| Of course there is FreePascal and Lazarus and all that if
| you really want to play with Pascal without touching
| Delphi. Both are neat, even though Delphi is also now
| available as a free community edition.
|
| What I'm saying is: Go forth and write more `:=`
| beaconstudios wrote:
| There would be curly braces and everything!
| busterarm wrote:
| I would bet it's mostly just PID in software.
| mothsonasloth wrote:
| Just reminded me of this video of G-LOC
| https://youtu.be/s0Xgff1NsL0
| rtkwe wrote:
| Tom Scott (who has a great channel btw) went through a
| simulator for it too. The complete reboot of people passing out
| is really interesting.
|
| For a funnier version (caused mostly be excitement rather than
| lack of blood) that doesn't involve people being moments from
| disaster check out the numerous Slingshot ride videos of people
| passing out.
|
| https://youtu.be/DMKcO-T5Y4o
| ed25519FUUU wrote:
| > _That suit dynamically responds to what the jet is doing, and
| squeezes the pilot's lower body, like a high-tech blood-pressure
| cuff._
|
| I'm generally bearish on the supposed incoming AI dark winter,
| but aircraft navigation and dogfighting seem like they're going
| to be much better suited flown by a computer.
|
| They can design aircraft that are much smaller and lighter, and
| can maneuver in ways that would cause a human to black out
| instantly.
| bluGill wrote:
| You can fly a drone from your nice safe office which doesn't
| need to be anywhere near the war. No need for AI, though that
| is already used for the easy parts. For exactly the reasons you
| state.
| Animats wrote:
| Auto-GCAS is over 20 years old now. Here's a more technical
| description.[1]
|
| [1] https://www.f-16.net/f-16_versions_article8.html
| sandworm101 wrote:
| Software is the implementation, but this is a large an nuanced
| program. I find the most interesting aspect is that this is
| software specifically _ignores the pilot_. If the g-locked
| /unconscious pilot is slumped over the controls the computer will
| ignore his stick inputs and substitute its own best judgment of
| the situation. (Pilot's stick says down, computer decides to
| ignore and pull up instead.) That is a really powerful change in
| pilot culture. It conflicts with the 737-Max fiasco where we all
| screamed that pilots should have final authority over computers.
| Getting this into f-16 cockpits must have involved many very
| heated discussions.
| neurotech1 wrote:
| Not as much as you'd think. During early evaluations, AGCAS
| proved itself a lifesaver. I'm pretty sure there is a way to
| override, if it malfunctioned. There are cases where the system
| falsely detects an unsafe condition, the pilot hears the
| warning tone, before AGCAS takes over.
|
| One thing the 737 Max doesn't have, which the F-16 has, is
| ejection seats. The pilot can eject if AGCAS puts them in an
| unsafe situation. I don't believe there has been a single case
| of a pilot ejecting due to a false AGCAS activation.
| FartyMcFarter wrote:
| I'm not an expert, but I think F-16s were designed as fly-by-
| wire from the start, while 737s had mechanically-linked
| controls. This probably made it an easier sell on the F-16
| case.
| ckozlowski wrote:
| Indeed. And another thing to consider is that some modern 4th
| gen performance aircraft _require_ that fly-by-wire by
| design, as they 're designed with inherent aerodynamic
| instability. You'd rapidly lose control of the plane if there
| was a FLCS (FLight Control System) failure. Checking status
| of these is part of the startup sequence.
|
| These systems are often triple or quadruple redundant, and
| will prevent the pilot from executing some maneuvers if it
| would put too much load on the aircraft. This can be relaxed
| for say, wartime situations, as placing high-Gs on the air
| frame reduces it's lifespan.
| MaxBarraclough wrote:
| > some modern 4th gen performance aircraft require that
| fly-by-wire by design, as they're designed with inherent
| aerodynamic instability
|
| The F-16 itself does exactly this. https://en.wikipedia.org
| /wiki/General_Dynamics_F-16_Fighting...
| blunte wrote:
| Watching videos of "normal" people riding as passengers in
| fighter jets, you often see them pass out briefly. The pilots are
| have the training and strategies to push their G limits much much
| higher, but even so it's still a risk.
|
| I wonder how long until we see a G-LOC accident in a modern fast
| accelerating electric car... I'm sure today's fastest
| accelerating street legal cars can do things to a body/brain that
| some people wouldn't be able to tolerate. (And also, if you
| consider how much ground you cover in the very brief 0-60 of a
| modern Tesla, it suggests that a poor choice with the right foot
| could lead to a very quick bad situation!)
