Cermark ZD Fly 383 (Eagle I) Electric Power Sailplane Standard & V-Tail Review - RC Groups

Cermark ZD Fly 383 (Eagle I) Electric Power Sailplane Standard & V-Tail Review

Cermark sells this electric sailplane in both a Standard and V-tail configuration. We review it both ways.



Wing Area:631.3 sq in
Weight:38.3 oz.
Servos:6 x 9 gram servos
Transmitter:JR X9303
Receiver:Spectrum AR600X
Battery:3-cell 2200 65C Genesis Power
Motor:1400Kv Brushless
ESC:30 Amp ESC
Manufacturer:ZD Fly
Available From:Cermark

Cermark distributes the ZD 383, Eagle I electric sailplane, and it is available in both a V-Tail and a Standard-tail or Conventional-tail. These are two separate kits so be sure you buy the one you want. I was impressed by the Eagle I when I got to see it fly at the Arizona Electric Festival on Friday. The power package with 1400 KV brushless motor and 30A ESC was able to quickly and easily get the plane to altitude with a 70 degree plus rate of climb with a fresh battery pack. I couldn't tell how well the plane telegraphed thermals that day as it was power on for most of that first demonstration flight. Its size is nice at 81 plus inches in wingspan (slightly more than two meters, too long for two meter competition.) Unfortunately, for me they sold out of the Eagle I at the AEF but I was able to get a couple of them at the RCX show and with help from my friend Richard Andersen we assembled them and put them through their paces for this review. We felt both models were a heck of a deal for the price. Dick flew the V-tail version and I assembled and flew the Standard tail model.

Kit Contents

Kit Contains

  • Two fully assembled 1/2 wings with aileron and flap servos installed
  • Wing carbon fiber wing rod
  • Plastic wing joiner box with screws
  • Fuselage with brushless motor, 30A ESC and two servos and control rods installed
  • Foam Tail sections (Differs between Standard and V-tail models
  • Two wing mounting bolts and two piece tool to tighten and loosen the bolts
  • Bag with clevises and hinges which were not needed
  • Pieces of Velcro like material and two sided tape
  • Little Allen wrench for control rod locks on servo arms
  • Instruction Manual

Items I supplied

  • Velcro type product to secure battery pack
  • Genesis Power 65C 3-cell 2200mAh battery Pack
  • Spektrum AR600X 6-channel 2.4GHz receiver
  • JR X9303 2.4GHz transmitter
  • 2 4mm x 3/4" screws for front of wing mount to fuselage
  • Servo reversing Y-connector harness for flaps
  • Foam-safe CA
  • Shoe Goo for securing Mike's control rods as "Keepers"



The wings and stabilizers came in thick plastic bags and inside a thick brown box so they arrived in very nice condition. Before starting assembly of my standard tail Eagle 1 I worked all of the foam hinges to help break them in and make it easier for the servos to properly move them. I moved the rudder back and forth 30 times full throw in both directions and the same with both sides of the elevator. For the ailerons I disconnected the control rod for the aileron control horn and bent the aileron back and forth 30 times on each wing half and then reconnected the control rod to the aileron horn. I did the same for the flap control surface on both wing sections but focused more on bending them down only bent them up slightly. I reconnected the control rods to the flap control horns. All of the control surfaces moved more freely after this quick break-in bending exercise.


The wing came assembled in two halves. As mentioned above flap and aileron servos were mounted in both wing sections with their wires coming out at the root of each wing half. Using colored tape I marked the aileron connectors with blue tape and the flaps with yellow tape. Y-connectors came with the kit and I marked one pair with yellow tape for the flaps and one set with blue tape for the ailerons. There is a very long wing rod that goes into a long tube in both wing sections and there is a two piece plastic wing connector box that mounts from the top and bottom sections of the wing with two circular wing mounts per wing half that fit into holes on the wing section. The top piece fit into the holes on the top of the wing perfectly. The bottom four mounts were slightly larger then the holes in the wing for them. Four screws were provided to go into the mounts on the top of the wing to be screwed into the section under the wing to join the two halves together. All four of my screws were the same size and all fit the back mounts where the foam was thinner in the wing. I found two 4mm size screws that were about 3/4 inches long that fit the front mounts of the wing joiner. The wing will later mount to the fuselage with two supplied plastic bolts going through the wing joiner box. A two part tool was supplied to tighten and loosen the bolts. I glued the metal part into the plastic handle with some Shoe Goo. To separate the wing back into two halves one only has to remove the four screws and take the wing joiner box apart. I plan to leave my wing assembled in one piece for both storage and transportation which makes for very quick assembly at the flying field. I took this opportunity to add some of the supplied decals to the wing. I added some of the supplied decals to the top and bottom of my wing for color. (My wife was startled one day when she spotted a lizard on the wing as she first thought it was a real lizard as she hadn't noticed lizard decals before.)


