Official Freewing Twin 80mm F-14D Tomcat Thread

[Gvasiloff]

Gvasiloff Greg, thanks for explaining it further. I was having a hard time visualizing the dynamics involved of full span flaps, the lift and drag induced by them, combined with tailerons and the rudder mix. I understand and use rudder for coordinated turns and have noticed that my different planes require different amounts of rudder input to initiate the turn. With your response the light came on, I think. I apologize for walking my mind through the parts and pieces, taking ip space on this thread, but it's helping me grasp it better.
So, the flaps are just reshaping the wing, lift and drag, it doesn't upset anything, it's still just a wing. And slow deployment minimizes the effect on attitude. The taileron part maybe had me confused and thinking that the effect was the turn is being skidded, coming from the rear of the plane, and maybe blocking air flow over the inboard wing and maybe giving it an odd angle of attack. But that would only be occurring by holding rudder through the turn. And to repeat what you said, because now it's more clear to me, the rudder input happens with the initiation of bank angle. You aren't holding taileron through the turn so you're not holding rudder. That is the piece I was not seeing correctly. And rudder mix/input being 15%, minimal and what you found to be appropriate.
I guess I was overthinking it and not able to visualize the effect. Like I said, I haven't used full span flaps yet. I'd like to but really want to understand the dynamics beforehand. I'd like to use spoilerons too but just like the full flaps, I'm hesitant until I fully grasp what they will do to the attitude and flight characteristics. I hope I didn't come off as challenging, but inquiring. I'm not afraid to learn or sound dumb while I am. I really just want to understand so that I can comfortably start using full flaps, flaperons, spoilerons, tailerons on EDFs. And programming mixes.

Also, thanks for your service! I don't say that flippantly, it's full respect. I grew up as a navy brat and watched many E-2s, and all of the now retired jets, fly overhead at various bases. The first time I lived off base was when I went to college. I really want Flightline to make an E-2. I would love to have one! My brother was a career P3 pilot and retired a few years ago but still teaches in the sim. We talk a little about aeronautics and planes but he always wants to talk about anything else.
Thanks for taking the time to answer my neophyte questions!

Sure thing. I would say, don't overthink it. Just try the full span flaps. It flies just fine that way. Just do it up high first and then try some apporaches.
Also, I would love to see a Flightline E-2 as well!

[rifleman_btx]

Oh yeah after setting up with shutting off ailerons in sweep really makes it feel better in sweep. I also just ordered the components to setup an fpv canopy. Got the two gimbles in today, camera and transmitter is on the way. Also have the new canopy coming to install everything on to.

[SanExup]

kallend Thank you for that as well!

[SanExup]

Gvasiloff Greg, thanks for explaining it further. I was having a hard time visualizing the dynamics involved of full span flaps, the lift and drag induced by them, combined with tailerons and the rudder mix. I understand and use rudder for coordinated turns and have noticed that my different planes require different amounts of rudder input to initiate the turn. With your response the light came on, I think. I apologize for walking my mind through the parts and pieces, taking ip space on this thread, but it's helping me grasp it better.
So, the flaps are just reshaping the wing, lift and drag, it doesn't upset anything, it's still just a wing. And slow deployment minimizes the effect on attitude. The taileron part maybe had me confused and thinking that the effect was the turn is being skidded, coming from the rear of the plane, and maybe blocking air flow over the inboard wing and maybe giving it an odd angle of attack. But that would only be occurring by holding rudder through the turn. And to repeat what you said, because now it's more clear to me, the rudder input happens with the initiation of bank angle. You aren't holding taileron through the turn so you're not holding rudder. That is the piece I was not seeing correctly. And rudder mix/input being 15%, minimal and what you found to be appropriate.
I guess I was overthinking it and not able to visualize the effect. Like I said, I haven't used full span flaps yet. I'd like to but really want to understand the dynamics beforehand. I'd like to use spoilerons too but just like the full flaps, I'm hesitant until I fully grasp what they will do to the attitude and flight characteristics. I hope I didn't come off as challenging, but inquiring. I'm not afraid to learn or sound dumb while I am. I really just want to understand so that I can comfortably start using full flaps, flaperons, spoilerons, tailerons on EDFs. And programming mixes.

Also, thanks for your service! I don't say that flippantly, it's full respect. I grew up as a navy brat and watched many E-2s, and all of the now retired jets, fly overhead at various bases. The first time I lived off base was when I went to college. I really want Flightline to make an E-2. I would love to have one! My brother was a career P3 pilot and retired a few years ago but still teaches in the sim. We talk a little about aeronautics and planes but he always wants to talk about anything else.
Thanks for taking the time to answer my neophyte questions!

[kallend]

There isn't a general rule about needing rudder in turns. It all depends on the aircraft type and details of its control geometry. A typical high performance sailplane generally needs a lot of rudder in turns to counter adverse yaw from the ailerons, and a "yaw string" is often placed on the outside of the canopy in the pilot's line of sight to assist in getting the right amount. My (full size) Mooney has a compliant interconnect between the ailerons and rudder that almost counteracts the adverse yaw so only a little bit of rudder input is needed from me. I once had an R/C SE5a that would not turn at all with ailerons alone, it needed a load of rudder to make it turn.

