GliderKeeper F5J Timing Device Review

Jason Cole tests out the GliderKeeper and plays with all the cool features available.


Self Timing for F5J?

The GliderKeeper is a new device designed for F5J soaring pilots. It's sophisticated and has features that are pretty exciting. I was able to get a couple of units to test and review and see how it worked for self timed practice or contests. More on that later, but for now let's take a closer look at the unit itself and cover the features, installation and setup.

What's in the Box

Inside the package, you'll find three items. The GliderKeeper unit, a piece of 3M double sticky tape and a Quick Reference Guide. The Quick Reference Guide was pretty useless, but it does list the website here where you can get to the digital manual, which you'll want to read first before doing anything else.

Size and Weight:

  • Length: 52mm
  • Width: 24mm
  • Height: 6mm at thickest point
  • Weight: 14g including wire


  • Altimeter Recording - Functions just like an Altis or CAM unit for recording and displaying the F5J Starting Height compliant with FAI Rules.
  • Dual core 240Mhz MCU unit with native wireless connectivity via WiFi
  • Self Timing - Accelerometer based landing detection stops and displays flight time.
  • Flight Display - See your flight data graphed right on your phone or computer after the flight, no wires needed.
  • Wireless Settings - Change device parameters wirelessly


Installation is pretty simple, but there are a couple of important things you need to keep in mind that you probably are not be used to. It still connects inline between the ESC and the throttle channel on your receiver, but you can't just free float stuff it anywhere in the fuse like you might do with a CAM or Altis.

In order for the accelerometer to properly detect a landing, the GliderKeeper needs to be hard mounted to the plane. Velcro is no good as it gives too much, so the options are using double sided foam tape or glueing it. The manufacturer suggests attaching it to the canopy, but I had a perfect place in the bottom of my Neutrino fuselage so I used double sided foam tape and secured it there. The device does need to be installed longways inline with the fuselage and preferably as flat as possible. So that's it, once you have it properly secured and connected, you are ready to power it up and begin the setup process.


Before you can use the GliderKeeper, you'll need to go through a setup process to create a Wifi connection, update the firmware and make any parameter setting changes for F5J or ALES. I won't go into it step by step as you can follow the manual for the full process. It only takes a few minutes to get it setup and ready to go. It's nice to be able to use your phone without the need of connecting the device to a computer which means you can program it at the field if needed. Here's a look at the user interface on a computer. It's similar on a mobile device, but formatted to fit a vertical screen better.

GliderKeeper (4 min 17 sec)

Using the GliderKeeper

Once the parameters are set, using the GliderKeeper is similar to other devices. Power on your plane, launch and land. The screen on the unit is large and easy to read so you can see your flight number, flight time and F5J starting height. For normal contests, you'll just use the starting height for the scorecard. I had my Altis Nano Y-harnessed into the system so both the GliderKeeper and the Altis would record F5J Starting heights. The good news here is that both devices measured closely together during all test flights including a full 2-day contest.

Here's a few shots showing the Glider Keeper F5J Starting Height matching the Altis Nano. On subsequent flights and during a contest I never saw a variance greater than a full meter between the two devices.

On those three flights, my main goal was to test the F5J heights as well as see what kind of landing would or would not work for the timer. The first photo was more of an F3J style fairly hard dork landing. The 2nd photo was a typical F5J protect your motor kind of landing. The 3rd photo was the most incredible soft as a babies butt landing. As you can see, all flights except the last one recorded a flight time. For self-timing to work, it has to detect the landing and the super smooth one didn't work. I really don't see it being a problem and I never saw the device fail to record a time after that one flight where I purposely tried to trick it. Normal competition and practice landings should all return recorded flight times in my experience.

Now during the contest I was not tracking the time compared to my timers watch, there was just too much going on with flying, timing and covering the event for RCGroups. I did notice a few times that the time shown was sometimes over 10 minutes by several minutes over or waaaaay under what it should have been. I wasn't sure what to make of it at first, but then it clicked! At this contest I would power up at the ready area, then walk my plane over to the landing tape when my group was called. I was walking my plane NOSE DOWN! Putting the GliderKeeper nose down for several seconds activates Wifi mode instead of the normal ready to fly mode and then all bets were off. Once I figured that out I made sure to powered on the plane at the landing tape and did not point the nose down before launching. That did the trick, now all the times were coming in like I expected. So make sure your plane doesn't go vertical before launching and you'll be set. Also keep in mind the manual says to not disturb the plane for about 10 seconds after landing to give the computer a moment to fully sense the landing and process the data for your flight time.


After speaking with the manufacturer and looking at some data, it was determined that the false times I saw were due to the GK getting false throttle signal pulses from my receiver. They've added a filter now that should eliminate that from happening. So you might not have to worry about putting it into wifi mode before your flight. I'll need to test that and report back later.

Now say you want to look at the data from your flights. You don't need a cable or a computer, you can review your flight data right away. With the plane powered on, tilt the nose facing straight down for a few seconds and that puts the GliderKeeper into wifi mode. It will look for the network you previously set up so assuming you did that and have your mobile hotspot turned on, it will connect. Then you just pull up a browser window and type in the device address to connect to it. Once there you can see your data and look at a graph that shows the flight including the motor off time, F5J height and landing time. It's pretty neat and can be fun and useful to look at this data and see how your flights went.

Timer Tests

I managed to break a wing joiner on my Neutrino before getting to record and do some proper time testing, so I moved the GliderKeeper over to another review project, the Alpha 2M. I flew some shorter flights for times sake, but I was very curious to see how closely the GK time matched the actual stopwatch time on each flight. I'll post the photos below showing both the watch and the GK times. The results here are encouraging! Only a 1 second difference on 2 flights and the rest of the times were dead on the money. Now who knows if actual contests will allow you to self time with a GliderKeeper, but at the very least it makes it super easy for smaller club contests or practice sessions where you want to keep track of your actual times.

I originally got two Glider Keeper Units and gave one to a local pilot so we could fly together and have a self-timed 2-man contest that I could write about for this review. Sadly there was a death in his family so I put that idea on hold for a little while to give him time. I'll come back in and update this thread with that experience once we get to do that.


I am very impressed with the GliderKeeper. It's a little more expensive than current F5J altimeters at a little over $112, but for the feature set and what it does I think the price is well worth it. Being able to self-time for practice and friendly club contests is a game changer and it may find its way into being accepted as an official time for larger contests too. It's simple to install, easy to set up and provides useful data about your flights wirelessly and instantly. The screen is easy to read even for older eyes. The only thing you really need to be mindful of is not landing too softly if you want your flight time recorded. I can't wait to get our first 2-man self-timed fun contest in and report back with that experience. Stay tuned...

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Last edited by Jason Cole; Sep 11, 2020 at 03:37 PM..
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Sep 11, 2020, 10:27 PM
Tragic case
davidleitch's Avatar
Good review. The accuracy is enough I might give one a try. One thing I might have like to see extra was some size comparison photos. Some of us have pretty tight installations already.
Sep 11, 2020, 10:38 PM
RCG Admin
Jason Cole's Avatar
Thread OP
Thanks. I’ll get some photos like that tomorrow.
Sep 11, 2020, 10:56 PM
Registered User
Please inform me if it gets FAI competition aprooval
Sep 11, 2020, 10:59 PM
Registered User
Originally Posted by davidleitch
Good review. The accuracy is enough I might give one a try. One thing I might have like to see extra was some size comparison photos. Some of us have pretty tight installations already.
I would like to try it also
But would be great if it gets FAI competition aprooval
Sep 12, 2020, 07:09 AM
RCG Admin
Jason Cole's Avatar
Thread OP
I’m told FAI approval should happen very soon.
Sep 12, 2020, 10:17 AM
RCG Admin
Jason Cole's Avatar
Thread OP
Here's a couple of photos showing the Glider Keeper next to the Altis Nano. I don't have any other altimeters to compare to.
Sep 12, 2020, 03:41 PM
NorCal Electric Soaring (NES)
SoaringDude's Avatar
Interesting device and a very nice review. Regarding when they would be legal in F5J USA Tour events I'd like to offer some clarity on the suggestion that FAI may approve them "very soon." During the 2019 FAI F5J rulemaking process Bulgaria had submitted a proposed Scoring ( rule change that redefined the end of a flight as when " the model aircraft comes to rest after landing." This would enable (FAI approved) devices like this one to be used. In final CIAM F5 proposal voting that proposal was defeated 8-3. Steve Neu was the USA rep in that vote.

The next opportunity for this to make its way into the FAI F5J rules is during the 2021 rulemaking process that would produce rule changes that become active in 2022. And even if FAI approved it for use in 2022 the F5J USA Tour would need to discuss it and decide if it made sense for Tour events. So we have a ways to go before these things are a "go" in Tour events.

Sep 12, 2020, 03:58 PM
NorCal Electric Soaring (NES)
SoaringDude's Avatar
I'll see if I can get Steve to jump in here and share feedback on how the rulemaking discussion on this change went.
Sep 12, 2020, 04:13 PM
RCG Admin
Jason Cole's Avatar
Thread OP
Is that just for the “timing” part? It’s my understanding that an FAI approved firmware is coming soon, but I assume that it’s only for the FJ5 altitude part. You could totally use the GliderKeeper right now and just ignore the time on the device and it works just like an Altis or CamF5J. Why wouldn’t that be allowed in a competition?
Sep 12, 2020, 04:47 PM
NorCal Electric Soaring (NES)
SoaringDude's Avatar
Hi Jason, my comment was only about the "auto timing" feature (which is a neat idea). Sure if the device gets FAI approval for the AMRT functions it would be just like any other approved device. FYI we keep a current list of approved AMRT's here.
Sep 12, 2020, 04:54 PM
RCG Admin
Jason Cole's Avatar
Thread OP
Good to know. Thanks!
Sep 12, 2020, 09:39 PM
sneu's Avatar
Originally Posted by SoaringDude
I'll see if I can get Steve to jump in here and share feedback on how the rulemaking discussion on this change went.
Personally I like the idea of changing the F5J rule so the timing stops when the plane comes to a complete stop---which would make possible devices like the "gliderkeeper" to be used in larger contests reducing the need for helpers. Having said that I don't see it happening soon at the FAI level given the frosty reception it got in 2019---maybe people will come around to it---for sure it could be used by any group or club as a "local rule" if they want.

Sep 13, 2020, 03:47 PM
Originally Posted by sneu
Personally I like the idea of changing the F5J rule so the timing stops when the plane comes to a complete stop---which would make possible devices like the "gliderkeeper" to be used in larger contests reducing the need for helpers. Having said that I don't see it happening soon at the FAI level given the frosty reception it got in 2019---maybe people will come around to it---for sure it could be used by any group or club as a "local rule" if they want.

Hi there,
This is Javier from GliderKeeper.
Just to be accurate: Gliderkeeper detects first contact to terrain, so a touch and go is possible and landing time will be the first contact with terrain.

It still needs a "subtle" rule change for launch time to be throttle push which in our experiments, in a diligent launch (and diligent timekeeping...) is in the range of 0,3 seconds longer flight times than hand release.
We are proposing a penalty for those that would delay launching with motor on with no safety reason, to avoid non desired strategies.
Sep 21, 2020, 11:45 AM

We got FAI Homologation!

Hi there,
We finally got our First Class Competition Fw Homologation.
Wish you enjoy this little device.

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