Once Kolb’s FireStar was a new design; a second-generation evolution for the company then headquartered in Pennsylvania. The first Kolb single-seaters were later joined by the TwinStar, the company’s original 2-seater, all of which preceded the FireStar series.
Under the direction of Homer Kolb and Dennis Souder, the original Kolb Company followed their success with the FireStar by creating the Mark III 2-seater, FireFly single-seater, and SlingShot tandem 2-seater. They also worked on but never released the Laser.
In 1999 Bruce Chesnut and Brian Blackwood purchased Kolb Aircraft from Dennis Souder who, along with other partners had owned the enterprise since 1994. Chesnut and Blackwood renamed the company The New Kolb Aircraft Company and moved it to new facilities at the Chesnut Knolls Aviation Foundation Airpark in London, Kentucky.
The Kentucky-based company has focused on model revisions such as the Kolbra and King Kolbra, and the Mark III Xtra. Most recently, The New Kolb Aircraft Company has entered the powered parachute market with their Flyer, and to the proposed Light-Sport Aircraft segment with the Pelican Sport 600.
Our subject this month – the FireStar – is one of the oldest models from the company. Even though it’s a senior model, it remains one of the company’s finest in delivering an “ultralight experience.”
I had flown this particular FireStar back in the summer of 1993. Since it’s been repainted, factory airshow demo pilot Dick Rahill thought it was a little heavier than the original version. It’s a single-seater, though the addition of a second seat can be done later. Ray Brown, representing the factory, says, “The FireStar can be built for one or two occupants.” Formerly, if you wanted to add the second jump seat to the FireStar you built the two planes somewhat differently. If the older version was to be flown solo only and have no aft seat, you used only five wing ribs versus seven per side for heavier loads. Today, the factory makes the FireStar only with the seven-rib wing.
Update the FireStar?
Rahill said the factory has considered putting a wider nose on the FireStar much like they’ve done with the Mark III Xtra version. Rahill doesn’t care for the wide nose – he said some people had referred to it as the “catfish look” – so some buyers may not want to see a changed nose. I doubt it would accomplish anything other than making the new line look more similar. Contrarily, the change was useful on the Mark III, giving both occupants more foot room and keeping you from having to angle your legs toward the center of the aircraft. In the FireStar, you already have enough foot room and the negative leg-angling characteristic does not apply. Some buyers might like a sleeker appearance, but many prefer the appearance the FireStar has sported for many years.
We’re back to the theme of staying with what works and the FireStar works very well. It has also proven itself with a long service in the field, a fact that distinguishes it from newer designs.
The FireStar is also a simple ultralight-like design. It has few systems, looks best without an enclosure – though the company has one they’ll be happy to sell you – and behaves so much like an ultralight that it is in name only a registered aircraft. Since the FireStar doesn’t meet the 254-pound empty weight definition of FAR Part 103, you must presently have N-numbers and an FAA pilot’s certificate to operate it. The New Kolb Aircraft Company intends to participate in the proposed Light-Sport Aircraft category, as evidenced by their acquisition of distribution rights for the Pelican Sport 600. The company hasn’t yet decided to qualify the FireStar for the proposed new rule.
For the record, New Kolb still makes the FireFly, which does meet the parameters of a Part 103 ultralight even when powered by the 40-hp Rotax 447. Around 100 of the FireFly models are flying today and the company is committed to continue production. All other participants in the company’s model line are either 2-seaters flown for instructional purposes under an exemption to FAR Part 103, or aircraft that must have FAA registration.
Fortunately, the FireStar remains very ultralight-like in its qualities. As Rahill so enthusiastically demonstrates day after day at airshows, the FireStar can leap off the ground in 100 feet, climb swiftly at a remarkable angle, handle lightly and briskly, and fly at “ultralight speeds,” by which I mean mid-50s cruise and stall down in the 30s.
