Peter Jenkins

For what it's worth, I print out a 4 column table, and sellotape it to each of my LiPo packs. I put a single diagonal on the next number when I've flown the pack and after charging put another diagonal to form a cross. So, at a glance, I can see if I've used the pack. It does mean you need to put the first and second diagonals in place of course. The benefit is you can see at a glance how many cycles the pack has had. When I reach 100, I simply stick another table on top. I also record the charge details such as: charge put in, Pack IR, and cell imbalance. Before first use I measure the individual cell IRs to come up with a Pack IR, and as I charge my 5S packs in parallel I can also work out what my charger will measure as IR for the combined 5S in parallel IR. That way, I can track the "health" of the pack as I go along. It's also a useful cross check of the number of charge/discharge cycles. Aa you can see, Pack 41 had an over use on its 2nd last flight as I was co ducting a series of short flights to sort out my knife edge mix. I have no excuse for not noticing the charge used as its on the front page of my Tx info screen! Interestingly, only 1 cell remained below 3.0 v but the total voltage of the packs in parallel convinced my charger that all was well. If you look closely you'll see the charge input was 9,956 mAh into a 10,000 mAh capacity pack (2 x 5,000 as the 5,000 packs are in parallel). Pleased to say, the IR andbalance figures seem fine! Phew! Will see if this pack suffers any ill effects as it ages. Finally, I always check pack voltage before fitting the pack and on the Tx using telemetry. But on the multiple flight scenario I described I failed to heed the warning! I must not set capacity alarms using my telemetry -.something I had meant to do but never quite got round to.

Managed to get out for the last 2 afternoons to do some more practice with the Anthem. As usual, I was on my own for both occasions although just as I was about to fly my 4th and last flight, I was joined by Rob who wanted to fly out his last battery. Sadly, on both days my attempts to counter the cross wind had limited success! More practice needed. Today was a bit hotter than yesterday soI opted to set up shop in the only remaining shade on the patch!

I take it you mean Andy Symons. I would just observe that I have quoted from the 2025 booklet that Andy will have been instrumental in getting published. Tour interpretation does not fit with what is published.

I don't think so! Here's what the 2025 B Test says on the Stall Turn. Throttle may be used to ‘kick’ the rudder to the side for the stall turn, however the candidate must avoid performing either a ‘wing over’ or ‘chandelle’ or allowing the rudder to be pushed over the top of the aircraft in a semi-circle.

Just what I was thinking Jonathan!

For which market is this product destined?

That I could see. Thanls Ron.

Link doesn't appear to work Ron.

Made a last minute decision to go out and practice for this weekends competition. It was moderately windy - around 15 mph at around 60 deg to the display line but I though would be good practice at keeping the aircraft from being blown in. I was the only one at the field so was able to rattle through 4 flights with varying success! As you can see from the photo, the day was grey and at 11 C a tad cool. Still, it was good to get in some practice even if the individual flight scores were rather disappointing but, given the flying, only to be expected. I should point out that I'm using the Flight Coach system and its latest module that provides a scoring system based on the FAI judging rules. The program is still at an experimental stage but gives useful feedback that is based on the aircraft's actual flight path.`

No, the Red Kite has a forked tail whereas the buzzard has a triangular one. That's the main distinguishing feature. The Red kite is on the left in the photo. They are very similar in other respects. I know this because I was trying to identify whether it was a Red Kite or Buzzard flying over the house a couple of days ago so did a Google Search and got the gen!

Love the buzzard photo Kevin!

I'll have to bring mine along for some formation flying Ron!

You said it Paul!😉

Hi GG, I was just making the point that when you draw a surge of power from a battery, in this case my pack powering the motor, then there is a drop in voltage. The same holds true of a Rx pack that is independent of the Motor pack. Since Adrian is using an Opto isolated ESC then his Rx power comes from a separate battery. Perhaps I didn't explain it as well as I could have!

When I look at the power draw on the motor on my electric F3A machine, there is a significant voltage drop when a lot of power is demanded. I wonder if what you are seeing is just that. You must remember that voltage drops when there is a significant power draw from a battery. If you find that you don't have any servos hitting the stops then my observation would be that it's probably nothing to worry about. It's the issue of looking at something that we couldn't access before and being taken aback at what is happening. Remember that the IR of the battery or the BEC will have a say in what the voltage drops looks like as you draw a surge of power.

That's fine Learner. Just thought I'd throw in my penny's worth.

