Gyro Warning system

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Gyro Warning system

Unread post by TMGOLY » Wed Feb 03, 2021 2:09 pm

Below is a link to a video of a Gyro Warning System being develop by a gyro pilot and engineer in France. Check it out it may just save somebodies life some day!

The first TO is with 150 Rrpm, pre rotator off and WOT. You can hear the warnings « Flapping Risk » followed by « Flapping, Flapping, Flapping »

The second TO is 200 Rrpm but leaving the stick forwards, you can hear the warnings « Flapping Risk » followed by « Flapping, Flapping, Flapping ».

The third TO is done simulating a Hot, Heavy and High TO, it was none of those so I simply took off with less power. You can hear the alarm « Behind the curve ».

You can then see a downwind leg where I pull up on the stick and then push. This gives the warning « low G bunting risk ». If I continued to push it would give the alarm « Bunting Bunting Bunting ». This alarm still needs some work.

You can then see that I make too tight a turn onto base and finals and loose airspeed. The alarm « Behind the curve » sounds followed by « Max power descending » as the speed falls even further.

During the landing there is the inevitable "behind the curve" just before touch down.
This warning system has 2 levels of alarm. The first is a pre-alert that is warning the pilot that, based on the current rate of progression of different parameters, the prediction is that he is likely to get the second alarm. It’s really to prepare him mentally to be ready to carry out the appropriate corrective action if the second alarm is activated.

For the flapping warning alarm this graph:

shows the first TO in the video. The flapping “angle” and “state” (these are the different alarms) are on the secondary Y axis. There are 2 pre alarms that give the same message; these are alarms 1 & 3. Number 3 alarm is a predictive alarm using a logic/algorithm by Jean Claude Debreyer. Number 1 alarm uses real-time data in case there is a sudden change in one parameter that would be missed by the predictive logic such as a sudden gust of wind increasing the airspeed nearly instantaneously and flapping the rotor.

The second alarm is the Number 2 alarm it uses real-time data and the rate of change of different parameters to tell the pilot that if he continues at the current rate of progress he is very likely to flap the rotors within about 2 seconds and it’s time to carry out the appropriate corrective action that, thanks to the pre alarm, he should be mentally prepared to do

You can see from the graph that the number 3 predictive alarm goes off first giving a “flapping risk” warning. This is followed by a number 1 alarm giving the same message, followed by a number 2 alarm “flapping, flapping, flapping”. This N°2 alarm starts at about 17.2 secs and you can see that the flapping angle is increasing at such a rate that it would hit the 8° flapping angle at about 19.5 secs. 8° is when my rotor hits the flapping stops.

You can also see that from releasing the pre rotator to 8° flapping angle is about 6.5 seconds, things happen very fast.

This graph shows the data that would be available for any post crash investigation (assuming the SD card wasn’t destroyed in the crash). If this ever gets to a production stage we’ll be looking at some sort of fire protection. The only data that would not be recorded would be the flapping angle that is recorded on a separate device for my testing. We are adding engine rpm and there is an external switch for something like the canopy lock and a set of contacts for a warning light.

You can see the flapping angle on my telephone on the instrument panel. Knowing the flapping angle is important for me because that is what allows me to approach flapping with some degree of confidence. In my opinion it would be of little or no value to most pilots because it happens so quickly that by the time you saw it, it would be too late. That is why we use Jean Claude’s predictive logic/algorithm.

The voice on this prototype GWS is that of Mark Burton. For the production model the owner/pilot can record whatever message he thinks will generate the appropriate corrective action in whatever language he needs. If he thinks his wife’s voice saying “shut the throttle” will do the trick that’s fine.

The “inevitable” “behind the curve” warning as you flare is no different to the stall warning on most aircraft. In fact I’ve found it a good indicator that I’m not landing too fast. If I start to flare and don’t get that message I know something’s wrong. Also the GWS includes a volume controller (you can’t turn it down below a certain level) and a push button to stop the message for a set time period (actually at 20 seconds but adjustable).

For training there is an instructor push button to allow him to simulate the different alarms.

At the moment our thinking is that this would only be sold to manufacturers because it requires some serious flight testing to establish the different parameters for each gyro/rotor combination. Each manufacturer would have to decide where he wanted to put the limits for his machine. For example the bunting alarm at the moment is set with my personal G limits but a manufacturer may decide that they are too risky or too conservative, that must be his call.

Once they have established their parameters and created an installation kit they could offer it as a retro fit for existing customers if they wanted to.

Mike Goodrich
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Re: Gyro Warning system

Unread post by Sunray » Tue Feb 09, 2021 8:37 am

TMGOLY you must be frustrated by the lack of response to your post... You took the time to share the information with us so I guess it would be nice to get some reaction from the 160+ viewers of your post.
I think it is a very useful tool, more so for the new gyro pilot and training phases. Maybe all the readers of your post are all long time high hour gyronauts who fly by the seat of their pants and those 2 valuable instruments, airspeed and altitude and think of it as something like a new function on whatsapp - do you really need it?
My opinion is yes, very useful. As long as it doesn't add to the workload in the cockpit for a low hour pilot. I've been there, touch screen, turbo boost bleed screw, trim, fuel water warning device etc etc etc. Gyro's are supposed to be simple :D
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Re: Gyro Warning system

Unread post by gyronaut » Thu Feb 11, 2021 8:13 pm

Watch this space...
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