OS 50 Review
Simon Lockington

Since it hit the market, OS's 50 size engine has developed a reputation for being a real powerhouse. That combined with it's reliability and ease of use, have made it very popular.

When I started getting into doing flips and tic-tocs etc, I started to wish the OS 46 in my JR Ergo just had a little bit more grunt. It did ok, but I really wanted more grunt, both to do more, and to give me the power to get out of trouble when things got a bit messy.

I kinda investigated the option of getting a tuned pipe. However, once I balanced the cost with the percieved benefit, I came to the realisation that in this instance there is no substitute for cubic inches, so I sprung for an OS 50 from Cyberheli.

True to form, the package arrived from Cyberheli in about three days.

Because the OS 50 has the same engine mounting as the OS 46, it was just a matter of sliding the engine in.

Once the engine was slotted in, it was time for it's first ever flight. I richened up the needle a couple of extra clicks on the main from the setting recommended in the manual to ensure it was nice and rich. I'm running 10% nitro with 20% synthetic Coolpower.

To my surprise, the engine started on the first crank and idled perfectly! After having to fight with my 46 to keep it going between the time it started and the time I could spool it up, this was a god send!

I slowly advanced the throttle and the machine rose and settled into a steady hover, the engine humming consistently and producing a tonne of smoke. I was rapt! I was expecting it to be a bit of a dog given that it was running so rich. Not at all, it ran nice and consistent without any vibration or hassle!

After a tank of hovering on the lawn, it was time to head to the field for more comprehensive flying. Out to the field and the machine continued to purr. Just did a lot of hovering and slow speed figure eights at half throttle, with the occasional advance in stick movement for variation.

After about seven or eight tanks of this, I decided to start stretching the machine's legs. Leaving the needle settings where they were, nice and rich, I started doing some fast forward flight circuits. I hovered out to the flight area and gradually pushed forward on the sticks, and the 50 started to howl. My first thoughts were that the machine seemed to have much higher forward speed now and found myself flying round at about 3/4 stick getting used to it's new found performance.

Even with the needles set so rich, the vertical climbout performance left the 46 engine for dead, and the headspeed was still winding up at full stick (9 degrees)!

However, what impressed me most was the smooth delivery of power from the engine! Cruising in fast forward flight at 3/4 stick then begin a slow descent by bringing the stick back and letting the heli descend at low throttle. With the 46, it would normally make quite a fuss and wouldn't run evenly in the mid range. Not so with the 50, it dropped back to a purr and descended beautifully! Infact, sometimes I thought I was autoing it was so smooth! At the bottom of the descent I'd punch the collective and the 50 would light up and depart the area.

After another five tanks of this kind of flying, I decided to lean it off a click or two and start chucking the machine around a bit.

Clicked into ID2 and nailed the collective and the machine was gone! The climbout performance was breath taking! As the machine climbed I pulled back on the cyclic into a back flip and pulled in negative and continued the climbout inverted, still the little machine kept rocketing skyward. I felt a big grin coming to my face... You've just gotta love the sound of the blades as they beat the air!

Another thing I noticed was loops were MUCH bigger with the new engine than they ever were with the 46. I expect this is due to the increased flight speed. Slightly easing back on the cyclic see's the little Ergo make nice big loops now.

In summary, for those wanting more power for their 46 size helis, or those who are simply looking to replace their OS 46, the OS 50 is a very excellent option. For US$139 (from Cyberheli), why bother getting another 46?
The smooth and reliable nature of the 50 is awesome, let alone the tremendous power it produces! Fuel economy is good too! I'm getting at least (if not more) flight time out of a tank now as I was with the 46.

As I get more and more flying in with this engine I can see that going with the bigger engine option was the better one for me, as opposed to going the tuned pipe route.