Don't be Complacent with LiPo's
Avoid Tree Climbing
Safety – Think it, Talk it, Fly it
Although models are readily replaceable, in the confined area of the DAC flying field you are expected to fly your model as if it is not simply a “disposable item”.
There’s a lot of satisfaction to be gained from a continuous series of perfect landings – and a lot of time and money to be saved by not having to repair, rebuild or replace.
Happily, this coincides with our need to keep our environment safe and to get on well with our neighbours.
Is your plane up to the job? It is important that your plane is appropriate for its intended use, and flown in the conditions that suit it. There are some great looking planes now readily available, but not all of them are up to the task. Concerns include manufacturers skimping on control surface hardware, the thickness and quality of wing joiners, lightweight landing gear and light motor mounting systems.
Modellers often contribute to these problems by attaching motors that are more powerful than the plane can handle and flying them faster and in a more erratic fashion than the model’s frame can cope with.
An experienced modeller will have a good idea of the main stress points – and areas of potential weakness, however some of these may be hidden – so it is a good idea to do plenty of homework, asking others who have flown the model and do internet searches.
Do you need to make some adjustments? I was recently flying a simple Easy Star and one wing became dislodged in flight, causing it to no longer be parallel with the other wing – with the plane falling from the sky. The problem? The wing joiner was loose in the hole in the foam wing. Something I could have easily checked before take-off, and could have easily rectified with a little tape wrapped around the joiner bar to increase its thickness and so grip the wing better.
Motor mounts sometimes need some reinforcements, as do wing tie-downs, undercarriages, servo mountings, tail feather hold-downs, horns and anything else that may give way. CHECK your gear frequently, and every time your plane suffers from a hard landing or suffers “hanger-rash”.
Is your radio setup up to the job? Radio gear and servos must all be up to scratch and you must never take off if a model doesn’t pass its range-check or is being at all unreliable, or a servo is “iffy”. ALWAYS re-check your gear after a hard landing / crash.
Remember that on a 2.4GHz radio, the last “binding” you did becomes your “failsafe”, i.e. what your servos will revert to if your receiver isn’t receiving your transmitter’s signal. This could mean failsafe equals full throttle (!!!) so re-bind to your desired settings. For electrics, that includes NO throttle.
Park-flyer 2.4GHz receivers and transmitters are not permitted at DAC because their range cannot be relied upon. All 2.4GHz receivers and transmitters must comply with MAAA. More details here Radio gear
36 and 29MHz radios must be certified every 2 years and 27MHz is not permitted. If you are finding your 36 or 29MHz receiver is not up to the task, STOP using it.
Programming Radios: There are tricks and traps to this. One trap is having high and low rates on your radio so different that a switch inadvertently set, or knocked at the wrong time – causes violent and/or unexpected reaction when you move the sticks, or gives insufficient control surface movement to recover, e.g. in the case of an unexpected gust throwing the model off course.
Good use of the exponential functionality can allow smooth travel in the centre range of the sticks, but still allow larger amounts of control surface at the outer edges for manoeuvres and for emergences, such as being hit by turbulence over the trees on landing approach. A mentor can help you set this up so there are no unintended consequences from too much exponential.
With the many switches on modern radios, it is sometimes hard to know what they all do. Find this out BEFORE you fly, and disable them as required, ensuring an incorrect or knocked switch doesn’t cause a disaster.
Flaperons (both ailerons up) or crow (or butterfly) braking (ailerons up, flaps down) can cause a change to the attitude of your plane when deployed – but mixing appropriate elevator compensation can easily counteract this. Have your model turned of when you start building this mix. JR radios’ first default channel in mixing mode is usually throttle, and the motor can come to life when you are programming. Have the plane HELD when checking it on the ground, and when checking elevator compensation or new dual rate settings in the air, do it high, so if it doesn’t work as you intended, you have the chance to recover and come down safely before making further adjustments.
ALWAYS check left, right (rudder and ailerons), up, down and throttle BEFORE you take off, BEFORE TAKE-OFF is also a good time to find out if you are flying using the correct model memory (!!). Done it myself and seen it happen many a time.
