Once upon a time, the producer of a yellow LSA taildragger installed the industry’s most powerful engine resulting in a performance leader. This gambit succeeded handily and the builder enjoyed several strong years of sales. Others looked upon this success and saw that it was good.
So, of course, being aviation entrepreneurs, others worked to do the original one better. How about not only an excess of power but other features and macho good looks to cause jaw-drops at every airshow? You may believe I am writing about Just Aircraft and their magnificent SuperSTOL. I’ve enjoyed flying this aircraft and you can research it further here.
Adding exceptional wing qualities to a potent engine results in a sub-market within the LSA sector that has been drawing strong interest and the sales that follow. With newcomers offering appealing features and reducing the price into more affordable realms, it’s not hard to see why pilots are learning about these new flying machines and bringing one home.
Into the cauldron of development activity stepped Zlin and their Shock model. This Czech-based company is no newcomer. You already know their Savage models, reported here frequently as the former iCub and later the Outback and Nomad plus the one-of-a-kind Bobber.
With advice and suggestions from SportairUSA proprietor Bill Canino — himself already a highly skilled veteran of the SP/LSA movement — Zlin took the model SportairUSA sells as the Outback and added what Bill calls “the Shock options.” He words it that way because these fresh features can be retrofitted to earlier Outbacks. In addition, the auto-functioning leading edge slats can be removed (with only eight bolts) translating to great versatility.
Custom hydraulic, side-mounted shock absorbers with 12 inches of travel and suspension geometry integrated into main and tail landing gear virtually eliminates the problems of touchdown rebound and ground hop that are all too common with traditionally sprung cabane-style landing gear. The gear position is also moved forward to enhance braking capacity with less risk of overturning. As a result, the Outback Shock lands and taxis with remarkable control and stopping power. The tailwheel is also shock absorbed.
Looking deeper into the details, the Shock options include what SportairUSA calls the “hyper-STOL” wing profile boasting short takeoff and faster rate of climb. This incorporates slatted wings that move according to airflows without pilot involvement combined with two-element Fowler flaps and strategically placed vortex generators in numerous locations to optimize low-speed control.
Compared to earlier models the Shock’s wing is different in ways beyond the visible slats and Fowler flaps.
The newly designed wing has six inches of added chord length, all-new spars, stamped aluminum ribs plus strengthened attachments and other structural improvements. Truncated wing tips have wing tip fences (plates on the tip) to control tip vortex and reduce drag. Joined to a sturdy welded steel inner structure, Zlin successfully subjected the Shock-option Outback to more than 1,600 pounds at 6G holding this load for over two minutes without deformation.
A 40% increase in aileron surface area, together with a refined airflow design aided by vortex generators, allow the pilot to keep full control authority at extremely low speed on approach. Shock’s Fowler flaps extend 70% from their retracted area and the flaps can be equipped with mini vortex generators installed inside the vane (see video). Zlin and SportairUSA love VGs; they are available for the wings, rudder, flaps and horizontal tail.
As Bill notes in the video below, the tailplane also saw changes, beyond the shock-mounted tailwheel. Rudder and elevator surface area were extended more than three inches aft to balance the moment from the new wing design.
Alright, you might accept Outback Shock as a engineering marvel with all the right attributes to qualify as a “hyper”STOL but what does all this do for you?
The significant increase in wing lift provides added performance in landing and takeoff. With the 180-horsepower Titan engine doing the pulling, Outback Shock can launch in less than 200 feet at gross weight and land in barely over 100 feet. With a single occupant these numbers are halved.
One part of the takeoff and landing prowess of Shock is low stall speeds… really low. Stall in the airplane with a single occupant is an astonishing 18 mph or about 15.6 knots; even at gross weight stall occurs at 23 mph (20 knots). However, Outback Shock is not a particularly speedy cross country cruiser. “Max” speed is 115 mph or 100 knots. Typical cruise is about 90 mph or around 80 knots.
Shock lets you keep an better eye on your landing site thanks to a pitching moment generated by the deep flaps that results in a lower nose attitude on approach.
Shock pilots can operate from smaller fields and land in places you might not otherwise consider (although this comment is not intended to encourage risky piloting behavior).
Find out more from SportairUSA located at the North Little Rock Municipal Airport (KORK) in North Little Rock, Arkansas. You can come see the airplane at the upcoming Sun ‘n Fun airshow over April 4-9, 2017.
Find out more and see lots more detail of Outback Shock in the video from Aero 2016: