In this blog post, I summarise my experience with FPV drones in reverse chronological order.
2026-10-24, Saturday
The AxisFlying BlackBird BB39 propellers come in two versions with different pitches. BB39 V2 has a 4.35-inch pitch and is made of carbon fibre, while the BB39 V3 (current version) has a lower 2.6-inch pitch and is made of polycarbonate. Hence, it is important to buy the newer V3 version.
For low-pitch props like the AxisFlying BlackBird BB39 V3 (4.9x2.6x3) or the Gemfan Proxy 5127.5 (5.1x2.75x3), a Dynamic Idle value of 40 (i.e. 4000 RPM) is ideal. For somewhat higher-pitch props like the HQProp HeadsUp FPV R38, a lower Dynamic Idle value around 35 (i.e. 3500 RPM) is optimal. The higher the prop pitch, the lower the Dynamic Idle value. On very windy days, you can increase the setting slightly to compensate. A static idle around 5.5 % (default Betaflight setting) is good. It is only used just after arming or when DShot telemetry becomes unavailable.
To improve flight performance on very windy days, increase the D-term (gust resistance) and I-term (steady wind resistance) slightly (+5 points) in the PID loop settings.
2026-09-28, Monday
Damaged LiPo batteries have significantly reduced capacity- about half, in my experience. If the average cell voltage is already down to 3.8 V after a minute of flying, something must be wrong with the LiPo. Damaged cells have zero voltage after some storage time.
2026-09-27, Sunday
The low-pitch AxisFlying BlackBird BB39 props are pretty quiet and handle strong wind well. Especially if there is decent wind and traffic noise around, the drone noise becomes a non-issue if you are at least 10-20 metres away. This excludes severe throttle punches, of course.
2026-09-26, Saturday
Today was the first time I flew with another FPV drone nearby, with the operator a few hundred metres away and outside verbal range. However, I avoided flying simultaneously to avoid interference, as you never know what control and video systems the other person uses. ELRS 2.4 GHz supports hundreds of drones in the air simultaneously, so I was not too worried about this. Things might be more complicated with the DJI digital video system and its 5.8 GHz channel allocation, which is limited.
I tested very low-pitch props, namely the AxisFlying BlackBird BB39 4926 (4.9x2.6x3). In fact, these are the lowest-pitch props I currently own. They have pretty decent flight performance and propwash handling. Perhaps there is a slight lack of thrust (could also be too high throttle expo). The top speed is reduced, as expected. They are noticeably quieter than the HQProp R38 Racing Props I flew before, which is nice. I get around 7-10 min flight time on 1600 mAh. This might be a bit lower than the 12 minutes I got with slightly steeper props before, but it depends on the flying style.
Not using a drone landing pad draws less attention and makes it less obvious that a drone is in the air.
Landing becomes very easy when you realise that you simply disarm the drone when you are low enough over your target area.
2026-09-05, Saturday
I upgraded my ExpressLRS control link firmware to version 4.1.0. The Dynamic Power functionality now lowers the emitted power reliably and quickly. It works very well in practice and feels very responsive. The lowering was too slow in the previous version (4.0.x).
The HQProp R38 5138 Racing Props (5.1x3.8x3) fly well and offer more top-end speed than my lower-pitch freestyle props.
Sometimes Betaflight does not seem to remember that I switched rate profiles (freestyle -> cinematic). It might be worth adding a rate indicator to the OSD.