Cox Models Extra 300 EP 2.4GHz RTF RC Electric 20" Aerobat Review

The new Cox Models Extra 300 EP is really ready to fly in a matter of minutes and has some great new features.



Wing Area:62.4 sq in
Weight:3.35 oz.
Wing Loading:7.7 oz/ft2
Transmitter:4 channel 2.4GHz with dual rates
Receiver:4 channel 2.4GHz
Battery:2S 7.4V 250mAh LiPo
ESC:Not identified
Available From:Fine Hobby Stores Everywhere

My first flying plane was a Cox control line Stuka, and no plane will ever equal that one for the excitement and fantasy that it generated within me when I was a ten year old boy. More recently, I had one of the little Cox micro RC fighter planes and had some interesting flights with my rudder, elevator and throttle controlled micro Corsair. Since then, micro planes have come a long way, and this new Cox Extra 300 features four channels, a 250 mAh 2-cell LiPo, a 2.4GHz radio and some interesting safety features. I love to review planes where they make clear and bold promotional claims as they have with the Extra 300. It gives me something specific to test and discuss in the review so I will cover those points right off the bat under the heading of "Special Features." FYI: By my calculations this model is 1/14.55 the size of the full size plane with one inch equal to 14.55 inches on the full size Extra 300.

The Full Size Extra

The Extra 300 has been built in at least nine variants thus far including both one and two seat versions. The name comes from the designer, Walter Extra. The 300 has a welded steel tube fuselage and is covered in aluminum and fabric. The wing has a carbon fiber composite spar with carbon composite skins. The wing is symmetrical and mounted with a zero angle of incidence providing equal performance whether right side up or upside down. The design is an outgrowth of Mr. Extra's 280 that had a wooden wing.

Kit Contents

The Cox Extra 300 Comes Complete:

  • Fuselage with radio, motor, servos and ESC installed
  • One piece wing with aileron servo installed
  • Lipo 2-cell 250mAh flight battery
  • Battery charger for flight battery
  • Two propellers and spinners
  • Four channel transmitter with high and Low rates
  • Main landing gear
  • 4 AA Alkaline batteries
  • Instructional Manual

Special Features

Ready to Fly in Five Minutes

I tested this claim when the plane arrived. However, I first took my pictures of the parts as they arrived. I then put them back in the foam tray that came inside the box. I started a timer, and the challenge began. I grabbed the wall power unit and the charger that it powers. I grabbed the bag the battery pack came in and ripped it open with my teeth. I plugged in the battery to the charger and the power converter into a wall socket. By immediately putting the flight battery on the wall charger to start the charging process I would have several minutes more charge then the battery pack had when it arrived. I installed the wing to the fuselage. The servo controlling the ailerons connected to a wire from the receiver. There was a clear plastic piece at the back of the wing that fit into the fuselage and served as a securing tab for the back of the wing. The front was secured using one screw (they supplied two) and the supplied screwdriver. The landing gear quickly plugged into the bottom of the fuselage. Next I plugged one of the propellers and spinner onto the fuselage. It snapped into place. The package included a spare prop, spinner and both sides of the connecting snap. Then I added the four batteries supplied to the transmitter. I broke them out of their wrapping with a single twist. The battery cover slid off of the transmitter, and the batteries went into place as the timer showed I had a minute and a half left. I pulled the flight pack out of the charger and went to remove the battery cover on the bottom of the fuselage. I wasted 40 seconds figuring out how it came off, but it was simple once I did it the first time. It took me 30 seconds more to get the battery pack wire out of the plane and plug the battery into it, get the battery into the fuselage and the cover back on. I checked out the controls as I walked out of the house, and the timer went off as I stepped outside ready to fly. I made a short flight of a couple circles in the street and landed before any traffic came by. I was able to meet the five minute challenge. That said, if you are a newer pilot especially, I encourage you not to rush! I am seldom able to build anything as quickly as they say it can bebuilt. That fact made my success in this challenge surprising even to me.

Fly Alone or With Friends

Here they are promoting the radio system on 2.4GHz which lets you fly by yourself or with a bunch of friends without radio interference or frequency conflict. Additionally, the dual rates lets the beginner fly more smoothly on low rates as beginners tend to overcorrect and overcontrol, and low rates make the plane a little less responsive which is generally better for the beginner. With some experience, you can go to high rates and really wring out this little four channel plane.


The extra 300 is built with FlightFlex Foam that bends when you crash more often than breaking. The picture on their website pretty much tells the tale. While I don't recommend intentionally crashing your plane mine, was crashed by some new pilots and myself (I flew her out of range) in the course of this review. The crashes were to grass and hard dirt, and so far the extra has survived these incidents without damage.

