STOL CH 701 PILOT REPORT

ZENAIR STOL CH 701: An honest-handling, good performing short-field star - constructed using simple tools.

Tested by Peter Underhill
Condensed from Pilot magazine (UK),
December 1993.

Heintz’ design philosophy has focused over the past 20 years on ease and speed of construction; thus build time for his fully developed aircraft is usually much shorter than for similar, sometimes only partly developed competitors. For several years Zenair have demonstrated how quickly their pre-fabricated kits can be assembled by building one from scratch at the week-long EAA Oshkosh and Sun’n Fun conventions - the complete, unpainted machine takes to the air before the end of the show.

The STOL CH 701 follows typical Zenair construction methods, employing 6061-T6 aluminum sheeting riveted to aluminum angles, using aviation quality Avex rivets, which work much like ordinary pop rivets. The fuselage is a box-section, there are no compound curves anywhere, and construction is straightforward using simple hand tools.

The 45-percent kit comes complete with all necessary components and materials, from prop spinner to rear fuselage tie-down bracket - the only exceptions are paint, battery and upholstery. Wing and tail ribs, and fuselage bulkheads, are pre-formed, and skins are pre-drilled. The wing spar is pre-riveted at the factory using solid rivets, and all surface skins are pre-cut ready for fitting. All pre-assembled parts are treated with zinc chromate protection, and any welding, cutting, forming or molding is done by Zenair before shipment.

Flying off a grass strip on a lovely autumn afternoon, the STOL CH 701 was very much in its element. Take-off, normally flapless, requires nothing more than complicated than pointing the 701 along the airstrip, opening the throttle and easing back on the stick. The thing will be flying within a hundred feet - and that’s with two aboard. Solo, it can get airborne within seventy feet in nil wind, then climb steeply away at an angle which is quite incredible when seen from the outside. Experiencing it inside the cockpit, I wondered whether we shouldn’t have a Lexan floor as well as roof panel! Leveling out gave an indicated cruise of 75 mph.

Pitch controls is silky-smooth, the all-flying rudder powerful - indeed, at one stage I was flying the 701 semi-sideways pointing directly at the camera plane - and the general harmonization in all three axes was light and very acceptable. With its low wing-loading and high-lift wing design the 701’s forte is its twiddlability. Point a wing-tip steeply towards the ground and, at speeds as low as 40 mph, with a gentle roll and very little supporting rudder, the 701 will happily cavort like a horsefly on heroin, going round and round until told otherwise; I’d swear the turn radius was the same as the ground feature I was rotating around. The airframe, though strictly non-aerobatic, is stressed to +6/-3g, and thus will suffer no ill effects from such entertaining maneuvers.

The power-on stall is another exercise provoking a good deal of hilarity. With the fuselage pointing upwards at an incredible angle - I estimate about forty degrees from the wing’s angle on the horizon - the aircraft can be kept flying down at around 35 mph or less indicated, even less solo. Once it stops flying the 701 simply nods and mushes down with the stick still fully aft. To unstall takes the merest forward movement of the stick and the application of power, whereupon the 701’s slats seem to grab the air and it flies unconcernedly away. Even after several attempts, both with and without flaps, I could not discover any nasty characteristic. The 701 is indeed a stable, almost gentle airplane.

Back in the circuit, my first landing was flapless. Over the threshold all power was removed and the nose-wheel supported with progressive aft stick in the approved manner. The 701 simply plopped onto the grass at under 40 mph, and with judicious use of brakes a ground roll of no more than 150 feet was recorded. With one stage of flaps, approaching at 50 mph, this can be reduced to less than 100 feet.

The Zenair STOL CH 701 is a functional, honest handling, good performing short-field star, with an acceptable cruise and range. With a maximum weight of 960 pounds it can lift 490 pounds of useful load - slightly more than its own empty weight. Thus two average people plus full fuel still leaves a margin of 115 pounds for overnight baggage, flight cases, even an emergency can of fuel and some camping gear. When almost any small meadow is like Heathrow to the 701, it will make an ideal "rough tourer" - a sort of 4X4 of the air - able to overnight almost anywhere. Imagine taking a 701 on a summer beach-hopping tour of the Scottish Isles or Eire.

With the STOL CH 701, Chris Heintz has come a long way in his thinking, design and market research skills. The STOL CH 701 is just about as perfect a solution for its target marketplace as any. Builders’ comments on ease of construction, support level and after-sales service rate Zenair among the best kitmakers going.

© Pilot magazine (1993)

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NOTE: This article represents the viewpoints of the author, and not necessarily those of Zenith Aircraft Company.

© Zenith Aircraft Company
2006-09-01