I enjoyed flying the FireStar back in the early ’90s and I enjoyed it again, immensely, in the early 2000s. Time may change, but a good time in the air doesn’t. The FireStar delivers this feeling so I find no reason for Kolb to alter a formula that works.
You enter the FireStar by sitting down in the seat and swinging your legs inside. This is easiest to do when you select the windscreen as flown for this report. Cold-climate pilots will be happy to know of an extended windscreen design and even a full enclosure, but those choices will make for a more challenging entry.
Seated in the FireStar’s seat, I noticed two differences from the earlier model evaluated. The original model used a sling-style seat that supported me in a rather angled back posture. Once aloft, with the tail raised, the FireStar’s old seat felt good, ventilated excellently, and held me at the right angle.
My renewed experience with this FireStar placed me on a solid construction of aluminum sheet and padded upholstery. The lean-back angle seemed less and some will prefer this. It also felt comfortable in flight though the seat surfaces are flat and small, the padding thin, and the lack of shape meant no lumbar support. Aloft for an hour, the FireStar produced no ill effects for me though a longer flight might be different.
The FireStar’s few systems are convenient. Right below the pilot’s left leg are two kill switches. You can easily reach them even with the 4-point seat belt system cinched down securely. It’s vital to have engine kill capability while strapped in tightly.
Above my head I found a remote choke. This is convenient yet out of the way and an easy routing from the engine. Heel brakes angled back at me in an accessible manner that didn’t cause me to bump them accidentally. Differential brakes like these often have value when the pilot is maneuvering in tight quarters.
I was pleased with another change – that from a shoulder belt to 4-point restraint. Shoulder belts are far superior to lap belts (which aren’t enough for many incidents) but not as good as four or five points. The FireStar’s cockpit layout is such that you can have your belts tightened and still be able to see a huge swath of space all around you (except up and back).
At the end of my flight, I tried the pull starter just to be sure it was possible to use in flight. The FireStar’s tight belts were again assets as I could pull against them. The engine fired up readily, though it had just been running. I never tried the in-seat start with a cold engine. On my initial takeoff, I got outside help with the start; who doesn’t like a little service?
Taxiing the FireStar with its differential brakes proved effortless. After a pretakeoff check, I wheeled into position. Now, I have a lot of taildragger time, so it’s not always easy for me to spot the harder-to-handle models. Despite my “experience bias” I believe Kolb to be a very easy taildragger. As you look at the photos you’ll see the deck angle, or angle formed by a longitudinal centerline of the airframe relative to the ground, is very shallow. This helps reduce ground loop tendency. The FireStar’s tail is also quite light and the tail boom is quite long. While the boom’s rearward mass adds to the tendency, its long displacement works to lessen ground loop potential as the tail is in clean propwash soon after power is added. Finally, the FireStar leaves the ground so quickly – less than 100 feet with me aboard – that you are quickly flying and not rolling which eliminates the ground loop tendency altogether.
Partly because it is a taildragger and for other reasons, I don’t recommend the FireStar to very low-time novices. The model’s strengths can prove to be possible problems for inexperienced pilots: fast launch, steep climb, responsive handling.
In this particular FireStar it took a fair amount of left rudder on takeoff to hold a runway line. Rahill said he had observed the characteristic as well and said he would just put a fixed trim tab on it. Though Rahill had forgotten to tell me about the quality before my takeoff I didn’t find it to be any problem as controls are quickly responsive and powerful enough to control minor problems.
Fast and Light
The FireStar may not be a particularly fast cruising design, but it certainly is quick in handling. The ailerons are especially quite responsive; not surprising when you look at their barn-door size when viewed from the tip. The rudder is less powerful but put them all together and most pilots will find the FireStar to be quick and easy in the handling department. Not everyone prefers such qualities. For example, long cross-country trips can be tiring if you must fly the plane constantly.
However, the FireStar has been refined over the years to be a very precise machine. Despite low-resistance handling, I found the model to hold a line quite well with little input.
