Point and shoot

Since this was to be a homebuilt flying under the Experimental classification, a certified aero engine was not required. The humble and inexpensive Volkswagen Beetle motor would be more than good enough to power these lightweight, low drag airframes. Not surprisingly, KR-2s soon became very popular, with thousands of sets of plans sold worldwide, and hundreds of examples claimed to be flying by the end of the decade.

The type’s efficiency and low operating cost derive not only from its wood framed, fibreglass skinned, lightweight construction, but also from the Volkswagen engine power, for few other two seaters can fly behind this frugal air cooled motor. The really big thing is that so few Volkswagen powered aeroplanes can go quite so quickly. Ken claimed a maximum cruise speed of 156 knots or 180 mph at sea level, although, like all such claims, this should be taken with a generous pinch of salt. However, the type does have comparatively impressive cruise performance with low fuel consumption. It achieves this by being extremely light, with a very low wetted area, which in turn means it is short and compact.

The KR-2 has a simple wooden framework, with foam formers and a glassfibre skin. Its fuselage is basically a wooden box (known to Rand aficionados as ‘the boat’) with a flat bottom, tapering sides and a turtledeck of fibreglass skinned foam. The wings have twin built up spruce spars and foam ribs, as do the empennage and control surfaces. Many builders spend months filling and sanding the glassfibre’s weave to remove all undulations and even the tiniest of corrugations. While this usually results in a beautifully smooth finish, it adds weight, sometimes a lot of weight, depending on the type of filler and its depth, so often the less pretty but lighter examples actually fly better than the pristine but overweight ones.

The outer wing panels are detachable, leaving a short centre section (out to just past the main undercarriage legs) integral with the fuselage. The wing bolts and attach plates can be problem areas and the originally specified bolts were not truly big enough, so they should be carefully inspected.

Cables operate all the KR-2’s controls, which are all foam and glassfibre sandwiches, and quite generous in size for this small airframe. The engine is generally a Volkswagen of from 1,835cc upwards, although there is no reason a Jabiru or other engine of around sixty horsepower or more should not be used. This example had a 2,074cc Aeropower conversion, using a single magneto directly driven off the crankshaft’s rear end, with dual spark plugs and a secondary ignition system using a Hall-effect trigger in what was originally the dynamo hole.

The Rand’s main undercarriage legs are suspended on either end of a transverse lateral beam with very little up-and-down travel. The suspension is provided by torsion in this short beam, and it has perhaps ten centimetres of up and down travel. If either wheel rises too far (for instance from fast taxying or landing heavily on rough ground) it can hit and damage the underside of the wing’s top skin, so it is always preferable to fly a KR-2 off a bitumen or concrete runway, rather than from grass.

Being amateur built, you can expect all KR-2s to be a little different from each other. Most will have a higher canopy than the one I flew, so their forward visibility would be better (possibly much better). The original base line KR-2 was very basic, short and light. For comparison, the Turbulent, Taylor Monoplane and Corby Starlet single-seaters are all higher and longer, and only the Starlet has a smaller span. Few completed KR-2s will be as light as the prototype’s claimed 200 kilos, but you do need to be sure that you can carry your planned passenger if you want to fly one as a two-seater.

A subsequent development was the KR-2S with a sixteen-inch fuselage extension, two and a half feet more wing span and a new, three inch higher canopy, all of which must make a huge improvement in runway performance, forward visibility and handling, although they would certainly increase the weight and probably reduce the top speed.

Some later examples have a wider cockpit and/or additional wing tanks, and there are a few with fixed undercarriages and/or nosewheel landing gear. Longer span tailplanes and these and fins with more area are available, all of which should improve its pitch and yaw stabilities, while usefully allowing a wider centre of gravity range. New aerofoils have also been developed, claiming ten knots more top speed, but with both better climb performance and improved low-speed handling.

Unfortunately Ken Rand was not a big guy, and it is often difficult to complete the airframe within his stated weight, so although some KR-2s are true two seaters, most (like the example featured here) should be considered a roomy single seater that can be flown occasionally and over short ranges with two occupants. Nevertheless, a few years ago, one British couple did fly their KR-2 all the way out to Australia – a truly impressive undertaking!