Aileron differential can counter adverse yaw quite effectively (except it has the wrong effect when flying inverted). Flaperons are likely to increase adverse yaw so more rudder is needed. Spoilerons, on the other hand . . . . etc.

I find a little bit of AIL -> RUD mix helps some of my EDF jets when the flaps are down - reduces the workload on final approach. Again, it's counter-productive when flying inverted.

[Gvasiloff]

I guess I have assumed that holding rudder with bank will create a skidded turn and potentially stall the inside wing. And wouldn't full span flaps exacerbate that by creating more drag? I'm wondering what effect tailerons only has on creating or relieving adverse yaw? I thought with coordinated turns that you use rudder to initiate the turn but are looking to neutralize it once in the turn. I'm not claiming to know but simply trying to understand. I have yet to use full span flaps on any of my planes yet. Or mix in rudder control for coordinated turns. Again, I'm just trying to understand, to avoid the turn, stall, spin maneuver.

No, you are not "holding" rudder in with the turn. You only get a tiny bit of rudder when rolling into and out of the turn when you apply left/right stick. You are correct in the second part of your paragraph there. The rudders are neutral once in the turn with the mix. 15% is a tiny amount. I noticed without the mix, the plane tends to adversely yaw in the opposite direction when rolled with full span flaps. This mix fixed it. You can watch how mine flies on my youtube channel. Just search "Greg Hoff." It's painted up as the VX-9 Black Bunny bird. I got this idea from watching the flight controls on the real jets. I watch F-18s and F-35s come aboard ship on a daily basis. They all have rudder mixed in with their aileron/taileron control via a flight control computer to make less work for the pilots. Also I fly the E-2 Hawkeye for a living. It requires a lot of rudder turning in and out of turns, but it's all manual. Just got back from a sortie a few hours ago and I'm writing this from the ship as a matter of fact...

[xviper]

The 3 - 4 second flap deployment as already mentioned does help smooth the plane’s attitude change. I first started to do that but for some reason, it was too slow and created a glitch in the deployment - too choppy. I reduced the time to 2 seconds but that causes a somewhat abrupt reaction, making a bigger elevator compensation more necessary.

[SanExup]

I guess I have assumed that holding rudder with bank will create a skidded turn and potentially stall the inside wing. And wouldn't full span flaps exacerbate that by creating more drag? I'm wondering what effect tailerons only has on creating or relieving adverse yaw? I thought with coordinated turns that you use rudder to initiate the turn but are looking to neutralize it once in the turn. I'm not claiming to know but simply trying to understand. I have yet to use full span flaps on any of my planes yet. Or mix in rudder control for coordinated turns. Again, I'm just trying to understand, to avoid the turn, stall, spin maneuver.

[rifleman_btx]

My initial expectation was for it to "float" when flaps came down. I was quite surprised when it took a dive. Both my batteries are as far back as they can go and I believe the plane is balanced as per the book.
I just checked my TX. On full flaps, I've got 20% elevator UP compensation. In contrast, my OV-10 has 18% DOWN elevator comp.

Indeed, I can say that I do things when I fly I'm not even aware I am doing for correction when I fly. So I may be totally off base with my assumption of floating as I may be subconsciously adding up elevator without even thinking I'm moving anything. I don't know, but I'll find out tomorrow when I take her out again.

[Gvasiloff]

Gvasiloff Is your rudder mix the same direction as your flaperon input or opposite?

I reread your post and I guess you're using fullspan flaps as just flaps and tailerons for bank? So is your rudder mix yawning in the same direction as the tailerons or opposing?

Yes, the rudder is in the same direction as the turn. It helps the nose track around the turn and keeps the banking more coordinated with the flaps down. Another tip is to make them deploy over 3-4 seconds vice instantly. That gives your elevator mix time to cancel it out. If you do it with the aircraft nice and slow, the transition should be seamless and the nose shouldn't dive like others have stated bellow. It may take a few flights to get the amount of elevator trim just right. The way I do it, is I make my flap positions different flight modes and manually trim the elevator in flight to where I want it with the different flap settings. After I land, I go to the servo page of the transmitter and right down the position of the elevator servos at each flight mode and then zero them out. Then, I dial in elevator to flap mixes for each flap position until the servo position matches what i had written down from the trim positions of each flight mode.

[xviper]

My initial expectation was for it to "float" when flaps came down. I was quite surprised when it took a dive. Both my batteries are as far back as they can go and I believe the plane is balanced as per the book.
I just checked my TX. On full flaps, I've got 20% elevator UP compensation. In contrast, my OV-10 has 18% DOWN elevator comp.

[rifleman_btx]

My seems to float when I use my flaps, I'm not sure what I have different but it really doesn't seem to sink. As per my video I posted.

