FLIGHT TEST: Piaggio Avanti II - Hard to beat

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Piaggio Aero Industries has just delivered its 100th P180 Avanti, almost 20 years after the twin-turboprop business aircraft first flew. Many of those sales have been achieved since the long-established Italian manufacturer was reinvigorated by its mid-1990s takeover by a group of private investors. Now Piaggio has introduced its first major upgrade of the P180. With improved avionics and systems, the Avanti II replaces the original beginning with delivery of the 105th aircraft in November.

avantiThe P180 turboprop first flew in 1986 and was certificated and delivered to its first customer in 1990. Sales to date have been split roughly 60:40 between the USA and Europe. Production is running at around 20 a year and, with a backlog of 70 orders, a sale today translates into an early 2009 delivery. Airframe sections are produced at both Genoa and Finale, but final assembly and flight test are carried out at Piaggio’s plant at Genoa International airport. Aircraft can be completed either in Genoa or in the USA, currently at Stevens Aviation in Greenville, South Carolina.

The pusher-turboprop Avanti still looks as futuristic as when it first flew two decades ago. The small fixed forward wing gives the Avanti a fighter-like look and is unique in commercial aviation. Use of a lifting forward wing means that the rear horizontal stabiliser is also a lifting surface, resulting in a 34% decrease in main wing area. The three lifting-surface design is patented by Piaggio and even the fuselage is shaped to add to the aircraft’s total lift.

Up close the narrow-chord wing looks like it came from a high-performance glider. Piaggio says low-drag laminar flow is maintained to around 50% of wing chord, compared with around 20-25% for conventional tractor turboprops where propeller wash disturbs the airflow over the wing. The highly streamlined fuselage also maintains laminar flow to about 30% of its length, the company says.

An underlying reason for this ability to maintain laminar flow is the quality of surface finish. Although the Avanti is 90% aluminium alloy, the fuselage and wing look like they are moulded from composites because they are so free of surface imperfections. The reason for this is a Piaggio-patented construction method whereby the airframe panels are held in place in the jig during assembly by large vacuum pads so that the frames and ribs can be riveted from the inside. This makes for an exceptionally smooth surface finish and reduces drag.

The result is that the Avanti offers jet-like performance: a cruise ceiling of 41,000ft (12,500m), with a cabin altitude of only 6,600ft; a maximum operating speed of 260kt (480km/h) indicated/Mach 0.7; a maximum cruise speed of 398kt true; and a range of nearly 3,320km (1,800nm) with visual flight rules reserves. This range requires a fuel capacity of only 1,270kg (2,800lb) given that its specific air range at high altitude is 3.4km/kg (0.84nm/lb) compared with around 2 for current jets or 2.7 for other turboprops. The Avanti has no natural turboprop competitors, and its closest jet rivals are the Raytheon Premier I and Cessna Citation CJ2+.

Combined with certification for Category II instrument landings, steep approaches and flight into known icing, and the Avanti has the ability to operate on runway lengths of only 1,070m at maximum weight. The cabin provides a stand-up height of 1.75m and a width of 1.85m, dimensions only bettered by super mid-size jets. The cabin can seat up to nine in a corporate shuttle layout, six typically in the VIP role or two stretchers with attendants on a medevac mission. The Avanti is certified for single-pilot operation, but Piaggio say most operators prefer to fly with two pilots, and a crew of two is mandated for Cat II approaches.

Uprated engines

avanti The principal performance upgrades in the Avanti II are the uprated Pratt & Whitney Canada PT6A-66B engines that give increased power at altitude and an increased cruise speed at maximum continuous power of 398kt at 30,000ft. The airframe has also been recertificated to raise maximum take-off weight (MTOW) and maximum landing weight (MLW). MTOW is increased from 5,240kg to 5,465kg and MLW from 4,965kg to 5,195kg. This equates to an extra two passengers at the maximum fuel load of 1,270kg, or 1,043kg of fuel with the maximum payload of 907kg. Either way this greatly increases the Avanti II’s flexibility and choice of cabin configuration.

The biggest advances since the introduction of the aircraft in 1990 have been in navigation and safety systems, and a completely redesigned cockpit is central to the Avanti II upgrade. This is designed to keep the aircraft abreast of current and proposed aviation regulations for the foreseeable future, and the combination of the latest avionics and jet-like performance should allow the Avanti II to hold its niche market position against the latest light jets such as the Citation CJ2+ or Premier I.

At the heart of the upgrade is the Rockwell Collins Pro Line 21 integrated flightdeck, featuring three 200 x 255mm (8 x 10in) liquid crystal displays. The outer screens function as primary flight displays (PFD) for each pilot and the central screen as a multifunction display (MFD) shared by both. PFD modes are managed by individual display control panels mounted vertically on the instrument panel adjacent to and inboard of the appropriate LCD. MFD modes are controlled by a cursor control panel mounted on the central console just aft of the throttles and forward of the single FMS-3000 control display unit (CDU). The FMS-3000 flight-management system is GPS-based and is linked to dual attitude/heading reference systems as well as DME and VOR receivers. The FMS provides both lateral and vertical navigation (LNAV/VNAV) guidance to the dual-channel, three-axis autopilot.

