Hard deck, is the only way never to crash?

[extrapilot]

Originally Posted by justwannahavefun

The Skookum 720BE uses a Barometric Altimeter, as does the CoPilot II. The CoPilotII does require a length of tubing and what is essentially a funnel at the end of the tubing to keep the rotor wash from causing too much trouble. I assume the Skookum's GPS case is the alternative to tubing and funnel for rotor wash mitigation.

But.....The bottom line is that a Barometric Altimeter does work for bailout. I've used one many, many times and the other a handful. I'll assume there is at least some issue with the Skookum baro and I base the assumption on the fact that until they lost their supplier, Skookum added the option to get a Infrared or "Laser" altimeter. (They called it a laser and I think I read that it uses infrared but I could be wrong about that part.) The literature states that the "Laser" altimeter is simply much more accurate than the baro. As of a couple of weeks back there's still no "Laser" altimeters available for Skookum.

Now if their baro was working very well would they have added the option of the Laser altimeter? Who knows, I just thought it had merit to bring it up. But, again, a baro DOES work. I only have a lot of experience with the CoPilot II but not only does it work it works under many different situations and does it well. As a plus the CP II is cheap. Relatively speaking that is.

No mate- you didn’t read, or at least didn’t understand, what I wrote.

I wrote that you cannot take a generic TX/RX with telemetry, put a baro sensor on it, and set a trigger where ‘if altitude < 30ft, bailout’, and expect that to work well. A person in this thread who probably drank way too much coffee proclaimed a Taranis with a baro sensor was a ‘game changer.’ Except- this was demonstrated by Jmann and others more than a year ago, and nothing has changed.

To make the baro work reasonably well, you need a lot going on in the background (a trajectory planner), which understands the direction/vector of the machine’s flight path, and the current trend in baro pressure. If that path is ‘down at 45deg’ and the baro is showing pressure increase at whatever rate (say, 10ft/sec), then it is possible to know when it needs to bailout in order to not fall through the hard deck. Even then, it is not precise, because the baro sensor exists inside of a world where the static pressure of the air is not the same as ambient- because the machine is moving, and the rotor generates dynamic pressure.

There is nothing wrong with using sensors like these as part of a larger system. Laser proximity, or radar, are better- because they are not susceptible to error resulting from regionally altered static pressure around the machine. But even then, you still need to know rates of change- because in a nosedive at 100mph, a bailout which triggers at 30ft may not allow the machine to upright and slow before it hits the ground.

[CZorzella]

Originally Posted by extrapilot

No mate- you didn’t read, or at least didn’t understand, what I wrote.

I wrote that you cannot take a generic TX/RX with telemetry, put a baro sensor on it, and set a trigger where ‘if altitude < 30ft, bailout’, and expect that to work well. A person in this thread who probably drank way too much coffee proclaimed a Taranis with a baro sensor was a ‘game changer.’ Except- this was demonstrated by Jmann and others more than a year ago, and nothing has changed.

To make the baro work reasonably well, you need a lot going on in the background (a trajectory planner), which understands the direction/vector of the machine’s flight path, and the current trend in baro pressure. If that path is ‘down at 45deg’ and the baro is showing pressure increase at whatever rate (say, 10ft/sec), then it is possible to know when it needs to bailout in order to not fall through the hard deck. Even then, it is not precise, because the baro sensor exists inside of a world where the static pressure of the air is not the same as ambient- because the machine is moving, and the rotor generates dynamic pressure.

There is nothing wrong with using sensors like these as part of a larger system. Laser proximity, or radar, are better- because they are not susceptible to error resulting from regionally altered static pressure around the machine. But even then, you still need to know rates of change- because in a nosedive at 100mph, a bailout which triggers at 30ft may not allow the machine to upright and slow before it hits the ground.

EP, I agree with your thoughts; there is also another variable that should be taken in consideration when pilot hits the rescue button or the heli hits the hard deck; the head speed.

I use both HD systems (Skookum SK720BE and CP-II with HD option) and I've tested countless time and found out that both systems will take A LOT more time to recover from a vertical dive, if head speed is low.