When I flew the FireStar, Rahill told me it had a spring that went aft to pull the nose up somewhat. It required forward stick pressure to hold it in position. Providing trim adjustment is easy for owners by fitting a light spring on the joystick to help move it in the desired directions. More ambitious builders might prefer to add in-flight trim. As it turned out both FireStars I’ve flown needed some constant stick pressure.
Several years ago while testing the FireStar flight envelope, Rahill discovered some aileron flutter in the design (at speeds beyond listed Vne) which is why it now has mass balancing at the wingtip. The weight made the ailerons feel somewhat heavy on the ground though I didn’t notice it in the air.
The entire series of old Kolb designs – FireStar, FireFly, SlingShot and the Mark III “Classic” – have never been known as fast cruising ultralights. I saw 50- to 60-mph cruise speeds without pushing it, based on the installed instrument (the accuracy of which I could not determine). But Rahill reports that after mass balancing the ailerons he has taken the design to speeds beyond Vne to test the results. He reports seeing “30 on the go-around” of the installed airspeed indicator, by which he means the needle went past the 80-mph top number. Such an indication might mean 110 mph if the gauge works that way.
In my experience, I found 50 mph to be the most comfortable speed – relative to arm position and my preferred power setting to reduce noise and vibration.
If I didn’t push forward a little on the stick, the speed would back off to around 40 mph. The spring Rahill says was attached to the pitch controls pulled the nose up, yet the regular pilot is a lightweight fellow, Rahill says, so an aft-loaded spring doesn’t make much sense. A light pilot in the FireStar would more likely want to increase the tendency to lower not raise the nose, since the other main weight of the fuselage is the aft-positioned engine.
As in my earlier experience, I have great respect for the wing design prowess of original Kolb designer Homer Kolb, with help and some modifications from Dennis Souder. Not only is the wing very high lift – accounting for the rapid launches and aggressive climb – but the stall characteristics are also highly predictable.
The FireStar, and all other Kolb models I’ve flown, show a clear and clean stall break with the nose dropping. Except for full-power stalls, which become a little mushy, stalls tend to fall over straight with no observed tendency to regularly drop a wing. I prefer breaking stalls as they are easily identified; though some pilots prefer highly stall-resistant aircraft, which tend to not produce breaking stalls.
Even in accelerated stalls, the FireStar rolled toward level as part of the recovery process. Since the stalls are well down into the 30s (I saw 34-38 mph, but cannot verify instrument accuracy), landing approaches can be made as slowly as the mid-40s once the pilot has some experience. Approaches at these speeds make for small field requirements and short rollouts in the range of 125 feet.
A New Kolb from New Kolb?
The time value of money – more simply known as “inflation” – has its ongoing effect on prices. Something worth $8,000 in 1993 would cost about $10,400 today, based on steady 3% annual inflation. In 1993, the original Kolb company under Homer Kolb sold the FireStar for $7,995 with a Rotax 447. Factoring in the effect of inflation, the old Kolb Aircraft price would be about $10,400 today, or $11,200 with the 50-hp Rotax 503.
The New Kolb Aircraft Company prices the FireStar at $8,296 without engine. With a Rotax 447 today’s total should be about $11,500, a price premium of $1,100 in a constant-dollar comparison. If you prefer the Rotax 503, New Kolb figures the total at $12,500. The New Kolb’s 10.5% increase over the time-adjusted 1993 price reflects a fairly modest difference, which might be explained as an acquisition cost generated when Chesnut and Blackwood bought Kolb Aircraft.
My point with the math is that the FireStar remains a very effective purchase in today’s ultralight market. Of course, you’ll have to N-number it as even a simply equipped FireStar exceeds the weight limits of Part 103. You’ll have to build the design -– and it’s considered a significant project by many builders. Under FAA’s proposed Light-Sport Aircraft category, the FireStar might be available as a “90% kit” or even fully built. Naturally the latter option would raise the price considerably. However, The New Kolb Aircraft Company has not yet determined how they will sell the FireStar model with regard to the proposed new rule. At this time, the model must remain in the Experimental category, requiring an FAA inspection and certificate.
