CPII and Emergency Recovery - pls help me understand more.

[ricoalonso]

I completed my setup and install of the CPII on my 30-size electric Heli. So far so good, I only to work more on the trimming part. However, I have a question regarding 'Emergency Recovery' option and how it works.

Is my understanding correct that once the Emergency Recovery option is set to 'Y' that the CPII does the Emergency Recovery on it own as long as the CPII is ON?

For example:

• I set Emergency Recovery = Y
• Fly the Heli with CPII ON
• When the Heli goes into 45-deg (as per CPII Flow Diagram) from Level flight, will the Emergency Recovery activate by itself with no pilot interaction from the Tx? In order words, will it override the pilot's stick position and bring the Heli to level flight?

Thanks for any info you can share.
Rico.

[Tim Marks]

Originally Posted by ricoalonso

I completed my setup and install of the CPII on my 30-size electric Heli. So far so good, I only to work more on the trimming part. However, I have a question regarding 'Emergency Recovery' option and how it works.

Is my understanding correct that once the Emergency Recovery option is set to 'Y' that the CPII does the Emergency Recovery on it own as long as the CPII is ON?

For example:

• I set Emergency Recovery = Y
• Fly the Heli with CPII ON
• When the Heli goes into 45-deg (as per CPII Flow Diagram) from Level flight, will the Emergency Recovery activate by itself with no pilot interaction from the Tx? In order words, will it override the pilot's stick position and bring the Heli to level flight?

Thanks for any info you can share.
Rico.

Hi:

Yes, after you turn Emergency Recovery on, it activates automatically. At steep angle, it turns the gains up momentarily to make recovery to level faster.

Tim Marks

[Adventurer]

Originally Posted by Tim Marks

Hi:

Yes, after you turn Emergency Recovery on, it activates automatically. At steep angle, it turns the gains up momentarily to make recovery to level faster.

Tim Marks

Tim,

This not my understanding of ER. Please elaborate.

My understanding is that you have to turn it on when you need it, using the remote control. Then it will turn-up the gains and deactivate once the aircraft is level, and stay off until the remote control goes from low to high again.

From the FMA FAQ:

When ER is set to ON in Preferences menu, the following will occur:

ER activates when the following criteria are met:

1) The CPII is set up for Level Flight Mode on the Remote.

2) The aircraft is pitched away from level by 20 degrees or more; in either pitch or roll axes. (Inverted is considered more than 20 degrees away from level).

3) The Remote is changed from a low setting (nearly 0%) up to 100%; e.g., if Level Flight Mode is set up on a toggle switch and is moved from OFF to ON. In other words, ER is only activated by the changing the Remote setting from OFF to Level Flight Mode ON as in a panic situation.

What happens?

1) Gain is increased by a factor of 2x to bring the aircraft to Level faster.

2) The ability for the pilot to over-ride stabilization is greatly reduced. CPII ignores pilot input by 75% when ER is activated. Therefore any attempt by the pilot to over-ride stabilization is mostly ignored.

3) The duration of ER is 2 seconds.

[nightflyr]

Originally Posted by Adventurer

Tim,

This not my understanding of ER. Please elaborate.

My understanding is that you have to turn it on when you need it, using the remote control. Then it will turn-up the gains and deactivate once the aircraft is level, and stay off until the remote control goes from low to high again.

From the FMA FAQ:

ER is always on when CPII is on and when setup in that configuration, it will only go active when the helicopter is put into the situation(s) mentioned by Tim and the manual.

What I believe your referring to is the "bailout" switch where if you have the CPII off and lose control, orientation or a bad situation (high angle of attack) you flip the CPII on and it will correct to level attitude.
If your in an extreme situation (high angle of attack) ER will kick in and recover the helicopter @ 2X the gain settings once recovered the CPII returns to normal operation mode unless it is switched off.

[Adventurer]

The third unequivocal requirement in that FAQ is that a switch is thrown for it to activate, nothing about it going active any way except with a switch. Am I missing something? Stupid? Reading the wrong manual?

I've never bothered with ER and just use CP-II with reduced sensitivity because of that switch requirement.

There's nothing more in the manual about how it operates.

[nightflyr]

Originally Posted by Adventurer

The third unequivocal requirement in that FAQ is that a switch is thrown for it to activate, nothing about automatic anything. A bailout switch is the only way.

There's nothing in the manual about how it operates.

Of course the switch needs to be thrown..how else is the CPII activated..ER only operates while CPII is actively operating.

[Adventurer]

If I get a chance tonight, I'll go test this.

It shouldn't be difficult to trigger the ER while holding the heli in your hand outside. I expect that when ER triggers, I should see the swash move more than it normally does during normal stabilisation. Then if at the same time I put in some cyclic, it should be reduced for 2 seconds.

[Adventurer]

Originally Posted by nightflyr

Of course the switch needs to be thrown..how else is the CPII activated..ER only operates while CPII is actively operating.

The way I read this that if CPII is actively operating, you get normal recovery, if you let go the sticks. To get ER, the switch must be thrown while the heli is above 45 degrees away from level.

