Buying Utility STOL: Ignore the Ad Hype
Our top pick is the four-place King Katmai for its overall utility and short-field performance.
Whether for work or a heck of a lot of fun, if you’re in the market for a STOL/utility airplane—one that will let you commune with nature in the most rugged of backcountry airstrips as well as cruise at a reasonable speed and carry a little something—what’s out there and how do you choose among them?
We looked at what’s available in the production Part 23 (and CAR3) world for airplanes that are purposefully built for short takeoffs and landings, yet also have respectable cruise speeds—a tough combination, as serious STOL usually means snail-like cruise—to see how they stack up. We did not include LSAs in the mix for a number of reasons, including useful load and trying to keep the sample size reasonable. We did, due to the exploding refurb market, include one machine that is the result of a modification of a production airplane because of its cruise speed and backcountry/STOL capabilities.
The group that made the cut are, in no particular order: Maules (tailwheel and nosewheel), Aviat Husky series, American Champion Scout series and the Peterson 260/King Katmai series.
New, most of the airplanes fall into a $250,000 to $350,000 price range, depending on engine selection and options. As refurbs, the Peterson 260/King Katmai mods fall into the low end of the range, depending on the cost and condition of the Cessna 182 that is to be modified and whether the full mod is carried out.
All of the airplanes meet the old DoD/NATO definition of STOL—able to land or take off within 1500 feet over an obstacle on a standard day, at sea level. Beyond that, which one is best?
Our conclusion is that while the Scout has slightly better handling than the Husky and the King Katmai than the Maules, the question boils down to the needs and wants of the prospective buyer.
All are extraordinarily capable—if the pilot is willing to take a thorough checkout from a knowledgeable instructor. While often bought as second or third airplane by wealthy pilots, they are not toys and require serious respect. Each has particular features/quirks that must be learned in to obtain the performance of which they are capable—or they can eat your lunch.
As the prices are in the same ballpark, the needs of the buyer for useful load, seats and space become a consideration. Do you want a two-seater that you’ll use for fun or hauling a bit of stuff to your cabin, or do you want to take some friends along with you? All of the airplanes do pretty well when it comes to the fuel versus payload tradeoff (although watch it on older models).
In any discussion of utility STOL airplanes, it’s absolutely necessary to talk about the elephant in the room—safety. The combination of operating very near stall speed, in and out of backcountry airstrips or no airstrip at all, means the risk of things going south starts going up fast. When a tailwheel is added to the mix, the accident rate skyrockets.
Marketing of these airplanes is targeted at pilots who want to be able to land anywhere. That’s appropriate—but off-airport operations have a very high “Oh $#&@!” factor due to any number of things waiting to bite a pilot who lands where the deer and antelope play.
The advertising for these is classic macho—pure 1960s Marlboro Man, tough-guy-in-the-backwoods schtick. Hmm, nearly all of the Marlboro Man models died from using their product. Backcountry flying is incredibly enjoyable, but it requires a high degree of skill and judgment. Buying the airplane from the ad doesn’t make you a backcountry pilot any more than ski clothes make you a giant slalom competitor.
We strongly urge anyone considering a utility/STOL airplane to look beyond the advertisements and any performance numbers in them.
We constantly hear that nosewheel airplanes aren’t macho and one shouldn’t take them into backcountry airstrips because they can’t handle the rough terrain. We haven’t seen any data that supports the notion that a purpose-built nosewheel STOL airplane can’t go anywhere a tailwheel airplane can. We’ve looked at accident reports for years and have yet to see a report of a nosewheel breaking off due to terrain on a backwoods airstrip. While nosewheel pilots may generally self-select away from those strips, backwoods airstrips are regularly used by Cessna 182s, 205s, 206s, 207s and 208s as well as Cherokee 6s. If there were a problem with fragile nosewheels, the data would show it.
The real problem with nosewheels on unpaved airstrips is prop clearance. Plus, tailwheels aren’t perfect when it comes to dealing with rough terrain. We’ve broken one off, and know of others who have (although unless you've also done a lot of damage to the bottom of the rudder, you can usually fly home, something probably not possible if you break off a nosewheel).