The main displays are complemented by a radio tuning unit (RTU) that is used to select all VHF communications, VOR, ILS, DME, ADF and Mode S transponder. Additionally, weather radar, TCAS 1 traffic collision avoidance system, terrain awareness and warning system, emergency locator transmitter and a digital combined standby instrument are fitted as standard. Options include the ability to display Jeppesen charts (airport, approach and en route) on the MFD.

Piaggio has not just placed electronic screens on top of an existing cockpit layout to create a part-digital, part-analogue flightdeck, but has totally redesigned, relocated and logically grouped all the other systems switches and gauges to present a cockpit that now looks clean and as modern and well laid out as any new competing type.

There is an adage in test flying that states that “equipment doesn’t equal capability” and this is equally applicable to avionics upgrades. Displays and functions may look great in a glossy brochure, but the acid test is how well they work. Based on my experience of EFIS-equipped aircraft, including fully integrated types such as the Bombardier Global Express and Hawker 800XP, and “hybrids” such as the Avro RJ100, my remit was to assess how well Piaggio has incorporated the new avionics in the Avanti II.

Piaggio chief test pilot Marcello Vitale was the safety pilot for my evaluation of the Avanti II in September, in Genoa. The aircraft was the Avanti II testbed, registered I-PJAR. This is an early P180 prototype that was modified as the test aircraft, and its cockpit represented the new avionics in virtually all respects.

After about 60min of cockpit brief and avionics familiarisation with Vitale, we were ready to start and taxi. Rather than undertake more extensive ground preparation, I felt that if I was instinctively able to operate the aircraft, manage the communications, navigation and autopilot functions and interface easily with the displays, then the overall package would work well for other pilots new to a fully integrated cockpit, but having the benefit of an extensive ground school and simulator type course.

Logical layout

The Avanti is a DC electrical aircraft and an external power cart allowed us to load all FMS and route data and keep the displays fully powered during the 60min briefing (the aircraft has internal DC power that allows the FMS to be programmed before engine start over shorter durations). All engine start and run switches are centrally and logically located in one panel at the forward end of the centre console just ahead of the throttles.

A rotary test switch on the base of the console was used to check all ancillary systems such as hydraulics, electrics and de-ice, and the aircraft was ready to taxi 3-4min after engine start. Take off was from runway 29; wind was 11kt from 030°; temperature 19°C, aircraft fuel was 1,090kg, giving a take-off weight of 5,020kg; V1/VR was bugged at 106kt indicated for the mid-flap setting. Final take-off speed was bugged at 160kt. The flight director (FD) was set to go-around mode (the vertical bar set to 8° nose-up to cater for engine failure).

Take-off roll and rotation were simple to achieve and the FD easy to follow, but the aircraft was rotated initially to a nose-up pitch attitude of 12° once a two-engine climb was assured. Modes were then changed to heading and flight level change and the FD followed to achieve a speed of 160kt. Hand flying to follow the FD was easy and natural in these basic modes with no irregularities. The PFD screens were clear and well defined. I liked the enhanced PFD overlays that showed sea (in blue) and coastlines, airways, danger areas and training areas.

Levelling off at flight level (FL) 080 (8,000ft) while hand flying was easy, although the 1,000ft-to-go caution horn was a little loud in my opinion (Vitale says the volume is being reduced in the production aircraft). Pro Line 21 does not provide an amber mis-compare alert if different altimeter pressure settings are used on the two PFDs, so good operating procedures dictated that we both ensure the standard pressure had been set on our own PFD.

I engaged the autopilot and evaluated its modes, including height capture both above and below present altitude using both flight-level change mode with varying speed selections and vertical speed mode with varying vertical rates. The modes were accessed through the glareshield flight guidance panel and the mode and engage buttons were well separated and labelled. The altitude, heading, speed and course change knobs were easy to distinguish, with good tactile cues to tell them apart. The flight guidance panel has no “preset” windows, and the buttons have no internal “selected” lights to show engagement, so all selected parameters are shown in the PFD.

The autopilot was smooth and linear in all “basic” modes. The same result was obtained in VOR radial capture mode and FMS LNAV capture mode. The PFD display of the boundaries of the training area we were using was excellent, including changes in displayed range and I knew at all times where I was in relation to the airspace around me. At present the aircraft does not have an autothrottle or a thrust rating panel that can be used to set speed or thrust settings. Speed changes were so smooth and the internal feel so “jet-like” that I had to closely watch my speed control, as the airspeed presentation was a standard vertical tape/rolling digit display.