SafeProp Protection

Most planes have their props broken on nose in crashes. Admittedly, this is less so with smaller lighter planes, but Cox has taken this a step further. Their safe prop is very flexible and is designed to pop off in the event of a crash to protect itself and the plane. This claim has also been flight tested in the course of this review by my beginning pilot friends. The system works well, but they did supply a spare prop and spinner ... probably just in case the dog eats it. (Seriously, our cat loves to bite propellers on my planes.)

Cox passed my tests with all four promoted features passing my examination.


The assembly of the plane was covered above in the Ready to Fly in Five minutes Section.

The Transmitter

This is an identical transmitter to the one that came with the Proto Max helicopter I reviewed last year. The transmitter surprised me with all it could do. The transmitter was identified as broadcasting on 2.4GHz. Beyond that, no specific information on the method of broadcasting was supplied. I flew my Proto Max helicopter with several other aircraft on other companies’ 2.4GHz, and none of us experienced any conflicts. There were a maximum of about ten 2.4GHz aircraft/transmitters on during that test. The transmitter arrived in Mode 2 setting which is the most popular mode here in the US. The mode of the transmitter is posted on the screen of the transmitter when it is turned on. The transmitter can be converted to Mode 1, and the process is described in the instruction manual. It is a simple process that involves removing and reinstalling the antenna. FYI: The proper antenna position is the vertical position per the manual, and that worked well in operation with the Proto Max and with the Extra 300

The transmitter is a 4 channel transmitter, and in Mode 2 the left stick controls the throttle and the rudder. The right stick controls the elevator and the ailerons. There are trim tab buttons for both sticks, and their positions can be viewed on the transmitter monitor by where the trim tab bars are positioned on the screen. The trim tabs allow for small directional corrections that let me adjust the controls for neutral stick straight flight of the Extra 300.

The transmitter has both a beginner and advanced settings. These are dual rates: The low rate is the beginner setting and the high rate is the advanced setting. There is a circle split in half in the center of the monitor. When in the advanced setting, both sides of the circle are dark. When in beginner mode, only the left side of the circle is dark, and the right half is empty. Pushing the right stick straight down allowed me to go from beginner to advanced position and back to beginner. By looking at the circle on the monitor screen I knew instantly what rate was turned on at the time.

Range Test

Flying in Northern CA, I would say that I never had the plane more than 120 yards away from me at any time and I experienced no range problems with the Extra. At the Arizona Electric Festival I got a little carried away in the big desert setting, and I flew out of range. My calculation was that I lost control at about 180 yards away from the transmitter. The motor turned off and she dropped pretty much straight down. No long glide with motor off on this experience. Later I flew her ay a park and had control all around the football field while I stood in a corner of the end zone. Stay with 100 yards and you should have no trouble.

Binding the Extra 300 to the Transmitter

On the transmitter screen there are three large number spaces in the middle of the screen under the circle discussed above. To bind the Extra 300 to the transmitter they instruct that the transmitter needs to be turned on with the throttle stick all the way down and the trim tab centered. The three numbers on the monitor are the throttle position indicator, and they should read 000. With the transmitter properly set up, turn it off. Connect the now charged LiPo battery into the battery holder under the plane. Leave the plane sitting on its wheels. There will be a blinking red light inside the plane. Turn on the transmitter. In a few seconds the transmitter and plane should bind and the red light should go from flashing to solidly lit. The Extra 300 and the transmitter are now bound.


The included wall power adaptor and charger allows for charging the battery pack at home. If you have a 12 volt plug that matches the charger you can use the charger at the field but a 12 volt power plug was not included in the kit.



This is a 4 channel micro plane with ailerons, rudder, elevator and throttle. She can be flown slowly by those with will power and fast by the rest of us. She is a nice little aerobatic plane, and she is a lot of fun at the local park or school ground. The transmitter works very well, and the less experienced pilots will appreciate the low rate setting when they first start to fly her and the more experienced pilots will enjoy the high rate setting. The speed range was really a surprise to me. While she can be flown relatively slowly, she has surprising speed when given full throttle. I found I could fly her in a double wide gym but for indoor flying she is pretty fast even with will power and controlling the throttle. The bigger the indoor site the better. I like flying her outdoors better.

