Some Pre-Flight Questions..
 

Contrary to some advise I've been given. Im going to fly my F-16 by myself. I KNOW I can do it. If I fail, I don't consider it a total loss. The skills I've aquired building this jet give me enough satifaction alone. To know that I can just build another will keep me from commiting suicide. I also have a jet pilot to meet up with to inspect my F-16 prior to maiden.

Here are some things I need to know and some concerns that I have.

I weighed in at 20 lbs 9 oz dry. Whats the deal with that?

My brake system does not leak, After taxiing around for 10 minutes or so The system is down. I am using the brakes alot though, Stopping all the time. They are not setup proportionaly right now. I imagine this is just normal pressure loss since a flight consists of just using them on the rollout and taxiing.

Ive read the CG should be between 135mm and 145mm, I set my mark to 140 but still have yet to get it right. Does 140 sound ok?

Is it ok to fly without retracting the gear?

I may have the ok to maiden at a full scale airport here in RI, North central airfield. I will post more questions as I think of them.

Thanks so much! Pete

RE: Some Pre-Flight Questions..
 

Pete, due to the weight that it came out to dry I would make sure you have the turbine turned almost all the way up. I would try to get your gear working they fly so mutch beter when in the up position. Remember to fly the jet in when on final for landing and don't kill the power till you are sure your going to set it down, Its nice to have the turbine spooled up alittle if you have to go around, Beter throttle responce. F-16's will get alittle pitch sensitive at slow speeds in high alpha flight thats were throttle managment comes in to play. Also I would make sure the brakes do not pull to one side or the other due to the narrow stance.

Chris

RE: Some Pre-Flight Questions..
 

Pete -
my very first jet was a SpiderJets F-16, I maidened it myself after building it with the advice of
all the jet pilots here in Norway.... and it was JUST GREAT! Everything was fine, flew like a dream,
so just go out and DO IT! Good luck!! :D

Tor

RE: Some Pre-Flight Questions..
 

Yes, it still flies pretty good with the gear down, but no use in keeping it down, really.
You can break 10 times? I was lucky if I could break mine 4 times without the system going dead.

Expect it to be fast, and for it to go stealth when turning towards you.

Your bird is kind of fat. Put it on Jenny Craig or something, but it will fly. When landing, keep that nose up! You drop it, you lose it.

David

RE: Some Pre-Flight Questions..
 

How many lbs of thrust do you recommend I set the turbine to? If I turn it up all the way it's 23 lbs or so. Isn't that overkill?

What do you mean stealth when nose in?? [sm=50_50.gif][sm=what_smile.gif]

Thanks! Pete

RE: Some Pre-Flight Questions..
 

Pete,

all that was said here is great advice. The only thing I could add to it is, after you do a take off, throttle back abit and just get comfy with it. Don't try to do anything with it the first few flights. Just get it around the patch. You are not going to need full power after you level off so pull it back a bit and settle your mind down. I would advise you to have a spotter just incase you need to hand it off. I know what you mean about being able to build because I have for years but would be very nice for your first jet flight to be successful. It's going to be much easyer than you think. Let us know how it came out and even get some Vids if you can. Good luck my friend.

Hooker53

RE: Some Pre-Flight Questions..
 

Ok, Thanks for all the advise guys!

One thing. 21 lbs dry, How fast should I expect this thing to come in. I've watched enough videos to get a good idea but what would you guys recommend?

How much elev input for rotation?

Pete

RE: Some Pre-Flight Questions..
 

with the gear left down you get allot of drag after you pick up speed and you'll need allot of back trim to compensate, if you don't have any leaks with the gear up or down, no reason to not retract it, so...........positive rate, gear up...........

in response to 'going stealth' when you turn nose in the profile of the F-16 is very slim (even with your fat bird :) ) and can be quiet difficult to see, tip missiles not only help here but they also keep you from dragging a wing tip when taxing and it tips over (and it's gonna do that).

the biggest mistake i see people make who aren't familiar with the 16s do is they won't pull the nose up on landing, if you don't pull it up it won't slow down, the more you pull it up the slower she'll go, just use power to control rate of decent. don't worry about stalling it with the high AOA, it'll just drop the nose slightly and go back to flying if you get it too high. the biggest problem with the high AOA is dragging the tail cone and rubbing the paint off and eventually eating up the fiberglass.

myself i get all the stab travel i can without going crazy (don't use a 3" horn), just use a 1" horn and 100% ATV. with a flying stab you need allot more and the more you got the slower you can get on landing keeping the nose up. i pull full back stick till it rotates then let off as she climbs out.

