Paul Phelan/CAIRNS
There are still light-aircraft owners who mentally associate buyer-assembled "kitplanes" with two-stroke engines, wooden propellers and doped fabric stretched over wire-braced wings with alloy tube spars attached to plywood ribs.
The reality is that many home-built aircraft are now more sophisticated that any single-engined general aviation (GA) aeroplane now in production. If these aircraft could overcome the traditional certification barriers, they would be able to breathe new life into a market which began to stagnate when US product-liability lawsuits forced the big manufacturers to shut down most of their piston-single production in the early 1970s.
MARKET ENTHUSIASM
Unhampered by the spectre of product liability, however, kit manufacturers have established a notable share of the GA market. Having developed advanced products and manufacturing techniques, some are now seeking certification for aircraft factory-built using the same technology (Flight International, 17-23 June).
A market which has largely been deprived of innovative GA design for many years is cheering them on. A certificated aircraft with the performance of the Lancair IV kitplane, for example, could become a major challenger to Mooney, New Piper and Raytheon, the only US manufacturers still producing high-speed, four-seat, light aircraft.
An aircraft like the Lancair IV, as yet available only as a kit, has potential to satisfy two separate markets as a certificated factory product. First is the private owner who might pay around $500,000 for a fully equipped Piper Malibu or Raytheon Beech Bonanza, and who would be attracted by the capability to cruise at 25,000ft (7,600m) and 300kt (550km/h). Second is the market for single-engined commercial air-taxi aircraft, now typically unpressurised, and elderly Cessna 210s, Bonanzas and Piper Comanches with cruising speeds of 150-170kt and with maintenance costs which are escalating with age.
Lancair has chosen to pursue certification of the lower-performing Columbia 300 as its first foray into factory production of GA aircraft. If the Bend, Oregon-based company ever succeeds in gaining certification for a high-performance aircraft like today's Lancair IV, it could revitalise the GA piston-single market with a new level of capability.
FLYING THE IV
Flight International was offered an opportunity to fly a Lancair IV, newly completed by Qantas Boeing 737 captain Gary Burns, who has since established provisional records on the first legs of a round-the-world flight which started from Australia on 15 July, already recording average groundspeeds of up to 282kt on sectors of around 4,600km (2,500nm).
Burns bought a "standard" kit, but the aircraft has since become available as a "fast-build" kit, for which the factory completes the wing structure, with ribs and spars installed and flaps and ailerons complete, along with most of the fuselage structure, including the firewall and all bulkheads, and with the wing aligned. Lancair international sales manager Mike Schrader says that the fast-build model still meets the US Federal Aviation Administration's regulation that the home builder perform at least 51% of the work require to complete the kit.
"The FAA has a checklist, and we go through it and fill in what the builder and the manufacturer do, but there are some areas where the regulations allow us to do more work. For example, there is no restriction on the work we do forward of the firewall, and we can build the instrument panel and looms. If the customers opt for that, as most do, we're very close to doing 49% of the work," he says.
Lancair, which has produced more than 1,400 kitplanes, has sold about 300 Lancair IV kits, with almost 100 flying, including two in Australia, one of which is pressurised. Burns waived the pressurisation option to save about 110kg (250lb) of added weight, and also chose not to install optional speedbrakes to maximise fuel capacity in the two integral wing tanks.
Burns says the project cost him about $140,000 and 6,000h of work, but he admits that this time could be reduced with experience.
The blend of ultra-low drag - visually evident in the smooth finish of wing and fuselage - and the huge Teledyne Continental TSIO-550E1B twin-turbocharged, fuel-injected, engine promises impressive speed and range. The engine, a derivative of that powering the Piper Malibu and a turbocharged variant of the powerplant in the latest Bonanzas, is flat rated to 260kW (350hp) at 2,700RPM and 38.5in (980mm) manifold pressure. It drives a three-bladed Hartzell propeller, and sustains full climb power to 23,000ft.
Primary wing and fuselage structure is carbonfibre in an epoxy resin matrix over a Nomex honeycomb core, with the exception of the vertical fin, where glassfibre is used to provide a propagation medium for enclosed radio antennas. The fuselage and wing come as top and bottom halves, the fuselage sections provided with "joggle" overlaps which are bonded directly and further reinforced with glassfibre.
The main spar - made of unidirectional carbonfibre running spanwise to the tip - is pre-bonded to the upper wing skin at the factory, while the ribs are fabricated by the builder and bonded to the upper wing surface and spar before the wing is "closed" by bonding to the lower surface.
