Thursday, November 1, 2007

Black Horse Models Super Air Glow to Electric Conversion

When I was a boy my Father would take me to one of many local flying fields. My job would be to clean down the oil covered models after each flight. Or if I was lucky enough I got to hold a model and point it skyward during the all-important run up stage.

While I gravitated to the scale and warbird models, the guys who flew the pattern ships always seemed to have more fun. Unlike the warbirds that would fly the pattern, loop and touch and go the pattern guys were crazy! W.O.T passes inverted at altitudes nearly dragging the rudder were common! These pattern guys always seemed to press their luck and came away smiling even in the event of a disaster.

Flash forwarding 30 years the Black Horse Models Super Air looks a lot like the Birdies, Kaos and Kwiks that ruled the skies all those years ago.

I first saw this model sold under the Graupner name a few years ago. With a price tag of over $150 for an ARF I never seemed to be able to afford it. Till now that is.

The Super Air is now sold under the Black Horse Models name. For a mere $79 and a phone call to Hobby People you can have one delivered to your door ASAP!

My Model arrived double boxed and neatly packaged. The first thing you notice about the model is how light it is! You can read the complete build thread here but I can tell you the airframe alone with it’s ½ lb miscellaneous parts bag weighted in at a mere 3.5lbs!

The second thing you notice is the covering. As the model is made in Vietnam I would describe the covering as Vietnamese wallpaper! Seriously, if you have purchased any ARFs from the 80s you know exactly what I’m talking about. It’s the type of covering no matter how taught it is will wrinkle up like your Grannies left butt cheek after some time in direct sunlight. A heat gun is all it takes to return the tautness but this can get tiring for some.

Covering aside it really is a nice model. All the control surfaces are pre-hinged and those hinges are pinned. The hardware supplied is a grade above what normally comes with typical ARFs out of China.

Power System

I chose the E-Flite Power 46 outrunner for power coupled to a Castle Creations 80A Phoenix speed controller. The motor mounted easily using plastic standoffs found at the local hardware store. The standoffs are using the stock down and right thrust of the firewall.

Directly behind the nose gear a battery hatch was built. In the earliest conception I had thoughts of running a 4 cell Lipo in the 3500 MA range. This hatch would have worked perfect.

On a 4S 3300 Thunder Power Extreme I was able to make 700W on a APC 12x8E Prop. As I was looking for closer to 800W I moved to a 13x8E Prop. Now we were making 764W for a cost of 50A. However even with larger aftermarket wheels flying this model on a 13” prop would leave little margin for prop strikes on the ground.

As the model got closer to completion it also became obvious the small 3300 4S pack would not be heavy enough to balance the model. Even replacing the 2 elevator pushrods and rudder pushrod with 2mm carbon fiber rod was not enough.

Replacing the 4S 3300 with a Max Amps 5S 4000 gave me the added weight and power I was looking for. I mean rather then add a bunch of lead to the nose we basically just added a cell.

On 5S we were now making 1200W for a cost of 64A on the smaller 12x8E prop! That’s at or about 200W per pound! Oh yes, that’s a LOT more like it.

The all up weight of the model is 6 lbs ready to fly.

Maiden Flight Report

There is something majestic when a trike leaves the ground in a shallow climb. Even ugly planes somehow look graceful. Well forget graceful, the Super Air with 1200W will jump into the air nothing flat behind that 12” prop if you prefer that style of flying. I think the pattern guys of the 70s and 80s would have loved to see that!

Having read a lot of magazine articles I’m always amazed when I read about another pilots report of ZERO trim required. I mean come on, zero trim? Anyways apparently I have joined the Zero trim club. I did not touch the trim levers at all during the 5-minute maiden flight. How’s that for an ARF building straight and true right out of the box!

The model has a nice top speed straight and level with very little ballooning when moving from part to full throttle. My setup was right out of the manual. While the model tracked fine, and passed a dive test I think it flies slightly nose heavy at the advertised CG. The roll rate was ok as was elevator and rudder authority. Inverted flight needed a fair amount of elevator to keep the nose up. Rate of climb was especially nice with BIG loops. I set up and landed hot as I really did not know what to expect. My overall impression is this model gives away NOTHING to a glow at 1200 watts.

Tommy D