RE: Some Pre-Flight Questions..
 

" don't worry about stalling it with the high AOA, it'll just drop the nose slightly and go back to flying if you get it too high"

I'll be repeating that out loud over and over when It's time to land.

Is my jet really that much of a cow?? I thought A gentleman from Poland built one that was like 24 lbs dry....Or something like that (This is my justification system, There may or may not have been a guy from poland with a super heavy F-16, Just go along with it please;))

Thanks! Pete

RE: Some Pre-Flight Questions..
 

you're a little on the heavy side but it's not that much of a biggie IMO.

RE: Some Pre-Flight Questions..
 

Got AOA? :D question shold really be.............got ventrals? :D;)

RE: Some Pre-Flight Questions..
 

Also, at 23lbs of thrust you have a lot more power than you need. I fly mine with a Rabbit (19lb) turbine and it can climb pretty well at 1/3 throttle, so don't be tempted to go on afterburner!!

RE: Some Pre-Flight Questions..
 

Ill keep that in mind. I thought the tailcone will strike before the ventrals? Hey, Whats the purpose (other than aerodynamically) of the ventrals anyway? Are they stabilizing bodies for high AOA approaches?

Thanks! Pete

RE: Some Pre-Flight Questions..
 

Every F-16 I have flown was a lot of fun, but they are all very difficult to see when pointed straight at you. You will find that the last 1/4 of your upwind turn it will almost completely disappear, and I guarantee that you will panic a little when it happens the first few times.
You will also find that it will tend to bleed a lot of speed off in the turns, especially if you try to pull it hard in a pylon turn.

Try to keep the downwind leg out a little further to help keep the turns wide and you will keep the speed up easier, and use just enough elevator to keep the nose level in the turn. Don't try to yank and bank with it until you are used to it. Keep it in a little close on the downwind to upwind turn and the disappearing will not be quite as bad. When it does disappear don't panic, just keep your eyes on that section of sky and hold the same inputs you were giving for the first 3/4 of the turn and it will come back. I used to describe this as "flying on faith" with my little Yellow F16.

Landings are easy. Throttle back to about 25% and drop the gear after the speed decreases. Then you will notice the drag and want to get the throttle back up to about 50-60% to hold altitude. In the approach the throttle is your primary control for altitude, the elevator is your primary control for airspeed. A good approach is when the nose is about 8-10 degrees up and you have a nice gentle sink rate with about 20-30% throttle all the way to the numbers. When the runway is made, just smoothly bring the throttle back and hold the elevator input, it should settle right in on the mains and do a wheelie for another 50' or so.

Then it's time to drink heavily! :D

RE: Some Pre-Flight Questions..
 

That pic looks very familiar. I put a skid on my tail cone:)
According to my fish scale, which I really haven't checked for accuracy, mine weighed 22# dry (hopper full) with a P-60, full cockpit & pilot (heavy), and two heavy 5 cell NiCds and heavy ECU pack in the nose. It now has a Wren SS and even heavier batteries in the nose plus two more servos for ailerons instead of just tailerons.

Your brakes sound normal.

I think my CG is about 160mm.

With the Falcon I would pull the gear up and fly around at about 1/3 throttle and ease the speed up as you get it trimmed out and comfortable. When clean at certain angles coming toward you it will literally disappear if at a distance so don't let it get too far out.

Before landing make a few laps around with gear down at slow speed to get ready for the landing. At altitude see how slow you can fly it. Into a breeze it will almost come to a stop. But as others said, if you don't get the nose up some on landing it will scoot by so fast that even at an airport the landing will be too far away for comfort. Be sure to set your timer with time to spare for go-arounds which should be no problem with the Falcon.

Other than that it's a piece of cake:D

RE: Some Pre-Flight Questions..
 

RE: Some Pre-Flight Questions..
 

If you've read the old threads on the SM F16 you'll see that the CG range varies widely from 145mm to 175mm. Some guys swear that 145 is way nose heavy and some say it's perfect. I just split the difference and left it there. I think 145mm is a good starting point and the plane should fly fine but may need some up trim.

RE: Some Pre-Flight Questions..
 