| 70jS8h5L wrote:
| Even the latest Tesla only reaches ~1.5G - not even that. G-LOC
| won't happen until 5 or 6, so I think we're a way off yet!
| blunte wrote:
| Considering how faint some passengers have looked with my
| boy-racing in the past, I suspect the G limit for some people
| is much much lower :).
| offtop5 wrote:
| It wouldn't necessarily need to be g-forces, given how many
| Americans have severe underlying health issues, you might
| just go over a rough bump and have a stroke or something.
|
| Roller coasters tend to hit a good amount of gs, but if you
| pass out you'll be fine since you're not driving. One
| wonders if a Tesla detects its pilot unconscious can it
| bring itself to a full emergency stop. Automatically
| contact emts and then automatically distribute snacks to
| the arriving EMTs
| Symmetry wrote:
| That's for young, fit, etc people. Some quick googling says a
| particularly susceptible person might very well pass out at
| as low as 3 Gs. Still way below what a Tesla can pull,
| though.
| rtkwe wrote:
| Two things make that unlikely; cars have to grip the road and
| by the time you're getting close to G limits tires will start
| to skid and second the forces aren't in the right directions.
| For the former the closest a car gets to the levels that induce
| G-LOG are Formula 1 cars during braking (~5G) and during
| cornering (4-6G) [0] so even the highest performing cars out
| there you're just barely approaching where you might threaten
| G-LOC. The latter is why I think it won't really happen though
| because the acceleration is (basically [1]) never vertical like
| in fighter jets during climbs and turns. The forces in a car
| are, w.r.t. the human riding, forwards, backwards, and side to
| side and those directions don't force blood out of the head.
| Braking gets closest because the feet are furthest forwards but
| it's not quite the same.
|
| [0] Acceleration is a measly ~2G at peak
|
| [1] To avoid pedantry there is a case but that's on extremely
| high bank turns that only exist on test tracks really, NASCAR
| track banks might get close but I don't think get Gs there get
| high enough before cars break free up into the wall to threaten
| G-LOC.
| ben7799 wrote:
| Indy cars IIRC have run into the problem on banked tracks.
|
| They did something to slow the cars down and remove the need
| for G-suits.
|
| Indy cars got to around 5G, which is pretty hard to sustain
| without a G-suit.
|
| The 9G stuff in the F-16/F-22 absolutely requires the G-suit
| and the reclined seat which changes the force vector.
|
| I've motorcycled on a NASCAR track, but not a very steeply
| banked one relative to the superspeedways. Even the lower
| banking changes the way turns feel in a very dramatic way
| though.
| michael1999 wrote:
| Cars generate horizontal forces, and won't drive the blood out
| of your head into your legs.
| kube-system wrote:
| Unless the road is banked:
| https://en.wikipedia.org/wiki/Firestone_Firehawk_600
| stefan_ wrote:
| There is a video of what it sounds like:
|
| https://www.youtube.com/watch?v=WkZGL7RQBVw
|
| That automated recover voice is quite eerie.
| joncrane wrote:
| This is an incredible video. Hearing the pilot gasp for air
| while a) his wingmates yell on the radio and b) seeing the
| details on the HUD are amazing.
|
| The airspeed goes above Mach 1 while the altitude drops from
| about 16,000 ft to 4,000 ft. The pilot sustains over 9G when
| the automated system pulls him out of the dive.
|
| Wow!
| vmception wrote:
| how can you read that? I look at your comment and look at the
| HUD and can't match up any of the numbers and axis to your
| observations? how do you read this?
| Merad wrote:
| They probably used to play flight simulators (I did). The
| vertical ticker on the left is airspeed in knots. Ticker on
| the right is altitude in feet. Then underneath the left
| ticker find the word SIM, directly beneath it is the
| plane's current mach number, and diagonally below and to
| the left of that is a counter that tracks the highest G
| load the plane has sustained (it goes to 8.4 right as the
| pilot passes out then peaks at 9.1 during the pull out).
| ckozlowski wrote:
| Yup! And on the left side, the decimal number above the
| "C" is the current G on the aircraft, so you can see that
| number increase as he recovers.
|
| For OP, here's a great guide that ChuckOwl of the DCS
| community did for the F-16C in game. HUD breakdown is on
| page 35 of the PDF.