Runway Loss of Control
The biggest part of the safety elephant for utility STOL airplanes is the rate at which pilots lose control of the tailwheel machines on landing (and, sadly, takeoff). Just above, we reproduced the accident summaries from our most recent Used Aircraft Guides for tailwheel Maules and the Aviat Husky series. At least 60 percent of the reported accidents in those airplanes were landing-related.
We did an informal review of Scout-series accidents and found that its landing accident rate is comparable. By comparison, nosewheel landing-related accident rates tend to be one-third to one-half that of tailwheel airplanes.
We recommend that any prospective buyer of a tailwheel, utility STOL airplane go in with eyes wide open to the significant increase in landing accident risk, get a thorough checkout and understand viscerally that touchdown on a backcountry landing must be made with minimal energy—meaning either three-point or with the tailwheel only inches above the ground if there is concern about damaging it.
We also recommend following any manufacturer’s guidelines—such as Aviat’s call for tailwheel-first landings with full flaps in crosswinds—and respecting the maximum demonstrated crosswind speed.
STOLest of the STOL
It’s really the burning question in this world—which one will get in and out the shortest? The answer is, just about any of them with a big engine. On any given day nearly any of these airplanes can win a short takeoff and landing competition. YouTube is rife with videos of them getting in and out in only a few airplane lengths. If any of the big-engine versions of these airplanes is stripped of every possible bit of weight, flown by a skinny pilot who knows what she or he is doing and carries minimal fuel, they have takeoff and landing runs akin to a gyrocopter.
For the real world, at gross weight, at sea level, based on AFM numbers and our flight reviews, other than the King Katmai, the airplanes are almost so close from the standpoint of takeoff and landing performance that slight differences in pilot technique can cancel out the differences between the machines.
American Champion publishes a 417-foot takeoff roll on pavement for the 180-HP Scout; Aviat’s AFM for the 180-HP Husky shows 580 feet (the Husky AFM says no max performance takeoffs in crosswinds) and Peterson says 270 feet for the 300-HP King Katmai.
Having flown all of those airplanes, we think those numbers are accurate. The King Katmai is so short because its 31-knot stall speed is about 10 knots slower than anyone else.
Maule does not publish takeoff and landing distances. We disagree with that decision. Nevertheless, a number of recent takeoffs and landings in a 235-HP Maule M-7-235C and experience in other models indicate to us that the Maule-series performance is consistent with the Husky and Scout.
With corrections for temperature and runway elevation, we would be comfortable regularly operating any of the airplanes from unpaved strips of less than 1,000 feet (no obstructions) on a standard day, at sea level—after a thorough checkout.
The procedure for a max performance takeoff varies among the aircraft.
The King Katmai uses 20 degrees of flap for takeoff and lifts off at 35 knots due to influence of the canard. It requires pitching down after liftoff to a nearly level attitude with a climb speed of 45 knots. The ailerons are effective even at 35 knots, although we would be cautious about a 35-knot liftoff in a gusting crosswind until we knew the airplane well. We observed very good roll control at 45 knots.
The Maule M-7-235C uses 24 degrees of flap on takeoff, but no liftoff speed is published. We have lifted off from three-point attitude with good control authority in all axes. The Scout calls for just 14 degrees of flap and liftoff at 50 MPH, so the tail has to be lifted to keep the airplane on the ground to the published liftoff speed. It has good aileron authority down through stall speed.
The Husky manual calls for full flaps on a max-performance takeoff. It then presents a quandary—it says to hold the tailwheel on the ground, but liftoff at 53 MPH, which is impossible. The tail has to be raised to keep the airplane on the ground to 53 MPH.
If the tail is kept on the ground, the rate of acceleration is reduced, but a 180-HP Husky will lift off as low as 40 MPH in three-point attitude. That’s at or below the power-on stall speed—it flies because it’s in ground effect.
In a series of flights we conducted with Jeff Welch, a high-time Husky instructor who provides type-specific checkouts, we observed that there is about a 100-foot reduction in takeoff roll when the airplane lifts off three-point versus holding it on the ground to the recommended 53 MPH.