IMO this is an extremely important factor because different pilots flying different styles and head speed may lead to different perception about rescue performance. It's also important to take this into consideration when setting the minimum altitude for the HD, otherwise recovery may fail in certain situations.

Carlos

[extrapilot]

Hi Carlos

Yea, the thing about a real systems is that they tend to pull in a lot of data (i.e. not just gyro data, but also governor (headspeed, or pretty close…), stick inputs, historical data (i.e. what is the pitch rate for this machine given max cyclic inputs at this headspeed), etc. And with that, you can do a lot to determine when a recovery needs to begin. It is just really difficult to do this via telemetry, since FBLs don’t tend to send the data you need to derive a good solve on this via a script on the TX.

Its not that a baro trigger cannot work for basic stuff- it can, and it may help some people. But there is a difference between using it in 50ft hover training vs in acro flight with a 30ft hard deck- something that was claimed as possible by one of the participants in this thread (the game changer guy).

What matters is that people just be objective about what is possible/reliable, and make sure to stay within those limits if they want to keep confidence in the system. And since different systems have different capabilities (telemetry update speed, lag, filtering, etc), it really needs to be kept as sort of ‘here is how I did it, maybe it will work for you’ vs ‘this will change the world! A universal approach to preventing crashes for all’

[justwannahavefun]

Originally Posted by Luvmyhelis

Doesn't the barometer you can buy separately from Jeti work by itself? Meaning it can trigger your self level at certain pre set heights if you have self level on your fbl system? We were just discussing this over in the Skookum section awhile back. Jeti came out with a release note on it. We were comparing the low cost to the SK's gps feature.
I know it works with Jeti, but.
I can't help but wonder if some smart guy here integrated that into another system and made it work?

Like Mqgowen, I too toasted a heli last fall hitting th instead of my bail out, which I never use anymore and haven't for years. (5 helis equipped also). That one has Sk gps now. I also changed the Th toggle off my temp spring loaded toggle, which is now my bail out. And I practice hitting it at least once an outing.

I have a Jeti TX and a Jeti Malti altimeter and I can set it so that the Spirit Pro, or any other package with a bailout or self level to trigger directly from the Telemetry page. You can also give the trigger a time limit so that in the case of the Spirit Pro, once it's triggered and starts heading skyward, it will leave the rescue mode without you having to switch anything off. I understand that you can do the same exact thing with a Taranis which is much cheaper than the Jeti.

[neverland]

why do people put faith in bailout systems. its such a cop out expecting electrics to fly your heli. what are you, drone pilots or something lol. we are surely better than that arnt we. just get on the phoenix sim for a few years (other sims are available) and practice till your thumbs are sore and you can automatically control the damn helicopter yourself in every situation. then you have your own built in hard deck and auto bail out system at any height you want. dont walk until you can run i say . i think we have two types of pilot in this hobby. those who its all about practice and mastering control and maneuvers (on cheapo equipment), and those who just buy stuff. i think the second type of pilot is more common judging by the lack of posting in the flight school section :/

[CZorzella]

Originally Posted by neverland

why do people put faith in bailout systems. its such a cop out expecting electrics to fly your heli. what are you, drone pilots or something lol. we are surely better than that arnt we. just get on the phoenix sim for a few years (other sims are available) and practice till your thumbs are sore and you can automatically control the damn helicopter yourself in every situation. then you have your own built in hard deck and auto bail out system at any height you want. dont walk until you can run i say . i think we have two types of pilot in this hobby. those who its all about practice and mastering control and maneuvers (on cheapo equipment), and those who just buy stuff. i think the second type of pilot is more common judging by the lack of posting in the flight school section :/

Age sometimes brings changes that weaken your vision and eyes. Having the bailout function as an option allows us to fly more and safer. Isn't that enough reason for having a discussion about the matter?

Carlos

[peteski]

Originally Posted by neverland

why do people put faith in bailout systems. its such a cop out expecting electrics to fly your heli. what are you, drone pilots or something lol.

I don't think it's so black or white. Most people are not expert pilots. Most people crash quite a lot. That's why rescue has become a mainstream feature (not hard deck based of course).