[xviper]

Unlike many of my planes that "balloon" when flaps are deployed, this F-14 nose dives like a whale going deep. It has some of the most severe UP elevator compensation that I've seen on any of my planes. I also use full span flaps and on "full" flap deployment, the nose dive is very pronounced. Elevator compensation is quite astonishing and I was worried I might run out of elevator for pitch control when landing, but there is plenty left for the job. I don't hit full flaps till I'm on final. I keep some throttle as it descends and my last few landings were very greasy. I've also noticed that rudder input seems to augment the roll. Right rudder, right roll. I try not to use too much rudder when near the ground at landing. This can can cause a severe roll and cause a wingtip to drop suddenly. I lower gear and go 1/2 flaps on the downwind, then turn for final. Best is to get it lined up with the runway long before getting close to the threshold, hit full flaps on the straight and true, keep adequate throttle all the way to about 5 feet off the deck. If it goes crooked, lift flaps, go around and try again. Using rudder to straighten out is still too dangerous for me.
PS. I may have mentioned this before. My ailerons only go UP on the side that's needed and only a few mm (less than 5mm), even when fullspan flaps are deployed.

[SanExup]

Gvasiloff Is your rudder mix the same direction as your flaperon input or opposite?

I reread your post and I guess you're using fullspan flaps as just flaps and tailerons for bank? So is your rudder mix yawning in the same direction as the tailerons or opposing?

[Gvasiloff]

The forecast finally was OK yesterday so I took it out to maiden it but by the time I got to the field the vis. had dropped to 1/2 mile and the ceiling to 600ft and it was starting to drizzle, so I just flew my trusty old (Dynam) Meteor instead and came home.

Questions for those who have disabled the ailerons when the wings are swept - what did you do with the aileron rates? Also is it worth implementing full span flaps?

Full-span flaps definitely slow this jet down even more and look more scale, but it is a double edged sword. It does make the jet more prone to tip-stalling if you let the angle of attack creep up or try to flare too much, especially with a crosswind. I've found that making the aircraft roll with tailerons only and about 15% rudder mix with full span flaps down controls it nicely in the landing configuration and reduces the tendency of tip stall. She also needs a lot more power in the turns due to the extra drag and a lot of extra up elevator mix with the full span flaps, so keep that in mind. I have an "emergency" normal flap mix on a separate switch that I can use to go back to normal inboard flaps only if the crosswinds pick up while flying. She is much more forgiving in that configuration, but she comes in a lot hotter. Watch how Rich Baker (RCInfromer) and the RC Geek land this jet in their youtube videos. It's not a nose-high approach, but rather a flatter almost nose-down attitude with power off. Almost like landing a trainer. Feeding in a little power at the flare to help cushion the landing is a good thing and also helps reduce the tip stall tendency.

[kallend]

Looks like my maiden is going to have to wait for spring. 6" of snow today, and freezing temperatures all next week, then off to Costa Rica for 5 weeks.

At least the long delay has given me plenty of time to program the radio (iX20 + AR10360T) and make ordnance and "afterburners".

[Evan D]

Agree with disabling ailerons when swept and I kept normal flaps. I tried full span and liked the feel of the normal ones better.

[kallend]

Most of the guys flying the tomcat are locking out the ailerons during swept wing flight. About 60% rate on roll and 100% pitch for swept. On mine that gives a pretty decent roll rate and not too sensitive. Make sure you leave full pitch travel as it tucks the nose in a steep turn with the wings swept. As far as the full span flaps, They look cool but you lose quite a bit of roll authority on the approach and there is quite a lot of nose down pitch moment with the ailerons drooped as flaps. I personally had some pretty heinous landings in that configuration. Its much more predictable and docile with the factory flap configuration. Probably the best upgrade I did was replacing the stab servos with hitec d 85's and 440 hardware. Much more positive feel. It's fine in the meantime stock.
You will love this plane! It's like your own personal airshow.

Thanks. Good to know.

[pullupnow]

have fun

[pullupnow]

The forecast finally was OK yesterday so I took it out to maiden it but by the time I got to the field the vis. had dropped to 1/2 mile and the ceiling to 600ft and it was starting to drizzle, so I just flew my trusty old (Dynam) Meteor instead and came home.

Questions for those who have disabled the ailerons when the wings are swept - what did you do with the aileron rates? Also is it worth implementing full span flaps?

Most of the guys flying the tomcat are locking out the ailerons during swept wing flight. About 60% rate on roll and 100% pitch for swept. On mine that gives a pretty decent roll rate and not too sensitive. Make sure you leave full pitch travel as it tucks the nose in a steep turn with the wings swept. As far as the full span flaps, They look cool but you lose quite a bit of roll authority on the approach and there is quite a lot of nose down pitch moment with the ailerons drooped as flaps. I personally had some pretty heinous landings in that configuration. Its much more predictable and docile with the factory flap configuration. Probably the best upgrade I did was replacing the stab servos with hitec d 85's and 440 hardware. Much more positive feel. It's fine in the meantime stock.
You will love this plane! It's like your own personal airshow.