Facts and figures set aside, you must remember the FireStar is a Homer Kolb creation. It flies wonderfully and has attracted a large following with nearly 600 examples built and flying. The New Kolb Aircraft Company has wisely not changed the venerable design much. As a pleasant-flying, lighter-handling, fast-takeoff machine, the FireStar is nearly perfect. If you have a few dozen ultralight hours in your logbook, you should look this design over thoughtfully.
|Seating||1 (2 optional)|
|Empty weight||280-300 pounds 1|
|Gross weight||725 pounds|
|Wingspan||27 feet 8 inches|
|Wing area||140 square feet|
|Wing loading||5.2 pounds per square foot|
|Length||20 feet 3 inches 2|
|Height||6 feet 3 inches|
|Build time||350-400 hours|
|Notes:||1 280 pounds with Rotax 447; 300 pounds with Rotax 503, though company says “325 pounds typically.”
2One foot longer when wings are folded.
|Standard engine||Rotax 447 or 503|
|Power||40 or 50 hp|
|Power loading||18.1 – 14.5 pounds per hp|
|Cruise speed||60-70 mph|
|Never exceed speed||90 mph|
|Rate of climb at gross||650-800 fpm|
|Takeoff distance at gross||100-125 feet|
|Landing distance at gross||125 feet|
|Standard Features||Rotax 447 or Rotax 503 engine with B gearbox (though engine not included in kit price), factory-welded 4130 chromoly steel fuselage structure, folding wings and tail, steerable tailwheel, shoulder belt seat restraint, 5-gallon fuel tank.|
|Options||Hand lever or differential heel brakes, extra 5-gallon fuel tank, C or E gearboxes, full enclosure, streamlined struts, strobe light, electric starter, ballistic emergency parachute system, instruments, 2- or 3-blade composite prop, and various assembly options from finished wing ribs to a quick-build kit (cuts assembly time to 200-300 hours, says factory).|
|Construction||Aluminum wing structure with shaped aluminum wing ribs, welded steel fuselage, 7075-T6 aluminum landing gear legs, fiberglass nose fairing, Lexan windscreen, dope-and-fabric wing coverings. Made in the USA.|
Cosmetic appearance, structural integrity, achievement of design goals, effectiveness of aerodynamics, ergonomics.
Pros – Despite altering their Mark III and creating a new Kolbra design, The New Kolb Aircraft Company recognized that you don’t change what works; Homer Kolb’s 15-year-old FireStar model remains one of the best. Well-recognized and proven. Very clean and simple. Quick-folding wings still popular.
Cons – Without a 26-hp Rotax 277 (which it can use) the FireStar is too heavy for Part 103. Taildragger design with robust climb performance is not for all novices. Build time/effort is daunting to some, though Kolb offers quick-build options.
Subsystems available to pilot such as: Flaps; Fuel sources; Electric start; In-air restart; Brakes; Engine controls; Navigations; Radio; (items covered may be optional).
Pros – Pull starting is reasonable from the cockpit seat (though I accepted outside help). Overhead choke control. Kill switches easily reached under your left thigh. Refueling done in easily accessed area with good ventilation. Engine access is excellent with small ladder or chair.
Cons – Add many goodies and you’ll add unnecessary weight to this simple design. With 4-point belts you’ll want to keep switches off the control panel unless you have long arms. Small instrument panel can only hold the basics.
Instrumentation; Ergonomics of controls; Creature comforts; (items covered may be optional).
Pros – Pilot’s view in the FireStar is why many fly this design: huge. Seating, though basic, is comfortable. Four-point belts in test FireStar. Fuller windscreen available if desired. Entry is simple; start by sitting. New paint on the old factory FireStar looked good.
