Tuesday, August 9, 2011

E-Flite mCX "Tandem Rescue" Flight Review

Update:  Downgraded to F for poor quality.  Became unflyable after a few hours use with no crashes.


I got the opportunity to pick up a brand new E-Flite mCX Tandem Rescue Chinook for $39 bucks.  The price seemed a tad steep for a beginner coax, but what the heck, I know plenty of people who would love to play with such a fun little giant helo in exchange for a chain restaurant dinner--and I'm one of them.

After a little web surfing, I was a bit shocked to find an original price tag of $179 on this baby.  I mean, sure, it's a double-mCX which one could logically extrapolate to requiring twice as much money, or maybe more.  But come on, with a name like "Tandem Rescue" and the look and feel of a toy (albeit a pretty cool toy), I'm thinking more like $29 (great deal) to around $49 (pricey) would be a more logical range for a package like this.

That said, after you collect your jaw from the floor and walk away from the cash register with your new double Blade micro heli, this copter is really pretty neat.

Yes it is "just a coaxial" (or maybe it's a cocoaxial), and yes, it is even easier to fly in many ways than the monkey-compatible Blade mCX, but the design does have some unique capabilities compared to a standard mCX. For example, there is no need for a pitch servo, forward and backward movement is generated by varying the front/back tandem rotors relative RPM, much like yaw is controlled by varying the speed top/bottom rotors relative RPM.   This exaggerates the forward tilt of the ship as it breaks ground to go rescue drowning crickets.  Stopping forward motion is similarly cool, as you can hustle along - then slam on the brakes into a "flared," nose-high landing.  Not necessarily the easiest maneuver to execute perfectly, even though the basic coax skills are not challenging.

Another trait unique to the tandem arrangement is the ability to pirouette around just one set of rotors, or rotate about the middle of the helicopter.   And it is also a bit more challenging to align the longitudinal axis than a simple Blade mCX, since two rotors and some chosen pivot point are involved.

Adding interest, and perhaps utility as a basic trainer, is the counter-rotating prop wash which seems less problematic in general, at least as it affects the helo.  A single axis Blade mCX can get pretty beat-up in its own wash as it hovers low to the ground, and that wash increases as the mini-tornado builds over time, often shooting the micro out to one side.  The Chinook's prop wash tends to cancel itself over time; you experience more buffet but less wash-induced random directional motion. 

Other random benefits:  Two sets of rotors also build substantially more lifting power than an mCX. The helo has lots of flashing and steady LED beacons and position lights, making it a breeze to fly in total darkness.
But can it float?
All this adds up to a helicopter that is even easier to learn fly than a Blade mCX, and that is really saying something.  It also adds a certain level of increased interest and larger scale to a simple mCX.  As a basic RC orientation trainer, learning to push the stick this way when things go that way, the tandem mCX is hard to beat.

Some drawbacks are the bigger 1-cell battery requirement, and that fat battery's inability to fit into a typical 1S charger.  A one-battery-at-a-time charger with A/C adapter (finally) is included.  The helo will only run for about a minute using a more standard 150mAH 1 cell micro Lipo.

Another drawback is complexity.  And sure enough, mine broke without explanation or anything even resembling crash damage.  For some reason that I can't seem to solve, my helo can no longer pitch forward by increasing the tail rotor speed.   Going backwards (fast) is no problem.  Oddly, all the elevator trim and sub-trim in the world has no effect on this malfunction, almost like the tail rotor simply can't spin any faster for some inexplicable reason.  Changing the CG doesn't help either.  Bummer.  Unusable after 2 hours of solid fun.  $19.50/hr  ...seems steep.

Appearance: B
Neat - for a coax.

Flight Performance: B-
Certainly no aerobatic xtreme machine, but basic RC training potential is exceptional.

Build Quality/Durability: F
Toast after 2 hours.

Value:  D
I lucked out and picked one up for $39.  $179?  Good luck, E-Flite.

Overall Grade:  C-
Fun little excursion.  More child friendly than most.  Too complex and flimsy.