This is an interesting article as a number of ideas and criticisms here are still valid today and the subject of improving the Pioneer IId by Mike couts and Mat Redsell

Photo of bob Michener Flying his Pioneer

(LATER CALLED"SOAR'n'DIPIDY". )

This history is from: The January, 1978, Marske PIONEER Newsletter (OVER 25 YEARS AGO!)

THE PIONEER CONCEPT RE-EVALUATED

By R.Michener and Russ Flint, owner of Marske PIONEER IIa (C-GLUV )

"Where does the PIONEER IIa stand three years after Rick Apgar's discouraging flight testing (SOARING, July 1974)? Using Michener's N4SS (a modified PIONEER IIx with changed airfoil, non-symmetric panels, much air leakage, elongated sparbolt holes, etc.), Apgar found performance bettering a 1-26's only above 44 MPH but much poorer than predicted by Marske. Have the other 3 PIONEER IIa gliders flying since 1975 found the same problems? Have they found the traditional flying wing problems of longitudinal pitching and directional instability that dogged the Horten wings (from Ray Parker) and possibly the Northrop Flying Wing, tho not the Fauvel.

Now that we have experienced pilots in Russ Flint (over 300 hrs.) and Hazel Flint, instructors in the Winnipeg, Manitoba, Gliding Club that trains over 70 newpilots a year, who have over 130 hours in their own PIONEER II (C-GLUV), we can begin to find knowledgeable answers.

Overall the Flints are very pleased withthe PIONEER II. It has been flown by 4 different pilots with no problems, though Russ feels that due to it's sensitivity, it should be restricted to pilots who are already experienced at least at the 1-26 level of training (20-30 hours solo minimum); this is the same as for any pilot transitioning to a higher performance ship.

Russ and Hazel in their thorough-going flying have not found any design- inherent oscillation problems. Though PIOs are observable in most gliders with inexperienced pilots---and large, sudden stickmovements can do so in the PIONEER II, they have found them completely controllable. Others who have flown their ship had had no problems with it, having been prepared. Early on Russ had to abort a take-off from unfamiliarity; Michener has found PIOs on N4SS to be identical to his 1-26 flying.

Other characteristics that Russ briefs pilots on are:

-he finds considerable adverse yaw in C-GLUV (which he expected in tailless designs), but eliminates it by "leading" into a bank with the rudder;

-the ship "pitches up on the application of spoilers which must be compensated for by forward stick;

-normal flaring on landing often leads to a "firm" touchdown which can be avoided by spoilers being partly closed or "flying it onto the ground". Russ feels this is due to the sudden decrease in lift with theextreme up-elevator.

So does it ground-loop like flying are supposed to (and many standard sailplanes do)? LUV doesn't. The only true ground-loop experienced in N4SS was due to trying to pick up a wing (no wing runner available) in a brushy, unmowed runway extension with weeds up to 2 ½ ft. tall. Later a slight but uncontrollable arc to the left as the rudder lost authority in the landing roll was traced to an unrecognized bent axle due tofirm landings.

How aboutdirectional control in the air? As the Winnipeg movie shows C-GLUV has directional control at all times and at all attitudes. Considering this stabilityin the Marske PIONEERs, the FAUVEL, and Backstrom's PLANK, which all havegenerous rudder areas, one wonders if the Hortens' slight performance advantage was worth doing without one. Russ feels the rudder efficiency could be yet improved with a thicker rudder to reduce drag.

Directional problems did surface in another unique PIONEER built by Don Morgan and Jay Johnson. Their non-move ablerudder was built into the fin, and all turning forces were generated byactivating spoilers separately (like early PLANKs) for "drag". The Morganship's directional control was only effective at high speeds because the standard spoilers were too small and (normally located) too far inboard fortheir extended-span 15m.wing to have the moment to generate effective lateral control. Test pilot Daniels reported it was scary on early tow, "hunting all over the airport." [Daniels owned the PIONEER I,
building itwith Jim Marske.]

Spinning? The PIONEER IIa can not be spun with theC.G. within design parameters. Marske avoided the C.G. moving aft by oversight (as with lighter pilots) by designing the wheel location to be at the C.G. so that the nose must fall forward with the pilot seated ready to fly. At stalling speeds, the nose can be kept up; the ship just mushes into increasing sink. At Russ' 150-lbs., it stays non-mushing (unstalled) into the mid-30s speedwise, and retains good aileron control when finally mushing.

The modified N4SS mush-stalled inthe upper 40's. [Michener in his inexperience got into trouble by not differentiating between heavy sink and mush once. In a 30 kt. crosswind(45-deg.) landing, he had to cut his downwind leg short and still ended uplanding in the corn. Being in mush, hecould have dropped the nose to regain forward movement. Though it totaled his fiberglass fuselage,his wings and he were unaffected and lived to fly many other days.]

How many other sailplanes would have spun in from full stall?

The N4SS PIONEER IIx of Michener'spredictably lost low speed performance for the following unique reasons: (1) the L.E. "cusp" was removed from theairfoil; (2) camber was reduced to 1% with no camber in outer 18" of eachpanel; and (3) elimination of all reflex in one panel. (Marske and Fauvel used reflexed airfoils for stability in their flying wings.)

The first three PIONEER IIa fuselage kits would not allow for an angle of attack on the wing for takeoff, having an excess 4" length at bottom of the rudder post. Edgar Herbert reported some hairy takeoffs where his plane would not leave the ground on increasing tow speed until it hita bump and rocked back for the wings to "bite the air", jump into a steep climb, and then diving abruptly before he could satisfactorily control it.