To sample the KR-2, you step up a mere fifteen centimetres on to the small wing walkway, then down into the cockpit. Grip both fuselage sides to take your weight, and then carefully slide your legs forward under the instrument panel, ensuring you don’t skin your shins or inadvertently snag the landing gear downlock cables just ahead of the main spar. Sit down, strap in, and pull on the slim cable behind your head to lift and close the canopy.

Headroom and knee room were just adequate for this six-footer. At only ninety centimetres (0.9 metre) wide, this cockpit would be very snug with two men in it, but nevertheless full control throw is easy on both of the short control columns, and the stick forces are very light. Combined with those relatively big control surfaces and the airframe’s ultra-light weight, this suggests snappy handling.

Step on the toe brakes, switch on the master switch, twist open the fuel cock, pull out the choke knob, pump the throttle plunger twice and crack it a quarter-inch, turn on both ignition systems (this engine has both a magneto and electronic ignition), select “start’ and the diminutive propeller spins into life with a most un Volkswagen like purr, thanks to that full width silencer under the cowlings. Check the oil pressure, release the brakes and you’re slowly, gently away.

There are no springs in the tailwheel steering linkage, making it direct and excellent, with a nice tight turn radius at full pedal travel, but super fine precision at small deflections. The brakes are okay, but Allen has warned me they won’t hold the aeroplane against more than 2,000 rpm and I’ve already noticed they judder a bit, but for low speed manoeuvring, they’re fine.

Thanks to a non standard, super sleek Lancair canopy and my rearward seating position, the forward visibility is not very good over to the right, and ahead it’s only just acceptable, although it’s fine to the left; but I’ll have to rely to some extent on peripheral vision while the tail’s down on the runway. I’ve optimised my seating position with conformal foam cushions, so this is the best I can do, with my head hard up against that finely tapered canopy, and leaning slightly inboard.

The engine run up was straightforward, and that Hall effect electronic ignition was indistinguishable from the magneto, with similar rpm drops. With no flaps or electric fuel pump to worry about, pre departure checks were similarly minimal although, given the aeroplane’s history, I was particularly careful about checking the dual canopy bolts, double hinge latches and mechanical secondary lock. Allen suggested I should first try a few high speed runs, to get the feel of this very short coupled aeroplane, and who was I to disagree?

Lining up carefully, I opened the throttle slowly and guardedly, but I needn’t have worried. Acceleration was surprisingly rapid, and directional control was no problem, with just the lightest of left pedal pressures being needed to straddle the centre line. Within seconds I was able to raise the tail cautiously, immediately revealing a brilliant view of the runway speeding inches below my backside, and still there was no inclination to wander. Then I gently closed the throttle, and immediately understood Allen’s caution. The tail dropped almost immediately, and I over corrected for the tiniest tendency to veer right, promptly finding myself treadling the pedals to stay within reach of the centreline.

This aeroplane would be easier to fly off a grass runway, but its short undercarriage legs with their minimal spring travel would need a lawn bowls quality surface. After a couple more high speed runs on the narrow tarmac of Serpentine’s longest runway I quickly got the hang of it, and returned to discuss the situation with Allen before attempting flight.

That’s when I discovered that, despite its wing’s trusty and conservative RAF 48 aerofoil and stout eighteen per cent thickness chord ratio, the KR-2’s very shortness gives it a rather restricted centre of gravity range. I am taller and heavier than Allen, so he had to remove his normal seat and cushions to improve my leg room. The result was that my increased weight was further aft than his, so for my high speed runs the aeroplane had been very close to its rear C of G limit, if not perhaps slightly beyond it. For this reason, Allen has two removable one kilo ballast weights attached to his stern post. Undoing these and topping up the fuel tank to 33 litres moved the C of G forward into the safe range, and so now I could safely go flying.

This time I had no difficulty straddling the centreline, the tail rose gently as speed increased, and after around 300 metres I was airborne at 45 knots and accelerating nicely. I could have retracted the wheels there and then, but elected to raise the nose, peg the airspeed at seventy and climb to 500 feet before attempting any internal gymnastics or possible external aerobatics.

