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Seagull Mosquito weight


Ronos
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That's interesting Nigel, I have been flying my big BH Chippy too, mines electric, and I can do as Jon says, full flap around 50 degrees, and dive for the runway, without it building up too much speed.

That Chippy has done well in FO comps with a 1.20 in it. Always thought the quoted engine size was a bit excessive tbh.

Cheers

Danny

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Yes - it is an OS GF40 and is maybe a little overpowered but who flies at full throttle? I had one before with an NGH 35 2 stroke and it ran out of steam when going uphill! The vibration destroyed the Rx battery by breaking the tags between the cells (and the aircraft, and thank goodness it hit no-one) and I now use a battery backer on large models! The model is a delight to fly- it does lovely big, slow aerobatics - I can understand why you fly it in contests. Max flap is at 50 degrees - just measured it - and although they certainly slow it, I wouldn't call it parachuting down. Prop is 18x10 wooden and maybe, as Jon says, it could could do with increasing in size - it may be poss to slow the tickover.

If the Mossie flies half as well I will be very happy!

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  • 3 weeks later...

Hi Everyone,

I have now given the Mossie its first flight. I moved the CG back to 130mm and took both ailerons slightly up, as did Danny, to imitate some washout. She accelerated fast but I kept it on the ground until we had lots of speed and then climbed gently. It flies fast and I took it up high to try the stall with differing flap settings - no surprises and stall was straight ahead. Motors are Axi 4130/16 V2 and props are 16x10 contra spinning. A 6s lipo 4500mah on each motor and separate Nimh for both retracts and Rx.I reduced the throws of both ailerons and elevator to 60% and set expo at 40 for both. Rudder as per the book. I tried to get the engines at zero-zero on thrust and in the air it needed a little bit of left aileron, but the controls are about right for a soft, smooth response. A bit more aileron needed at slow speed but quite a sweet aeroplane.

The only time it bit me was on the landing, which was full flap and turned out to be "floaty". All ok until one ft up, then the nose dropped. My fault - I had allowed it to slow too much! Next time I will keep the power on about a quarter and "fly it on" Damage is only slight and has been mended. Lesson learned - yet again!

Thanks for the help and advice guys. Regards,

Nigel

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Nice work Nigel

You might want to take out some rates and remove the expo. the expo could have contributed to your landing issue as the elevator reaction to stick inputs may have been on the steep part of the curve causing the sudden stall.

40% really is alot and if you need that much then the rates are likely to high. Its personal preference i know, but i always aim to roll a warbird with more or less full deflection on the stick. I have my elevators set relatively soft as well to make life easier.

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Well done Nigel and good to hear you like the model's flying characteristics.

If you have a long runway and perhaps less flap you could try that or a as you suggest more power to overcome the drag.

On the same theme, but at a tangent!

Does anyone have the mechanical retracts and be willing to part with them? If so please PM to arrange suitable financial payment.

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Well done Nigel, I think you have me confused, " both ailerons slightly up, as did Danny, to imitate some washout."

I am not sure I said that, as I don't agree. Yes it simulates washout, but increases the wing loading, therfore increasing the speed, and more importantly the stall speed.

But anyway as long as you have had a succesful maiden that is all that matters.

Congrats, must get mine out again.

Cheers

Danny

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Posted by Danny Fenton on 27/03/2019 10:56:55:

Yes it simulates washout, but increases the wing loading, therfore increasing the speed, and more importantly the stall speed.

I would argue that control is the most important factor in this case as you cant land a model that is super sensitive to tip stalls. You end up landing it faster than it needs just to maintain a safety factor and a slight misjudgement can leave it in a bad situation.

If on the other hand you crank the ailerons up a bit and make the model more benign/predictable then you are likely to land it slower due to greater confidence.

I also would say that the change in wing loading will be pretty small, and i suspect that the centre section will tolerate a much greater angle of attack than the tips. As stalls are aoa related and not speed related then you may be able to land slower by taking more lift from the centre section of the wing and 'ignoring' the tips. Assuming you can maintain control.

