The Liberty XL2
The Liberty XL2 is the sole aircraft produced by US company Liberty Aerospace who, since gaining full production certification for the aircraft in May 2006, have delivered more than 100 aircraft; fairly decent stats considering the glut of new two and four seat aircraft which have appeared on the market after decades of coping with an ageing training and private sector fleet.
The XL2 in Australia received its type certification during the 2007 Avalon air show and thus became probably the only aircraft there to be trailered into the air show but flown out. It was initially marketed by its manufacturer as a two seat touring aircraft: a market which has, until recently, been sadly neglected. In the past, in order to obtain the comfort and load carrying capabilities necessary for cross country cruising, most options involved four seats and, while there are families and friends who flit around the country on a regular basis, the majority of touring aircraft contain only two people and two wasted seats. The wasted seats equate to additional purchase or rental costs and additional upkeep and fuel costs.
In a rebranding exercise, Liberty Aerospace has changed its marketing tack to concentrate on the aeroplane’s frugal operating costs. This a shame really as there are plenty of new aircraft out there that are as, or more, economical to run than the Liberty LX2 but there are few, if any, two seaters that can match the Liberty’s comfort and spaciousness.
A chassis of welded chrome steel tubing has been fashioned around the 48” wide cabin providing attachment points for the wings, landing gear and engine and designed to carry all ground and flight loads. It forms a frame around the cockpit which, together with the carbon fibre constructed fuselage, gives excellent strength and crashworthiness with great corrosion resistance. The computer controlled construction of the major components and its modular design enable parts to be replaced with exact replicas in the minimum time possible, thus saving on maintenance costs and downtime expenses which is particularly important when the aircraft is used for commercial operations. Liberty boasts that the wings can be removed in less than 30 minutes, utilizing a system where an electric motor mounted in the aircraft is used to drive three wing bolts which hold the wing on and can be withdrawn in the same manner. This not only saves on maintenance time, if the wings are required to be removed, but also means the aircraft can be easily ferried in a small sea container with minimum fuss.
The sleek shaped aircraft with its aluminium control surfaces, fixed tricycle undercarriage and small vertical fin presents as a very attractive aeroplane. The XL2 is powered by a fuel- injected 125hp rated Continental engine with a fixed pitch wood composite propeller. The engine produces a commendable 132kt cruise speed at 75% power and features Continental’s Powerlink FADEC – Full Authority Digital Engine Controls – with its computerized, electronic ignition system. Gone are the magnetos, priming system, mixture and carby heat. Basically, the pilot is there to start the engine and the FADEC does the rest. It has been described as idiot proof with just the throttle inputs left to the pilot and it certainly simplifies engine management. As the FADEC monitors all engine operations several times a second, it is probably much safer than a hopefully regular but sometimes neglected pilot monitored system but it does leave one feeling slightly redundant.
The system monitors throttle setting, RPM, CHT, EGT, fuel pressure, temperature, pressure and adjusts the mixture and timing throughout flight. The set-up comprises two computers run from the alternator with two batteries for redundancy. If the No.1 control unit fails, the second will take over instantly and the engine continues to run. Each control unit has two independent FADEC systems, FADEC A powered by the main bus while FADEC B is powered by a back up battery which is isolated from accessory loads.
In addition to this fully electronic system, the engine is fully diagnostic and warns the pilot of anything which is exceeding limits: the computer providing a full history of every engine parameter which is downloadable after each flight – invaluable for maintenance purposes.
To give the pilot something to look at and admire while he is feeling completely redundant, Liberty has incorporated a digital display on the left side of the panel which displays RPM, percentage power, manifold pressure, fuel pressure, oil temperature and pressures and electrical output. All of which read exactly what they should as the engine is being monitored by FADEC – sort of taking the proverbial by placing it there at all.
Thanks to the lack of many engine gauges, the instrument panel is tidy, uncluttered and modern. Only the presence of the trusty, still required mandatory instruments, remind the pilot that it is an aircraft and not a computer. The twin Garmin430s in the centre of the panel complete the modern picture and provides the little aircraft with a fabulous avionics package.
After being shown around and having checked out the exterior of the XL2, Liberty’s Australian distributor, Nigel Hutchinson-Brooks, then demonstrated the technique of installing oneself in the cabin with the minimum amount of fuss. This involves sitting on the (thankfully) low wing, shuffling backwards on one’s backside and then climbing into the cabin legs first. Actually not as difficult as it may have been thanks to the huge gull wing doors giving easy access. But a foot and hand hold somewhere would simplify and possibly dignify the procedure.