Taking Off and Landing

She does nice takeoffs from concrete and other hard surfaces, including a groomed baseball infield. When those aren't around, she can be launched with a simple hand toss. Landings on hard surfaces can be done very scalelike, and when done well, she looks very nice. Landings onto a groomed baseball infield almost always end up as crashes since the loose dirt stops the wheels so quickly she will often nose over causing the safeprop to pop off. These "crash" landings have done no damage to the plane. On grass I have been unable to take off so I hand toss or take off from the sidewalk at the park. On grass landings she comes to an instant stop; normally with a nose over by the Extra 300 at the end. Flying to and from a concrete surface has given me my best results.

Aerobatics/Special Flight Performance

WOW! On my second flight at the park I was shocked by how fast the Extra 300 can fly. I should have realized that with its two cell LiPo it would have a lot more speed then the one cell powered micros I have been flying but I didn't think about that until after the flight was underway. She is also very responsive with the transmitter set for high rate on the controls. I started doing full throttle ovals as if I was pylon racing, and an idea was born within me. Extra 300 racing! They can be raced in a small space. Fast for their size and with the flex foam and SafeProps they should be very durable. The cost would also be very reasonable as well when compared with some of the other racing options available. Guys would just need to make different color schemes to tell their planes apart.

Is This For a Beginner?

NO! When first reading about the plane I was thinking I would probably be approving this plane for beginners. It includes everything the pilot needs with nothing else to buy. The transmitter works very well with nicely functioning trim tabs and dual rates that turn on at low rate when the transmitter is turned on and that is best for the beginner. The SafeProp really does pop off in a crash and the FlightFlex foam can withstand a lot of abuse and keep on functioning. The plane can fly at a relatively slow throttle setting allowing time to respond. For all those reasons I though I would be recommending this plane for a beginner.

However, the Extra 300 goes where directed with no independent recovery to stable flight if the pilot goes hands off. Her directional movements are very quick and even on low rates may be too quick for many beginners. At full throttle she is too fast for most beginners.

I would recommend the Extra 300 as a second or third plane to most beginner pilots but for those with lots of game/flight simulator experience that have the confidence they can fly her I wouldn't say no because she has proven to me she can handle some abuse. After making my decision I went to the Cox promotional material and found the following: "It's the easy way to move up from a trainer — and a great way to start enjoying aerobatics." I independently came to the same conclusion after much thought.

Flight Video/Photo Gallery



The Cox Extra 300 lived up to all of the advertised capabilities, and that was a great beginning with me. As an experienced pilot I found her to be very fun to fly. Some of the guys who saw me fly her in Arizona stated that she looked bigger in the air than on the ground. While in range, she controlled very nicely. The plane's prop has never come off without first striking something, and I have no complaints that the prop pops off when hitting grass on landing. She looks good in the air and handles aerobatics nicely. Her speed and power allow her to be smooth in aerobatics when being flown by a good pilot. Her looks and speed have turned a few heads, and I have tested the Flexfoam more than I care to admit without any problems; All of that and she easily stores in her box when not in use. It's a very nice plane that I will fly more outdoors than indoors.


  • Nice little 2.4GHz radio system
  • Quick assembly
  • Easy to store and transport in original box.
  • Has good four channel control.
  • FlightFlex foam and SafeProp have been durable during this review.
  • Fun to fly


  • Only comes in one color scheme
Last edited by Angela H; Feb 22, 2011 at 11:03 AM..
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Feb 22, 2011, 01:16 PM
Registered User
mexico's Avatar
Is it just me or does the LE of the wing make it look like an Edge?
Feb 22, 2011, 07:10 PM
Registered User
jimjim06's Avatar

Nice review!

I have the Nine Eagles Xtra 300 (its the same plane), and agree fully to your review, good one!

Flew it as my first out doors 4 channel micro, and maiden was on a windy day, where I found the low rates way too low, an instant swap to High rates saved the day.

Had some hard landings and soft crashes, the only thing broken so far is 1 propsaver, the piece on the prop, and one power lead came loose from the motor.

Loved mine from day one and looking forward to the smaller NE 4-Ch birds, the YAK 54 and P47.

Regards/ Tommy
Feb 23, 2011, 12:02 PM
Registered User
rpstar's Avatar
Wing cube loading is 11.7 which seems too high for 3d. The video seems to confirm this. I'm building a shrunken copy of the 3dhobbyshop extra that will have a wing cube loading about the same as this one has and think I need to enlarge it slightly based on the way this one flies. Good review though. Thanks very much.
Feb 23, 2011, 05:15 PM
Registered User
This is a neat looking plane. It's just a shame the manufacturers can't somehow standardize. This is one of many I would consider if they were compatible with my transmitters. I fell into the horizon camp when I started this last fall and have a dx6i and dx7 and consider my transmitters the most valuable part of my collection thus far. They are so much above the little rtf transmitters. I suppose you can change out the receiver, but then you have extra expense and hope that all the plugs will be compatible, so I and many others I'm sure just take the easy out and wait for the next newest neat toy from Horizon.
Feb 23, 2011, 09:55 PM
Fighting Gravity
elgecko's Avatar
Thanks for the great review and video.