The fuselage came very nicely packed in plastic wrap and inside its own brown box for protection. It arrived with the motor and speed controller installed along with the folding prop and spinner. Further back in the fuselage were the installed servos for the rudder and elevator along with the control rods for the elevator and rudder and an adjustable connector for them on the servo arms for the rudder and elevator servos. I loosened the connectors on the control rods and bound my receiver to my transmitter and connected the rudder and elevator servos to the receiver and centered the servos. I carefully started to cut off portions of the control rods in front of the servo as the control rods were too long. I installed the wire with the 90 degree bend into the respective rudder and elevator control horns. I looked in the little bag of hardware for some wire keepers but there weren't any, only clevises that were not needed.

Mike's Standard Tail

The vertical and horizontal stabilizers fit together and fit into spaces on the back of the Standard tail fuselage. I used foam safe CA and fit and glued the pieces together and onto the back of the fuselage. Later I had to add more glue to one side of the elevator/fuselage bond so I made sure I had a good even coating of glue and while I pressed the parts together I had a friend spray some kicker on the spot. Now my tail and fuselage are one. A bunch of clevises were supplied with my Eagle. Unfortunately, there is no need for clevises but I could have used two control rod keepers. Both the elevator and rudder control rods had a 90 degree bend in them with the short bent portion to go through the control horns on the rudder and elevator. I did that and then put a small drop of Shoe Goo on the end of the control rod and let the glue dry. The drop of glue would serve as a keeper on the control rod in the control horn if needed. So far both control rods appear to be staying right in place in the control horns and that is with the test flying completed.

Richard's V-Tail

The V-tail comes with a fuselage designed for the Standard Tail to be fitted in the back and includes plastic mounting hardware and screws. Richard used those along with Foam safe CA to assemble the tail onto the fuselage and said it was straight forward and he just followed the instructions and did as shown in the pictures. He also got unneeded clevises and hinges but he had some keepers in his parts supply and he used on his Eagle as can be seen in the pictures. With the assembly done it was time to consider the programming options. The V-tails are connected to two servos which on the Standard Tail control the rudder and elevator. At a minimum the servos can be programmed to operate the V-tail as elevators only or mixed to work as both elevator and rudder.

Richard chose to program the V-tail as elevators only. Thus he uses the ailerons as the main turning control and the V-tail as elevator control. I borrowed Richard's Eagle I and using my transmitter programmed the tail to have a mix of elevator and rudder. This will be discussed below in the flight section.

Radio Installation

As discussed above the aileron and wing servos came installed in the wing and both the flaps and the aileron servos were installed in what I call the "aileron position." That means if connected together with a Y-harness and plugged into one channel of the receiver when one aileron goes up the other goes down. The ailerons worked exactly in that manner on both my Eagle I and Richard Andersen's V-Tail Eagle I. I tried a second Y-harness with my flaps in both the gear channel and the flap channel and they also worked as if they were ailerons with one flap going up and one down. (I had tried the Y-harness thinking one of the servos might have been a reversed servo but that was not the case with my plane.) I switched from the supplied Y-harness to a servo reversing Y-harness and then my flaps worked as designed with both going the same direction. (It was necessary to mark one of the servos wires and one of the reversed Y-harness so that they got plugged in correctly at the flying field.) The difference on the flaps between mine and Richard's Eagle was different to say the least.

Richard Andersen had just the opposite result of what I experienced. He used a supplied Y-harness and plugged his flaps into his retract channel and they both went down together. The instruction manual showed one of the flap servos as reversed and I can only guess that Dick's V-Tail had a reversed flap servo and my Standard Tail did not. However, as mentioned above, using a servo reversing harness had my flaps worked properly.


Setting The Brake on the ESC.