Hey Pete:

My SM F-16 1/8 weight was 24.25 pounds and it flew very well.

If you set the CG in 145mm it will be nose heavy, so as Mark said set the elevator for a little trim up. At take off, don't release the elevator stick until you have enough altitude. In my first flight, when I released the stick, the nose came down so I need to give more elevator to keep climbing.

After a few flights, I just learned that for a smooth take off, I set the elevator trim in +12 (cliks) in my Futaba 12FG and for level flight, the trim was back to + 6 clicks. (I was using flapperons).

Some warnings:

During flight, just after take off with tanks full, be careful with steep turns because with CG in 145 mm (UAT full and tanks empty, gear down), the model will dive suddenly. If it happens, just level wings and pull up. Try to make turns close to you and at a safe altitude just to keep track of the model in case of a sudden dive.

When landing, reduce speed to less that 1/2 throttle, and set the trim for level flight with the nose up. Gear down and throttle up to 60%. Set trim again to keep level flight with nose up. When downwind, push a little the throttle up because the jet try to lose altitud a little because airspeed is reduced when you fly downwind, and throttle back again on upwind to keep level flight. (Nose up all the time).

Fly one or two complete patterns until you decide to land. At this moment, just go into final and reduce throttle until the jet starts to descend. With throtle, manage altitud and with elevator manage speed.

And yes, It was my first jet and I decided to fly it by myseld. Why not? I have never flight jets but I am a very experienced flyer.

Set the time in no more than 5 minutes. 2 Litters of kero for a 23 lbs turbine is no too much.

Guillermo

RE: Some Pre-Flight Questions..
 

Something else to remember is the throttle lag. You can't simply jetk the throttle stick up and down and get the instant throttle response like you get with a glow / gas engine. You have to wait for the turbine to spool up before you will get any response from it. With that being said, be sure you are flying ahead of the aircraft and don't get behind the throttle lag; if you do then you will end up ripping gears out or worse. When you advance the throttle, wait till you hear it spool up before bringing the stick back down. Just going back and forth like a prop plane don't work...It took me several struts before I got the hang of it. But me are uh slo learned peoples. :) Have fun and best wishes with your maiden.

Les


P.S. what MFG F16 is it and what scale? you never said....or I missed it in the posts.

RE: Some Pre-Flight Questions..
 

Hey Les, Its a Skymaster 1/8th

Thanks for all the info guys. Im gonna have my buddy shoot the maiden with a nice camera and tripod.

Pete

RE: Some Pre-Flight Questions..
 

Pete, do you have gear doors? If so, i wouldnt fly with the gear down at all, F-16 doors are like two huge speedbrakes. I have built/flown 4 f-16's and i would advise you to retract the gear, hopefully our gear has no detectable loss for at least 45 minutes, that gives you some fudge-factor (this shouud be done in the gear up position).

You should aim to land way nose-high on these little f-16's (if You got your cg right). This pic was the maiden flight of my TJ F-16 (These lil things could almost land backwards in a wind)! Good luck, and do-fly it yourself, it is rewarding! Nick

RE: Some Pre-Flight Questions..
 

Yes sir, I do have G doors. I leak about a pound every 10 minutes on my Gear and door system.

BTW right now my CG is set to 140 and it is slightly nose heavy with just the UAT full. I dont have much room at all to move things, Ill see what I can do. I dont want to have to add weight to the tailcone.

Thanks! Pete

RE: Some Pre-Flight Questions..
 

BTW, Would it be a bad thing to glue weight in the tailcone area?

Thanks! Pete

RE: Some Pre-Flight Questions..
 

Good luck Pete!

My first jet flight was a pusher F16 at the sod farm in Kingston. I miss RI. Enjoy the runway at North Central.

I think you have a lot of good advice here and while I have limited F16 advice (I fly a Kingcat, F18F and F22), what I read here was true for the original F16 I flew as well. One other thing I noticed was the sensitivity of the nose to want to pitch down a little in turns, so watch that if it occurs and ease into the turn and level the wings if necessary as stated above. May have been a CG issue too.

Have fun and say hello to Andy Argenio if you run into him,

Dave

RE: Some Pre-Flight Questions..
 

I wouldnt glue it to the actual tailcone, but probably right in front (on the actual fuselage). If the tailcone is removable,whih i am sure yours is, then under g's the weight may actually pull the cone off (depending on how much weight it is)