The wing area is 93m² (100ft²), and the 15.6kg/m² (32lb/ft²) wing loading at the 1,450kg maximum take-off weight is close to that of a McDonnell Douglas DC-9. Large Fowler flaps reduce stall speed from 68kt to 61kt. Electric-hydraulic undercarriage retraction appears similar to that used on the Cessna 210, but an ingeniously simple mechanism provides fully mechanical retraction of doors with the gear either retracted or extended.
Entry is through a single door over the left wing, a horizontal cabin width of 1.17m (46in) giving ample shoulder room and excellent seating comfort for two relatively large people. Sidestick controls, to which the unaccustomed pilot will adapt in minutes, add to the feeling of cabin space.
Burns' aircraft is equipped for instrument flight rules (IFR) operation, but there is spare room in the wide panel for the autopilot, still awaiting installation. Extensive use is made of modern JPI Electronics backlit instruments in which digital readouts are supported by an analogue-style light array.
All circuit breakers are on a separate engraved panel, and the aircraft is wired with two auxiliary power outlets for a laptop computer and satellite communications, as well as being internally plumbed with electronic-demand oxygen outlets for four occupants, supplied from a tank providing 50h at oxygen for two.
The castoring nosewheel is steered by differential braking, and rudder control becomes effective at about 20kt. The wraparound windows and raked windshield provide excellent visibility in every phase of flight except final approach, where it is slightly limited by the high nose angle.
Acceleration is as brisk as expected, given the power available, and normal rotation is at 65kt. Burns has installed a safety device which prevents gear retraction below 95kt, to stop inadvertent retraction on the ground. Maximum rate of climb speed is 123kt, providing about 3,000ft/min (15m/s), but we opted for a cruise climb at 160kt indicated airspeed (IAS), achieving a steady ascent rate exceeding 1,300ft/min. An altitude of 25,000ft was achieved in 22min at 160kt and the climb rate did not change until we began to lose rated power at 23,500ft.
Engine cooling at cruise climb is good, with cylinder head temperature reaching only 210° near the top of climb (the limit is 238°C), dropping to 182°C as we picked up speed.
At 25,000ft, airspeed builds quickly to 210kt IAS for a true airspeed of 310kt, and a cruise fuel consumption of 75 litres/h (19.8USgal/h) at 75% power. The 450 litres fuel capacity at long- range cruise power (about 65 litres/h) gives a total endurance of almost 7h. (Burns had another tank fitted for his round-the-world flight.) High-speed cruise consumption is 83 litres/h.
The aircraft is extremely stable at altitude because of the winglets, necessary to meet Australian yaw/roll-coupling stability requirements for IFR approval. The winglets change the effective dihedral, adding stability without reducing speed, while also slightly decreasing the wing loading. Cabin noise is moderate, and conversation is not difficult without headphones and intercom.
GENTLE STALLS
Descent requires jet-style forward planning, to avoid the shock cooling of hot engine components. Burns recommends starting the descent with a manifold pressure reduction of only 1in/1,000ft, or 3in/min, while reducing power from 70% to 40%, and achieves that by beginning descent at a distance calculated as 5.5km from destination for each 1,000ft.
Stalls are quite gentle in all configurations. At 61kt with flap and gear extended, stalling induces a high nose-up attitude, and warning buffet is so ample that the Australian authorities did not require installation of a stall warning device. Any small wing drop can be picked up with rudder, and the aircraft is flown out of the stall by lowering the nose slightly and increasing power. Clean stall occurs at 68kt.
The aircraft has been spun inadvertently in the USA and occupants reported that they lost considerable height because they built up so much speed in the recovery. The Lancair is not certificated in Australia for aerobatics, but Burns (a former Australian aerobatic champion) believes that a smooth barrel roll could be achieved in about 4s.
Although the ailerons are slightly stiff at high speed - as would be expected - all controls are briskly responsive at lower speeds and handling in the circuit is superior. The Lancair IV would present no surprises to any pilot competent in a Bonanza. Maximum flap speed is 168kt IAS, and 150kt IAS for the gear, but slowing to those speeds requires pre-planning. Using a circuit speed of 120kt IAS and a target threshold speed of 80kt IAS, controllability is excellent right to the touchdown, which occurs with little float.
The jaded pilot of more conventional aircraft who really enjoys flying is likely to remember every moment in the Lancair IV.
Source: Flight International