[extrapilot]

Originally Posted by neverland

why do people put faith in bailout systems. its such a cop out expecting electrics to fly your heli... i think we have two types of pilot in this hobby. those who its all about practice and mastering control and maneuvers (on cheapo equipment), and those who just buy stuff. i think the second type of pilot is more common judging by the lack of posting in the flight school section :/

Is this a really bad attempt at a troll, or is it just that unclear to you that there are a slew of sources of randomness/error in the world?

Ever lose radio link? Ever have the sun glint in a way you didn’t anticipate and blind you briefly? Ever had a bug land in your eye?

But the idea that a person with training doesn’t make errors, or have instances of loss of orientation, is simply ignorant. World class pilots, both model and full scale, make mistakes that lead to loss of aircraft (and life full scale). There is no special pride in leaving a smoking crater in the ground, as proof that you are a real man who doesnt rely on electronics to assist his flying (well, except for your FBL/stability management system, your tail gyro, your digital radio link with expo and mixing as required, etc)...

[Ace Dude]

Originally Posted by neverland

why do people put faith in bailout systems. its such a cop out expecting electrics to fly your heli. what are you, drone pilots or something lol. we are surely better than that arnt we. just get on the phoenix sim for a few years (other sims are available) and practice till your thumbs are sore and you can automatically control the damn helicopter yourself in every situation. then you have your own built in hard deck and auto bail out system at any height you want. dont walk until you can run i say . i think we have two types of pilot in this hobby. those who its all about practice and mastering control and maneuvers (on cheapo equipment), and those who just buy stuff. i think the second type of pilot is more common judging by the lack of posting in the flight school section :/

It's quite simple actually, some pilots prefer to fly smarter rather than harder.

[nightflyr]

Originally Posted by neverland

why do people put faith in bailout systems. its such a cop out expecting electrics to fly your heli. what are you, drone pilots or something lol. we are surely better than that arnt we. just get on the phoenix sim for a few years (other sims are available) and practice till your thumbs are sore and you can automatically control the damn helicopter yourself in every situation. then you have your own built in hard deck and auto bail out system at any height you want. dont walk until you can run i say . i think we have two types of pilot in this hobby. those who its all about practice and mastering control and maneuvers (on cheapo equipment), and those who just buy stuff. i think the second type of pilot is more common judging by the lack of posting in the flight school section :/

To simply answer your first question:
Because they work.

If you get your satisfaction out of the hobby by your method(s) that is great.

If someone else get theirs from applying technology that can help reduce crashes and make it less stressful, I see no harm in that either.

There are many factors involved:
Financial, time constraints, life priorities, sometimes age or physical limitations.
The beauty of this hobby at present, is that there is now available a much wider range of technologies that make it possible for many who, if the technology situation never changed from years ago, would never had any chance to experience the hobby.
For what ever reasons limited them in the past.

So to berate those who take advantage of those technologies is a bit close minded.

[justwannahavefun]

Originally Posted by CZorzella

EP, I agree with your thoughts; there is also another variable that should be taken in consideration when pilot hits the rescue button or the heli hits the hard deck; the head speed.

I use both HD systems (Skookum SK720BE and CP-II with HD option) and I've tested countless time and found out that both systems will take A LOT more time to recover from a vertical dive, if head speed is low.

IMO this is an extremely important factor because different pilots flying different styles and head speed may lead to different perception about rescue performance. It's also important to take this into consideration when setting the minimum altitude for the HD, otherwise recovery may fail in certain situations.

Carlos

I wonder, remember I say wonder, if you guys have used any of these systems and how much. Also, are any of these systems something that you ever really wished you had. The reason I say these things follow. I can only go by my experience, what I read in these posts, and many videos watched on YouTube as well as quite a few others that won't be found on YouTube.

In my extensive experience with CoPilot II, a small sample with Skookum, and now also with Spirit Pro, Jeti, and an altimeter, as well as the posts and videos mentioned. I have found all of these systems, when set-up properly do what any reasonable person should be able to expect them to do.

