Glasair Super II-S Prototype Flight Report

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Glasair Super II-S N902S, at Copperstate in 1998.
Glasair Super II-S N902S, at Copperstate in 1998.

Flight report by Jay Blass, II-S RG builder.

More than a decade in Naval Aviation gave me the opportunity to fly some exciting aircraft in somewhat demanding situations. However, during my career I continually missed the personal freedom and satisfaction unique to general aviation operations.

Eventually a career change made the goal of a personal aircraft feasible. A few months after hanging up my G-suit for the last time, I began the final search for an aircraft that would satiate my desire for solid acrobatic prowess, uncompromising strength and practical cross-country performance. This combination could only be found in a kitplane, and my several years of analysis at Oshkosh and Sun ‘n Fun kept pointing to the Glasair as the answer to my requirements.

The final phase of my research culminated in flight evaluations of three different Glasair models. The generosity of Glasair builders based in Fort Lauderdale provided the invaluable benefit of several hours in two customer built Glasair I variants. This served as a benchmark for later comparison of the II-S model. I was particularly fortunate to spend 30 minutes of formation flight immediately after my first Glasair takeoff. Having not flown formation for almost a year, I was impressed at how the aircraft’s handling qualities made the evolution very comfortable in spite of my few minutes of Glasair time.

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The airplanes all performed well, and handling was marred only by a less than optimum trim system and somewhat light pitch forces in comparison to roll. The aerodynamic cusps found in the early Glasair ailerons and flaps probably contributed to this phenomenon.

Additionally, I desired a bit more cockpit room for my 75″ frame.

Glasair Super II-S N902S

Satisfied with the handling qualities that I experienced during these early Glasair flights, I scheduled the trip to Arlington for what turned out to be a lengthy demo in the factory’s unmodified II-S. I was aware of the ongoing stability issue at the time and used the two separate evaluation hops to closely look at the aircraft’s characteristics near and at the aft CG limit.

Stoddard-Hamilton’s Bill Sprague (Chief Pilot and Director of Marketing) allowed me free reign to consider the aircraft’s handling throughout its envelope.

Without going into too much detail, we flew with almost four hundred pounds of pilot, minimal wing fuel and no baggage. This put the aircraft very near the aft CG limit with this loading, I found that an instrument approach did not require excessive pilot attention, nor did basic acrobatic maneuvers.

Therefore, I was amazed that the aircraft exhibited lackluster pitch stability during our checks. This was also manifested as a very light pitch feel that made smooth attitude control more tedious than I prefer.

Smooth operation of the installed electric pitch trim was also hindered by the quick pitch response, and full lateral stick inputs during aileron rolls sometimes induced an unwanted pitch bobble. As I gained experience with the control feel of the airplane, these effects were diminished. I placed a deposit on a kit, feeling that the existing airplane was well suited for spirited sport flying, and cross country utility would ultimately benefit from the ongoing redesign effort I delayed delivery pending the redesign efforts, and remained particularly interested in their progress.

I accepted delivery of the kit only after the new horizontal tail was retrofitted and flown in the factory demonstrator. The new empennage was included in the crate and was completed uneventfully after the instructions arrived. I was well into the wing construction before N902S was stretched and flown in its full Super II-S configuration. I was intensely interested in how it would handle.

The Sun ‘n Fun EAA Convention at Lakeland, Florida presented a much appreciated opportunity to fly the new Super II-S demonstrator. A forty-five minute evaluation revealed that Stoddard-Hamilton Aircraft has succeeded in enhancing the stability of the redesigned aircraft while retaining the superior handling, performance and utility that is prevalent in the Glasair line.

Shortly after arrival at Lakeland, I sought out Bill Sprague and heartily petitioned for a quick evaluation flight to assess the impact of the redesign. Late in the week the frenetic pace of demo flights slowed just enough to allow Bill to hand me the keys to N902S.

Glasair Service Manager Brian Costello would accompany me on the flight with the primary responsibility of ensuring safety. I wisely transferred the keys to his capable hands.

