Pilot Author Woody McClendon hovers the AW139 over Runway 5 at MMU (Morristown NJ).
Some 15 years ago, AgustaWestland embarked on an aggressive product development campaign, anticipating a worldwide market for a new generation of rotorcraft. The AW139 targeted what the company saw as a gap in the existing medium twin helicopter market.
By combining the best of its existing technologies with emerging technical advances, AgustaWestland brought several new models to the marketplace, including the new-generation AW139. During the type’s development, AgustaWestland worked closely with potential customers, using their input to determine present needs and requirements and anticipate missions these customers saw in the future. The AW139 was first displayed in mockup form at the 1999 Paris Air Show.
Deliveries began in 2003 and today more than 100 aircraft are in service worldwide. AW139s are built not only in Finmeccanica’s facility in Italy but also on a new production line at PNE (Northeast Philadelphia PA).
AgustaWestland engineers selected powerful engines, a clean aerodynamic profile, a state-of-the-art rotor system and Honeywell’s Primus Epic avionics suite. The result was a helicopter with superior performance, low operating cost, and an operating profile expanded by Primus Epic’s capabilities.
Honeywell’s corporate flight department recently took delivery of a new AW139. It joins a fleet of 4 jets based at the company’s headquarters at MMU (Morristown NJ) and replaces an 11-year-old Sikorsky S76B. Management teams will use the AW139 for trips around the northeastern US, exploiting the aircraft’s ability to take passengers to destinations away from airports.
“We view the AW139’s larger cabin, good performance and low operating cost as an unbeatable package,” says Honeywell Aviation Services Chief Pilot “Ed” Newton. “It was clear to us through the whole process of development and completion that we made the right choice—and the fact that Honeywell is a major partner in the aircraft made it a natural for us.”
Standard Primus Epic
Primus Epic avionics suite is baseline equipment. Providing far more than navigation, communications and autopilot, Epic is fundamental to the AW139’s design and flight characteristics. A full-time stability augmentation system (SAS) and attitude hold (ATT) feature give the pilot a consistent, pleasant set of handling qualities isolated from the nonlinearities of the aircraft’s stability and control profile—in a word, very much like fly-by-wire.
Technology briefing at Honeywell’s MMU (Morristown NJ) facility. (L–R) Honeywell Flight Ops Capt Marc Lajeunesse, Senior Tech Mgr Aerospace Electronic Systems James Nicholls, Principal Scientist AES Center of Excellence Human-Centered Systems Gang He and Pilot Author McClendon.
Two dual-channel 4-axis autopilots are always online. Pilots can select from the usual inventory of operating modes to manage departure, cruise and arrival in the same manner as an Epic-equipped jet, but with the enhancement of a few helicopter-specific features. These include slowing the helicopter from airplane-like approach speeds to a flare and level-off—DCL and ALVL modes—and finally to hover mode. Simple, intuitive mode controllers make it easy to select and sequence the avionics as the flight progresses.
A crew alerting system (CAS) provides colorful graphic information on aircraft systems operation, and urgent system issues are alerted to the crew by gongs, chimes, audio warnings and a large inventory of CAS messages.
Navigation tasks are managed through dual flight management systems (FMSs) that will be instantly recognizable to any pilot who has flown the NZ2000 series or any of its newer variants. FMS computations in the Epic are mechanized using a different method than in the older federated boxes. Flight management and navigation functions are part of a large, aircraft-wide data acquisition and computation model. So, while the internal hardware architecture of the Epic FMSs is drastically different, the pilot still uses an NZ2000-style control display unit (CDU), retaining a standardized level of comfort for pilots.
Epic adds significant capability to the AW139’s operating envelope, enhancing the helicopter’s safety and efficiency as an IFR platform and providing ultraprecise guidance for a host of missions. Honeywell Electronic Systems Senior Technical Mgr James Nicholls says, “We view the AW139’s extensive precision navigation capabilities as an opportunity to develop a whole new system of helicopter approaches woven into the fabric of complex metropolitan airspace.” He adds, “Primus Epic is the optimum tool to conduct IFR operations in dense airspace like New York and get our passengers exactly where they want to go.”