|
| https://www.mudspike.com/chucks-guides-dcs-f-16c-viper/
| ckozlowski wrote:
| Yeah, he was already booking it.
|
| This looks like it was an air combat exercise. At the very
| start of the video (0:07) you see a big round circle and some
| lines that are spread a the top and close together at the
| bottom. That's the EEGS gunsight, and in the censored
| portions of the screen is likely the bandit/hostile he was
| tracking. (Exercise of course.)
|
| Either his target slips out of gun range or he switches to a
| different mode, but regardless it looks like he pursues,
| rolls 90 degrees and "buries the stick in his lap" (F-16 has
| a side stick that doesn't move, but whatever. =). I'm told
| you have to be careful with this, and probably in the F-16
| doubly so. (As C.W. Lemonine has said in a few of his videos,
| the F-16 _will_ try to kill you.) In the top left of the HUD,
| straight up from the "C" is a decimal number showing the Gs
| on the aircraft, and it climbs rapidly from 3-4G up to 9G. He
| loses about 100knots of airspeed (still pretty fast though!)
| but then you hear that exhale around 0:18 and he starts to
| slip off the horizontal and enter that dive. His 9G turn
| probably is what knocked him out, and yeah, breaks Mach 1
| briefly as he heads downward.
|
| Then as ya said, he pulls another 9G when the system pulls
| him out of the dive.
|
| The "knock it off" calls after are to indicate that they're
| not fighting anymore. As I understand, that's not slang,
| that's the actual terminology used.
|
| Crazy stuff.
| 35fbe7d3d5b9 wrote:
| From what I've read in the past, Auto GCAS computes a 5G
| recovery pull. Speculation was that the pilot came to
| consciousness at some point during the recovery and applied
| some _extra input_ to hit 9Gs.
| reasonabl_human wrote:
| Agreed, even if he was conscious during that nose dive,
| pulling 9.1 G's would send him right back into GLOC before
| fully recovering.. and likely into the ground as he was
| already so low...
|
| Only this computer system could've pulled off such a save.
| Awesome!
| baybal2 wrote:
| I think it was his wing mate
| stefan_ wrote:
| I guess thats possible, but it seems quite.. regular?
| throwanem wrote:
| The repeated "Recover!" is indeed the formation leader, not
| an automated warning. It's as regular as it is because
| pilots, and especially military pilots, are trained to
| maintain a very strong radio discipline, and also (as Brian
| Shul notes in _Sled Driver_ , his SR-71 memoir) because as
| a point of personal and cultural pride everyone wants to
| sound like Chuck Yeager on the radio. It makes sense, too;
| things can go wrong very fast in an airplane, and it does
| no one any good for a pilot to lose their cool in an
| emergency.
|
| Listen closely, and you'll notice that the formation leader
| lets that discipline fray a bit in the second and following
| calls, when some urgency bleeds through. This is because he
| suspects his trainee is about to die, which is what would
| indeed have happened if AGCAS hadn't been available.
|
| (You can also tell it's a radio call and not an annunciator
| by the form of address - the full call is "Two, recover!";
| "Two" is what someone else in the formation calls its
| second member. "One" is the formation leader; in a four-
| ship formation you'd also have "Three" and "Four", and so
| on for larger groups.)
|
| _edit:_ corrected some terminology
| l33tman wrote:
| I guessed that he probably suspected he's unconscious or
| something, and therefore warranted shouting.
|
| After all, the leader had probably seen Top Gun, where
| this almost happened to Cougar :)
| nanis wrote:
| > Listen closely, and you'll notice that the element
| leader lets that discipline fray a bit
|
| Actually, the moment I heard him, I thought there was
| terror/panic in his voice which is warranted because
|
| > because he suspects his trainee is about to die
|
| came _very_ close. Went from over 16,000 ft to under
| 5,000 ft.
|
| One thing I did not think was "this is a machine
| talking".
| throwanem wrote:
| Yep. The actual AGCAS annunciation is the pair of
| chevrons advancing from the sides of the HUD into the
| center, and the blinking cross and "FLYUP" indicates that
| the system has engaged.
|
| For audio, there's a very noticeable horn during
| recovery, as well as a "Fly up" automatic voice
| announcement - that's a little hard to pick up due to
| overlap with a call from the formation leader, but you
| can catch it if you listen closely.
