RocHobby P-39 Cobra II High Speed 980mm Review

Review by Luke Barnett

Equipment Used:

P39 PNP

Pros:

- Beautiful design and flawless finish

- Robust metal retracts with no sign of potential failure, even in grass

- Tail mounted rudder and elevator servos with very short control rods (provides very positive control throws)

- Fast, Fast, Fast….right out of the box. - Ungodly fast with a two blade prop.

- Easy to build requiring no glue at all

- Little to no mechanical or remote trimming required

Cons:

- Takes a bit more up elevator to overcome nose wheel drag upon take off (Easily remedied with take off flaps)

- Nose gear is a bit long and clumsy looking but stands true with the authenticity of the real P-39

Disclaimer: This writer is now doing reviews directly for ForceRC and FMS. My hope is that they were written with 100% honesty, but I felt it was worth informing the readers of the situation for the sake of transparency.

 

Introduction:

If you’re like me and have a fondness for the vintage war birds of the past, you most certainly know of FMS/Roc Hobby and their amazing product line of World War 2 era planes. I personally have several of them because at their average price point, the quality, accuracy of design and all out performance capabilities are near unmatched. Others come close, but most fall short of FMS’s “Excellence in the Skies.” When I was given the opportunity to try out the newly released Roc Hobby P-39 AiraCobra (High Speed Version), I was more excited than a kid in a candy shop. I personally love fast war birds and have an overwhelming attraction to yellow…….so it was only fitting that I was drawn in by this new plane from FMS. During this review, I will give my personal accounts on five main categories as to provide the most well rounded summary of my opinions on this plane. I will focus on items such as the un-boxing/build process, setup and trimming, maiden flight (including speed, stability and performance), landings and finally, the pros and cons section.

 

Un-boxing and Build:

FMS is well known for its packaging of planes as they do a very good job of designing their packing material to fit the plane’s profile very well. Upon arrival, although a bit banged up from shipping and customs, the box seemed to be held together well. After opening it up and a full visual inspection of the parts and pieces, I noticed no damage whatsoever to any of the items included. The finish was perfect with hardly any visible paint flaking or foam casting flaws…..nice and smooth. Assembly on this plane was a breeze as it required no glue at all. The tail section was held together with a keyed spar and two machine screws to hold it in place. I liked this because I’m impatient and don’t like standing around waiting for glue to dry so I can fly. All control surfaces were intact and the only issue I came across during the build was that the standard 70 amp heavy duty ESC was disconnected. This required me to disassemble the nose to get to the huge 3648 KV770 motor and reconnect the ESC. The only difficulty with this was the heavy magnets on the motor kept robbing my screws from my screwdriver (which FMS includes in all of their plane kits). I love these screw drivers, they fit everything and even fit the hole in the front of most aluminum nose cone nuts. The hardware included went together with no issues as all holes and other connections lined up almost perfectly. My hardware bags were not labeled from the factory, but if you’ve ever put an FMS plane together, they normally label them and section each set out into individual bags. This is great and saves time…..again for impatient guys like me. They even included extra hardware just in case, also standard for FMS.

 

Setup and Trimming:

Mechanical trimming was a piece of cake thanks to the ball end links and speed adjusters and the electronics “plugged and played” just as expected. The wires even tucked out of the way and looked very clean “under the hood.” The standard channels were plugged in and worked as labeled and even the flaps and landing gear were set to the switch channels and locations that I normally fly with. The dual rates and other settings as suggested in the manual will later prove to be right on. Everything was going great…….and it gets better.

 

Maiden Flight (Take off, Speed, Stability, and General Performance):

This is where my review goes from positive to “super positive.” I expected, as I do with most all FMS/RocHobby planes, for the maiden flight to be near perfect with little to no adjustments. Let’s start with the take off; the AiraCobra is a tricycle gear plane and for those of you who fly this type of setup from grass fields, you know the front gear creates a bit more drag than the tail draggers do. I had to give the bird a bit more up elevator than what normally feels comfortable to me, but as soon as enough air got under those wings, it shot up and leveled off perfectly. What I say next is what blew me away while flying the AiraCobra. It needed absolutely no transmitter trimming……..NONE!!! How is this possible? I’ve maiden’d many a planes and they all require some……right? This is my first that needed nothing. Even FMS’s CG recommendations were spot on with a 2200 mah 4 cell pack inside. I found myself pressured into giving it one click of up trim just because I felt superstitious and thought it might be bad luck if I didn’t. As soon as I “hit the gas,” that up-trim click got taken back out because the power was just intense. It wanted to buck like a horse and take off onward and upward. After four flights, my trims are still set back to zero.

 

Like I mentioned above, the speed is insane (awesome) for a stock plane made of foam. It will easily do the 80+ mph speeds as advertized and even more. Change the four blade prop out to a more aggressive two blade and prepare yourself for breath taking, neck breaking speeds.

 

With the recommended rates, it also handled and responded like a dream. It had no bad manners that I’ve discovered so far, even at low speeds. No tip stalls either. War birds inherently dive during a bank, at least mine do, so I have made it a habit of installing gyros into my planes just to make sure they behave the way I like for them too from the very get-go. Since I knew I needed to write this review without any influences from items like gyros and other flight stabilizers, I chose to fly this mild mannered “speed demon” without one. To say the least, it flew better than most of my war birds did with gyros in them. It was incredibly stable, even in the 15 mph wind I was flying in, and became even more predictable as more power was rolled in.

 

Let’s talk about flaps; The AiraCobra comes stock with flaps that work great. I did have a minor issue in which the nose pitched up as I engaged the flaps, but that was an easy fix with a bit of down elevator mixing in my flap settings of my transmitter. After that, kicking the flaps in became uneventful and it slowed the plane down to a decent crawl for landings.

 

Landings:

If you are anything like me, I place allot of value and gravity on how well (easy) a plane lands, especially in grass……where I fly. I like good control, slow speeds, and quick, level stops. I also like to be able to taxi with ease thereafter. The AiraCobra delivered on all accounts. The line up and approach was 100% predictable and the plane did everything I told it to. The flaps engaged flawlessly bringing the plane to a level crawl with no “crabbing.” The plane touched down with the grace of a ballet dancer and rolled to a quick stop with no tipping. As you know, the AiraCobra is a tricycle gear so “nose overs” are not a worry. A great plane for grass landings. I landed about 200 feet away from myself and decided to taxi in for recovery and the plane did just that. I was a bit worried about the integrity of the nose wheel as it is very long compared to other tricycle geared planes. The metal retracts held up even in tall grass as the plane taxied in to the pits. Success!!!! Three more flights after this proved to be just as successful as I became more accepting of the fact that maybe FMS really did build a “perfect plane.”

 

Thank you FMS for allowing me to try the new plane. FMS has built a cost effective, quality driven, and fun reputation for themselves and the new Roc Hobby P-39 Racing AiraCobra 2 has fallen nothing short of “Excellence in the Skies.”