FxRES November 2024 F3L/F5L Monthly Duration Challenge

[martynk]

FxRES Monthly Postal Rules

This is a “for fun” challenge for UK based pilots. Anyone may enter with:

1. a bungee-launched F3L specification glider using the reduced length Hi-Start. The reduced length Hi-Start bungee has a maximum of 10m of 6/4mm surgical tubing and 50m of static line (minimum 30lb breaking strain). Lighter/smaller/shorter bungee rubber may be used.

OR

2. an Electric motor launched F5L specification glider fitted with an Altitude Limiter set to 60m and a maximum motor run time of 20 seconds.

Object: Fly your F3L or F5L glider for as long as possible from a flat field. Each monthly challenge will commence on the 1st day of the Calendar month and  the person who's time is unbeaten at the end of the Calendar Month 'wins' and a new challenge will start. The annual challenge league will end on the 31st December of each year. A new annual challenge league will then commence on the 1st of January.

Rules:

Models must comply with the Model Specification rules for F3L or F5L as appropriate.

You may self-time your own flights

Flight times begin when the tow-line falls from the tow-hook  for F3L or in the case of a F5L glider when the motor stops.

The model must land in the launch field or (if there is no field boundary) within 150m of the launch position for times to count. There is no landing bonus.

If you are using a bungee launch (for this event or any other), then the launch line MUST be secured using a corkscrew dog tether or similar bungee stake to minimise the risk of injury caused by a loose stake.

Scores must be submitted on the relevant monthly postal event posting on the FxRES forum at www.barcs.co.uk/forums/   

Scoring flights must be submitted within 24 hours of the flight taking place.

A flight log graph from the Altitude limiter should also be submitted if entering with a F5-RES glider.

All scoring flights must start with a hand release from Ground Level with (if applicable), the motor running.

No flight information telemetry permitted except for Received signal strength and Receiver battery status.

Submitted scores will be amalgamated into an annual league. Points will be awarded as follows:  1st -25 points, 2nd - 22points, 3rd - 20 points, 4th to 22nd, 19 to 1 point respectively.

You may enter as many times as you wish using as many different models as you wish, but only your longest duration flight will count towards the league position. Separate entries (best flight in each) will be recorded for those who fly both F3L and F5L.

Please enter your best/latest monthly scores below in the following format...

ON THE FIRST LINE OF YOUR POST

Model Name : Class (F3L or F5L) : Date of flight : Time Claimed

Any text or commentary or images please add afterwards.  Thanks  

[Carl]

Magic 2 SL : F5L : 01/11/2024 : 12 mins 23 secs

Even though there's been some lovely sunny days lately, it's been quite windy down my way for the past couple of weeks. Finally a lot calmer today, in fact dead calm. This morning was pretty chilly with thick cloud, so thick you couldn't see where the sun was. So I wasn't expecting very much. Tomorrow onwards is forecast to get windy again, so with no real prospect in the coming week ahead, I made the best of what conditions I had today.

At first, with my streamer not indicating anything, I launched far with a shallow climb to get as smooth a transition to power off as possible. Then just allowed the glider to float with minimal inputs, guiding it around the perimeter of the field, and coming in closer as it got lower (to avoid the trees). Got quite a few 5 minute flights doing that.

After doing that for a while, my streamer did appear to start indicating very light thermals, but the cloud was still grey and thick. So I turned my attention to try and use them, resulting in some longer flights. This 12+ minute flight was my best today, but difficult as I was pretty much flying directly above me. It was nice to see on the graph, a climb up to 115m in the conditions today. 

Another 10+ minute flight was nice because I needed to use a number of low and light thermals to get the time.

Every time I fly the Magic 2 SL, it impresses me. It certainly was worth the effort to build a competition level RES glider. My Magic 2 SL, built as F5L, weighing in at 390g is brilliant in these light lift conditions, but still covers the sky easily. I have just started building a Magic 2 EL, which will have a more powerful motor, and be heavier for when it's a little too breezy for the SL version. Hopefully I'll be able to adjust the weight by simply changing over to a lighter or heavier battery as it's carried in the centre of the wing.

Carl

[Richard Newsham]

Wow, quick out of the starting blocks. 

[cirrusRC]

Purito | F5L | 2nd Nov | 1.30pm | 11 minutes. 

Drizzle, low cloud, grey, wind 5-7mph.  Really challenging.  Wind indicator was changing direction all the time but the lift was too narrow and turbulent, often it just vanished.

I only had a couple of climbs and both times I was at limit of vision down wind, so had to abort.   Even with DLG it was tricky.   By 2pm there was nothing.

Let's try again tomorrow.

 

[MikevE]

Encanto | F5L | 2 Nov | 14:00 approx | 9 mins

 

[Richard Newsham]

Hi Mike, 

Is this your first entry in the Monthly duration challenge? What were your conditions like? 

Richard. 

[MikevE]

I think I did one last year with my then Medina. Conditions were overcast, cold, grey, but a little lift around. Very little lift. Some downwind drift, but not too bad.

[cirrusRC]

Welcome aboard Mike.  The encanto is a nice model, a few in my club. 

[MikevE]

12 hours ago, cirrusRC said:

Welcome aboard Mike.  The encanto is a nice model, a few in my club. 

Hello mate! Now I finally know who you are.  @MikeDLG has also just bought himself one.