As we walked up to the airplane the six inch forward fuselage stretch was apparent. The fuselage retains clean aerodynamic lines and its Glasair III heritage is accentuated. The longer span of the horizontal tail was also evident and matched the installed extended wingtips well.

Glasair Super II-S N902S instrument panel
The instrument panel.

I settled into the left seat and immediately perceived an improved comfort level due to increased cockpit room. The new wing location has also moved the pilot away from the instrument panel. The result was a roomier perception in the cockpit which was verified by the fact that my rather large carcass fit comfortably with the standard installed upholstery.

Adequate head clearance in the unmodified II-S had required removal of most of the seat cushioning to accommodate my tall seating height.

We had an excellent day for an evaluation flight: ramp temperatures in the mid sixties, calm winds, clear skies, and smooth air.

Brian quickly ran through the pre-start checklist and got us underway. I noted that we had twenty gallons of fuel in the wing and a full header tank. The two of us along with a few items in the baggage compartment put the center of gravity in the middle of the envelope. Significantly, the same load and distribution put the CG close to its more restrictive aft limit in the original II-S.

Taxi was uneventful. I did not feel that the longer nose adversely affected forward visibility during this phase. The additional length is obvious, but it doesn’t seem to get in the way. Differential braking for directional control was positive and effective.

Legroom and rudder pedal geometry was improved over the shorter II-S.

We began the takeoff roll essentially at gross weight.

The nose stretch and cosmetic filling required to bring the factory demonstrator to full Super II-S status has significantly increased the empty weight. Depending on builder installed gadgetry, current production Super II-S aircraft should average 100 to 200 pounds lighter than the avionics-hefty demonstrator.

During takeoff power application the rudder became fully effective as the throttle hit the forward stop.

Directional control was remarkably smooth and no differential braking was required to accurately track the centerline. My first experience with the new tail occurred as we achieved the 65 KIAS rotation speed.

I had speculated that the new aft wing location and resultant change in the landing gear geometry might require extra down force and a tendency to over rotate. I was wrong: the aircraft transitioned to flight smoothly and the pitch forces were firm enough to make the transition positive and easy to control.

Slotted flap hinge detail on N902S.
Slotted flap hinge detail on N902S.

Gear retraction required eight to ten seconds with no apparent trim changes. Flap retraction from the takeoff setting of ten degrees resulted in an almost negligible nose up pitch moment.

Due to the high traffic levels surrounding Lakeland, we chose to optimize forward visibility by establishing a cruise climb with the nose slightly below the horizon. With the power at a climb setting of 25″ and 2500 rpm we saw 1000 fpm on the VSI at 120 KIAS . The airplane felt solid in climb and trimmed up nicely. Rudder forces required to center the ball were light, confirming my hunch that rudder trim would be superfluous with 180 hp installed.

Once established in a climb away from the field, I pitched the nose up until we subtracted ten knots from the trimmed speed and released the stick: the moment of truth had arrived. This resulted in a remarkably tame, long period phugoid oscillation that damped completely in two and a half cycles.

After leveling at 7500 MSL I repeated the test at 155 KIAS with similar results. Upon release of a more ambitious twenty degree pitch input, the aircraft duplicated the well damped oscillation, returning to the trimmed condition in two to three slow period cycles. The oscillation is strongly damped. The nose bottomed out less than ten degrees below the horizon during the first cycle, and each cycle resulted in a smaller amplitude than the previous. Pretty docile response, a different animal from the original airplane. I was relieved.

The larger elevator surfaces and enhanced stability manifests as a more solid feeling aircraft that can be easily trimmed to maintain the desired attitude. Roll stability remains essentially neutral. If the controls are released in an angle of bank, the aircraft maintains the established angle without further pilot attention. This combination significantly reduced pilot workload in cruising flight.

A couple of cursory airspeed checks using uncorrected airspeed values were performed at 7500 MSL and an OAT of 16 C. Without referencing charts we set 75% power and saw 160 KIAS yielding a true airspeed of 182 knots at a fuel flow of 10.6 gph. At 65% and 9.4 gph we saw 155 KIAS for a true of 177 knots. That’s 3-5 KTAS faster than I saw in Arlington in the standard winged II-S using the same technique and under similar environmental conditions. Could be the extended wingtips working as advertised.