Honeywell AW139 features a Gulfstream-like cockpit with 4 brightly colored 8 x 10-inch flat panel displays, two NZ2000-style FMS control display units and a large Sagem map display in the center panel for wide-scale orientation and planning.
As a point of reference, FAA’s Special Aircraft and Aircrew Authorization Required (SAAAR) program enables highly precise but flexible arrivals, approaches and departures tailored to tightly defined flightpaths that can only be flown with high-tolerance RNP equipment and special crew training. SAAAR will be the mechanism for developing and gaining approval for these arrival and departure procedures.
Precision guidance capability is fully 3D. Through a set of operating features that will soon be available in the Epic Phase 5 upgrade, the precision guidance is applied to the search-and-rescue (SAR) application—a mission for which the AW139, with its large power margins, long endurance and good performance is well suited.
Mark on target (MOT) mode is a powerful tool in the SAR mission. During a search, if a downed aircraft, boat or person is spotted, the pilot can select MOT on the guidance controller—this marks the spot. MOT mode will then compute and execute an approach pattern, returning the helicopter to a point 50 meters downwind and 50 meters to the left of the MOT point in a 50-ft hover—and, not incidentally, into the wind. This positioning will put the MOT point visible in front of the helicopter and out the right door—the station for the winch operator charged with spotting the target and setting up the hoist line directly overhead.
These navigational features, along with Epic’s systems management and maintenance tracking functions, increase the AW139’s utility and efficiency by—literally—orders of magnitude.
Epic hardware packaging
Primus Epic packaging is an elegant system which eliminates individual boxes. The subcomponents of the AFCS, FMSs, CAS and other functions are built on cards that slide into a cabinet called the modular avionics unit (MAU). Modules for the navigation and communications components are racked in a similar box called the modular radio cabinet (MRC).
McClendon (L) is briefed by Honeywell Flight Ops Capt Marc Lajeunesse on the Sagem map display before engine start.
Another feature of the Epic suite is that the components are common to all aircraft that use Epic. At the Honeywell flight department, for example, the AW139 shares many common modules with other Epic-equipped aircraft. Thus, a processor or IO card that was last used in a G550 or some other jet can be drawn from Honeywell inventory and shipped to MMU for the AW139. The Epic system contains an aircraft personality module which identifies the unique configuration of the Epic system for that aircraft type and the options installed on that individual aircraft.
In this case, when a replacement card is installed in the AW139, its hardware and software configuration are checked automatically, and a CAS message is generated if it doesn’t conform to the approved configuration for this particular AW139.
A maintenance technician can respond to the CAS message by entering commands to the system through the central maintenance computer. These commands load the AW139-specific data into the new card from either the MAU internal database module or an external PC. The system configuration is then rechecked automatically, and the CAS generates a message that the system is now configured.
For pilots, the front end of the Epic system—with 4 colorful 8 x 10-in flat panel displays—is a joy to fly. An interesting side note is that I was able to see all the features in both the primary flight display (PFD) and multifunction display (MFD) without using my reading glasses—a first in a long time.
A combination of bright, sharp colors and larger-than-usual characters sets the Primus displays apart from most I’ve seen and used. Admittedly, we were flying in bright daylight, which minimizes the effects of presbyopia, so night-time might have found me with the old specs hanging from my nose again. But I suspect that the crisp clarity of the displays would have been as evident at night as it was in daylight.
Flying the AW139
Honeywell AW139 Project Pilot Marc Lajeunesse took us on a walkaround of the new aircraft, N139H. In its utility configuration—the dominant setup in the fleet worldwide—the AW139 can seat up to 12 passengers. In executive configuration the spacious cabin is a shining asset. Almost 9 ft long by 7 ft wide, and nearly 5 ft high, it is furnished with 5 executive-style chairs and ample cabinetry for the usual amenities.
Most significantly, Honeywell’s AW139 has a cocoon-style interior insulated sufficiently to provide jet-like low noise levels without using headsets. One could ask how, historically, anyone could justify paying millions of dollars for an aircraft that demanded its passengers wear headsets, yet that has been the corporate helicopter market until now. The AW139 puts that to rest.
Epic flat panel displays are bright, with large clear characters. These are on the right-hand side of the cockpit—ie, the MFD is on the left and the PFD is on the right. Note the power index display on the left-hand center of the PFD and the magenta triple tachometer opposite it on the right.
