Mike as you say the audible stall say on a C 150 was as a good indication and not a distraction.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).
Thanks for your interest. When I've managed to get a vaccination and can travel to the USA, I'll plan a visit to Florida, I probably need to update you on the latest PB4 features and will bring a prototype GWS for testing.
At the moment the GWS does all you ask up to number 6. You can see from the graph the different outputs, the height is barely visible because in that particular test I never took off.
We are looking at adding engine rpm and it doesn't seem to be a problem.
Fireproofing is something that we're looking at but needs to be discussed with those manufacturers who we will be working with to see how much they want to do. Since they have to find somewhere to fit this black box they may have better solutions than us.
As a point of interest does anybody have an idea of which zone of a gyro is the least likely to be affected by a crash and fire?
The GWS also has a set of contacts for a door/canopy lock alarm.
We hope to work with interested manufacturers and this may produce other requirements.
Keep at it @Mike GProgress has been slow on the GWS due to Covid and other things. I finally installed the first prototype Mk1.2 version of the GWS and went flying.
This new version now includes OAT compensation to go with altitude compensation so that the GWS automatically corrects the alarm parameters for density altitude. It also now logs engine speed and has an optional canopy/door lock switch warning.
It has the hardware for a CAN bus system and the idea is to connect the GWS to a small data logger that can be housed in a fireproof box elsewhere on the gyro. Our thinking here is that putting the current GWS in a fireproof enclosure would be expensive, large and heavy and make installation even more difficult. A small fireproof data logger could be put somewhere where the risk of being in the centre of any post-crash fire was reduced, if such a place exists. It could also be linked to other devices on board such as GPS, so that after a crash we would have the maximum of data to review to analyse what went wrong.
My main interest now is to improve the bunting warning and we're working on a new algorithm looking at the G level and rotor rpm decay rate to better predict an approaching bunt scenario without giving too many false alarms. Here is a video of a quick circuit due to low cloud base just to test the system and audio. I seem to have some audio distortion, not sure if that's the GWS or the cheap Go Pro I'm using.
You can see my smartphone acting as a G meter in the middle of the panel.
You can also see quite a lot of vibration because we've fitted a very large diameter rotor for the future Hi speed flapping warning and this only turns at about 300 rpm giving a 2/rev which is very close to a 9 hz natural frequency in the tail, so literally the tail wagging the dog.
Thanks to all who have offered encouragement.
Continuing the discussion from the G-PALT accident thread, here is a GWS recording of a typical “forward stick” type take off. In fact it’s the second TO in the first video of this thread.
What you can see is that at 28.2 seconds the pre-rotator is released at a Rrpm (red line) of 205 rpm, the throttle is fully opened (WOT) and the airspeed (yellow line) increases.
3 seconds later the first pre-alarm (red triangle on line 3 of the right hand Y axis) tells the pilot in his intercom that there is a flapping risk, this same message continues (red triangle on line 1 of the right hand Y axis) but is caused by a different algorithm.
1 second later the major alarm (red triangle on line 2 of the right hand Y axis) tells the pilot he’s about to have an accident.
You can see from the flapping angle (the blue line) that the angle is still quite acceptable at about 2 degrees (read off the right hand Y axis scale), but from the data and calculations I can assure you that if you pulled the stick back after the major warning this rotor would go almost instantaneously to over 8° (max flapping angle for this rotor) and it would very difficult, if not impossible, to hold the stick.
View attachment 1153101
This is what the GWS recording of the G-PALT accident would look like had one been fitted except that there wouldn't be a flapping angle line and all the lines would drop to zero at about 33 seconds as he pulled the stick back and flapped the rotor. If the pilot couldn’t remember what happened, or worse didn’t survive, we wouldn’t have to try to guess the cause we would simply know.
The question that I now ask myself is “upon hearing the warning, would the pilot make the appropriate correction??”
The GWS allows the owner to record what ever message he wants for each of the alarms, the current alarms are the ones I chose for myself. An instructor could decide to record the corrective actions such as “stick forwards, close throttle, abort…..”.
None of my clients who made this mistake were idiots and none of them were too cheap to get enough training.I think the instructor can record a message like this
You are an idiot and needed more training but you are too cheap and now you are about to pay for it.
May be that's too long and may be too politically incorrect for US sensibilities? Well when this ever happens to me, you guys have my permission to call me a dummy.
None of my clients who made this mistake were idiots and none of them were too cheap to get enough training.
For a high time fixed wing pilot centering the controls and opening the throttle for takeoff is a hard habit to lose.
We all make mistakes; some are more expensive than others.
I feel Mike's gyro warning system will likely save someone a lot of money one day.
Most pilots I know are not idiots and Mike's warning system likely has value for them anyway.
The GWS has recently made it's first real live potential save.
I was testing something with two PB4s at the same time and just as I left the ground I saw on my tablet (strapped to my leg) that the wi-fi that links the PB4 to the tablet had disconnected and reconnected to the wrong PB4. So I started to fumble about with the touch screen trying to reconnect when a voice over the intercom said "behind the curve". I looked up and there I was with full power, the nose pointing to the sky, the airspeed falling and me at 100 feet over the houses at the end of the runway.
As fara said one of those blond moments that can happen to any of us.
I'd like to think that I would have caught it anyway but who knows.