Who doesn’t love biplanes, especially those with round engines? Bill Bowne first learned about the Waco YKS series in the 1990s, so he built one back then. With over six square feet of wing area to carry her Astro Flight geared 40 and twenty heavy NiCads, that first Waco was a delightfully steady flyer, capable of mild acrobatics and rock-steady passes. The design has been updated for a brushless system and LiPos. At just over 5.1/4 pounds this Waco is over two pounds lighter than the old one and flies very easily on a Power .32 brushless outrunner and a 4S LiPo pack.
- Model name: Waco YKS
- Model type: Sport scale biplane
- Scale: Approx. 1/6.75
- Designed by: Bill Bowne
- Wingspan: Top: 58.1″ (1476 mm) Bottom 49″ (1245 mm)
- Wing area: 860 sq.in. (15.55 sq.cm)
- Wing loading: 14.2 oz./sq.ft.
- Length: 45″ (1143 mm)
- Weight: 85 oz (2410g)
- Motor: Power .32, kV 770
- Prop: 12 x 6E
- ESC: E-Flite 60A
- Battery: 3S 3300 mAh LiPo (gentle flying) 4S 4000 mAh LiPo (aerobatics)
- Published in RCM&E June 2022
She isn’t museum scale but is an easily recognisable model, without sacrificing the flying ability for details invisible from 10 feet away. So this is an easy to fly sport scale ship, which is a cruiser, designed for relaxed flying on calm evenings, so we recommend not to overpower yours. This Waco will do rolls, stall turns and loops, but she’ll do them at her own dignified pace.
Whilst the Waco’s a gentle sweetie in the air, she does take a bit of experience in building. Even if you’re an ace flier, if you haven’t built a complex design before, please take your time!
Bill Bowne flies the Waco for the first – It took a brief application of full throttle to get the Waco moving but once she started, she rolled easily and was off in under ten feet. After that, it was time to throttle back to around half-power for the climb out. What a pussy cat!
Up the Waco went, for a quick test of her stalling tendencies (a habit from my glow days; I always want to know what to expect from a model should I suddenly find myself with a dead stick. And, yes, electrics can have sudden power failures, too!) The stall proved to be pretty mild – all that washout pays off!
Chopping power and pulling full back on the elevator produced a series of mild, wings level pauses and shallow drops; relaxing the elevator and adding power brought the model back into level flight. I did have to crank in some down trim, due to not having built-in enough down thrust (shown on the plans!). When the Spektrum lady’s pleasant voice announced it was time to land, I brought the Waco in for an easy, gentle touchdown. Thanks to the drag of all those struts and that big, flat cowling, a touch of throttle was needed to keep the Waco from landing short. But it was no sweat!
So far, the Waco has continued to be an absolute pussycat to fly, being stable, manoeuvrable and absolutely reliable.
What’s in a Laser or CNC Cut Wood Pack? – A CNC or laser cut wood pack contains most, if not all, of the intricately shaped parts shown on the plan, which would be difficult or time-consuming to cut out by hand. It does not contain any sheet or strip wood, which you will need to buy separately. Alternatively, you can purchase an Additional Wood Pack, if available. Our Laser or CNC Cut Wood Packs only contain balsa, ply and lite ply and do not include other materials that may be required to complete the model, such as hardwoods, metals and GRP sheets.