Sloppy linkages are also often a cause for bad landings and it is a simple matter of making sure these are robust, reliable and well set-up. Having linkages attached to the inner holes of both horn and servo will increase the possibility of slop, and also possibly flutter at higher speeds. Have your mentor assist you with this.
Another cause of losses is a lack of differing colours and shapes top and bottom of your model, so you can’t easily see its orientation.
Is your flying up to the job? Get to know the danger areas. Too low and too far away; too far down-wind; directly above you; into the sun; near the trees (or “leafy magnets” as Doug calls them); and in or near no-flying areas, including over pits, shed, people and west of the strip.
Pushing your plane to the limit. Don’t do this at DAC. You won’t know your plane’s limits till it breaks. That may be okay in a wide-open paddock – but not with constraints of our use of the DAC field.
Pushing yourself to the limit. The same thing as above. ALWAYS have a safety margin.
Are you too tired to fly? Tired people make more mistakes. If you are tired – don’t fly until you’ve rested. Sit down – have a break and a natter and wait until your brain’s fully functioning. You then get to enjoy your flying and to go home with a car full of undamaged planes, and the rest of us have a hassle-free day.
Air (and ground) Traffic Control. Sharing the sky and obeying the “traffic control” rules of flying circuits, calling launches, landings and “on the strip” and communication with other flyers are all essential.
Landing close. Landing close means not having any safety parameters. All may be well when everything works, but with no margin for error – any error can mean disaster.
Aim for the centre line of the strip EVERY time, and then taxi in safely. Or if your plane doesn’t taxi, loudly call “on the strip,” WAIT for a response, look around to double check things are safe – then retrieve your model.
There are 4 possible causes of flyers landing close: mistakes, not being aware of the dangers, laziness or not caring about other flyers. If either or both of the latter two apply to you, please have a good hard look at yourself. No matter how good a flyer you are, models don’t always do what they’re told and you MUST allow a safety margin.
Restraining your model. I think the most recent person to have an argument with a propeller was me – and this was totally avoidable. I was in front of the plane and had disconnected the battery, then I turned off the transmitter. Fine – except that in fact I had NOT disconnected the plane’s battery and BOTH motors came to life, and I caught the two props, one in each hand. Ouch! Lots of blood, but only 3 stitches. If you had a car accident I would say that was unfortunate. If you had a car accident and were not wearing a seat belt I would say you were a dill. Not using a model restraint is being a dill.
When range testing an electric model, ALWAYS have it restrained. The best way is to have someone holding it, and they can tell you if there is any jittering – which you might not detect from 25 metres away.
Mentoring. We have lots of experienced modellers at DAC, always feel free to ask for advice.
Conclusion. Make sure the only way you fly at DAC is safely.
While enjoyable, our hobby has many risks. This section is aimed to grow as a set of not so gentle reminders of the what happens if our attention slips.
The starting point is one of the most frequent injuries that still sends shivers up my spine. This is a real example from late 2003.
The aeromodeller involved had just completed a new model ready for first flight on the Sunday. On Saturday morning they took it into the backyard and restrained it ready for its first engine run. Fuelled up, started, first couple of adjustments of the needle valve and then . . . reaching over from the needle valve to the throttle on the radio (sitting over to the right of the model) a slight slip of attention and the left thumb went through the path of the propeller.
This was a 50 sized glow motor, and the propeller hit the thumb 7 times, fracturing the bones in three places. The extent of the damage is clear from the two photos below -- and this is after many hours of micro-surgery.
This modeller is fortunately one of those of good humour and is the first to acknowledge this was totally avoidable but for a slip in concentration. And as they said 2 days after the incident: "Bloody good engine" sat there and idled after it chomped me 7 times !!??".
So the takeaways are:
Please take this as a reminder to be alert at all times -- and electric power these days can do just as much damage.
*** 31 December, 2016 11:36 PM +1100 ***
Last updated 31 December, 2016