| jaywalk wrote:
| There's also an automated (and very calm) voice
| announcement saying "altitude" 2-3 times before the
| urgent "fly up!" and horn.
| Cthulhu_ wrote:
| Well yeah, formal radio comms have to be. It's not like Top
| Gun.
| hackerNoose wrote:
| The automated one is the female "altitude, altitude, pull up,
| pull up". The screaming dude is his wingman.
| Toutouxc wrote:
| I wonder how many WW2 (the eastern front kind) and early-jet
| dogfights were won not because of airplane damage, but because
| one of the pilots GLOC'd himself and hit the ground.
| lakecresva wrote:
| Or just exhaustion. There's an interview with a Japanese ace
| Honda Minoru on yt in which he talks about how pilots were so
| exhausted from flying eight hour combat missions every day of
| the Guadalcanal campaign that they would fall asleep at the
| controls, slowly fall out of formation, and hit the water. They
| (amazingly) had no radios in their aircraft at the time, so
| they just watched it happen.
| fishnchips wrote:
| IIRC they _did_ have radios but those were so unreliable due
| to poor quality of vacuum tubes that many pilots chose not to
| use them, sometimes to the point of removing the antenna
| mast.
| openasocket wrote:
| The Japanese had a variety of issues with radios. Some Type
| 0 pilots did remove their radio system, to save weight, but
| only on land-based fighters. For carrier-based ships radios
| were still essential, because they used radio direction
| finding for navigation. Japanese carrier-based operations
| also suffered issues because they tended to use a single
| radio frequency for all air operations (meaning the channel
| could get disorganized). Japanese carriers also had their
| antennas on the sides of the ships rather than at the top
| of the island, which meant they often couldn't receive
| longer ranged transmissions, so it would be up to escorting
| cruisers to receive messages and then transmit them to the
| carrier. The book "Shattered Sword: The Untold Story of the
| Battle of Midway" has some good information about some of
| these nitty-gritty details.
| arethuza wrote:
| I'm pretty sure I've read that exhaustion was a factor in the
| Battle Of Britain - the RAF took measures to ensure that
| pilots were reasonably well rested between sorties whereas
| the Luftwaffe just kept throwing them in again and again.
| bluGill wrote:
| The Germans tended to put their trainers into combat roles
| meaning that they had trouble training new pilots. In the
| later days of the war they sometimes told pilots to eject
| if they saw an enemy plane over friendly ground - there
| were plenty of airplanes so better to make it back alive
| and try again than to risk death.
| throwanem wrote:
| The Japanese did the same thing, toward the end of the
| Pacific War. It wasn't by preference in either case, but
| because they were so low on pilots that it became a
| question of whether to use instructors as combat pilots
| or just not have anyone to fly those missions at all.
| noneeeed wrote:
| I've definitely heard stories from old pilots of blacking out
| and coming too while out of control, and then having to wrestle
| control back while coming round. I wouldn't be at all surprised
| if many more never recovered in time.
|
| I remember a WWI era flight-sim called Red Baron that included
| this in it's mechanics. If you tried to pull a turn too fast
| you'd start to black out and lose control.
| jki275 wrote:
| Most flight sims model gloc, I remember it as far back as the
| 1980s Chuck Yeager series and it's definitely a thing in the
| F18 and F16 in DCS today.
| openasocket wrote:
| Dive bombers actually subjected pilots to some serious
| g-forces. Some planes (at least the Stuka) had an automatic
| pull-out that would cause it to pull up at a certain altitude
| (or when the bomb is released, I'm not sure), so the plane
| could recover even if the pilot blacked out. Though apparently
| some pilots didn't like this feature and disabled it, because
| they felt always recovering at the same height made it easier
| to anti-air defenses to target them.
|
| Another fun fact about the Stuka: you know that weird whining
| noise you hear in WW2 movies when a plane is dive bombing,
| almost sounds like the engine is acting up (like this
| https://youtu.be/5uvqhA4_2tU?t=39 )? So that noise is unique to
| the Stuka. It's not the engine, the plane has sirens fitted to
| the dive brakes! It was meant to scare soldiers on the ground.
| closeparen wrote:
| From this talk [0] I get the impression that a large part of
| the "chess game" of a dogfight is about the aircraft's
| momentum. You're trying to get the enemy into a situation where
| his aircraft has too much or too little energy to respond to
| you, and can't accelerate / decelerate in time.