The undercarriage mechanism is in the cockpit’s centre, to the right of your inboard knee on the main spar’s forward face. First, you pull on the upper toggle to withdraw the locking pins via cables – although Allen suggested it would be easier to press down on the mechanism’s upper knuckle. This allows the main gear’s transverse beam to swing to the half way position under air loads. Then you push the lower toggle forward until the whole, very visible mechanism rotates through ninety degrees. There was a satisfying double click as the pins popped into the up-locks, easily checked, and I sensed the acceleration as, relived of nearly half of its drag, this nippy little aeroplane surged upwards.

Both the VSI and my stopwatch measured 800 feet per minute – which is not half bad under Volkswagen Beetle power, particularly on a red hot 35°C day! The controls were light and effective, and I needed just a slight left rudder pressure to keep in balance.

Reaching 3,500 feet, I first let the aeroplane accelerate, and then retarded the throttle to 3,200 rpm, at which the Rand steadied at a commendable 120 knots indicated, or 125 knots/144 mph TAS. Reducing a little to 3,300 rpm gave 125 knots IAS, while a gentle 2,800 rpm still returned a steady 95 knots. All these numbers are extremely good when you consider this two litre VW burns only from eight to twelve litres per hour, giving a fuel consumption of over fifty mpg in the old numbers – and that’s at over 120 mph as the crow flies!

As you might expect, this short coupled little aeroplane was only just stable in pitch – but as befits a professionally designed aircraft, it was positively stable, and even under full power in the climb, which is usually the limiting case. It was also surprisingly strongly stable in yaw, considering its short fuselage. Unfortunately, we must have removed rather too much tail ballast, because I had to slide the trim lever fully rearwards after take-off, and there was still a small residual pull force needed in all flight phases, so it was difficult to precisely establish roll stability, but I would say it was probably neutral.

I have to say I was pleasantly surprised at the Rand’s handling, which was much better than I had expected. It is a lively, responsive, point and shoot aeroplane, with nice, crisp controls and a good, fighter sharp roll rate, but not at all twitchy or squirrelly. Control forces were comfortably light in all three axes, and it needed the merest breath on the rudder to coordinate turns. I have to say, its general handling was exemplary.

And so were its low speed manners. Completely closing the throttle caused a very slight pitch down, and the speed was slow to decay, but it gradually unwound through sixty, fifty and forty knots, when a slight trembling buffet started in the airframe. Finally, at 38 knots the stall warner sounded, and at 37 the nose gently nodded away. Holding the stick back against the stop merely caused it to rock and wobble, still in light buffet, but there was never any untoward behaviour. Allen had warned me of a left wing drop, but provided the ball was centred, I experienced no such phenomenon.

Even at just 45 knots indicated, although it felt mushy, there was still good control in all axes, while setting 1,800 rpm depressed the stall speed to 35 knots. Looking out at those tiny wings, I was amazed at the Rand’s good manners, however a glance at the VSI revealed a trap. The needle was pointing was well down past 1,000 feet per minute. So, now I knew why Allen used a higher than expected approach speed.

With that sink in mind, I thought it prudent to fly a couple of practise approaches and go arounds at altitude, carefully observing the VSI throughout. In fact, I could find no problems, and everything went well at Allen’s recommended speeds, even during prolonged sideslips and slipping turns at 55 knots, although full rudder did cause some airframe buffet. I even practiced cycling the undercarriage a couple of times to get used to that. The only factor of note was a slightly increased requirement for stick back pressure when the wheels were extended (as you would expect from their position). This made it a little more difficult to hold the airspeed accurately in check, but of course that was preferable to the airspeed decaying if I was distracted.

Back in the circuit, I followed Allen’s advice, reducing airspeed early to enter the downwind leg at eighty knots. Easing further back on the stick to decelerate to 75, and reaching forward to my right, I pulled first on the upper undercarriage toggle and then on the lower one to extend the wheels. At this airspeed it was not difficult, and Allen has extended them in an emergency at over 100 knots, although he says the pull force does become higher with increased speed.

Flying a curved base leg at seventy knots with 1,600 to 1,800 rpm gave me the best visibility of the runway. Reducing speed on final to sixty raised the nose, causing my view to deteriorate, but I could still see enough for accurate positioning. A little right rudder sideslip helped considerably, although it did further increase the required backpressure.