If think about it, this is the way it has to work, otherwise you would never be able to do aerobatics with co-pilot and ER on.

For the hell of it, I'll switch on ER and try a loop tomorrow with Co-Pilot on, if what Tim says is true, then I should fail miserably.

[nightflyr]

The only way I ever had a completed loop was to have ER off, stick priority for almost full pilot control

Your thought about "bail out" ER is correct via a switch, but the switch does not turn on ER it turns on the CPII which in turn engages ER under certain conditions.

[Adventurer]

Originally Posted by nightflyr

The only way I ever had a completed loop was to have ER off, stick priority for almost full pilot control
.

Thanks for the warning, I'll have to try this high up. I've had way too many unplanned contacts with terain latey.

[ricoalonso]

Thank you all for the quick response.

Adventurer: That is exactly the reason why I posted this question in this thread. At first, after reading the FAQ and some posts around, it sounded like one has to toggle the Remote switch from ON to OFF then ON again to activate the ER. But then I thought- that doesn't make sense because if the CPII is already ON then all I need to do is let go of the stick and it should bring the model into level flight. So, I kind of convinced myself that ER must have been Automatic and will override the pilot to bring the model into level flight. But, of course I want someone to confirm it... and so I posted the question here.

Tim and NightFlyr: Thank you for confirming that my assumption and understanding of the ER operation is correct.

Adventurer: I just saw your new post while I am writing this... yes, pls do share what you find if you are able to experiment with this tonight.

Thanks again, folks.
Rico.

EDIT: BTW, pls don't push it if it's not possible to test... I'd hate to learn that someone lost a heli just because of this thread.

[Adventurer]

Yes, I think that the manual could stand an update to clarify this.

The thought that CP could simply take control from me is quite scary. I fly on a smallholding with chain-link fences on all sides, and my loops generally start with a eye-level high-speed pass (If I start higher, I can't see the damn thing at the top). So if CP takes control and levels the bird at eye-level, I gonna end-up with fries on the other side of the fence.

Lets start with the static test first.

[nightflyr]

One thing I can tell you....

When Tim tells you something concerning the CPII you can bet the farm 99.99% of the time he's correct.

One of the benefits of being the President of FMA Direct

[Adventurer]

Just got in from my static tests.

Method:

• Enabled ER in CP-II.
• Powered radio & heli
• Turned on Cp-II
• Took heli outside and slowly tipped it till it was nose down pointing directly at the ground.
• Switched Cp-II off then on from the radio
• Repeated tests 2 more times

Observations

• as heli was tipped forward, swash was observed to tip backwards. Guesstimate about half -> ¾ of what I could get using the elevator stick.
• When Cp-II was turned off the swash centered
• When Cp-II was turned on again, the swash moved to very backwards tilted position in three steps at about a quarter of a second intervals. The amount of tilt was way more than I could achieve with the elevator stick.
• After a further approx 1 second, the swash jumped back to the position it was before toggling the switch.
• The swash cyclic movement was possibly slightly reduced from normal during the large swash deflection. Certainly not a pronounced reduction in movement.

Conclusion
The CP-II Emergency Recovery does not work as claimed earlier, but rather as documented on the FMA web-site, to wit:
The ER says inactive until the CP-II remote control is changed from a low to a high value. Subsequent tests indicate that the initial state of this control is irrelevant, i.e. CP-II ER is unaffected by whether CP-II on or off when it entered the extreme attitude. I was unable to reliably test if ER would engage while the helicopter was level, but assume that it would not.

[Adventurer]

I find these results comforting. At least CP-II is not going to take control without being invited.

[nightflyr]

Happy to hear you proved it out for yourself

[Adventurer]

Yep, I've always wondered about Emergency Recovery, the CP-II documentation being somewhat lacking, now I know.

To be honest, I've never missed ER. CP-II seems to be able to recover the bird from some scary attitudes just fine, given a reasonable amount of altitude. I guess that ER would come in handy at low altitudes, like errr maybe for a Hard-Deck

[nightflyr]

Might that be a subtle hint to FMA perhaps......

[Adventurer]

Howard said that there's a new version imminent. I'm also sure that you know what's in it. Maybe that's a not-too-subtle attempt to extract a hint of what new goodies FMA have for us.

[ricoalonso]

Adventurer:

Thanks for the actual simulation and confirmation to what you formerly said that ER should behaved based on the Manual and FAQ.


So now, that brings up more questions for me:

• If that is how the ER actually behaves then what is the use? If one has to feel for the remote switch and toggle it from ON-OFF-ON to activate the ER, wouldn't it be faster to just let go of the stick which allows the CPII to bring the model back into level flight?
• If this is how the ER functions at present, then is it really what was expected or was there a misunderstanding between the requirement and the implementation as far as the CPII firmware? I ask this since Tim himself seems to have understood it as to be ON all the time as long as CPII is ON.

I actually wished/hoped that ER was put there in case the pilot forgot to let go of the stick (or still trying to save the model) while the model is already in a very bad atittude (mostly applies to newbie).

It would be good to hear more from Tim/Howard (FMA) on this. I guess I'll leave ER set to N for now.

Thanks again.
Rico.