Seagull Dual Ace Laser Build

[Chris Walby]

Well its not very good looking and to be honest its going to be a means to an end, but that's for another build (assembly) blog! I recon its going to be a good step on the path to the "dark side" of IC (as I have only 5 years in the hobby and was brought through with foame's that's my perspective).

Firstly thanks to Inwoods and Jon for their advice regarding suitability and specification of various bits and bobs. Kit was order and arrived 3 days later, plus the engines are sitting on Jon's shelf awaiting collection so I had better get on!

There are a few known issues with the Dual Ace that I intend to iron out during the build and I am sure with forum members help the ones that pop up can be resolved.

• Lead required in nose to get CofG, well with a couple of 70 that should sort that out
• Engine reliability with twins, buy British, great support and Laser reliability should reduce the issue
• Wheels too small and nose wheel steering support on the weak side - can beef that up
• Cockpit crew missing - can be sorted

Initial inspection and I would say the build quality looks good and really not much to do.

I'll start digging through the box of bits and report back if anyone interested?

[cymaz]

Yes! I have had two...great docile planes - when both engines are running. . I will try and find some info I did a on my second DA....( first one was a mid- air...not my fault, honest).

I did several modifications and improvements.

[Denis Watkins]

Totally interested Chris, great project

[cymaz]

 

 

I bought one of these for the nose leg....believe me it is worth every penny. There are strong and make the ground handling so much better. On the single strut, the leg wants to dig to one side and tip the plane and corkscrew it into the ground.

Put a closed loop on the rudder. The pushrod is simply not up to it.

I put Slec tanks in...the biggest tanks that will fill the bay without modifications to the woodwork.

I fly on two Irvine 40’s. There is plenty of power with those. I didn’t add any lead for the CG, battery is under the canopy hatch. The bigger the engines, should one fail , the bigger and more violent the torque spin.

4” low bounce wheels are ideal. Any more stuff I can think of, I will post. Ask away!

Edited By cymaz on 24/02/2018 08:29:31

[Paul Marsh]

I have one of these, A while back I was flying it and one engine cut - ran out of fuel, the other was on full chat - went into a spin straightaway, couldn't get out of it. Just broke its back on a clean break, but fixed it and is flying again. Has 2 x OS 40 SF engines.

[Paul Marsh]

Probably the best ARTF for IC were this. a Hobbico Twinstar, but it was unavailable in the UK and only found this by luck, hanging up as a second hand-new model in Mikes Models, Birmingham.

The Dual Ace is a fast model and doesn't like flying too slow - just remember that...

[Chris Walby]

Thanks for the feedback and suggestions. The intension is to get plenty of hours and fun into the engines + experience with setting them up for their ultimate resting place.

I need the experience of "flying them in" as I am still rebuilding my mistake of a warbird with full flaps and not a forgiving tip stall (all my fault, but still a bitter lesson). Changing subject my Speed Air 40 with a Laser 70 is really nice and had to add 15g of lead on the tail! just a pity the airframe is so tied.

I'll order the nose leg up and go tank hunting as I forgot a servo (the other elevator ) which brings on to the first set of questions?

1. Is there any benefit of putting the elevator servos on different RX channels or just Y lead?
2. I was going to put each aileron servo on a separate channels just so I can add a bit of differential/flap if needed in the future?

best regards Chris

[rcaddict]

dont think i would like to start my ic journey with twins - one engine is enough to going on with - IMHO

[Jon H]

That dual springy thingy nose leg is pretty cool. It would certainly be stiffer than a single leg. I wish my old Ripmax harmony had one.

For the radio install I would keep it simple. Y leads unless servo direction is a problem but make sure you use good quality y leads with a solid block at the join. Many are just soldered and wrapped in heat shrink and a small tug is all that's needed to crack the solder joint. It wont fail immediately but It will fail. I almost lost a model to this and a friend did loose one so they are best avoided.

I would not recommend flapperons as they will increase the angle of attack at the wing tip and could make it more prone to tip stall. If you want flaps then cut the ailerons in two and add another servo somewhere to make them wiggle.

Regarding Pauls comments about his engine out spin that is always a risk but properly handled will not be a problem. The biggest issue is the short period of time between engine out and a spin. Under most circumstances you have about 5 or 6 seconds to figure out that an engine has gone and take corrective action. If you didn't hear the engine go then its likely that by the time you noticed your 5 seconds was already up. Airspeed is the key, keep your airspeed up and you will be able to maintain control with one engine. If you do spin it should be recoverable if you throttle back to idle. I did loose my harmony once in a spin I couldn't get out of as my idle was just high enough to keep it spinning. It was my own fault anyway though as I only got into the spin as I wanted to try single engine aerobatics. It all went well until my carthrinewheel stall turns!