Stall speed is a bit of misleading thing anyway as it relates to the minimum speed the aircraft needs to maintain height at maximum angle of attack. So if we are able to increase the maximum angle of attack the wing will tolerate as whole by slightly decreasing the aoa of the tips with washout then we will likely end up with a net improvement in both critical aoa and stall speed.

The final variable is power. In the case of the mossie you have two fans blowing high velocity air over the wing and flaps. This lowers the relative angle of attack and along with it the stalling angle of that part of the wing. If you read up on Eric Brown's attempts to land a full size mossie on a carrier he comments on this and in his attempt uses masses of power and high angle of attack to get the job done.

Just dont forget that pulling the power off takes your lift with it as well so dont chop the throttle off completely until its on the ground.

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A couple of years ago my son rebuilt a 3m HE 111 that was originally powered by 2 ST 75's and converted it too electric. On the first flight he lost directional control just before landing which resulted in a heavy landing but without any damage. I spoke to the pilot who originally flew it and he said that he did not have problems like this. My son and I discussed this and decided that we need to keep the props turning like a glow motor on IDLE and found that landings were better when this was done.

I try to do this now with all my scale electrics as it does keep more air moving over the tail surfaces at a critical time in the flair.

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I agree Chris as my BH mossie needs nearly 1/2 throttle with full flap and gear down to keep a constant speed. Chop the throttle and the drag increases off the three blade props and it will bite big style (crying).

Its one of the reasons I like my Seagull Laser as some unfounded paranoia + I like the sound means I keep the revs up a bit. On one of the Jon from Lasers describes a very good technique for landing warbirds with full flap by using a steep approach, made a lot of sense to me as it reduces the risk of depth perception issues with flatter approaches (I just need to practice them more!).

IMHO with electric warbirds its very tempting to chop the throttle and not fully appreciate the high drag and less forgiving stall characteristics.

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Danny, Don't worry nothing wrong with mine, just thinking about another model I have that has mechanical retracts with loads of slop...Thanks for the advice.

With all this nice weather I should dust her down and do the preseason checks smiley

Edited By Chris Walby on 30/03/2019 06:15:51

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  • 2 months later...

Hi guys,

Picked my mossie up today and very impressed. Going electric with overlander motors and 6s per side. Has anyone thought of fitting the esc into the leading edge between the nacelle and fus. The real one had rads installed there ???

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Hi, the Park Zone mossie has the ESC's fitted in the wing between nacelle and wing so a good idea as it keeps ESC to battery lead length quite short + easy cooling.

My Black Horse mossie gains almost all of its wing strength through the leading edge box section, so I would be very careful cutting lumps out unless you are really sure its not going to weaken the wing structure. This will be especially relevant as you will have increased weight in the fuselage (batteries) where with the IC most of the weight is in the nacelle (engine, tank and lead to get CofG).

The nacelle bolts to the wing so you should be able to work out where SG have added the strength for that and work out a plan for the ESC. Pity you can't get the lipos in the nacelles and solve all of the issues (worth a really good measure and see, even if you have to make new nacelle boxes.

Hope you c=keep us posted on your build and welcome to the mossie club!

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Hi Chris , looking at the wing and from inside the root its definitely doable. Was expecting to see a largish leading edge with sheeting but its not. Got sort of a flat brace thats drilled all along to which a small leading edge is glued/ sheeted.

The trick is going to be getting the air out. Im thinking a kind of scoop that goes over the top of esc that will direct the air downward to a slot cut into the underside. I think it will work in theory just got to make it neet and tidy and hide it all amongst the "black" of the radiators. Will post a pic or two up when i have it sorted.

Thanks

Andy

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Andy.

Good to hear your investigations have been fruitful, should be no issue getting the air in as there will be plenty of prop wash.

Will the air not work its way out of the U/C "hole" or failing that a slot towards the TE of the wing?

I made a couple internal scoops for the Vulcan so as to keep the underside total flat and allow the air passing over the surface to help pull the air from within out. Works and does not spoil the look.

PS if the rads look nice and scale I might be tempted to fit them to minewink

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  • 1 year later...