I originally wanted this plane from Nine Eagles when I first saw it. Then I saw they came out with a Yak 54 which I want more.
I'm hoping the Yak will be picked up by Cox and have the good review as the 300 received.
Feb 24, 2011, 07:37 AM
Registered User


Nice review Michael, always like to read yours. I got one of the Cox 300's recently and am also impressed with it's performance. Even in a 10mph wind it does very well, though I finally did lose a prop in mid-flight somehow...maybe the snap-on part had weakened after having popped off a dozen times or so landing in grass! I'm also using 350mah batts. from Hobbypartz, balance is still in OK limits but had to cut out some foam to fit. I toss-launch in grass and just leave off the gear. Really neat plane.
Feb 26, 2011, 07:43 PM
Registered User
Cheese5's Avatar
Nice review! Is the motor brushed or brushless? How does this compare to the sukhoi xp?
Feb 28, 2011, 08:39 AM
Registered User
jimjim06's Avatar
Originally Posted by Cheese5
Nice review! Is the motor brushed or brushless? How does this compare to the sukhoi xp?
Brushed and bigger, about 3 times heavier.
But if you could read youŽd already know that.

Cox is an old American brand, reduced to sell rebranded Chinese stuff. You can get The exact same plane (apart from the stickers) at half price if you buy the "Nine Eagles brand" from Hobby King, but hey, Cox needs money too.

Anyone buying "Not Made In China" products These days? I know I have a hard time avoiding Chinese offerings...
Everything here seems to be, not "Not Made In China"

American design, yeah right, just American retailers rebranding Chinese products, "if you canŽt beat them, let them take over"

Last edited by jimjim06; Feb 28, 2011 at 08:52 AM.
Feb 28, 2011, 04:54 PM
J. Titors gr8 grandson...
Sonofagun's Avatar
.The airplane can give you the pleasure which only exists in the flight of fighter planes.
Feb 28, 2011, 07:07 PM
Sopwith Camel's Cousin
Originally Posted by jimjim06
... You can get The exact same plane (apart from the stickers) at half price if you buy the "Nine Eagles brand" from Hobby King, but hey, Cox needs money too.
One thing about large items like planes. If you live in the US, that price differential gets reduced after you add shipping. Shipping from Hong Kong is a lot more expensive than within the US.
Feb 28, 2011, 08:23 PM
Registered User
Cheese5's Avatar
Originally Posted by jimjim06
Brushed and bigger, about 3 times heavier.
But if you could read youŽd already know that.

Cox is an old American brand, reduced to sell rebranded Chinese stuff. You can get The exact same plane (apart from the stickers) at half price if you buy the "Nine Eagles brand" from Hobby King, but hey, Cox needs money too.

Anyone buying "Not Made In China" products These days? I know I have a hard time avoiding Chinese offerings...
Everything here seems to be, not "Not Made In China"

American design, yeah right, just American retailers rebranding Chinese products, "if you canŽt beat them, let them take over"

Ah, no brushless, I'll stick with my sukhoi xp for now.
Feb 28, 2011, 09:32 PM
Registered User
Jimjim....The Airfoilz line of depron planes are produced in Middlesex N.J. and are designed in Bridgewater N.J. so there are some american made planes out there...
Mar 01, 2011, 06:43 PM
Originally Posted by jimjim06
Brushed and bigger, about 3 times heavier.
But if you could read youŽd already know that.

Cox is an old American brand, reduced to sell rebranded Chinese stuff. You can get The exact same plane (apart from the stickers) at half price if you buy the "Nine Eagles brand" from Hobby King, but hey, Cox needs money too.

But actually Tower hobbies sells the Cox Extra-300 RTF $27 cheaper than HobbyKing NE Xtra-300 RTF (same plane) $110 vs $137 plus shipping.
Mar 01, 2011, 10:18 PM
Sopwith Camel's Cousin
Originally Posted by rocco
But actually Tower hobbies sells the Cox Extra-300 RTF $27 cheaper than HobbyKing NE Xtra-300 RTF (same plane) $110 vs $137 plus shipping.
That is before you log into HobbyKing. In reading the discussion and/or reviews on the HobbyKing RTF version, once you log in, the price will drop to something like ~$60 (not including shipping).
I believe this is done to satisfy having a minimum publicly advertised price (MAP).

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