N4SS was built with a nose hook for towing, but Marske preferred C.G.hooks on underside of the wing fairing with a towing bridle. The main advantage was higher climbs in winch launches, which were commonly used in the 1950s and 60s. Russ found a nose hook was easier in tow than C.G.hooks, which could quickly lead an inattentive pilot to get out of position, especially on turbulent days. Michener frequently found himself diving after towing through thermals to return to position due toN4SS' lighter wing loading.

Russ found towing at 70 MPH with a standard 180' line most comfortable. Michener found 60 MPH too slow to keep the nose down and see the towplane over the instrument panel. On one busy day a towpilot even towed N4SSat 80 MPH ("hardly even knew that you were back there"), entirely too fast for safety. The "standard 120' tow rope"was often less than 100' with splices when measured; we prefer 200 or even 300'for easier control in turbulent conditions.

With the correction of the rudder post length, basically no dangerous flying characteristics have been discovered by experienced pilots. NOTE: THIS IS STILL TRUE 26 YEARS LATER! Russ found that pull-up response at high speeds is delayed (possibly due to blanking of the elevator?), and sideslip recovery can not be made by rudder alone. Rather than being dangerous by a suspicious, unfamiliar planform, the PIONEER II has proved a very forgiving ship and much safer in astall-produced crash. If trimmed, Marske's claim that it can land itself safely on flat ground without obstruction (or turbulence) could well be true.

Performance wise,Russ feels his standard PIONEER IIa equals or exceeds many gliders accepted as having a glide ratio of 30:1. LUV easily outclasses 1-26s and a Cherokee, gives Terns and a well-build BG-12 very good competition, and compares favorably in climb with an RHJ-8 (2-placeHP-14), losing out only at cruising speeds.

The Miller-Girard PIONEER IIa was clearly comparable to arecently "cleaned and filled" (to eliminate the "starved horse" look of taut fabric on wood-ribbed wings) Skylark 3G in cruising in the 50-90 MPH regime, and actually did a 100-ft. better over a 5-mile comparison run.

It should be noted that the Skylark has a measured L/D of 42:1 though Dick Johnson estimated it at 36:1. It has a span of 60 ft., 50% more than the13m PIONEER IIa. It should be noted that all these PIONEERs were flown with unwaxed/unpolished wings, which Marske estimates loses 10% efficiency at lower speeds.

In pursuit of objective performance data, we feel the PIONEER IIa can speak for itself. Michener approached DickJohnson (Dallas GC) and Paul Bikle, who had offered in 1974 to conduct performance tests on the PIONEER, with the offer of delivering C-GLUV (with Russ' permission) for such tests. Bikle pleaded age and the Johnson group only investigates production models, not homebuilts.

In marginal condition circling performance, Russ' PIONEER C-GLUV has no peer in the largeWinnipeg Glider Club. Michener observed him thermalling in late afternoon lift on a weak day with other experienced pilots, staying up 45 mins. longer in an informal competition. The reason seems to be C-GLUV can circle more tightly (under 15sec.circles), allowing him to stay closer to the liftcore of the rising air. This allowed him to stay about 200' above the others (BG-12, RHJ-8, etc.). Russ feels that only in strong, broad thermals could other ships reduce his PIONEER advantage.

Thermalling effectiveness is important to the pilot who wishes to have an optimum chance to stay up after an expensive tow and who can not plan
his flying for only strong days. In the northern U.S. and Canada, the marginal days outnumber the strong.

LUV has a good roll rate. Russ feels it is about5 sec. from 45-deg to 45-deg. He estimates a standard sink rate of 150-200 fps at the slower flying speeds with his unwaxed wings. (N4SS MUCH LATER ACHIEVED 130 FPS.)

Russ is an experienced glider pilot and instructor (over 300 hours). His performances are as much due to him as C-GLUV.

Construction wise the Flint ship is interesting. The highly varnished, laminated wood of the short canopy frame contrasts attractively with the unpainted interior of the fiberglass fuselage. The controls operate effortlessly with no binding or stiffness, reflecting care with linkages; the floor tubing of theolder style side-mounted stick is enclosed by 3 nylon roller bearings. The seat is "stepped" over the wheel housingto allow for parachute (and more leg) room without pushing the pilot (and C.G.)forward. A tie-down kit is mounted behind the seat and a recording barograph above the aileron linkage.
Aluminum strips were installed in the aft fuselage as ground plane for the radio antenna.

Interesting improvements were ASI and Braunshweig intakes mounted on the fin for total energy compensation. Flying comfort isimproved by an adjustable trim: forward trim would hold about 70 MPH and rear about 45 MPH. At Russ' weight, he had added 7 lb. weight to the nose to dampen pitch sensitivity should any large, sudden stick movements be initiated. OnN4SS inspection covers on underside of fairing make for easy access to drag spar bolts; though Marske
disapproves, it saves strained contortions from crawling over the aft linkages prior to flying alertness.

The C-GLUVwings were well-sealed at the roots and spoiler boxes. However, his ship (like N4SS) had a distinct whistle when flying ("stampeding cattle when flying over"), suggesting a leak somewhere. Russ had heavy wing covers for tie-down protection as it is left out all summer at their glider port. The 13m.+ wings are actually 14" longer than designed, but weigh a remarkable 100 lbs. per panel! (N4SS panels came out 150-160 lbs.) C-GLUV is 410 lbs. without pilot. Where N4SS has a castoring tail wheel, C-GLUV has a 2"spring-assisted steel skid.

Russ has reduced the elevator sensitivity by extending the elevator horn 3", and has increased aileron differential movement by increasing the ball-crank angle to135 degrees and slightly extending the short arm to 1.7".

The only real improvement prospect was smoothing and waxing the wing L.E. for Marske's estimated 10% improvement, and it flies so well already!

Back to the workshops, friends. LET'S MAKE '78 THE YEAR OF THE PIONEER!