It was necessary to for me to program the brake to the on position in the ESC. An instruction manual for the ESC was included but to understand it I needed to read the entire instruction because: What we got here was a failure to communicate. To me Brake Off means: the propeller will not be stopped by the ESC and is free to spin in the wind even with the throttle off. To me Brake On means: the ESC will quickly slow down the propeller when the throttle is moved to off and the propeller will not spin in the wind which creates a great deal of drag. According to my definition of Brake On the ESC stops/brakes the propeller and so I just read the instructions as far as to see how to set the brake ON and I did that...multiple times and the propeller kept free spinning in the air with the throttle off. After several flights at the field and multiple attempts to set the brake at home following one beep in the brake setting mode; AS A LAST RESORT; I read all the way through the instructions on braking. I can only assume that the writer of the instructions sees this issue 180 degrees differently from me. Reading the explanation of Brake On and Brake Off they describe Brake On as the propeller being allowed to spin freely (In which case the propeller would act as a brake for the plane.). While Without Brake: "When the throttle stick is pushed to the lowest position, the ESC will stop immediately." THAT'S IT! That is what I want but they call it "WITHOUT BRAKE!"

I went back to program the ESC and at the brake setting I waited until it had beeped twice in brake mode, for "Without Brake," and selected that option. I exited programming and ran the throttle. When I lowered the throttle to off, by my terminology, the brake came on and stopped the propeller from spinning and did so very quickly. I went out to a flying site and flew my Eagle I and when I reduced the throttle to off the prop stopped spinning. I had a working electric sailplane. Let the true flight testing begin!

FYI: Richard had the same understanding about brake on and off as I did. When I called him and shared my information with him he was able to set the brake to work to stop the prop as mine was now doing. If I made this too confusing... When programming the brake to stop the prop from spinning wait for two beeps (not just one) before exiting the brake programming mode.

Center of Gravity

The instruction manual supplied a range to use for balancing the plane on the Center of Gravity. The back of this range was 3 1/5 inch behind the leading edge of the wing. What first surprised me was how far back I had to install my flight battery to balance the plane there. To be fair my Genesis Power 11.1V 2200mAh 65C battery is a bit on the heavy side for a 2200 mAh pack but still it was a surprise to see how far back the battery went to balance at the back of the recommended C/G. It was behind the cockpit under the foam in front of the wing and the front portion of the wing. I had started in the middle of the recommended range but by the second battery I was at the back of the recommend C/G and tested from there. I trimmed the sailplane so that it is at maximum glide angle with motor off. With the motor on this means the glider will climb unless I hold in down elevator. (I have since programmed a launch position for the elevator and the neutral glide position. I just toggle a control to go between the two settings.)



As stated above I initially had my Standard Tail Eagle I trimmed so I had to hold in some down elevator when the motor was operating. I have her trimmed for maximum glide and neutral elevator with the motor off. I presently have her trimmed with the C/G at 3 1/4" back from the leading edge of the wing and while I might go back another little bit with more practice I have found her nicely responsive at this C/G balance point.

Richard's V-tail is programmed by him to just serve as an elevator and he is able to control the eagle very well with the ailerons and elevator and he even gets nice circles for thermal flying. I prefer to program a V-tail to serve as elevator and rudder and believe the Eagle I is even more responsive and quicker turning with that set up than my rudder and elevator Standard Tail. Pick your preference but remember they are separate planes so you can't switch between Standard Tail and V-tail unless you buy one of each.

Taking Off and Landing

All flights start with a good firm toss straight forward into the wind or at most at a 10 degree upward angle again into the wind. I usually have the throttle between 1/2 and 3/4s on when I toss her and move it up to full throttle when I have both hands back on the transmitter. With a fully charged battery pack I build up speed in a slight climb and soon convert to a 70 degree climb up to altitude where I shut off the motor, the prop stops and folds as well. For landings I go for a three leg landing and adjust the distances of the down wind leg depending on the wind conditions and the sailplanes altitude and speed. I want the Eagle I to land at my feet facing into the wind. Using the flaps and practice this becomes possible to do. I have had no problems with launches or landings thus far with my Eagle I.

Aerobatics/Special Flight Performance

For aerobatics the Eagle I can make small to very large loops and looks great doing them. She can make aileron rolls but with the long wings these rolls are only so-so in my opinion. The special performance that I seek is the ability to quickly get to altitude and with motor off soar! When I finally had the brake so that it would stop the prop and the battery positioned so that the Eagle I was balanced properly for maximized glide with motor off I had a great flying session on a perfect Sunday morning. After the second climb of the day I saw the Eagle I's right wing lift and the glider got pushed to the left. I circled around and into where I expected there was lift and the Eagle I's tail lifted and she started climbing. I was able to core my circling around the thermal and stayed in her as she drifted to the southeast. Within a couple of minutes my Eagle I was about a block to the southeast and about a 1,000 feet high and disappearing as she went higher. I deployed flaps and put her into a slight dive and brought her back over the field with a huge smile on my face. I caught another thermal and got back up a few more hundred feet but about that time the wind started to pick up as well. I got five full climbs and some additional motor runs on the first battery pack. On the next battery pack I caught a little lift a couple of times but the thermals were drifting away to the southeast much more quickly and I wasn't staying with them nearly as well as I did the first time. I found that once I had the Eagle I in the circling pattern that I wanted she held the slant and circled pretty well with my use of rudder and some minor elevator input.