|
| [0] https://www.youtube.com/watch?v=22u4qxm1YjY
| HeyLaughingBoy wrote:
| There's an excellent biography about Boyd
| (https://www.amazon.com/Boyd-Fighter-Pilot-Who-
| Changed/dp/031...) the pilot who formalized using energy &
| momentum into actual combat techniques. The book is really
| good reading.
| Cthulhu_ wrote:
| I wonder if the planes from back then could handle G-forces
| like that back then.
|
| (they probably could)
| laurent92 wrote:
| As early as it was, their construction was probably sturdy.
| It's only now that we calculate material margin at 110%
| instead of x5 or x10. The B52 is so stretched it famously
| leaks fuel at ground level, the operating guideline says "6
| droplets per minute" to 20 droplets per minute for a dozen
| points of the aircraft (mostly around the wings).
| dudul wrote:
| Why only the eastern front? Pilots of the RAF were completely
| exhausted during the Battle of Britain and the Blitz since they
| had such a numerical disadvantage compared to the german air
| force.
| Toutouxc wrote:
| Eastern front dogfights were generally fought at lower
| altitudes, where GLOC is much more dangerous.
| d33lio wrote:
| Especially when you consider that most of the German
| Luftwaffe were jacked up on "pilot's salt" (meth) [0]. Makes
| sense that the US AirForce now has a widely known Modafinil
| kick ;)
|
| 0 - https://worldwarwings.com/the-hidden-risk-faced-by-
| german-pi...
| throwanem wrote:
| Not just the Luftwaffe, either, and not just speed. Tablets
| formulated with both methamphetamine ("Pervitin") and,
| later, cocaine, were issued throughout the Wehrmacht. [1]
| Some branches also had speed-laced chocolate bars,
| _Fliegerschokolade_ and _Panzerschokolade_ for pilots and
| tankers respectively. [2] They also broadly issued opioids
| - including oxycodone ( "Eukodol")! - and drunkenness was
| likewise extremely widespread, at varying times both with
| and without official sanction and material support (i.e.
| liquor rations).
|
| [1] https://www.spiegel.de/international/the-nazi-death-
| machine-...
|
| [2] https://time.com/5752114/nazi-military-drugs/
| greedo wrote:
| Not just the Luftwaffe. Benzedrine was a normal thing to be
| given to Army Air Corp Pilots (in fact it was issued to
| almost all US military units).
| sep_field wrote:
| who gives a fuck about two military murder-men. the world would
| have been better off if they had crashed and burned. fuck the
| capitalist imperialist slave-state. death to all military.
| numlock86 wrote:
| The article makes it sound like all Block 40 and newer F-16 have
| AGCAS. While this might be correct, it's worth mentioning that
| AGCAS was implemented around 2014 and started rolling out on F-16
| after. Block 40/50 F-16s are way way way older than 2014 ... plus
| most non-US F-16 units didn't and won't get the update at all.
| cgearhart wrote:
| Similar story for the F/A-18, but even later. The technology
| exists--Boeing even did a demonstration in the early/mid
| 2010's. Navy only finally approved installing it in FY2019
| budget, so it may not even be fielded yet.
|
| I used to work with a Marine F/A-18 pilot who came to the
| program office with an _axe_ to grind about this. He requested
| meetings with PMA-265 (not our office, but same building--this
| was a very weird thing to do) to _politely_ show them the USAF
| F-16 AGCAS video and a list of folks he personally knew who
| died because we didn't have AGCAS in F /A-18. I just looked him
| up, and he's been promoted to Lt.CoL.; now working as the air
| systems lead for legacy F/A-18 in PMA-265-and it sounds like
| even legacy hornet is going to get AGCAS. I'm impressed (but
| perhaps not surprised) that he's been able to get them to
| invest AGCAS in a platform that hits end-of-life in 2030. 11/10
| would work with SOCK again.
| Tade0 wrote:
| Huh, nice to see something that I imagined would be introduced
| eventually, but didn't expect to arrive so soon.
|
| A while ago I came up with an idea for a short sci-fi story and
| it goes something like this:
|
| An AI assisted fighter jet is being developed which not only
| recovers from situations like in the article, but also performs
| some of the fight-related duties - often faster and better than a
| human pilot would - learning as it goes.
|
| The top brass is impressed, so the fighters are eventually sent
| on their first mission.