As an aside, I found that I could pick up a wing using rudder due to the enhanced dihedral effect of the extended wingtips. I don’t remember being able to achieve this with the standard wingtips. Extended tips might be a worthwhile investment.

We descended a few thousand feet and transitioned to the landing configuration. Pitch changes are nonexistent with gear extension. Flap extension causes a mild pitch down. We ran the stability checks in the landing configuration. Once established at 85 KIAS with full flaps, I induced a ten knot loss and released the stick. The result was the now predictable oscillation that died out in three progressively smaller pitch cycles. The oscillation was slightly less damped due to the lower entry speeds. Pitch feel and speed stability in this configuration were much better than in the unmodified aircraft.

At Brian’s suggestion we investigated the stall characteristics in the landing configuration. With the power at idle we experienced aerodynamic buffet approximately 3-5 knots before seeing any loss of lift.

If the back stick input was fixed at the value required to induce buffet, the aircraft would mildly pitch down to a slightly nose low attitude and fly out of the stall.

Continuing to hold the stick fixed resulted in a series of mild porpoises alternating between buffet and recovery. Easing the stick forward at buffet onset instantly stopped the buffet without causing the nose to pitch below the horizon. Ailerons remained effective during the maneuver.

A pilot would have to be remarkably inattentive to get into trouble in the slow flight regime. The aircraft exhibits a good buffet margin and recovers in a straightforward manner. Only an aggressive aft stick input (as in deliberate ham-fisted yank) after the onset of buffet resulted in a well defined stall break and pitch down. Sufficient aileron and rudder authority was available to stop any roll/yaw moments during the stall break. The aircraft recovered promptly as the aft stick was released and accelerated rapidly. Note: I failed to adequately warn Brian of my intention to investigate an aggressive stall. The fact that he sat calmly through the maneuver revealed his confidence in the aircraft. I apologized and told Brian that I had seen enough which prompted us to clean up and head for the busy Lakeland traffic pattern.

During descent the pilot has many options. For example, at 15″ and 2500 rpm we saw a 1000 fpm descent rate without much effort. Run the speed halfway into the yellow and a descent rate in excess of 2000 fpm is available if desired. The luxury of a 6 G airplane makes this high speed descent technique a viable option. A simulated engine-out glide yielded a descent rate of approximately 700 fpm with the prop at minimum rpm.

Lakeland tower asked us to make a short approach from a tight downwind. The airplane handled it well.

By extending the gear and using the full forty degrees of slotted flaps we were able to intercept a normal glide path as we rolled out on an abbreviated final at 80-85 KIAS. Speed control did not require excessive attention during this dynamic approach maneuver.

Again Brian’s exceptional poise was evident as he suffered through my premature flare and recovery.

The aircraft retained sufficient energy during the round out to forgive my unpolished technique with a well cushioned touchdown. I was able to hold the nose off and aerodynamically brake down to fifty knots before we elected to manually lower the nose to visually pick up our taxi director. Elevator authority and pitch feel were exceptional, my tendency to PIO in the unmodified II-S was absent. I expected to, but did not, find over the nose visibility to be a restrictive factor during the approach and landing. Differential braking provided good directional control with only minor braking required to make the assigned turnoff.

Once we had shutdown in the chocks I admitted being both relieved and impressed to have discovered a much improved aircraft. The aircraft met my objectives and should appeal to both the weekend sport pilot and the serious cross country traveler.

Prior to the flight I was asked to write my impression of the new Super II-S for publication as is… seemed awfully bold at the time, but I now understand that Stoddard-Hamilton has produced a beautifully handling aircraft that speaks for itself.

The fighter pilot side of me enjoyed the aircraft’s superb handling and performance. By any standard, the overall control feel is still light, crisp and precise.

Roll rate is comparable to an F14. Control harmony is much improved, making maneuvering effortless.

Nothing has been sacrificed in maneuverability. If anything, the superior control feel should make aerobatics very straightforward and enjoyable.