If it ever warms up and we can fly I might see if I can shoot a video of my twin and how I handle an engine out. I will just short fill a fuel tank and go from there.

[Denis Watkins]

In a nutshell Chris, teach you to suck eggs

Motors, run in, tuned correctly, clean fuel, will run on standard tank at least 15 minutes

Just fly 10 minutes, and land under power until such time as you are comfortable.

Always have plan B in your head

On a normal flying day, fly your favourite sedate model around during your normal routine for 5 minutes without touching the ailerons

Get flying rudder/elevator until rudder is appreciated

If you are already a rudder landing man, whereby wings are not up and down coming in, then just practice now and again

A run in motor, with good plug, clean fuel and tuned correctly will very rarely dead stick

Have rudder plan B in your mind flying the twin

Stay in the landing circuit for most of your initial flights

If one motor stops, idle down the other, or cut it to your choice, then bring it in

I would give the twin a good talking too before you go up !

[Chris Walby]

Hi oldgit,

I have been cutting my teeth on a very worn BH Speed Air (was electric, now Laser 70) and loving it. I have very nearly finished off a gallon in less than 2 month of winter flying!

Yes its has dead sticked me twice but that has just been my inability to tune it correctly (Thanks to Martin for 5 minutes of master class) I am getting better!

Dead motors are not exclusive to IC as I had my PZ mossie shed a prop blade, stripped a aileron servo and went in. I asked advice, did some practice and had plan B for when my BH mossie (electric again) motor connector fail. The result was no damage apart form a new pair of pants !

My view is that there is risk and you can manage it as best you can, then go out and fly to enjoy what you do.

[rcaddict]

[cymaz]

Twins are sods when one engine goes. I’ve had only 2 engine problems...both old plugs. It’s something you have to think about alll the time when flying them. Shut the live engine down to idle, drop the nose to get airspeed and do a landing...don’t even worry about if it’s a down wind landing or not. Stopping the spin with airspeed is the best bet. Be gentle on the control inputs.

Of course , this is all fine and dandy, if you can spot an engine dying and going out ! The DA will be very sluggish on response to inputs, it will slow up with out warning and will rock its wings before spinning.

I’m speaking from my experience....someone else will have a different idea, I’m sure.

And another thing....( I use Futaba 9c)....it’s a pain to set up the idle end points and WOT. Below is the mixes used so I can adjust this on the Tx....

I use an 8 channel FrSky Rx and use separate channels for each throttle.

[Paul Marsh]

Reason why It went into a spin, as it was at a fly-in, and couldn't hear the engines. With 50-100cc models flying, when the engine cut, I had about 3-5 seconds to do anything- as long I knew when to act, but the engine stopped and only when the model went into a spin, did realize the engine had stopped. Flew for so long, that one 9oz tank was empty and the other only had another 3 mins in it.

Make sure you use a timer!

[Paul Marsh]

I have a C160 Transall and one engine quit on take-off, no-where to go and kept full power and full rudder to clear the hedge, cut the throttle as it flick-rolled, but leveled off and landed heavy in the field - the only damage was a bend wing tube and one wheel came off.

Twins are a great way to expand your skills - it would be boring if everything was easy. Engine-outs have killed full-size pilots, so not restricted to models. This is a classic case:

Edited By Paul Marsh on 24/02/2018 12:17:01

[cymaz]

 

 

 

So so you want to fly twins......I read this ages ago and thought “yep!”

**LINK**. How not to do it......

 

Edited By cymaz on 24/02/2018 12:29:30

[Jon H]

As I have said before, I 100% do not recommend the cut and glide method. It usually ends in tears as you will end up short of the runway and then add power so you make it. At that point its all over.

Its a far better idea to bring the other engine to full power and maintain your speed until you are on a normal approach. You can then cut and glide once you know you are going to make the runway.

Twins glide like bricks so don't attempt it.

I'm just about to shoot out so don't have time to fully read the link cymaz posted but I have already seen a few things that are nonsense. He states that if you are at high speed with high power you are safe, then suggests throttling back which slows you down and puts you in the danger zone. At 50% throttle with one engine dead you have at best 20% of the power you once had and the model will not be flying very long like that. Running the engines rich is also a dreadful idea as they are more likely to cool and give up the ghost.