|
| Enemies are engaged and dispatched one by one, but two things
| seem off: the planes start making increasingly sharp(and
| effective) turns and contact with the crew becomes limited at
| first and stops altogether later on.
|
| As the last enemies start falling back the unit begins pursuit -
| even though they were ordered to return to base.
|
| No response. Meanwhile the aircrafts' movements become even more
| erratic - to the point where eventually they fall apart one by
| one from the sheer strees put on the parts.
|
| Recovered blackbox recordings indicate that by the time the
| enemies started retreating the pilots were all either unconscious
| or long dead.
| bluGill wrote:
| At this point the WWII dogfight between planes is dead.
| Missiles have more than enough power an maneuverability to take
| down any plane their are pointed at. There are ways to deal
| with missiles, but none are maneuvers by the target. You can
| maybe out fly a missile, but that is because it was launched at
| close to maximum range and so you get out of range.
|
| Drones are a different story. The future is pilots on a
| different continent from the actual fight. They will sometimes
| take the controls, sometimes push the "do this maneuver"
| button, and sometimes let the AI take care of it. As AI get
| better and better their role becomes more as the final human in
| the loop agreeing to kill an identified target. There are still
| gaps in making this work in the real world, but the signs are
| all there. Without a human in the plane you can do things that
| would kill the human.
| greedo wrote:
| Your first paragraph isn't accurate. For example, one common
| maneuvering tactic against radar guided missiles is to fly
| perpendicular to the radar, trying to hide in the doppler
| notch.
|
| Against IR guided missiles, maneuvering is also a part of the
| counters used (in addition to flares). Maneuvering helps
| deplete the missile of energy. You'll never out turn a
| missile, but you can make it run out of fuel/energy.
|
| That said, modern AAMs have tremendous no escape zones where
| it's quite difficult to survive if the missile is employed
| properly.
|
| And drones flying counter air missions will probably happen
| when level 5 self-driving is successful.
| dragonwriter wrote:
| > There are ways to deal with missiles, but none are
| maneuvers by the target.
|
| Countermeasures combined with maneuvers to break lock and
| prevent reacquisition is, as far as I know, still doctrine
| because it has a high enough probability of success to be
| useful (and to be worth equipping planes for).
| niea_11 wrote:
| This reminds me of an episode of Ghost in the shell (the serie,
| season 2 episode 4).
|
| from the description of the episode:
|
| _the pilot of the helicopter suffers a massive heart attack,
| and the Jigabachi begins to spin out of control. The on-board
| Artificial Intelligence gets the helicopter back under control,
| and the military officers running the drill decide to abort it
| out of concern for the safety of their troops. However, the AI
| aboard the Jigabachi refuses to acknowledge the order to return
| to its parent JMSDF aircraft carrier. Acting on the assumption
| that the chopper is under attack, the AI overrides the flight
| controls of other armed Jigabachi aircraft, an air tanker from
| the carrier, and several nearby military bases, ordering these
| units into a tight defence formation in the heart of the
| Niihama Refugee Residential District._
|
| https://en.wikipedia.org/wiki/List_of_Ghost_in_the_Shell:_St...
| Tade0 wrote:
| Thanks for the pointer - I've only seen the movie and
| actually had no idea that a series existed.
| rcxdude wrote:
| The series is very good, perhaps better than the first
| movie (and definitely better than the other movies, though
| those are still worth watching).
| brmgb wrote:
| Heartily disagree. Half of the serie first season (the
| complex episodes) is somewhat interesting. The rest is
| mostly the usual sci-fi trops and goes from mostly
| avoidable (the other half of the first season) to plain
| bad (everything after). It has neither the depth nor the
| artistic chops of the two Oshii movies.
| niea_11 wrote:
| I agree. The tv series is better because with 50+
| episodes, the creator(s) were able to present a more
| detailed version of the future described in the movies
| (I'm talking about the first one from 1995 and
| Innocence).
| jolmg wrote:
| There's multiple movies and the original manga, too.
| mikece wrote:
| 1. I'm curious what happened to the pilots: did they remain in
| their role as fighter pilots or were they transferred to other
| airframes that pull fewer Gs?
|
| 2. I can't help but think about the possibility that software
| that can take over when it thinks the pilot is non-responsive
| could be hacked to crash on purpose or be taken over remotely.
| Perhaps this is a "feature" that will allow the F-16 fleet to be
| used as UCAVs without telling the public (or our enemies) about
| it?