From my perspective, the more negative leaning opinions I've read here very recently are just simply picking these systems apart as if these were multi thousand dollar systems with incredible guarantees of making helis crash proof. I can't say exactly why the folks that want these systems want them. If they're like me, they simply want something that's going to get the heli back to a manageable attitude when the occasional loss of orientation, brain fart, or hard core brain lock occur.

My experience tells me that these systems work to a high degree of success. Something I also wanted to mention is that the way the heli and electronics are tuned are extremely important and change the reaction times of the systems in question to an almost unbelievable amount. There are warnings for instance in the Spirit Pro manual about being careful as to just how much speed and travel you allow your control surfaces during a bailout as it's not rare to have parts of the heli break from the stress of those extreme bailouts.

Head speed is of course a huge factor. Are you headed straight for the ground, upside down, at terminal velocity? If so, you had better have your deck set high enough to allow the necessary time to recover. Of course all other factors mentioned above are more than a little important as well.

I have seen the least expensive and least complex system on the market, CPII, stop my heli from crashing in just the situation outlined above. The, hard deck was set for 30 feet, and head speed and other factors were set to about three quarters of their limits or more. Did it appear violent? You bet it did. Would I want to try that over and over? No. Am I happy I had the system on the heli. Hell yes.

So as the voice leaning more towards the glass if just plain full, I say if you're tired of the occasion wherein you simply weren't having a good day and your brain faded, or you hadn't been practicing enough, then you will be pretty happy with one of these systems. Including the somewhat maligned in this thread "add an altimeter to your setup to trigger your bailout" system.

In fact, why in the hell wouldn't you want to add an altimeter to your bailout package? Here's why I say this. You can train yourself, or not, to hit your bailout switch when you get into trouble. The "not" was me at first. Sometimes you hit it in time and you will be happy when that happens. And sometimes, it's not that you didn't hit it in time, it's that you simply forgot you even had a bailout switch in the first place. So if you choose the add an altimeter plan here is what will happen if you set it up as I and other folks have. When you get into trouble, and remember the switch, in time, you'll hit it and all will be well. If you do forget or DON'T hit it in time, the altimeter/TX combo with trigger it for you, and you will still be even happier you added it.

If, and here's the deal that I really think is completely evading the guys talking about vectors and algorithms and what not. If you have a rescue that actually fails on you. Set your deck higher for the next time. Or in the case of the Skookum, maybe try the soft deck instead, as it also looks at how fast you're going and how close you're getting to the deck. Also, you can tweak your setting a bit to help speed up the recovery.

In other words, it will be like everything else you do with your heli. A matter of trial and error. That's what's supposed to be part of the fun and challenge.

You guys are really overthinking this whole thing. There is a cheap and easy way to add this system to your heli now. If you think it may just be the thing for you, by all means give it try. Just keep in mind it might be JUST like all your other heli experience. You may have a few problems before you get to where you want to be. In my mind that's what makes this hobby so much fun.

Things that are easy right out of the gate don't hold your interest in the same way as things that aren't. That's being a human being.

Why am I so "vocal" about this and other issues heli? Because I hate to see what I fear are posts that will serve to discourage folks from trying something they may have been on the fence about. So I do what I sincerely hope will do the exact opposite. Help to convince someone to try something they may be a tad afraid to try. If that person gets to have the same level of fun I have when something finally works, that eureka moment, then I'm a happy camper. Don't most people want everyone around to them to experience the joy of an experience they themselves have had? I think so.

To anyone thinking a hard deck may increase their level of enjoyment in this hobby. Go for it. Ignore the naysayers and find those posts and videos that tell you just how great it is. And that it is, indeed, a game changer.

Of course there is one other way to look at this. A lot of folks, myself included, will try ten times harder and longer to do something once someone tells them it won't work. So maybe the naysayers are doing them a bigger favor than I am. HMMM???

(Just try it.)https://www.helifreak.com/images/smi...ing%20grin.gif

[peteski]

Originally Posted by justwannahavefun

In my extensive experience with CoPilot II, a small sample with Skookum, and now also with Spirit Pro, Jeti, and an altimeter, as well as the posts and videos mentioned. I have found all of these systems, when set-up properly do what any reasonable person should be able to expect them to do.