I split my twin flights into 3 categories when it comes to engine failure and they are as below with the action I take:

1. sags/cuts on takeoff roll. Kill the other engine and abort.
2. sags/cuts on climbout. Kill the other engine and land ahead. This one is the hardest as it depends where on climbout the engine fails. If you are a foot of the ground abort, if you are higher and have good speed I would keep going. To help me out I always takeoff at about 70% throttle and climb to a safe height at this power setting before giving it the beans.
3. Sags/cuts in normal flight. Immediately throttle back to half, level the wings and get into a shallow dive. Open slowly to full power, work out which engine you lost and hold opposing rudder. Call landing and do a normal approach with the engine at full power and then glide the last part of final. DO NOT attempt to go round again or you end up like the poor people in Paul's video.

[Paul Marsh]

Bob Hoover said it best.

Flying a twin engined aircraft is the same, the wing still works the same, as long as you've got airspeed, the aircraft doesn't know what engine is cut, as long as you keep the minimum airspeed.

[Paul Marsh]

Posted by cymaz on 24/02/2018 12:28:14:

 

 

 

So so you want to fly twins......I read this ages ago and thought “yep!”

**LINK**. How not to do it......

Doesn't count - it's not a twin, it's a triple...

I start and set one engine up, to just slightly rich, stop it and do the other one. Once that is done, start the first engine again and fly it. Doesn't matter if the revs are slightly off, better than having a slow engine, then one which isn't running. If one engine is too fast, compared to the other one, richen the fast engine slightly.

Normally I have many flights without engine cuts - in fact one model, I never had a engine out, even after loads of flights, but they can happen, even how much you try.

Edited By Paul Marsh on 24/02/2018 14:35:56

[Paul Marsh]

What about this, it's a twin, lose one engine, full chat on the other - makes no difference!

[cymaz]

Posted by Paul Marsh on 24/02/2018 14:31:48:

Posted by cymaz on 24/02/2018 12:28:14:

So so you want to fly twins......I read this ages ago and thought “yep!”

**LINK**. How not to do it......

Doesn't count - it's not a twin, it's a triple...

Edited By Paul Marsh on 24/02/2018 14:35:56

True....but he had a wing engine out. Slammed open the throttle and oops. It was a twin when it crashed , just.

[Jon H]

i didn't see the video of the ju52 on my first pass.

He made 2 mistakes beyond the less than ideal landing approach.

First he smashed the throttles forward to go around. This is a bad idea on a single let alone a twin.

He then couldn't decide what to do. leave the engine on and go round, or cut it and plonk it down. In the event he sort of did both, and yet did neither and the result was clear. Looking at the video i think he would have made a go around if he had left the engine flat out and got full rudder in. Instead he forgets the rudder, throttles back, slowing down further, then piles the power on again, still with little to no rudder input, then it eventually stalls.

I know its very easy to sit here after the fact and make a judgement, but this is the sort of situation that needs a plan already in the pilots head. He should not have to even think about what to do should XYZ occur. That is why I have might flights broken into the 3 categories I mentioned earlier. I now what I'm going to do with the problem before I have even had it.

[Chris Walby]

Well the dead has been done and what a lovely matched pair

And thanks guys for the various suggestions and advice so far with modifications and flying techniques and so I now need to move on with the build.

I know what ARTF means, but from experience nothing ever quite fits (I am sure you guys can think of a suitable meaning to the acronym?

Tonight's conclusion is that everything has to shift back about 30mm (about the distance of the black section on the nacelle box), Good news is that the SLEC 9 oz tank looks a good fit if I use the space where the servo normally resides.

Due to the size of the SLEC tank it will sit a little higher and thus miss the step in the nacelle box.

I think the existing bulkhead will end up being overly perforated so I'll make new ones and beef up

The throttle servo looks to drop in behind the existing nacelle to wing support (where it is in the photo) without too many issues.

• Sprung nose wheel on order
• Need to pick up a couple of SLEC tanks
• Closed loop kit for the rudder
• Another servo as I forgot to get for the "other" elevator on

Once the engines are in I can have see how the C of G is starting to work out

[cymaz]

I reckon the Rx battery might be somewhere down in the tail ! Anyway , lovely pair . See that they want for nothing, can’t afford an engine out ! I can take some pictures of mine if you like...

[Chris Walby]

Cymax, oh thanks for the laugh and as you say it might need it to be back there however the 70 went the Speed Air and I only put 15g of lead on the tail because I wanted easy access for the RX battery on the canopy.

Photos would be appreciated of the engine and RX installation for me and anyone else looking to take on the Dual Ace.