| zucker42 wrote:
| I don't understand your second point. How could a F-16 be
| hacked remotely when there's no remote access? There's no
| attack surface. How is this different from any other fly-by-
| wire system?
| greedo wrote:
| There is remote access. Fighters routinely exchange data via
| datalink like LINK 16 and JTIDs. It's not inconceivable that
| this could lead to some exposure. It would depend on how
| segmented the flight control computers are from the other
| computers. A lot of the cyber warfare plans are attempting
| this type of attack.
| jki275 wrote:
| Link-16 is JTIDS. It doesn't have any connection to flight
| controls or any controls of anything it's deployed in
| (which is just about everything). It's also type-1
| encrypted.
| greedo wrote:
| So it sits on a separate bus, physically disconnected
| from any other flight computers?
| jonplackett wrote:
| I wonder how close they actually got to the ground.
|
| It says it _engaged_ at a few thousand feet but at fighter plane
| speed that could have been seconds until hitting the ground.
| rkangel wrote:
| That was the most interesting bit to me. I am learning to fly
| an autogyro - 2000 to 3000 ft is our normal cruising altitude
| and I haven't been above 5000. The idea that you need to pull
| up at 4000 to not hit the ground says a lot about the speed.
| implements wrote:
| > I am learning to fly an autogyro ...
|
| Just to say, HNs had a comment yesterday with a terrifying
| video illustrating 'the one big safety problem' with
| autogyros - rotor disk unloading followed by "bunt over" (I
| think).
|
| I hope you don't mind me saying ... please don't skip any
| safety training, particularly if you come from conventional
| aircraft.
| rkangel wrote:
| I'm learning in the UK where you aren't permitted to skip
| anything. Even if you had a PPL for fixed wing (which I
| don't) it's only worth 15 hours of the required 45 in the
| gyro.
|
| I'd be curious to see the video, but modern gyros are less
| susceptible to it and it's simple to avoid as a pilot (far
| easier than stalls and spins).
|
| I find it alarming the degree to which US pilots can fly
| gyros with minimal specific training - they're very
| different to planes.
| implements wrote:
| Here it is:
|
| "Gyrocopter low g power push over crash"
|
| https://www.youtube.com/watch?v=CfjBzrSDrV0
|
| Warning: From the description: "This is a pretty sobering
| piece of film and its pretty obvious the pilot didn't
| walk away. So if this is likely to upset you please don't
| watch."
| revax wrote:
| Can you link to the comment, that sounds interesting!
| throwanem wrote:
| Assuming we're talking about the typical example
| (https://youtu.be/WkZGL7RQBVw) - in the HUD, altitude is the
| right-hand vertical tape. (The left one is airspeed.) It looks
| to bottom out around 4400 feet during the AGCAS recovery.
| ceejayoz wrote:
| Loses about 10k feet in about 13 seconds starting at the 0:23
| mark. Yikes.
| throwanem wrote:
| The airspeed at the bottom of the dive is "yikes" all over
| again, too. Maybe four seconds tops if AGCAS hadn't kicked
| in.
| randerson wrote:
| With Altitude meaning feet above sea level, this could have
| been pretty close to the ground. (Arizona is largely around
| 4000' elevation it seems.)
| throwanem wrote:
| I'd need to look it up to be sure, but I would assume by
| default that this is a radar, not a barometric, altimeter.
|
| (To expand on that: A barometric altimeter works via air
| pressure, and thus shows height above sea level; a radar
| altimeter measures the time taken for microwaves to go from
| it to the ground and back, and thus shows height above
| ground. I wouldn't be surprised to find both types in a
| fighter, but I would be very surprised to find that a radar
| altimeter _wasn 't_ the default, because it's going to be
| the one that provides the most accurate information and
| thus the most useful to a pilot who needs to worry about
| avoiding CFIT during complex maneuvers.)
| jki275 wrote:
| No.
|
| The radar altitude is shown further down the right side
| (the box with the "R" next to it). It bottoms at 2970 as
| I saw it at with the tape showing 4370MSL.
|
| The right side of the tape is MSL.
|
| If you watch that box through the video, you can see why
| you don't use the radar altimeter for everything. Any
| time you don't have clear line of sight to the ground
| with the belly of the aircraft, the radar altimeter
| blanks out completely. If you're in a roll, it will give
| incorrect information as it's not pointed directly at the
| ground.