The old fogey airline pilot side enjoyed the improved stability as well as the enhanced utility and cockpit comfort. In contrast to my previous experience, the electric trim now functions as the workload reducing asset that it should be. The airplane trims solidly in all phases of flight. Throughout the flight the higher pitch forces of the increased span stabilizer reduced pilot tasking. The firmer pitch feel was perhaps the most appealing characteristic of the new aircraft.

In fact, the workload is now low enough that in spite of my growing appreciation for the utility of an autopilot in airline operations, I do not anticipate installing one. An aileron trim servo for the capability to trim out the weight of a passenger and take advantage of the neutral roll stability will be quite sufficient. That is about the only currently unavailable option that I’d like to see Stoddard-Hamilton directly support in the future.

I came away from the flight convinced that the modifications were worth the considerable time and financial investment of those involved in and affected by the redesign effort. The world of experimental aircraft is indeed unique in allowing ethical kit manufacturers to address problems and make required design changes. My hat’s off to Stoddard-Hamilton for the forthright manner in which they attacked and solved the II-S stability issue. A refreshing attitude that has resulted in a safer, more versatile aircraft.

Glasair Super II-S N902S

Flight report by: Douglas L. Dodson, Jr., CFI, FTE, Glasair II-S FT builder

Thank you for the opportunity to fly the new Super II-S. As an Air Force trained flight test engineer and an FAA trained CFI, I have some observations about the Glasair II-S that may be of interest to prospective buyers and low time pilots.

Part of the Air Force Test Pilot School curriculum is qualitative flight testing. All students are afforded the opportunity for one or two flights in a variety of aircraft (I flew 28 different kinds from gliders to fighters). Also included are three flights in a Learjet that can be made to handle like nearly any aircraft or simulate any CG loading (including a CG so far aft that the aircraft becomes unstable). I planned and conducted my flight in N902S as I did these flights.

The worst part is the reports that always seem to be required!

I had no data system on board other than my hands, eyes, and ears. All observations are qualitative in nature. I estimate the CG for our flight to be no further aft than the middle of the CG range. Payload consisted of no baggage, myself at 140 pounds, Bill Sprague at XXX pounds, and about 30 gallons of fuel. N902S has the enlarged stab/elevator, 6″ longer nose and aft wing location making it representative of the current kit design but not representative of most flying II-S’s. Airframe options included slotted flaps and the wing tip extensions (without fuel).

I conducted no performance flight test, preferring instead to concentrate on flying qualities. N902S is too big for me (Bill did not bring enough info packs for me to sit on). I had trouble seeing over the instrument panel and I could not reach the rudder pedals (not even close). Luckily, it is much easier to make a cockpit smaller than it is to make it bigger (it is not difficult to relocate the pedals aft). Bill did the taxi and takeoff (duh).

Visibility is excellent out the front, the sides and up (wonderful in the pattern). Visibility down is impossible. The pilots sit towards the aft of the low wing. This blocks all view of the ground within 10 miles while in level flight. Lowering a wing gives a good view of the ground closer to the aircraft. (5 degrees of bank and you can see the runway of downwind but remember, I needed some extra info packs to be comfortable). Seeing the runway on final was also a problem for me but now I’m beating a dead horse.

Longitudinal stability is very good. In the cruise configuration, short period frequency is shorter than typical production aircraft but damping is actually better. I observed no overshoots following pitch doublets (stick free). A wind-up turn to 3 g’s showed stick force to be steadily increasing with no tendency to overshoot or reverse. I would estimate about 2 pounds per g. This is much lighter than typical production aircraft (a 152 is about 8 pounds per g and a 182 over 20). What this means is altitude and airspeed are easy to track but a light touch is required. I found this to be extremely pleasant, the plane goes where you will it. The phugoid period is very long and lightly damped. This is a cruise mode.

Holding altitude should be no more difficult than any retractable single but if you neglect it, your deviation will take longer to occur and be much larger than in typical production aircraft.

Since I could not reach the rudder pedals, my observations in the lateral-directional axes is limited.

