DocPrinter

I was hoping this wouldn't happen. I was specifically asing about legal requirements, rather than BMFA guides, or even rules that may not be legally binding. I do however appreciate that the BMFA rules may need to be followed in order to fly under their insurance. @Ron Gray that's excellent, thanks. Almost exactly what I had originally planned. Didn't think it was too far fetched. I do have GPS, barometer, and high spec IMUs on board. It would have air speed sensor but thought that would be vunerable in my learning stages!

@GaryW I realise there will be personal preferences and opinions on what is best practice. I'm just trying to establish whether people have begun to muddle best practice with a legal requirement.

@Simon Chaddock thanks for those links. So those describe explicitly say land, but not cut throttles. This is more along the lines of what I expected as it would allow a quad copter to make a controlled direct decent and my proposed circle down method potentially acceptable. Technically it does say land, rather than crash land so I'd want a better read around that point.

I know that's the general guidance, but is throttle to idle in a piece of legal legislation? I've scanned through CAP 722 and article 16 and couldn't see it.

Morning, I realise this topic can easily get inflamed, and so am treading carefully. Are the main benefits article 16 brings; the ability to fly from a younger age, the ability to go above 120m, and the potential to fly heavier models at designated sites? Article 16 does not cover airborne drones (fixed wing or otherwise) that are flying under the control of an autopilot, stabilisation is exempted from being defined as an autopilot for clarity. The way I understand it if I wished to test automatic flight I would discuss this with the club (or of course fly it elsewhere), fly as if it was a general public area where flying was not forbidden, and fly to the drone code. Is the throttle cut a written legal requirement of article 16, CAP 722, or another piece of legislation? I have the ability to define a rally point for my plane. For my clubs site I had intended to pick a location beside the normal flying circuit where if the plane detected a fail-safe it would go to and circle (under with GPS, so no drift) to give the operator a chance to resolve any ground transmitter issues. If this fails for a long period of time then the throttle can be set to cut and the autopilot would attempt to maintain the circle with lower airspeed, and so sink to the ground and likely crash land. It would be capable of performing a fully automatic landing (with flair etc) but I thought this unsafe at a club as the plane does not know what is on the landing area. If cutting the throttle cut is a legal requirement it basically cuts the above process down to a controlled crash, removing the potential on the ground of resolving the RC issue before landing under full manual control. This would not be what I would expect of a fail safe on a quad copter where I would expect it to use motors to control decent, not fall like a brick. Given the amount of ground distance a model could cover in a throttle cut fail-safe I think the circle option to be lower risk overall. I will be discussing how the system handles GPS faults and how these effect the ability of the plane to control crash in the Ardupilot forums directly. I have an interest in both fixed wing auto piloted fixed wings as well as pure RC planes. My first plane to hit the air has the ability to autopilot (Ardupilot, rather than just stabilise) but is set up to default to manual control mode for learning, where there is no interference from the autopilot. Finally I would like to recognise that while I am putting a fair bit of thought into this I hope to never encounter a RC failsafe, let alone find out what a controlled crash lands like! I hope that appropriate range checking, regular visual inspections, and a decent routine with battery charging will reduce the risk to a minimal level.

I've got a XFly Glastar V2 ready to fly, but missed some perfect flying weather due to family birthdays and a break away! Will be starting soon. I appreciate that's a light weight and will follow it up fairly soon after with a balsa trainer that I've been repairing. I'm guessing my Fun Fly adventures will be hapening sometime after passing the A Cert. Which plane that's with depends how quickly I get the balsa plane sorted!

Fair point. I was looking at a youtube video and hadn't really appreciated the lightness of the models. So I guess if anything exceptionally large chord for the weight and low aspect ratio with the horizontal tail plane/elevator as close as they dare to the main wing. Screen shot from: I do realise that is no where near a sensible starter model.

In an earlier edit of this post post I did ask are they as they are because of trends and or being easy to rebuild, but scrubbed that just in case it came across wrong...

On that subject, sorry! 😂 I was interested to see asymetric rather than fully symetric wing sections. I would like to understand why there seems to be a preference for such short tail fin & rudder to wing spacing. So short that some have the horizontal tailplane and rudder set further back, with it being limited by downwash off the main wing. Other than that I think you've largely answered my question thanks! What sort of power to weight ratios are they aiming for in the entry level class?

Morning all, Curious about the design of the fun fly planes. Any good reads to that are specifically related to fun fly? Looking for a primers/intros to read and catch up with while I learn to fly this season. It also looks like a great way to rapidly hone developing basic flight skills. I do already have a model aerodynamics book, but hoped there might already be a web article or two kicking around more focused on these unique machines!

I have seen frame rates for digital servos goes of 333Hz, which is more like 9ms. Certinally relevant to RC cars like 1/12th carpet racers. Easily hitting 50kph, 13.9m/s, or 0.28m of travel between servo updates on a 50Hz PWM signal. The track lane is not much more than 1.5m wide, and so reliably hitting apexes on hairpins and chicanes warrents faster responce from the servo. I'm yet to fly my plane (NW UK weather and family birthdays conspiring to keep me off the field!) but struggle to see why this would help fly an docile by design plane flown line of sight at more than 100m away. Raise speed, or bring it close and the argument improves. That said if you have any sort of electronic stabaliser, flight controller, or advanced failsafe on board then these could certinally make use of faster response & speed servos. "Digital" servos may also grant many other benefits other than responce & speed. For exxmple; accuracy, repeatability, and potentially reliability. Starting with the latter brushless and hall sensors over brushed dc and potentiometer position sensing strengthens two weak points of traditional analogue servos. Repeatability is one I hadn't given much thought too but it the ExpressLRS world there was a real fuss about temperature issues effecting the Tx and Rx circuitry. Anyone ever tested if the analogue servo goes to the same posions up high on a cold day vs your ~18 to 20C workshop? Sure, if your setup process is consistent, not an issue but changing servos even within make/model could add unnecessary unknowns to your re-maidens. Anyway, as with all things you pay your money and take your choices. A set of brushless, hall sensor, programmable servos would cost more than many to most aerobatic plane kits ready to fly. Technology is slowly creaping down the price chain, but too slowly in my mind. PWM is archaic, and only recently being superceded by canbus (simpler wiring, improved reliability), even so only really at the highest price points. I don't know much about sbus, but generally steer clear of proprietary formats where possible.