Just for clarity, are you using Spirit + altimeter + Jeti? If so, what minimum height can you realistically set the hard deck to trigger rescue?

I'm pretty happy with a manually triggered rescue, but a hard deck would be nice if it didn't get in the way of my actual flying.

[CZorzella]

Originally Posted by justwannahavefun

I wonder, remember I say wonder, if you guys have used any of these systems and how much. Also, are any of these systems something that you ever really wished you had. The reason I say these things follow. I can only go by my experience, what I read in these posts, and many videos watched on YouTube as well as quite a few others that won't be found on YouTube.



In my extensive experience with CoPilot II, a small sample with Skookum, and now also with Spirit Pro, Jeti, and an altimeter, as well as the posts and videos mentioned. I have found all of these systems, when set-up properly do what any reasonable person should be able to expect them to do.



From my perspective, the more negative leaning opinions I've read here very recently are just simply picking these systems apart as if these were multi thousand dollar systems with incredible guarantees of making helis crash proof. I can't say exactly why the folks that want these systems want them. If they're like me, they simply want something that's going to get the heli back to a manageable attitude when the occasional loss of orientation, brain fart, or hard core brain lock occur.



My experience tells me that these systems work to a high degree of success. Something I also wanted to mention is that the way the heli and electronics are tuned are extremely important and change the reaction times of the systems in question to an almost unbelievable amount. There are warnings for instance in the Spirit Pro manual about being careful as to just how much speed and travel you allow your control surfaces during a bailout as it's not rare to have parts of the heli break from the stress of those extreme bailouts.



Head speed is of course a huge factor. Are you headed straight for the ground, upside down, at terminal velocity? If so, you had better have your deck set high enough to allow the necessary time to recover. Of course all other factors mentioned above are more than a little important as well.



I have seen the least expensive and least complex system on the market, CPII, stop my heli from crashing in just the situation outlined above. The, hard deck was set for 30 feet, and head speed and other factors were set to about three quarters of their limits or more. Did it appear violent? You bet it did. Would I want to try that over and over? No. Am I happy I had the system on the heli. Hell yes.



So as the voice leaning more towards the glass if just plain full, I say if you're tired of the occasion wherein you simply weren't having a good day and your brain faded, or you hadn't been practicing enough, then you will be pretty happy with one of these systems. Including the somewhat maligned in this thread "add an altimeter to your setup to trigger your bailout" system.



In fact, why in the hell wouldn't you want to add an altimeter to your bailout package? Here's why I say this. You can train yourself, or not, to hit your bailout switch when you get into trouble. The "not" was me at first. Sometimes you hit it in time and you will be happy when that happens. And sometimes, it's not that you didn't hit it in time, it's that you simply forgot you even had a bailout switch in the first place. So if you choose the add an altimeter plan here is what will happen if you set it up as I and other folks have. When you get into trouble, and remember the switch, in time, you'll hit it and all will be well. If you do forget or DON'T hit it in time, the altimeter/TX combo with trigger it for you, and you will still be even happier you added it.



If, and here's the deal that I really think is completely evading the guys talking about vectors and algorithms and what not. If you have a rescue that actually fails on you. Set your deck higher for the next time. Or in the case of the Skookum, maybe try the soft deck instead, as it also looks at how fast you're going and how close you're getting to the deck. Also, you can tweak your setting a bit to help speed up the recovery.



In other words, it will be like everything else you do with your heli. A matter of trial and error. That's what's supposed to be part of the fun and challenge.



You guys are really overthinking this whole thing. There is a cheap and easy way to add this system to your heli now. If you think it may just be the thing for you, by all means give it try. Just keep in mind it might be JUST like all your other heli experience. You may have a few problems before you get to where you want to be. In my mind that's what makes this hobby so much fun.



Things that are easy right out of the gate don't hold your interest in the same way as things that aren't. That's being a human being.



Why am I so "vocal" about this and other issues heli? Because I hate to see what I fear are posts that will serve to discourage folks from trying something they may have been on the fence about. So I do what I sincerely hope will do the exact opposite. Help to convince someone to try something they may be a tad afraid to try. If that person gets to have the same level of fun I have when something finally works, that eureka moment, then I'm a happy camper. Don't most people want everyone around to them to experience the joy of an experience they themselves have had? I think so.



