basimpsn

My Feedback: (5)

Hi guys

I was trying to balance my S/M F18 when i ran into some problem. Do i need to retract the landing gears before balancing?. Secondly it seems to take alot of weight to the nose close to 5 lb of weight including receiver and ECU battery[X(]. Is this normal??. Power plant RAM 1000.


BASIL

Aero65

My Feedback: (2)

Hi Basil

A good cg for the F-18 is on the front set of screws for the front wing spar. We currently fly most of our F-18's around 1/8" behind the front screws. I think you can go as far as 1/4" inch behind, but for the first flight I would recommend on the screws. This might save you some nose weight. As you move the CG back just remember to have your elevator dual rates set as you will need to cut down the throw a bit, as the Hornet will get lighter and lighter on the elevator stick.

5 Lbs does sound excessive. Most of the F-18's I have put together have taken 18 oz to 8 oz if I remember correctly. However if you are trying to balance to the fwd location shown in the online manual it might take that much. Balance is with the gear down.

Here are just some tip's that you probably already know FYI, just in case.

For take off I have found that make sure that you tell yourself to use the aileron's on the take off roll before you punch it; Like most F-18's with scale gear as you get fast and you correct with steering the wing's will tend to dip away from the yaw. Not a big deal just be ready for it.

I usually start slow to get it rolling before hitting the throttle as this is a narrow gear bird. After it gets to around 20 mph I apply full elevator and hold it till rotation; as soon as you see that nose gear lift off ease off the elevator and climb out. Due to the trailing link gear the rear wheels are so far behind the cg that it is difficult for the airplane to rotate until you reach quite a high speed, because you are holding so much up to rotate it will really jerk the airplane into the air if you do not ease off the elevator quickly. If it does jump off no big deal though you will be plenty fast to fly by then, just doesn’t look great.

After climb out if you are at the rearward cg settings you might want to switch to lower rate on the elevator as the high rate will tend to make the airplane a little pitchy. If the cg is on the screws it will be ok and stable.

Landing i like to use around 15-20 degrees of flaps for the first landing. Make sure you test them up high first. The F-18 is fairly easy to land just set up a good approach and drive it in. Lately I have been trying to setup a nose up final and then just fly it to the ground with a little flare at the end. Once the F-18 touches down it sticks well.

When I try and grease it I tend to over flare and then it gets too slow and plops in on the second up and down. It will fly pretty slow, but be aware that if you have high elevator rates it is very easy to start a little PIO (pilot induced oscillation) during the flare. Until you get used to flying it you might want to land it at a med speed and not try for the super slow landing. We fly out of a 360 Ft asphalt runway with 400 ft gravel / rough asphalt overrun so I try to get the airplane as slow as possible on landings. If you have lots of runway it should present no issues at all.

Here is my friend Woody's maiden flight

http://www.hawaiijets.com/aircraft/f-18/f-18.htm

PM me if you want to chat on the phone.

DavidQ

My Feedback: (12)

Duke,
Do you recommend stronger springs for the main gears. It seems a little soft and on a hard lading may damage the gear doors!
David

basimpsn

My Feedback: (5)

Duke
Thanks you for all your information. I will do all the above on my maiden flight. I fly off a 500 Ft asphalt runway at Markam park so I guess its enough runway. So its safe to put the C/G at the front spar set screw.

Can 10- 15 degrees flap on take off help with better rotation?. And what weight margin can i expect before fueling.

pilott28

My Feedback: (27)

I have mine set up as Duke suggested. Balance point is just behind the screws for me.

I have a 1400 MAH JR pack, the Jetcat ECU pack and about 6 oz of lead in the nose. Not sure what that adds up to, but I'd guess nothing near five pounds. Something seems wrong if you need this much weight.

One thing to add to Duke's note on takeoffs --- use flaps. They shorten the roll a bit and seem to dampen the tendancy of the plane to jump off the runway. I also ease the elevator in as the plane reaches flying speed.

Aero65

My Feedback: (2)

Hello

The stock springs are ok for me. I have not hit the doors on the F-18C.

Good suggestion Keith for the takeoff. I have used flaps on take off and it helps. If you have a longer runway Keith's technique of takeoff is probably a better way to do it. We have to get it off in the minimum distance so we kind of go for it lol.

Yes the front spar wing hold down screw are ok for the cg this is a more optimized setting so the elevator control is lighter and still smooth. The CG setting on the Skymaster website is conservative and very stable.

dbarrym

My Feedback: (47)

Ditto on the 10-15 degrees of flap on t/o....mine jumps off when it hits flying speed, I hold about 1/2 up (on mid-rate elevator), slowly feeding in the elevator sound good - thanks for the tip, pilot28!

I have 6 oz. of nose weight using a 5 cell 2700 maH NIMH Rx pack and a 2000maH NIMH ECU pack...they are all the way up in the nose. I am balanced on the rear edge of the front spar now and it is not at all sensitive at low fuel/landing flare. May move it back a bit by pulling another ounce/ounce and a half out. First flight was on the front edge of the spar (8 1/2 oz in the nose) and it is definitely better with the CG a touch further back.

Sweet flying bird, just stay off the steering on t/o and landing roll, I have the NWS throw dialed way down (1/4" each way) except for taxiing.

Barry