Tale of a Twin – the Vulcanair P68C
One of the most popular light, twin-engined aircraft of the eighties and nineties was the Italian manufactured P68 Partenavia, a six seat, high winged twin with non-retractable undercarriage.
The Partenavia’s external appearance has always made it stand out from the similar sized and much more prolific, low wing, Cessna, Piper and Beechcraft twins of that era but it found its niche in the private, business and training arenas and won much affection from its admirers.
The Partenavia factory in Naples commenced production of the P68 in 1972 and went on to deliver hundreds of aircraft around the world including nearly 50 finding owners in Australia. However, due to the decline in demand for new aircraft in the struggling GA market in the late eighties and nineties, the mainly government owned Partenavia mothballed the production facility. The manufacturing rights were eventually purchased by three Italian businessmen and Vulcanair was born with the Partenavia rising from the ashes, well mothballs, and becoming the Vulcanair P68C.
Very commendably Vulcanair started by asking the people who matter, the owners and operators around the world, what they liked and didn’t like about the P68: what worked and what could work much better. After this consultation process they set about producing an aircraft that has kept the strengths of the old P68 e.g. the ever popular Lycoming engines, but has been altered and additions incorporated, to strengthen an aircraft that already had an excellent reputation for versatility and reliability.
I had the opportunity to test fly the Vulcanair when Charles Gunter, Vulcanair’s Australian distributor, flew into my home base on a delivery run to Bunbury Aero Club. The busy aero club recognized the P68C as the ideal platform to cope with the growing demand for charter and training out of Bunbury.
Outwardly, the Vulcanair appears little changed from its predecessor, the most noticeable addition being the swept up wing tips. This is an aerodynamic enhancement to improve the P68C’s handling in turbulence and to give crisper control response. A perfectly smooth day did not give me the opportunity to test the former but control responsiveness was excellent at all airspeeds.
Another more obvious change has been the necessary addition of a pilot door, unfortunately not on the pilot side but, nevertheless, a welcome relief for former Partenavia pilots who were forced to inelegantly board the aircraft through the passenger door and then squeeze themselves between the passenger seats to get to the front row. Although a little bit of effort is still required to clamber over the right hand seat and around the controls, it is a great improvement.
Also altered for increased instrumentation space is the slight angle that has been introduced to the nose profile which had been a straight line from the top of the windscreen to the nose tip. One of the less obvious external changes is the increased loading on the spring steel undercarriage and heavy duty brakes to help overcome an old overheating problem. Similarly additional strength has been the result from using two actuators to the rudder and stabilator, removing a mandatory 50 hour inspection formerly applied to the P68.
The Partenavia wing spar was time-lifed, originally at 8,000 hours prior to being upped to 13,000 hours. A re-engineered and strengthened spar has made this requirement obsolete: an important factor when considering maintenance costs.
Inside the aeroplane the changes and modernisations are much more noticeable. The extremely comfortable reclining seats are high-backed and the rear four can be arranged in traditional or club seating style with a quick, simple method of changing between the two. In the cockpit there is ample leg room and the seats can be adjusted forward and aft as well as in height. It is not an overly wide aircraft but there was no claustrophobic feel about it. The passenger compartment is accessed through a door on the left hand side with no acrobatic manoeuvres required to climb in and out. The rear baggage compartment is accessed through a large cargo door on the right and can hold a very useful 122kg. Easy removal of the seats enables the aircraft to be quickly converted into the freight configuration to allow carriage of bulkier items and increased weight. A nifty little additional feature is the seatbelts which are fully contained within the seats leaving no dangling seatbelts to stow or store away when carrying cargo.
The new state of the art glass cockpit is well laid out with the Sagem Integrated Cockpit Display System and Primary Flight Displays set on either side of the avionic panel with the necessary analogue instruments found at the top. Fuel pump and magneto switches are easily to hand on an overhead panel with the electrics to the pilot’s left.
Settling ourselves in the cockpit, we worked through the straightforward checklist to fire up the engines. The P68C remains powered by two Lycoming IO-360-A1B6 engines each producing 200hp with two bladed, hydraulically operated, constant speed Hartzell propellers as standard. There is also a turbocharged version available with an option of three bladed props on either model.
On the ground the P68C is easy to handle with good visibility over the nose and to the sides. Having set the required take off flap, 15º, fuel pumps on, and obtained a take off clearance, applied full throttle, the aircraft smoothly powered its way along the runway. The Vulcanair boasts a minimum take off distance to 50ft as 400m and it was clear to see that this would be very achievable. The acceleration was great and we were soon airborne, climbing out at the recommended 90kt. Flaps are retracted at about 500ft with a very noticeable nose down pitch, quite a lot of back pressure being required to hold the airspeed but with a yoke mounted electric trim to help. The climb performance on two engines is great and we arrived at circuit height without adjusting the power to its climb setting. No worries though – the Vulcanair can be flown at full power continuously if necessary. Further climbs with climb power set and at best rate climb speed achieved climb rates of 900 fpm and more at sea level.