To anyone thinking a hard deck may increase their level of enjoyment in this hobby. Go for it. Ignore the naysayers and find those posts and videos that tell you just how great it is. And that it is, indeed, a game changer.



Of course there is one other way to look at this. A lot of folks, myself included, will try ten times harder and longer to do something once someone tells them it won't work. So maybe the naysayers are doing them a bigger favor than I am. HMMM???



(Just try it.)

I really don't get why you've quoted my post and then wrote a lot of unrelated arguments; you could instead have picked a post from a naysayer with negative leaning opinions, but mine?

Quite the opposite, If you haven't read my comments, I'm an early adopter of rescue systems since 2012, and an enthusiast, like some of the pilots who have actually contributed by sharing their experiences in a positive way.

Carlos

[phatburner]

There is something you can do to help out with the terrible physics of heading for the ground at 50mph that the naysayers keep dooming about. I don't know anything about jeti but I know this works on taranis. You can use a few more logical switches. Set two altitude thresholds, a high one and a low one. The low one can be used to trigger the rescue based on a simple altitude < x argument. The higher one gets combined with a vertical speed < -x argument with a logical AND operator. Now if the helicopter is falling out of the sun from on high at 50mph straight down it gets rescued at the higher altitude threshold which gives time for all the nasty physics and phase delays to happen. If the heli is flying around below the upper threshold but at moderate vertical speed then it isn't heading for the ground at 50mph and won't trigger the rescue unless it gets too low.

Happy flying.

[CZorzella]

Originally Posted by phatburner

There is something you can do to help out with the terrible physics of heading for the ground at 50mph that the naysayers keep dooming about. I don't know anything about jeti but I know this works on taranis. You can use a few more logical switches. Set two altitude thresholds, a high one and a low one. The low one can be used to trigger the rescue based on a simple altitude < x argument. The higher one gets combined with a vertical speed < -x argument with a logical AND operator. Now if the helicopter is falling out of the sun from on high at 50mph straight down it gets rescued at the higher altitude threshold which gives time for all the nasty physics and phase delays to happen. If the heli is flying around below the upper threshold but at moderate vertical speed then it isn't heading for the ground at 50mph and won't trigger the rescue unless it gets too low.

Happy flying.

I really doubt that any telemetry system would gather and process information fast enough in order to avoid crash if you set the hard deck level too low and under certain circunstances.

The hard deck is all well and good if the heli is fairly level, so it's more suited to pilots in the early stages that need a safety net.

The problem being, there is very little wiggle room where mild gyro settings can affect the recovery time, and/or the heli is dropping fast and far from being level. Hence a higher hard deck level must be set.

In my experience with Skookum SK720BE + GPS, demonstrates that soft deck mitigate the issue because it allows for all of this and gives the system enough time to rescue the heli, it just means the proper recovery takes place a bit sooner.

Co-Pilot with Hard Deck option works fine, but it doesn't offers a soft deck option.

AFAIK, no other FBL rescue system offers such hard/soft deck feature, although most of the currently available rescue systems works perfectly well when you manually hit the rescue button.

IMO, having a rescue button is a must in any flying machine. Since I started using it in my helis, I haven't had any crash due to dumb thumbs in years, though I don't fly with the hard/soft deck activated as often as I did in the past; so this technology must be something good, isn't?

Carlos

[extrapilot]

Originally Posted by phatburner

There is something you can do to help out with the terrible physics of heading for the ground at 50mph that the naysayers keep dooming about. I don't know anything about jeti but I know this works on taranis. You can use a few more logical switches. Set two altitude thresholds, a high one and a low one. The low one can be used to trigger the rescue based on a simple altitude < x argument. The higher one gets combined with a vertical speed < -x argument with a logical AND operator. Now if the helicopter is falling out of the sun from on high at 50mph straight down it gets rescued at the higher altitude threshold which gives time for all the nasty physics and phase delays to happen. If the heli is flying around below the upper threshold but at moderate vertical speed then it isn't heading for the ground at 50mph and won't trigger the rescue unless it gets too low.