I have since had a few more flying sessions with Eagle I and find I am able to find and stay with thermals in conditions from calm to a breeze about 10 mph. Above that speed of wind I may as well just fly for fun as even if I find a thermal I have not done well staying with them. But that is OK with me because I find the plane a lot of fun to fly around the sky as I think can be seen in the videos below. I have flown her in a 20 mph plus breeze and she had plenty of power to penetrate and was very easy for me to control despite the wind.

Is This For a Beginner?

The Eagle I is a very nice and stable plane and could be a good first plane if the Beginner has an experienced pilot to work with them and check out that the plane is properly balanced. However, I would generally recommend the Eagle I as a second plane as it has a long glide when it comes time to land and beginners often try to make turns that are too sharp with their plane too close to the ground. Accordingly, I recommend that Beginners start with more of a trainer plane. I strongly recommended a large field for flying this plane to have lots of room to land until you get used to handling her although the flaps do work very well for slowing her down and landing where desired.

Flight Video/Photo Gallery




The Eagle I is capable of vertical climb with a fresh battery and thanks to the flaps with some practice can be brought in to consistently land in a small area near or at the pilot's feet. Best of all she gives tells when thermals are encountered as she will kick up her tail when flying straight into a thermal and does get pushed slightly aside when hitting the edge of a thermal. I have been able to core my Standard Tail version in several thermals and drift away from the field in the thermals while climbing. I can reflex the flaps when I am in sink and need to penetrate to get out of the sink without having to use the motor. My 3-cell 2200mAh 65C Genesis Power battery gives me at least five very strong climbs and some additional motor run time as well so I have lots of time to search for thermals. The Eagle while not really fast enough to be a Hot Liner supplies very good speed as seen in the video for some fun passes.

The only problem I have to report was the programming of the brake discussed above and hopefully no one who reads this article will have a problem with that. The fiberglass rods installed in the wing supplied the necessary stiffness for the wing to handle the high speed dives and maneuvers that I have put her through and Richard and I agree that the Plug and Play Eagle is a very good deal for the money. Take your pick, Standard or V-tail; both models assembly quickly and fly great. Available from hobby stores that carry Cermark products or directly from Cermark.

Pluses and Minuses


  • Quick and easy assembly
  • Powerful motor
  • Lots of flying time with one battery pack
  • Glides and thermals well when properly balanced


  • Limited cooling in the fuselage if motor run for extended periods
  • Fuselage belly should be taped if landing in rough landing zone
  • Would have preferred control rod keepers over the supplied clevises
  • Richard's flaps worked with a Y-harness, mine required a reversing Y-harness
Last edited by Angela H; Jul 10, 2012 at 10:10 AM..
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Jul 10, 2012, 01:55 PM
Registered User
Wingman26's Avatar
How about posting the video on YouTube? Its a lot better to watch a streaming video rather than waiting for a complete video to download before you can watch it.
Jul 10, 2012, 02:55 PM
Suspended Account
Thanks for the review, and the video! Another one to drool over.
Jul 10, 2012, 02:58 PM
RC Nut
OldeWolfe's Avatar

Some things to mention about the Eagle I glider

I've had two of these planes and plan on getting a third because they fly so well.

My first was destroyed when the elevator servo failed in flight. The plane was unrepairable. I replaced the elevator, rudder and aileron servos on the second plane due to two servos failing just during testing prior to flying. Replaced with HTX900s.

Motor cooling:
Driving the 10x8 folding prop with the NeoDym 450 1400kv creates a lot of heat. There is no provision for motor cooling on this plane and I burned out the motor on the second plane when flying on a warm day. I ended up replacing the motor with a NeoDym 450 1100kv and cutting cooling vents in the nose cowl. (it's thin plastic and easy to mod.

Battery/Esc cooling:
Again there is no provision for cooling here. It's easy to cut an air scoop in the front of the canopy with an exhaust hole in the back of it.

Both of my aircraft were an older version than those reviewed here. There was no wing joiner or V-tail version provided.