75% power will produce a TAS of 160kt in the normally aspirated version with fuel usage at this setting quoted as 75lph: very economical compared to most twins. A reduction to 65% power drops the fuel consumption to 69lph and gives the long range version, with its 670 litres of usable fuel, an endurance of almost 10 hours. Standard tanks contain 520 litres of usable fuel. The fuel system is another area that has benefited from Vulcanair listening to Partenavia operators. Increased safety has been achieved by simplifying the system; it is now simply ‘on’, ‘off’ or ‘crossfeed’ with the inboard and outboard tanks interconnecting and self-levelling.
The Vulcanair turned out to be a delightfully easy aircraft to fly. Although it has a MTOW of 2084kg it was very much like flying a bigger, faster 172 or 182; it sat well in the cruise when trimmed and was easy and light to manoeuvre. The first part of our flight was spent in a slow cruise as we conducted some air to air photography. Dropping the power to 17” and trimming out a relatively high nose attitude, the airspeed stabilized at around 100kt but there was no slow speed heaviness about the Vulcanair – the controls remained light and effective with manoeuvres being effortless.
But no point in having a twin and flying at 172 speeds so with the photoshoot complete we upped the power to 24” and 2350 RPM and started the fun bit. This cruise power setting achieved 145KIAS with impressively crisp control responsiveness. Even steep turns required no power increase with the visibility in the turns being excellent with the high wing far enough behind the pilot not to block the view. Visibility from the passenger seats is also excellent thanks to the high wing and large windows, an important consideration for passenger charter operations.
The aircraft’s stall characteristics are docile in the extreme; in level flight the control column has to be completely aft requiring significant effort. There was a slight stall buffet and minimal altitude was lost in the stall. Even holding the aircraft in the stall there was no tendency for a wing to drop and it was easily unstalled with slight forward pressure. Next we looked at the P68C’s single engine performance. In the cruise configuration it was simple to control the resulting yaw and to set it up trimmed in single engine mode. The IAS dropped to around 110kt but the aircraft still felt light on the controls and was easy to turn even against the operating engine. Setting up a simulation of an engine failure after take off with 15º of flap, take off power and climb out speed required a little more effort. Rudder pressure was manageable short term with full trim eliminating control pressure completely. The rate of climb though dropped to 150fpm, quite low considering there were only two of us on board.
Returning to the airport requires a bit of forward planning with no undercarriage to extend to slow the aeroplane to a suitable speed to fit in with slower traffic. I brought the power back to 18” but also had the option of extending the first stage of flap at a whopping 151kt. I waited until we had joined the circuit to take flap and had the aircraft at a manageable speed to start the approach. I admit to being a bit of an approach freak when I’m in a larger aeroplane: the increased speed means you must stay ahead of the aircraft and it’s a real buzz to set it up correctly and land it well. It is recommended to bring the Vulcanair in at 75kt, well below blue line speed of 90kt. I left it higher than this on base and early final, about 85kt, but dropped it to 80kt after taking the final stage of flap. A further reduction to 75kt on short final and a smooth reduction in power over the runway lead to a nice touch down for which I gave myself the credit but I suspect the Vulcanair is always straightforward to land if the approach is made at the correct speed.
The P68C is an aircraft that will follow its predecessor as a machine that will fit well into a variety of roles. Its useful load of over 700kg makes it a far more attractive option than other six seat twins that have much lower load carrying capabilities. It will fit well into both the passenger and freight charter categories, will make an easy initial twin trainer with its simple systems, but is perfectly equipped for personal and business use with its comfort and spaciousness ideal for long distance trips.
Economic considerations are top of the list for operators and the Vulcanair meets this demand well. The low fuel consumption is a huge plus in these days of soaring fuel prices; the non-retractable undercarriage not only saves weight to increase payload but also saves a not inconsiderable amount on maintenance costs. In addition, the aircraft has been designed with easily accessible servicing points to save time, and thus money, during maintenance. In effect, the Vulcanair offers the running costs of some large singles with the added safety of the additional engine.
It is always sad when anything popular with its own set of aficionados ceases to be made and, in the case of the Partenavia, this was definitely the case as it was an aircraft with such a variety of uses. That it is being manufactured once more is a decided bonus for general aviation and I am sure the Vulcanair will become as well known and loved as its predecessor.