Happy flying.

It doesn’t work that way. Baro sensors work off of static pressure. Problem is, once the heli is moving, it sees dynamic pressure. For us, there is an inverse relationship between the two; higher airspeed normally means lower static pressure. And it isn’t trivial. Just moving from hover to 30mph sees a drop of about 2mbar, which is about 30ft near sea level. This is approximate, because it depends on temperature etc. But the point is, it isn’t inches- it is 10s of feet.

The real problem is that there is an exchange between dynamic and static pressure. So if your baro sensor is in a bad location, it may see high airspeed (and low pressure) in FFF, and then the reverse in FRF or in lateral flight (i.e. funnels).

And this is a problem, because for a typical setup, in a nosedive where you are picking up speed, the sensor will typically report very little loss in altitude- or even a climb.

This is why you need some data from the flight management system- where if it knows you are nose down, it can estimate airspeed based on gravity and drag, or on GPS ground speed, etc. It is basic geometry, but if you don’t know the angles, you can solve the problem.

[phatburner]

Originally Posted by extrapilot

It doesn’t work that way. Baro sensors work off of static pressure. Problem is, once the heli is moving, it sees dynamic pressure. For us, there is an inverse relationship between the two; higher airspeed normally means lower static pressure. And it isn’t trivial. Just moving from hover to 30mph sees a drop of about 2mbar, which is about 30ft near sea level. This is approximate, because it depends on temperature etc. But the point is, it isn’t inches- it is 10s of feet..

Can you describe your setup? What are you using for a pressure sensor? Where have you got it mounted? Which FBL unit are you testing this on and what radio? I've got 3 setups working now with various mounting locations on 180 up to 450 sized helis and I'm not seeing this problem. I think you might have things set up wrong or something. Did you zero your baro sensor at a low hover?

[newbheliusr]

Flying things crash. No matter how much technology you put into them, they will sometimes crash.

[corywrx]

Originally Posted by neverland

why do people put faith in bailout systems. its such a cop out expecting electrics to fly your heli. what are you, drone pilots or something lol. we are surely better than that arnt we. just get on the phoenix sim for a few years (other sims are available) and practice till your thumbs are sore and you can automatically control the damn helicopter yourself in every situation. then you have your own built in hard deck and auto bail out system at any height you want. dont walk until you can run i say . i think we have two types of pilot in this hobby. those who its all about practice and mastering control and maneuvers (on cheapo equipment), and those who just buy stuff. i think the second type of pilot is more common judging by the lack of posting in the flight school section :/

Here's a novel idea: let people enjoy the hobby in the way they choose to. Just because it doesn't live up to your standards doesn't make it wrong

[extrapilot]

Originally Posted by phatburner

Can you describe your setup? What are you using for a pressure sensor? Where have you got it mounted? Which FBL unit are you testing this on and what radio? I've got 3 setups working now with various mounting locations on 180 up to 450 sized helis and I'm not seeing this problem. I think you might have things set up wrong or something. Did you zero your baro sensor at a low hover?

This is a law of fluid dynamics, it has nothing to do with the sensor type.

The thing is, if you find a place where static pressure = ambient for most of the flight, you are in much better shape. Full scale, a lot of effort goes in to finding the best compromise for that location- but assumptions are made (i.e. fixed wing assumes no lateral flight, no rearwards flight, etc).

But there is no single spot on a frame where that works for all angles of flight (ie an install on the bottom of the machine may be fine for FFF and lateral, but not for vertical punches, etc). There are tricks you can use where there are multiple inlets and a T from them, etc, so that you end up with a good average static pressure. But there will always be some bias in motion for some orientations.

And even if this were not a problem (it is), there is still the issue of latency. That is specific to a setup type, but it doesn’t change with airspeed- even though lead time required for bailout does. That is something more complex systems can manage better- since a typical 300ms lag in that sensor->telemetry->TX script->virtual switch->RX->bailout init loop means 20 feet travelled at 50mph before anything even begins to happen.