| throwanem wrote:
| Ah, good to know. Thanks!
| Alex3917 wrote:
| If you're going to park 600 military planes wingtip to wingtip,
| you might as well just program the software to purposely crash
| them all into the ground. Didn't we learn anything from Pearl
| Harbor?
| jcims wrote:
| I would guess that the presence of AGCAS is, in part, why the
| pilots were willing/allowed to push themselves so hard in
| training.
|
| I didn't really say if the system only intervenes if it believes
| the pilot is unconscious or if it always intervenes if the fligh
| path is within some envelope of terraforming.
| rcxdude wrote:
| I doubt this is the case: the system was developed in part
| because blackouts were one of the leading causes of deaths
| during training.
| saberdancer wrote:
| I doubt they changed their training methods due to AGCAS.
|
| From my understanding, system works automatically and does not
| take into account whether pilot is conscious or not. It is not
| meant just to save unconscious pilots but also those who are
| disoriented (in fog, confused, ...).
|
| Given that it is a military aircraft, it's likely the system
| can be turned off if deemed necessary, for example if you are
| avoiding a missile it might be less risky to dive close to the
| ground than to pull up.
| Kolokius wrote:
| I would guess there are two possibilities. The system won't
| override pilot input or the system only kicks in when it's
| 100% certain that a crash is inevitable.
|
| > If the system predicts an imminent collision, an autonomous
| avoidance maneuver--a roll to wings-level and +5g pull--is
| commanded at the last instance to prevent ground impact."
|
| Sounds like by the time the system kicks in, you probably
| need it to kick in.
| jcims wrote:
| There's a short article here with a little more detail,
| sounds like it overrides pilot input as well (i.e.
| 'nuisance flyups')
|
| https://sofrep.com/fightersweep/in-the-seat-with-agcas-
| those...
| darkerside wrote:
| Engineering doesn't typically work this way. There needs to
| be a tolerance because you can't account for all variables.
| The question really is, at what probability of likelihood
| of a crash do you want to attempt to avert it?
|
| Averting 99.5%+ of crashes probably eliminates flexibility
| beyond what is appropriate for a fighter pilot.
| Kolokius wrote:
| > "Auto-GCAS continuously compares a prediction of the
| aircraft's trajectory against a terrain profile generated
| from onboard terrain elevation data. If the predicted
| trajectory touches the terrain profile, the automatic
| recovery is executed by the Auto GCAS autopilot. The
| automatic recovery maneuver consists of an abrupt roll-
| to-upright and a nominal 5-G pull until terrain clearance
| is assured."
|
| https://sofrep.com/fightersweep/in-the-seat-with-agcas-
| those...
|
| It predicts a trajectory. Either that trajectory looks
| like it'll hit the ground or not. If it doesn't, then
| there's no need to intervene.
| aflag wrote:
| Any nose dive will look like it will hit the ground,
| won't it? The question is at which attitude does it need
| to pull up. Obviously, there are many factors involved,
| but there may be other factors the system is not aware
| of, that's why it probably makes sense that's
| overridable. I bet there is a way to do it.
| jsmith45 wrote:
| It is mostly likely timing based. It may well calculate
| how much time is left until collision, or perhaps until a
| 5G pull will become insufficient to recover. When that
| time remaining drops below N seconds (which from looks to
| be perhaps 1-3 seconds if it is the until insufficient
| time metric, or perhaps an extra few seconds for time
| until collision) it will activate.
|
| Obviously there are other criteria to prevent a landing
| approach from being seen as an imminent crash etc. But an
| override system that cannot be accidentally held by a
| disoriented or unconscious pilot seems plausible.
| dTal wrote:
| By the time it's 100% certain, there's nothing it can do.
| Any control input the system can make, the pilot could also
| be theoretically planning to make.
| Kolokius wrote:
| I didn't say "it's 100% certain that no matter what,
| there'll be a crash". Implied is that "100% certain of an
| impending crash without any extra input".
| jki275 wrote:
| AGCAS was developed because pilots in the F16
| specifically were blacking out from excess G forces and
| flying into terrain. An unconscious pilot isn't likely to
| make any useful control input at all.
| jcims wrote:
| Watching people convulse as they recover from GLOC in
| simulators makes me think that pilot input is probably
| best ignored.
| alvah wrote:
| The plural of "aircraft" is not "aircrafts". Isn't English a
| requirement for sub-editors?
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