[Matthew]

Red Eagle | F5L | 3rd Nov | 3 min 4 sec

A very grey and overcast sky, there was some lift about, but nothing that would make the Red Eagle go up, only go down slower. Still it was good to be out in the field and flying.

[Pete in Northiam]

On 03/11/2024 at 15:22, Matthew said:

....A very grey and overcast sky, there was some lift about, but nothing that would make the Red Eagle go up, only go down slower. ...

Three minutes beats dead-air time! Sounds much like most of the day for the last national league round in Cruckton. I found going down more slowly gave a better lesson - just breathing on the stick as Lawrence would say.  Going up is too easy!

[martynk]

Good start to the month..

 

 

     

 

[AnthonyB]

Not relevant, so delete if some are offended !

Today is Guy Fawke's Day and a whole lot of farm detritus gets burned, all round the Ribble Valley.

As we all know, the sun warms the ground and that warms the air and hot air rises.......... Simples.

So how come that hot air from a large bonfire does NOT rise ?

How come, in The Gulf of Mexico (twice last month) there has been 100% very thick cloud and the biggest suckiest thermals on the planet. Massive pressure drop from the rising air, causing storm surges, measured in many feet of water ?

[Pete in Northiam]

Good question @AnthonyB! I've often seen the same with my own bonfires and others across the valley.  But there seems to be a critical level of burn above which the smoke kicks through and rises vertically. Something tricky with a low inversion I guess but I don't quite get the physics.  As an aside, many moons ago I flew a full-size glider up in a thermal directly (far) above a bonfire. It was bumpy!

[martynk]

Probably a temperature inversion where warm air is trapped by an impenetrable layer of cold air. This happens when there is high pressure over the area. We have had a high pressure window stuck over the UK for over a week now, it is slowly dissipating..

[AnthonyB]

Thank you for the 2 replies.

Rightly or wrongly, I have viewed “inversion” as an excuse for losing a thermal (including me). At my local club 50% of the time a couple of fellow thermal followers called the lift “wave lift” – and they do fly (full size) round the area. We are only a few miles from Pendle.

The horizontal smoke from fires (most are large) is too common and perhaps too low (all day). I also have a Cement works up the road, which always has a plume, that also is usually horizontal. Perfect (for 40 years) to show the wind in relation to Pendle.

Also many times I have seen horizontal smoke and at the same time groups of Gulls thermalling away happily !

Jane (wife) has, within her remit, about 12 Thermal Oxidisers. Their minimum temperature is 850deg C, so they run at 900 – 950deg C. They are BIG. They also go horizontal a lot.

The storms round the Gulf of Mexico are another “no sun thermal” - I don't really think that would pertain round me. Maybe at a really weak level, but I am 25 miles inland and that works best over warm water.

https://www.facebook.com/reel/1312892596371744

[cirrusRC]

Purito | F5L | 9th Nov | 1 pm | 47 minutes 13 seconds.

I'm sure everyone is sick of this high pressure gloom now.   Looks to be changing tomorrow onwards!!      Arrived at field to find no sheep and grass cut - bonus!    8 degrees but felt colder  (wellies + fingerless gloves and big coat).   Low cloud, damp and gloomy (forgotten what sun looks like).    light winds 3-4mph.

Purito is an awesome model in light lift with that fat wing.   It held on to the tiniest wisp of lift.       2 really good agonising slow climbs with micro inputs.    The golden rule is to never leave lift once your in it,    but both times I had to abort as the model was disappearing into the gloom a long way down wind.

Fingers were dropping off towards the end.   Very chuffed with a flight this long on a cold November day.     Slightly annoyed that on landing, I turned round to see a dozen seagulls circling in lift high up.    Must ALWAYS look around for signs when the lift dries up.

 

Let's see what tomorrow brings.

[Pete in Northiam]

I've not read this fully myself yet but the pictures speak a thousand words and confirm your examples @AnthonyB  https://en.wikipedia.org/wiki/Inversion_(meteorology)

[AnthonyB]

Pete an inversion is where warmed air rises and hits the inversion layer. It cannot penetrate and so it spreads out just below it.

If the fire is in a layer, any layer and if the emissions are hotter they will rise. That is simple physics, except where there is no gravity.

It simply cannot be that there is always an inversion layer just at the height of a bonfire or a chimney – just not possible. Joseph-Michel and Jacques-Étienne Montgolfier told me that.

There has been a layer making it all a bit grey for the last week, but I would say the layer was at 4 – 500m here. Not affecting a fire on the ground.

My own version is that most of the “smoke” is in fact water droplets. Those droplets of water cannot be lighter than air, hence they do not rise. However much of the water will be vapour and will be much lighter than air – that will rise (together with CO2). As they are both invisible you do not see them.

My current interest is the other part, where there are strong up-currents without sun. (we get that here). Where large groups of Gulls rise up. Here the only factor (lack of sun) has to be “sucky clouds.” We all know on a normal sunny day the main lift can be under a cloud.

Hence if you take away the sun part, there should still be the lifty cloud part. Very reduced, but still lifting. How else can it rain (a lot) all through our dingy winters.

I have now finished a collection of remote rising air detectors, for across the fields – time will tell !

 

[Pete in Northiam]

All I can say is read the Wikipedia article. That explains formation of an inversion as cold air falling not hot rising. I don't understand why the hotter air doesn't always punch through but that's what seems to happen. My guess is viscosity is involved but fluid dynamics isn't my forté by some distance...