Hi Guys, 

I know this is old but someone may be able to help. I've never had a twin but am thinking of buying the Seagull Mosquito.

It would be electric. Has anyone put the batteries in the nascelles. I dont have any measurements so its just a thought as there seems to be the space left where the fuel tanks would live.

Counter rotating props, standard rotation on the port or starboard?

I've read that there are some CG issues and it may be beneficial just to push a battery as far into the nose as possible.

 

 

 

Any other advice welcome

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  • 1 year later...

I have read this string with great interest and am fascinated at the amount of thought that has gone into building and flying this beautiful plane. I was thinking of buying one until I read the RC universe articles on the model. The ‘expert’ pranged his plan on the first landing. He went on to repair it and had another stall at 100 ft from which he could not recover the plane. That persuaded me that it was a project that was beyond my limited abilities. However looking through all the comments and suggestions I have read above, I am considering the idea again. Are you able to answer two questions:

how are you getting on with you planes now a couple of years down the line and:

For a relative novice with warbirds, would you go IC or electric

 

 

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3 minutes ago, Peter Witherington said:

I have read this string with great interest and am fascinated at the amount of thought that has gone into building and flying this beautiful plane. I was thinking of buying one until I read the RC universe articles on the model. The ‘expert’ pranged his plan on the first landing. He went on to repair it and had another stall at 100 ft from which he could not recover the plane. That persuaded me that it was a project that was beyond my limited abilities. However looking through all the comments and suggestions I have read above, I am considering the idea again. Are you able to answer two questions:

how are you getting on with you planes now a couple of years down the line and:

For a relative novice with warbirds, would you go IC or electric

 

 

 

I would be very wary of the views of many 'experts'. There are many youtubers and other 'influencers' who call themselves experts and produce slick looking reviews. Not all of them however fall into the 'expert' category and some are decidedly lacking when it comes to their skills. Honestly i want to smash my fist through the screen watching some engine 'experts' talking online. 

 

When it comes to powering a warbird it will mostly come down to your own preference and the model in question. A small one is probably best electric, medium size could be either, big ones tend to be ic. 

 

I personally think that 60-65 inch 80-100 4 stroke powered warbirds are a good entry level to 'heavy metal' warbird flying. Many foam warbirds are very light and are easier to fly so they do not fall into the same category when it comes to skills/experience needed to fly them. 'Heavy metal' warbirds, be they electric or i/c, have high wing loadings and are unforgiving of mistakes. 

 

When it comes to flying skill i look at it like this. Two pilots...One pilot can do it all. They are all over the sky, inverted, loops, rolls, no problem they are wringing the neck of the model every flight. But, they lack finesse and just stick bang their way out of trouble. Its not uncommon for a model to bite the dust on a low inverted pass. 

 

Pilot two cant do all the tricks pilot one can. He likes to fly smooth with sweeping turns and gentle aerobatics at a safe height. He knows his limitations and flys within them, has a methodical and procedural approach to his flying and rarely takes a model home in a bag. 

 

Which of those pilots are you? and which one do you think will make the better candidate for warbird flying? Spoiler alert, its less about the skill and more about the thinking. If you slap a warbird around without a plan it will bite you. Think about it, respect it, and they are awesome. Just dont expect it to fly like all your other models. 

 

One great thing about warbird flying is you do not have to do anything fancy for it to look good. Take off, gentle figure 8 circuits with wingovers at the ends, sweeping low pass, land. As an intro that is all you need. Later add loops and rolls, half cuban 8's and quarter clovers as you feel more confident. 

 

I guess the big question now is what are you currently flying? and how do you rate your landings? They are quite critical. Oh and the rudder, how much do you use that once in the air?