Hi Chris The prop hang is done at less than WOT unless you are right on the limit of 1 to 1 power to weight ratio. I am not talking about that situation. On the ground, with the aircraft restrained you place a brake on the ability of the aircraft to start moving and thus to reduce the load on the prop. For electric motors, where if you over load them they will eventually burn out trying to overcome the load on them. An IC engine will just slow down and stop in the same situation. The two power units are fundamentally different in their characteristics. For an aerobatic aircraft, whether 3D or precision aerobatics, you want more far better than 1 to 1 power to weight ratio. In the case of precision aerobatics, as opposed to 3D, you are looking to fly the aircraft at the same speed throughout the manoeuvre. So, in a large loop, you are looking for power on the way up and drag on the way down. The modern F3A machine is built to be draggy to help in this respect and the use of electric motors with ESCs that provide proportional braking is a great help. The introduction of contras and now governor ESCs moves us to a very different way of increasing drag when you want it and power when you want that. I would suggest that your experience may not have included how to set up a modern aerobatic aircraft where drag is actually quite a good thing as you are trying to operate in quite a narrow speed range. The excess power needed in precision aerobatics and the airframe drag and prop drag a way of combating the effect of gravity on up and down lines. The old F3A models were the other way around where engine power gave speed and that was needed to produce the large vertical manoeuvres since the engines were limited to 10 cc. This then evolved into todays' situation where we no longer have really fast aerobatic aircraft. In general, they look, and are, relatively slow. Next time we're up at the field I can show you what I mean. Peter

Hi Learner Good bit of data there. What I found that the figures obtained on the ground with the aircraft tethered is up to 20% higher than achieved in flight. The problem is the prop is more highly loading the motor when tethered and that will make the motor draw a higher current and therefore power. It slso means you will have less power available once airborne. I found that out with on-board telemetry! On the ground, my setup (2 mtr F3A with a 10S pack) drew 3,600 W and 99 A! I closed the throttle pdq! In the air, with the aircraft flying very slowly, I pulled to the vertical while applying full throttle and recorded just under 2,800 W and 80 A. I use a sensor called the UnisenusE. It's very light and can easily be moved from model to model. In addition to V and A it slso provides rpm and height data. The UnisensE can be set to communicate with slmost all current radio brands. I wouldn't be without it!

Hi Folks I recently received a request for help from Martin Dilly whom I met when was a member of the BMFA Council. I remember Martin being a regular contributor to Model Aircraft magazine when I first started buying it back in 1963! He was, and still is, a great free flight enthusiast and flew in many competitions representing the UK. Martin is after input on RC contest Classes and aerobatics in particular. Please read his message to me below (pdf attached) and the attached document which is where he currently is with his drafting. If you are able to fill in even a small part of the picture, please will you get in touch with me? Here’s what he sent me: Hi Peter, Some time ago I wrote a history of model flying, which was included in the earlier version of the the BMFA website. It lacks much coverage of RC contest classes and I wondered if you might be able to remedy this lack. I've attached what we have already, along with a few memory nudges to me at the end, suggesting what else might be needed. It does seem to me that there needs to be some sort of overview of the whole of model flying, so people can see what else is going on apart from what they fly themselves, as well as how we got to where we are now. Having it on the website seems the best place to make it accessible. Best regards, Martin Many thanks Peter HISTORY OF MODEL FLYING.pdf

Good choice of car Paul! I can get 2 x 2 mtr models and a 70 size model in mine and the front passenger seat can still be used!

Nutters, flying that close to themselves at that speed!

Just one more point Birgir, if you are taking off in a cross wind, as soon as the aircraft starts to move, and sometimes before if its a strong wind, the model will act like a weather cock and the fin/rudder will yaw the aircraft into wind. If you had a wind coming from the left when you take off then that will also have added to the yaw to the left. I always think to myself before I start the take off, which way will the wind swing the aircraft so which rudder to apply, left or right? On a strong wind day, you might start with rudder deflected, in the correct direction, before you apply power and then adjust with the rudder to keep the aircraft straight. Remember also that applying, say, right rudder will also cause the aircraft to roll to the right as airspeed rises so be prepared for a touch of opposite aileron to the rudder to keep the wings level - it won't be much aileron but it might stop the wing being tipped over. Also at no/low speed, especially for a high wing model, the wind can "get under" the wing and blow the model over as well. So, thinking about what the aircraft can do before you apply power will help to prevent situations like this occurring. Also, if you need to land on a runway as opposed to into wind, the cross wind take off will help you to remember that on approach the aircraft's track should be along the runway heading but the aircraft's heading will be to the windward side of the runway. As you round out to land, you will need to squeeze on enough rudder to align the aircraft's axis with the runway and the direction to move the rudder will be the same as you used for take off. Again, be ready for some opposite aileron to prevent a roll in the direction you have applied rudder. There is a lot going on when taking off and landing and indeed flying a good circuit to give a good stabilised approach path is the precursor to a good landing.

Hi Colin, quite understand. It's a shame you don't have the space to fly a schedule. I think Miss Wind is an earlier design compared with the Axiome 70 bipe. I've been flying designs from BJ Craft and each new model has benefitted from lessons learned and design changes. I started with the Agenda, then Element and now Anthem. Each has been better by small but noticeable amounts than its predecessor. However, setting up and trimming play major roles as you no doubt know. There is a 70 size bipe offered by BJ Craft that will be a more advanced design than either the Axiom or Miss Wind. This is what it looks like: https://www.bondaero.co.uk/BJ_Encourage_70/p1085152_20098103.aspx# I'm sure there will be second hand versions available at a more attractive price.

Do you fly in aerobatic competitions Colin?

Well done Simon. Look forward to seeing it in action at Knettishall.