The plane flies extremely well and is quite stable even in strong winds. Thermalling is easy keeping the wings level and using rudder turns.
It has plenty of extra lift for installing a camera. I made a mount at the top of the vertical stab for a 30 gram HD video camera and was able to just move the battery forward to achieve CG.

Overall a great flying airplane. Adding the mods to increase reliability will ensure many hours of enjoyment.

Oh, my second plane was lost after a mid-air with my flying buddy sheared the tail clean off.

Mid-air at 7:00. Nice landing between the berms at the end. (8 min 36 sec)

Mid-air at 7:00

Jul 10, 2012, 03:58 PM
flycracker's Avatar

Cermark Eagle II

Originally Posted by porcia83
Thanks for the review, and the video! Another one to drool over.
Instead of a reversible Y harness could one just reverse one servo so they are not mirrored, but both facing same way? That is how my other plane is set up for the flaps.
Jul 10, 2012, 05:26 PM
Registered User
Michael Heer's Avatar
Yes the direction of one of the flap servos could have been reversed instead of using the reverse harness. However I already had the harness and it was easier to install it.
Jul 10, 2012, 05:49 PM
flycracker's Avatar


Originally Posted by Michael Heer
Yes the direction of one of the flap servos could have been reversed instead of using the reverse harness. However I already had the harness and it was easier to install it.
Thanks Mike. Re:flaps.
Back in the day I would have my flaps set to 75 to 85 degrees to really plant my sailplane where I wanted. What degree are the flaps on this plane capable of?
Jul 10, 2012, 09:07 PM
JimNM's Avatar
Do you have a rate of climb measured? Around 1200 feet per minute would make this a good candidate for altitude limited electric soaring ALES.
Jul 11, 2012, 12:43 AM
Registered User
atckirk's Avatar
Originally Posted by OldeWolfe
I've had two of these planes and plan on getting a third because they fly so well.

The plane flies extremely well and is quite stable even in strong winds. Thermalling is easy keeping the wings level and using rudder turns.
It has plenty of extra lift for installing a camera. I made a mount at the top of the vertical stab for a 30 gram HD video camera and was able to just move the battery forward to achieve CG.

Overall a great flying airplane. Adding the mods to increase reliability will ensure many hours of enjoyment.

Hey Ted do you work in the business park? I used to live on the NE side of that ridge. I used to fly a lot of fpv out of one of the vacant buildings parking lots across from GEICO a little west of the water tank up on the hill. Looked like a Santa Ana day-strong winds indeed!

Jul 11, 2012, 05:45 PM
RC Nut
OldeWolfe's Avatar
Originally Posted by atckirk
Hey Ted do you work in the business park? I used to live on the NE side of that ridge. I used to fly a lot of fpv out of one of the vacant buildings parking lots across from GEICO a little west of the water tank up on the hill. Looked like a Santa Ana day-strong winds indeed!

Yes! I work in the building just west of that ridge. We have 'Flyday Fridays' and climb to the top during an extended lunch to fly all kinds of aircraft. The Eagle I glider was what I would fly the most since it handled so well. Definately getting a third.

Hey, somewhere in that ravine below is an HD wing camera from Hobby King with what should be some awsome footage of that midair from my plane's perspective.
Jul 11, 2012, 05:53 PM
flycracker's Avatar


I have tried email, phone with no answer on phone or email. Phone just keeps ringing.
Afraid of that.Dontt want to use web site. Want to be told they are in stock and available to ship.
Last edited by flycracker; Jul 11, 2012 at 06:00 PM.
Jul 12, 2012, 06:26 PM
Registered User
Michael Heer's Avatar
Dick's Flaps are close to 60 degrees of movement +/-. I have mine at 40 degrees down, neutral or about four degrees up for penetration.
Jul 15, 2012, 02:34 PM
i12flyrc's Avatar
I had the same issue with my prop spinning whenever the motor was off. Darn props wouldn't fold. Thanks to your review I programmed the brake "off" like you said and that did the trick.

I also did the same thing with longer screws for the main wing assembly.

Your review is spot on.

Thanks again.
Last edited by i12flyrc; Jul 16, 2012 at 07:32 PM.
Jul 16, 2012, 03:27 PM
Registered User

Removable tail?

Any idea if either the horizontal on the standard tail or the complete v-tail could made removable? My primary mode of transport requires removable tails.
Jul 16, 2012, 07:30 PM
Registered User
ForeverFlying's Avatar


Do you have any idea what airfoil is on it?

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