At altitude, Welch had us fly the airplane just above stall speed, with full flaps and full power and observe the sluggish aileron response and effectiveness, and high adverse yaw, when moving the stick stop to stop for roll command.
Of the airplanes we flew for this review, we observed the Husky to have the slowest roll rate and least effective ailerons at speeds close to the stall with full flaps. It was also the most difficult to coordinate when rolling, slightly edging out the Scout—although none, except the King Katmai, were anywhere close to easy to coordinate.
Welch explained that in 2005 the span of the Husky’s flaps was increased, which reduced the span of the ailerons. The ailerons were redesigned with a longer chord, but he observed a reduction in roll rate in what he referred to as the new wing airplanes. We contacted Aviat and asked about the roll rates of the two wings, but did not get an answer.
Welch expressed concern about uncommanded roll of the airplane following a full-flap takeoff in three-point attitude in a crosswind (a procedure contrary to the Husky AFM). Lifting off at or below the power-on stall speed makes the airplane vulnerable to one wing stalling. Application of aileron to counteract the roll may not be productive due to the high adverse aileron yaw rate, which can aggravate the rolling tendency.
Welch referenced six shortly-after-takeoff accidents that he believes were due to uncommanded roll. He teaches his students to follow the Husky AFM by making all crosswind takeoffs with the flaps up and to keep the airplane on the ground to 53 MPH when making a full-flap, max-performance takeoff.
The Husky, Scout and Maule all have very high adverse aileron yaw when maneuvering at low speed. The Maule line has an interconnect between the ailerons and rudders (simplified explanation) that assists with coordinating the controls.
All require dedicated effort by the pilot to learn how to keep the airplane coordinated and to do so in low-speed operations, especially in turbulence on a short field takeoff or landing.
The Husky and Scout—except the Denali—have flat (no airfoil) horizontal stabilizers. The effect is to increase the airplane’s tendency to roll off abruptly in a cross-control stall. A cross-control stall in those airplanes can mean a loss of several hundred feet even if the recovery is done precisely right.
The Husky’s trim system requires a new pilot to spend a little time getting used to its operation and how to recover from an out-of-trim event such as a go-around.
Some of the airplanes have fuel systems require education—on many Maules a transfer pump is used to get fuel from the aux tanks into the mains. On most Scouts two wing tanks are interconnected, which means using care when filling the tanks to assure they are actually full. We like the Husky's fuel system because the 100 Husky accident reports we reviewed reflected no fuel-related accidents due to the system itself (one pilot lost track of time on a survey flight and ran out of fuel; the other accident involved a pilot who left one fuel cap off and siphoned the fuel out of that tank, leading to fuel exhaustion).
Cabin comfort varies, even though all offer high-end interiors. The Husky is more difficult to board than the Scout and has slightly less room once inside. Maules and the Petersons have much more room to carry people and things, although the 182 conversion is roomier for occupants. We particularly like the door arrangement on the Maules—it seems like the entire side of the airplane opens up, making loading large items easy.
It still boils down to landing—and that a new pilot become comfortable with the very low approach speeds required for the backcountry. That requires training so that low-speed flying and rudder coordination become second nature. It means understanding that it’s never appropriate to tack on extra speed on approach or touching down at the speed of heat if making a wheel landing.
We treasure the time we have flying utility/STOL airplanes off unimproved airstrips. For sheer fun, nothing beats a Husky with the door open. We think that open door beats out the Scout’s slightly better handling when it comes to sales.
Nevertheless, in the two-place, utility/STOL market, we lean toward the Scout for its low-speed handling, slightly easier entry, easier trim use and cabin comfort.
While the two-seaters win the fun battle, for the price per seat, overall utility and short-field performance, we favor the Maule and Peterson/Katmai lines. Between the two, we like the amazing STOL ability and roomy cabin of the King Katmai.
Rick Durden holds an ATP with type ratings in the Douglas DC-3 and Cessna Citation, is a CFII and the author of The Thinking Pilot’s Flight Manual or, How to Survive Flying Little Airplanes and Have a Ball Doing It, Vols. 1 & 2.
This article originally appeared in the February 2018 issue of Aviation Consumer magazine.