Slowing to 55 knots as I crossed the fence, I tilted my head back to raise my eyes right up to the canopy for the best possible view. Unfortunately, that had me peering though the magnifying, reading part of my bi-focal sunglasses, so I had no alternative but to open the throttle and go around. There was no sink, although the Rand did take a couple of seconds to accelerate to seventy knots, after which the manoeuvre was routine.

Everything was easier without the sunglasses, and the merest of flares led to a positive three point touchdown after I gently pushed off the drift. As Allen had advised, I simply let her roll, concentrating on steering while holding the stick fully back of course, as Allen had warned me of his aeroplane’s tail lightness. Slowing to a walking pace within perhaps 500 metres without any braking, I finally squeezed gently on the brakes at around twenty knots and turned off the runway.

I would say this was not the easiest aeroplane I’ve ever flown, but it was far from the most difficult, and it was tremendous fun – very rewarding. A higher canopy would have made it much less demanding, and you will be hard pressed to find a sleeker or faster two-seater on Volkswagen power.

Sidebar: A KR-2 owner/builder reports

Allen Buzza is the 65 year-old proprietor of Aviation Signs. Having flown since 1971, he currently has 350 hours, but before flying his KR-2 had only flown Cessnas and PA-28s, plus ten Jodel hours and two in the Rand’s right seat with an instructor.

So pleased is Allen with his KR-2 that he is well advanced with another, longer KR-2S, so he might be prepared to sell this, his first one should anybody be interested.

How long has he had it?
“I built it over a fourteen year period, and first flew it in 1997, but then had to almost completely rebuild it again over another five years after a high-speed forced-landing when the canopy flew open immediately after take-off. Remarkably, the canopy was undamaged and my only injury was a compressed vertebra, so now I use energy absorbing cushions.”

Allen says, “It is a very strong airframe. I know, I’ve tested it to destruction!”

Allen says, “I fly twenty to thirty hours each year, mostly just flying and having fun.
I like it because it looks good, and flies ‘point-and-shoot’ like a Spitfire.”

“It is cheaper to run than a car. I do my own annual checks and change the engine oil and adjust the tappets every ten hours, but the cost is negligible – say $100 per year plus insurance and hangarage, which aren’t much for such a small aeroplane. Apart from the damage repairs, after ten years, my only significant maintenance costs have been replacing worn control cables and out-dated flexible fuel lines.”

How does it perform?
“I reckon on a 120-knot cruise, with four hours safe endurance, which takes me 500 miles. A realistic payload is myself, full fuel (56 litres) and a 60kg passenger. It will fly from a 500-metre runway and copes with up to ten knots of crosswind.”

Like many prized homebuilts, KR-2s don’t often change hands, and good ones fetch reasonable prices, although still generally less than production aeroplanes. If you would enjoy flying a spirited but frugal aeroplane, you could do worse than try a Rand KR-2.

ENDS
3,281 words
© R J Grimstead 2009
THE RAND KR-2
Dimensions
Wing Span 6.30 m
Wing Area 7.43 sq m
Length 4.42 m
Height 1.07 m
Seating 1+1
Weights & loadings
Equipped empty 287 kg
Max take-off weight 500 kg
Standard fuel 56 lit
Max wing loading 67.29 kg/sq m
Max power loading 6.25 kg/hp
Manufacturer’s quoted performance
Sea level Vne 186 kt
Max speed 156 kt
Max cruise (5,000ft) 156 kt
Economy cruise (12,000ft) 148 kt
Stall 39 kt
SL take-off dist 244 m
SL take-off run 122 m
SL landing dist 305 m
SL landing run 152 m
Sea Level climb rate 800 fpm
Service ceiling 16,000ft
Engine: One two-litre Aeropower Volkswagen conversion producing 80 hp at 3,600 rpm
Propeller: two-bladed, all-wood, fixed-pitch propeller.
Price: Featured aircraft, perhaps $40,000
For plans and an information kit, contact: Jeanette Rand at: 7071 Warner Ave, #F, PMB 724 Huntington Beach, CA 92647-5492 USA. Tel: +1 714 898 3811.
There is a big Rand builders’ forum at: https://www.krnet.org