The doors, even though huge as mentioned, are solid and close easily and quietly – none of the old Cessna slam required here and the visibility offered by their design is fantastic. The extra wide cabin has comfortable, carbon fibre seats upholstered in leather with a wide console between the seats containing the hand operated brakes with pitch and roll control offered by use of a central control stick. Adjustable rudder pedals and a 42” high cabin make this a comfortable and spacious setting for even large pilots.
Starting the engine presented no problems; fuel pump on and activate the starter switch, the FADEC system comes to life and does the rest. Start checks, as with all other checks, are minimal. After a few beeps and flashes all engine gauges were reading correctly and being monitored habitually by me but more regularly by FADEC. The Liberty has a full castoring nosewheel with differential finger brakes. This method takes a little time to adjust to and initially I was pleased there were not too many other aircraft parked in close proximity for the start of my taxi practice but it does not take long to get the feel of the brakes and steering and it allows the Liberty to turn exceedingly well on the ground.
Using one stage of its electric flaps for take-off, the XL2 accelerated away quickly and in very little time and distance we were climbing away from the runway and retracting the flap to achieve a climb speed of 80kt. Not much of a trim change is required when retracting flap and what was needed was achieved by a momentary tap on the panel mounted trim control. Climb rates are good in the Liberty with a maximum rate of climb in the vicinity of 880fpm. My climb rate on the day was an effortless 700fpm with a comfortably high nose attitude. Control response throughout the flight was excellent with control rods rather than cables producing excellent responsiveness.
The visibility in all phases of flight was brilliant thanks to the large windows which extend back well behind the seats increasing safety throughout. Turning was effortless with just a touch of rudder to balance and very little back pressure to maintain height. The extra weight of the aircraft over most other new two seaters makes for a more stable ride as well as increasing its attractiveness as a tourer with its useful load of 272kg and heaps of baggage space behind the seats to boot. Fuel consumption is miserly: even at 75% power and 130kt it will only use 21 litres per hour. Reducing the power setting to 65% still achieved around 100kt and would reduce the consumption rate to around 15 litres. Not a gas guzzler by anyone’s standards and, with a range of 500nm, it deserves to be recognized as an ideal cross country machine.
Checks throughout were minimal with the FADEC only neglecting to deflect and retract the flap, something I’m sure will be offered by someone one day soon. Approaches to the runway were stable and easy to control but the power does need to be reduced positively to slow the Liberty down and to lose height. Taking full flap reduces the speed to its final approach speed of 65kt and is simplicity itself to land, requiring a bit of back pressure in the hold off to keep it from settling onto the runway too quickly. I was probably a little cautious of the castoring nosewheel during our touch and go landings but I managed to keep it fairly straight with the engine powering right back in as soon as the throttle was advanced.
A comfortable, fun aeroplane to fly, Liberty has also been designed with low maintenance costs in mind. Aside from the computerized print-out of engine parameters throughout flight, there are no magnetos to overhaul, no vacuum system to check, the control rods are less time consuming to check than cables and the XL2 has far fewer inspection panels than conventional aircraft, saving costly time and making the engineer’s life easier. With maintenance costs a major component of operating an aircraft, any savings in this area that don’t compromise safety are very attractive for private owners and flying schools alike.
With a base price of approximately $AU190,000, depending on the exchange rate of the time, the Liberty is not the cheapest of the available two seaters but, for what you get for your money, it leaves the lighter two seaters well behind and compares very favourably with its only real competitor, the Diamond DA20-C1. Slightly more expensive, the Diamond has a slightly higher cruise speed with a similar range, fuel usage and useful load.
As a training aircraft, the LX2 may have to wait for the rest of the aviation trainers to catch up. Learning to fly in a Liberty will be fine if you are not going to fly anything else but if you do, remember to do an awful lot more engine monitoring. But as a touring aircraft, it makes a very attractive package. It’s comfortable and enjoyable to fly, it’s stable, which is so important for those longer flights, responsive in control and very comfortable. Its suitability as a touring aircraft is obvious with the benefit of baggage space, comfortable seats, a good range and fuel flow with high levels of safety and reliability. If you are in the market for a two seat touring aircraft, take the Liberty of trying this one.