Cons – Windy cockpit if using the small windscreen; get a helmet. Some won’t feel adequately enclosed and too far in front of the wing. Stick hits your legs in the FireStar’s rather narrow cockpit (though I never lacked full control). You can create a larger enclosure if you wish but why?
Taxi visibility; Steering; Turn radius; Shock absorption; Stance/Stability; Braking.
Pros – The FireStar’s ground handling is good thanks to its long tail displacement; good tailwheel authority with light pedal pressures. Low weight at tail and nearly flat deck angle make this taildragger easier than many. Firm gear feel (no bungee). Traffic-check visibility is superb. Differential steering with heel brakes.
Cons – If you are psyched out by taildraggers, the FireStar may not interest you – or the buyer you hope will buy it (it’s is easy as taildraggers go, but many pilots aren’t convinced). Heel brakes take more concentration than toe brakes, most agree. No other negatives.
Qualities; Efficiency; Ease; Comparative values.
Pros – Low mass aft and a flat deck angle help reduce ground loop tendency; it’s much better than some taildraggers. Ground roll is very short and climb is fast with a breathtaking angle; good for obstacle avoidance making some short fields usable. Good control authority for crosswind landings. Sink rate lower than average. Massive visibility during approach.
Cons – The FireStar’s climb is so powerful and steep, some pilots overdo it. Glide is not as long as I expected from this clean design; you should anticipate this for approaches. Carry adequate speed on landings; ground effect kinetic energy bleeds away. No flaps. Slips aren’t very effective due to small vertical surface.
Quality and quantity for: Coordination; Authority; Pressures; Response; and Coupling.
Pros – Kolbs have always boasted light, fluid handling; the FireStar has continued the earlier tradition for many years. Stick forces reduced along the way for improved control linkage, says factory. Alteration also gave more feedback. Roll rate is middle of the field. Adverse yaw is moderate.
Cons – Adding the mass balancing and the changes made (see “Pros”) make controls somewhat more ponderous; you feel their mass on the ground. Control harmony is good but ailerons overpower the rudder slightly. No other negatives.
Climb; Glide; Sink; Cruise/stall/max speeds; Endurance; Range; Maneuverability.
Pros – The FireStar’s performance and handling package is one of the best in ultralight aviation; both very good without being overwhelming. An exception is Kolb climb: simply stunning, particularly the angle. I can’t think of any design that will outclimb a Kolb (assuming comparable engines). Clean design makes for rapid acceleration with a Rotax 503. Lower rpm will still hold the FireStar aloft, a good sign of efficiency.
Cons – Rapid climb performance and angle may be overload for novices (experienced general aviation pilots have also been fooled). High cruise speed is better on some other designs if that’s your goal. Glide is weaker than I expected (though sink rate was good).
Stall recovery and characteristics; Dampening; Spiral stability; Adverse yaw qualities.
Pros – Stalls are quite predictable and occur at low speeds (about 35 mph). Banks at medium steep angles held angle well with little input (better than the Mark III). Adverse yaw is modest, surprisingly so for a design with large ailerons. Test FireStar came with 4-point seat belts as many prefer.
Cons – Stalls do break convincingly though easily controlled. Couldn’t perform pitch stability checks due to nose-light trim condition; I had to push forward lightly most of the time (an easily corrected problem). Like all Kolbs, throttle response is reversed: high thrust line pushes noses over.
Addresses the questions: “Will a buyer get what he/she expects to buy, and did the designer/builder achieve the chosen goal?”
Pros – The New Kolb Aircraft Company has done the Kolb tradition well; keeping the FireStar is one good decision. Well proven. If built carefully, should last a long time. Durable design both in longevity and market acceptance over a long time. Priced reasonably. Good manuals. Testing has been thorough. A pilot with a few hours can hardly go wrong with a FireStar.
Cons – Building the FireStar is said to be time-consuming though an optional quick-build package can speed things. Beginning pilots should proceed slowly (true of most new planes). Sold from the factory which means phone or e-mail builder support (no local dealer help).