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What a helpful response thank you very much.
I have been flying RC models for over 30 years but have never done anything too clever. I have learned from many mistakes such as check batteries, make sure your hinges are sound (and many others). I now have a variety of models - 3 biplanes going from a .46 size ultimate, a super skybolt to a 1.3 scale Pitt’s. I also have a Weston Cougar that I use to practice slow flight using rudder and ailerons for turns. 20 years ago I built a 65 inch spitfire. A beautiful model that I flew a bit but eventually it succumbed to a tip stall in a final turn that was too tight. It is still in my shed waiting to be repaired. I have always fancied a twin and that’s where the idea of the seagull mosquito came from - and that would not take the hours it took to build my spitfire. But the reports in rc universe put me off - if their review could prang it on the first flight and total in on the second, what chance would I have. However the comments and advice in this string has given me more confidence - so thanks again and maybe I will pluck up the courage. 

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With the skybolt and pitts you should be familiar with relatively high wing loadings. Many Pitts are like bricks, so this is good experience to have. 

 

What i would recommend is you fix the spit, on the basis that it owes you nothing and if it dies its not such an issue given its current status. Once that is done get a sport twin as a trainer. I recommend this as twins, like warbirds, are different. Not difficult, but different and require specific sets of skills. An i/c twin needs careful handling should you loose an engine and you must practice it. Electric is viewed as safe in terms of an engine out, but i have seen electric models loose motors so its not completely safe. 

 

if you go this route, the Spitfire can help you brush up on your warbird skills, the sport twin can ease you into multi engine and let you practice single engine flying. If you try to combine both in the one model it is just too much to deal with all at once and its likely to end in tears. 

 

I recommended a twin trainer to Chris before he got his Mossie and i dont think he regrets it. 

 

 

 

 

 

 

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Tend to agree with a lot of the above, Pitts and your other Bipes draw gasps from some regarding flying them, reality is they're different and require handling accordingly, no big deal though with a little thought.

 

First twin ? If it was me and my pocket stretched to it I would go the sports twin route first, simply to build experience and confidence in myself, having said that I'm not implying a Mossies beyond you, just the route I would take.

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As I am relatively new to the hobby I sought advice from various people (Thanks Jon and Martin) as I progressed from A to B cert and high wing foam trainer to IC warbirds. Electric warbirds just don't do it for me (Parkzone mossie and BH Mossie although the sound of three bladed props on a low fast pass is nice!). So IC was the lead in and reliability being key. Hopefully not tempting fate, but I have had more electric twin quit one than I have IC (more on that later).

 

Talking to Jon, a plan was hatched with a Seagull Dual Ace and to fit a pair of Laser 70's. Then once I had experience with setting up, operating and flying a twin I would obtain a SG Mossie and use the Dual Ace engines.

 

Result with the Dual Ace as no added weight even with the two 70's up front and actually its at the lighter end of the target weight. Nose wheel bulkhead has to be reinforced, but other than that is a great model. Flies on the quick side although that's no bad thing and has no surprises up its sleeve so well recommended.

 

Now for the SG mossie and this is my opinion, but I have watched plenty of them fly and go in. Take a look at my maiden with the mossie 

 

Now with IC I really (and I do mean this) like to hear the engines so I'll accept I come in quite fast and close to 1/2 throttle. This is where I think most of the electric ones come to their end. Take off with loads of power, circle around and all seems ok, then gear down (added drag) + flaps at 1 (added drag) and because you can't hear the electric motors people back off the throttle... That just leaves an aileron turn onto finals and the mossie bites. Its not its fault as the owner has just blead too much speed off. It will fly slow, but not if you are using the ailerons and just watch mine bleed the speed off once the throttles are backed off.

 

I would recommend taking the same route as myself if you want a SG Mossie that sounds fantastic, flies well and you'll enjoy. If you intend on taking a different route talk to Jon as a pair of 80's could work with C of G as its quite a draggy wing, but 70's work well (it will loop, but don't back off until well over the top or it will do an inverted spin - don't ask how I know, but it took all +3 mistakes high to recover it! and a cup of tea).

 

 In summary

  • Twins, what's not to love
  • Never ever take off unless both engines are spot on
  • Better to come in too fast and go around than too slow and need two bin liners

 

If you need any info on either the Dual Ace or Mossie conversion, please send me a message

 

PS - There are various views on what to do if one quits be it electric or IC and my view its just do everything you can to stop it in the first place, bit Jon's recommendation to always have a plan B holds up well.

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