The weather radar and TCAS 1 dis­play modes were easy to operate. Comm­uni­cation/navigation frequencies and transponder codes were easy to set or change via the single central RTU, which could be reached and seen clearly by both pilots. The FMS CDU was well positioned on the console between the two pilots seats, but reprogramming it would be a task for the pilot not flying. The CDU was clear and logical, the buttons easy to find and press and I liked the use of colour and the data-required boxes that needed to be filled before operation.

Unplanned diversion

We then evaluated an unplanned diversion to Albenga to carry out a localiser/DME approach to runway 27. We had no Jeppesen paper charts; I had never been to Albenga and had not studied the approach; I had only been airborne about 25min in the Avanti II and gave myself less than 5min to set up the approach. With Vitale doing the radio we turned from the training area at FL080 towards Albenga about 40km away at a cruise speed of 200kt.

avantis

He entered a “new route to” in the FMS CDU; I bought up the approach plate in the central MFD, and set the required frequencies and course from the displayed chart. I descended, lowered flaps and gear, briefed Vitale on the height/range calls, and took radar headings and approach capture. The aircraft captured the localiser smoothly, with no sign of overshoot or non-linearity, and I flew the descent in vertical speed mode, adjusting my rate based on information given to me by Vitale, but which I could also read from the chart display on the MFD. At the minimum descent altitude, I was properly positioned to land at Albenga.

The Avanti II had passed the test: the aircraft, avionics and crew “package” had operated in harmony to carry out a non-precision approach safely and efficiently, and the avionics greatly assisted a pilot new to the aircraft, the airspace and the airport. At all times my situational awareness was high, and I was always in full control of the aircraft and its configuration. It was an impressive demonstration of the capabilities of the aircraft’s upgraded systems.

Instead of landing I carried out a go-around (GA). This entailed pressing the GA button on the left-hand throttle, following the FD, raising gear then flap, and selecting LNAV on the flight guidance panel to follow the full missed approach procedure as detailed on the FMS. The go-around in the Avanti II does not disconnect the autopilot, so the procedure was simple and straightforward. Since Albenga lies in a basin surrounded by high hills, I could see the TAWS display of the terrain surrounding the airfield. Terrain colour was coded in “pixel” fashion rather than solid colours used by the weather radar display. The display was clear and distinctive although, having followed the missed approach procedure correctly, no audio warnings were triggered.

We flew back to Genoa’s runway 29 to carry out in sequence a Cat I ILS to a roller landing, a Cat II ILS to a roller landing and a GPS approach to a full stop landing. During these approaches I evaluated the VNAV functions, RTU auto-NAV frequency tuning for approach and auto-LNAV/VNAV transition into ILS approach mode. The overriding impression was of a system bursting with capability, but one where the cockpit crew must interact well with each other and use good operating procudures to ensure each knows what the other is displaying on his PFD, what the pilot flying has selected for NAV source, what the pilot not flying has programmed into the FMS, what the autopilot will fly and when the pilot will intervene.

At final landing, flight time had been 2h 20min and we shut down, after a short taxi in, with 410kg of fuel remaining. It is clear from a short evaluation flight that the Avanti II upgrade is a successful integration. Although Pro Line 21 is an off-the-shelf system designed for aircraft in this class, the feel in the Avanti II is of a modern flightdeck designed from the ground up. The upgrade adds to Avanti’s safety with TCAS and TAWS, and adds to its capabilities with 8.33MHz VHF radios, datalink, precision RNAV, VNAV and ELT. Options include HF radio, cockpit voice recorder, satellite communications and electronic chart overlays. An automatic torque limiter/thrust rating panel and autothrottle would further reduce pilot workload, but these are desirables not essentials and, because the engines are not digitally controlled, may not be cost effective.

Easy to use

The avionics are easy to use and understand and the PFD/MFD screens outstanding in image quality and displayed information. The electronic chart overlay on the MFD reduces pilot work and is to be commended. But with all this capability comes the need for proper training and operating procedures, particularly if flying as a two-person crew.

Piaggio will have an Avanti II Level D full-flight simulator available from the second quarter of next year at FlightSafety International’s West Palm Beach, Florida centre. Rockwell Collins conducts a two-day Pro Line avionics course for new pilots and Piaggio provides an avionics computer-based training package with each aircraft sold. This is wise, as management of the avionics lies at the heart of getting the most out of the outstanding performance this aircraft offers.

The Avanti II really does have jet-like characteristics, which no other turboprop can match, so that its true competitors are the latest generation of light jets. If pure top speed is not the overriding criteria, the Avanti II’s combination of fuel efficiency, cruise speed, range, ceiling and cabin size are hard to beat. Piaggio has moved to secure the future of the Avanti with this avionics upgrade. The aircraft deserves its “Ferrari of the skies” title, and can hold its own against any similar sized jet. -

PETER COLLINS / GENOA images by PAUL BOWEN

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