The ball remained about 1/4 left during a 100-kt climb and about half that at 140 kias. I had some trouble maintaining level flight during bank to bank rolls and steep turns due to not knowing the proper pitch attitude and being so low in the seat, but there was almost no adverse yaw. Stick forces were well harmonized with pitch. Bill gave me a rudder doublet and dutch roll was damped with 2 overshoots. This is almost identical to a 152. The dutch roll was mostly yaw, about a 4 to 1 yaw/roll ratio. I got no sideslip data. The aircraft would roll off to the right at about 2 degrees per second from a left or right 20 degree bank. This agreed with the ball. If I could reach the rudder pedals, that would not have been so.

During cruise this would be annoying but an adjustment of the trim tab, an autopilot or longer legs would correct the tendency.

In the landing configuration (gear and flaps down, 100 kias), short period damping was still well damped with 1 overshoot. Adverse yaw become more noticeable but feet on the floor is still not uncomfortable. The general feel is much less precise, stick forces are slightly higher and stick displacement is much greater. I preferred to pick my arm up off of my lap and grip the stick rather than hold it like a champagne glass as I did in cruise. Compared to production aircraft, the feel is similar to a 152, though control displacement is more in the Cessna.

Lowering the gear produced very little trim change.

Extending the flaps produced the typical change but since forces are so light, I felt no compulsion to rush to trim the force. The pitch attitude for level flight was lowered significantly with the gear and flaps down. I spent the entire pattern trying to get to landing speed, the Glasair doesn’t like to go down and slow down at the same time. I flew the entire pattern without the rudder, Bill handled the rudder through the flare and took the plane for the roll out.

I flared high (a common error according to Bill due to the very low stance of the Glasair II), so the touchdown was firm but there was no tendency to bounce.

The optional electric pitch trim rate was just right.

Fast enough to trim forces as fast as they build, but slow enough to predict. On downwind, I trimmed full nose up then full nose down and could handle the forces with no problem with one hand. I feel that since the forces are so low in the first place, electric trim is a luxury for Jet Jocks that don’t know what a trim wheel is and gadget freaks. It is nice, but by no means required.

I did no stalls. That’s what happens if you don’t write down what you plan to do!

I have made numerous references to “typical production aircraft”. There really is no such thing.

Typical high performance production singles have high control forces, are very stable in cruise and downright stiff in the traffic pattern. The closest thing I have flown which compares the Glasair is a T-34 Mentor. Stick forces are light, response is honest and its really fun. The Cessna 152 has slightly heavier stick forces but comparable stability (that’s right, it flies like a trainer!). There are some notable exceptions. N902S is equipped with retractable landing gear, a constant speed prop and a 180 hp fuel injected engine. This is more like a Piper Arrow.

Anther notable exception the reluctance for the aircraft to slow down. This is more like a Mooney.

This tendency will be more pronounced with fixed gear (retractable landing gear is draggier when extended than fixed gear with good fairings). Lastly is the altitude (over 18000 feet) and range (over 800 miles) capabilities of the Glasair.

Training considerations would be as follows. The complex systems can be left out (fixed pitch prop, fixed gear, lower horsepower) or a transition training course could be developed. This would be no different that a transition course available at your local FBO for checking our in an Arrow, C182, Mooney or the like. I have personally checked out 2 pilots with less than 100 hours in a retractable 182 (235hp). This is a much more difficult aircraft to fly because the pitch forces are so high that trim must be anticipated for smooth flying. Getting the Glasair to slow down requires careful advance planning (the 182RG has this problem too but not as bad as the Glasair). This can also be taught along with increased emphasis on shock cooling consequences.

The problem is not one of skill but of planning and judgment. Lastly, for low time pilots, the altitude and range capabilities will present problems never before encountered. Most of these are physiological and weather related, not aircraft related.

I would summarize by saying the Glasair II-S is an excellent handling aircraft. It handles more like a trainer than production high performance singles.

This is not to say transition training is not a good idea, but exceptional skill or proficiency is not required for normal operation. Please realize all conclusions are based on my own observations, without objective data collection equipment, on one 30 minute flight. Also, proficiency and training should be taken seriously. My point is not that training is not required to fly a Glasair, but rather any pilot can be trained without undue effort to fly a Glasair.

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