Ron101

My Feedback: (22)

I have just finished up my Yellow Twin F-18. Mine is twin EDF with two of Tams 128mm Dynamax conversions (12s 8000mah x 2 ) for a total of 12,000 watts.
The plane is 41 pound 4oz loaded ready to fly. I have the CG set with gear up on the front spar packs loaded ready to fly.

I wanted to check with some of the guys that have flown this plane and pick your brain to help me dial in my radio and flight plan for maiden.
My throws are setup by the book:

Ele: High 1 1/2 " Low 3/4" ( I measured at the rear of the stab but see some measure at the front)
Aileron: High 7/8" Low 1/2
Flap Deflection: 15 take off (take off & landing approach) 45 landing (final over runway) ( mixed in 1/8 up ele)
Rudder: 1" each way


I have -30% expo on everything (futaba). I have a few questions about yellows flight plan in the instructions, they have this to say:

"Take off and fly on high rates but land on low rates.
Take off distance will depend on the thrust of the engine, the weight of the airplane and the headwind. In any case it should not require more than 300 ft on pavement. Make your first turn fairly wide and let the plane gain speed. Once the plane is on step you can do any scale maneuver. Do not make very tight turns as it will bleed off speed rapidly.
Flaps will cause some nose down pitch so be ready with up elevator. If you can program ele/flap mixing into the radio do so. Start with about 1/8. Make sure you are on low rates ele when landing so you don't get into a porpoising motion on final"

So my questions
1. are the throws twitchy at high (over sensitive)?
2. my normal landing pattern gear pass, turn downwind, fly downwind, pull full flaps and I start making my turn around into the wind for base. They want you to add landing flap for your turn to base the full flap over the runway on final..... I would hate to be messing with my flaps at this point am I fine to just pull full flaps before my turn to base like I always do?
3. They want you to land on low rates..... that seems some what odd to me. It's nice to have plenty of throw when landing. Most of my planes I fly on a mid rate for the entire flight so I don't have to mess with my switches. I was going to just set a mid level throw in the middle of yellows and fly the whole flight there (how does that sound?)

any input would be great!!
Thank you much
Ron

Shaun Evans

Hi,

Don't land on low rates. The ailerons are effective at all speeds (even at relatively low deflection), but the stab effectiveness depends in large part on speed. If you're measuring at the TE, the stab rates could be a lot more. No law says you have to go full deflection all the time, but having it available can't hurt. If you induce a low-speed stall by adding too much elevator, then things will have gone desperately wrong already.

I didn't experience down-pitching with flaps. Again, CG has a lot of influence there. I wouldn't program any mix until I flew it and saw what happened. It's not like the absence of the mix is dangerous even if your does pitch down. You'd just have to use your thumb to mix it the first time.

Make sure your mains are tracked true. Some use a bit of toe-in, but if you do, don't go more than a half degree. More important is that they're equal. If they are, the plane will track arrow straight without any need for gyros or all that stuff. The tires will last longer, too

Get her upstairs and fly her around high at lower power settings to get used to the low-speed handling. You'll love her.

powerjets

My Feedback: (1)

That is one nice bird, I've seen one of these fly on electric, very impressive.

Seemed to handle very nicely, good luck!

kevinthoele

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I have well over 1000 flights on Yellow Twin F18's. I do add a little up trim with landing flaps 40 degrees. 15 degrees for takeoff. You will need power on landing approach as it is a very draggy airframe. My technique is to set landing flaps on the downwind and power till the plane maintains altitude with power setting keep that power until you turn base and final simply reduce power a click or 2 to shorten landing and add a click or two to extend. I use high rate aileron and elevator for entire flight.

Good luck with the maiden.

Ron101

My Feedback: (22)

Thank you much guys this is great advice!!
Just to clear up one thing do I measure the stab throw on the leading or trialing edge? every plane I've owned it's the trailing

I will take it all into account and check my setup and put the flight plan in my head

thanks again!

sysiek

My Feedback: (176)

It's a nice jet wish you the best on maiden flight ,instal battery telemetry ,,the quantum it's the best will monitor all 6 cells and totall voltage,, I was using the on my electric gripen 14-16s with Xps edf to fast and the static thrust from 27 to 30 lbs on rhe ground ,I did change back to turbine when after 3 minutes of flight on electric the jet was ready for gear pass and landing ,,very heavy,, the back to turbine it's much better ai least for gripen.the f-18 have much bigger wings and originally df version you should be good with good-lock.

Ron101

My Feedback: (22)

Thank you Sysiek, I've been thinking about messing with the quantum or other telemetery systems.... I'll pick one up to mess with
As you know flight time with electric really comes down to the setup, mah and throttle management... I have a comp arf spark which is a very clean airframe and I get 7:00 flights with on 5000 mah packs.
I have a Jet Legend Hawk that is pretty draggy with a 22 pound really to fly weight with 12s 8000 mah... it can do 5:00 to 5:30 of hard flying.... pretty good for a large EDF. I have done extensive mods to make the most of the F-18 as an electric from fan location, new inlet and exhaust ducting, cleaner splitter plate install, gear door mods to keep them as clean as possible, moving the fans back in the fuse to give the air more time to clean up before it hit the fan and to allow the use of 12s 8000 mah x 2 packs for CG. I hope it will all pay off...

This plane was just a dream for me, I'm not expecting long flight times but do have hopes I can get 5:00 minute flights thats my goal with a go around left in the 8000 mah packs.... I feel it will reach that goal and for a large heavy warbird I will be more than happy with that. I was bit really hard by the electric plane bug in 2007 and have never looked back, I just really enjoy it and that's what this hobby is all about doing what you enjoy

pogoed

I'll soon be maidening a much smaller (44" ws, 9 lbs.) 90mm Hornet and so find advice like this- the characteristics of the F-18- very helpful. What about rudder?- I've heard their use causes a good deal of roll (in the same direction) so I'm wondering if mixing in some opposite aileron would be a good idea?
Tom

edgeflyer

My Feedback: (15)

Ron, we have been waiting a long time for this and fully expect a video up soon. This plane has got to be the most timeless jet ever produced. You did a great job. Good luck!!!!!