Two large doors—1 on each side of the aircraft—afford access to a cavernous 120 cu ft baggage compartment, which in some interior configurations can be accessed from the cabin while in flight. With the executive interior, and in particular the cocoon, the baggage compartment is walled off from the main cabin. For military and SAR operations, access to the baggage compartment in flight is essential, and the numerous military and government agencies flying the AW139 take advantage of the feature.
Viewing ports allow checking of all system fluid levels from the ground. Fold-down steps and work decks provide easy access to the main rotor deck and work spaces for minor maintenance.
The AW139 has 2 batteries—a 44-amp-hour NiCad and a secondary (backup) 22-amp-hour unit. In the spirit of good battery management, organization pays off, as the prestart flight control checks require running the electric hydraulic pump for a minute or more (to a limit of 2 minutes continuous operation) plus the usual systems and preflight setup.
Preflight setup
We computed our takeoff weight on the FMS. BOW was 10,705 lbs with 2442 lbs of fuel (versus 2767 lbs max), 3 passengers and 2 pilots, bringing the TOGW to 13,997 lbs—just short of the 14,110-lb MTOGW. Local weather had improved from several days of cold rain and low ceilings to a balmy 6° C, winds 330° at 16 kts, gusts 27 with 2000 ft overcast. Checking the RFM for the day’s ambient conditions, we found the HOGE was 8050 ft. Cat A operations would require no penalties whatsoever.
With the GPU plugged in, we loaded our passengers and settled into the cockpit. Lajeunesse completed the flight control check, then we entered our filed flightplan to SWF (Newburgh NY), where we would do some instrument approaches.
Since the weather had improved, we opted for a VFR flight to SWF to save time, rather than the filed IFR flightplan.
We started the engines by placing the left engine switch in the idle position. The P&WC PT6C-67C (1679 shp for takeoff) executed its start sequence under engine electronic control (EEC). Once it stabilized, we started the second engine.
After start checks and system reviews using the CAS were completed, both engines were selected to “flight.” Rotor rpm stabilized at 100% per the triple tach display on the right side of the PFD, and we were cleared to taxi off the Honeywell ramp.
AgustaWestland specifies that the cyclic is to remain centered during ground operations, as Lajeunesse explained. Cyclic position on the ground is shown on a small centering display near the PFD’s airspeed scale. To taxi the helicopter, the pilot simply raises the collective very slightly. Since the rotor system is rigged tilted forward several degrees, the helicopter will start moving. Directional control is via toe brakes.
Lajeunesse cautioned that taxi mode would take some getting used to, but I found it as easy as taxiing a Learjet. We taxied out, held short of Taxiway Alpha and called for takeoff clearance, which was issued for takeoff on MMU’s Rwy 31, with a right turn on course.
Pre-takeoff procedures call for both autopilot channels to be engaged, which brings the SAS online full time. The SAS works downstream of the pilot’s flight controls, generating inputs to maintain stable flight and provide ideal flying qualities. ATT is also on full-time, allowing the pilot to be hands-off if required for other tasks while the AW139 retains the pitch-and-roll state selected by the pilot.
After hover taxiing to Rwy 31 and setting down for a final departure check, I lifted N139H into the air and accelerated into a 120-KIAS climb. Landing gear was retracted at 150 ft agl, and the AW139 stabilized at a 2000-fpm climb.
Takeoff and departure
This helicopter was an instant joy to fly, with perfect harmony between pitch and roll and comfortable, consistent control forces in maneuvering flight. A trim button set exactly where one’s thumb is on the cyclic gives the pilot the option to “beep” the roll and pitch attitude for small corrections or changes. Or, if more robust maneuvering is preferred, the pilot can press and hold the force trim switch, then release it when the desired attitude is achieved.
Our plan was to engage the autopilot, so as we climbed through 1500 ft we set 2000 ft in the PFD’s altitude select data box and engaged the altitude acquire mode (ALTA), which is similar to flight level change (FLC) in many jets.
As we approached 2000 ft, a gong advised that the altitude was capturing and the helicopter leveled imperceptibly. In its design specifications for the AW139, AgustaWestland requires selected altitude and other vertical path modes to be the reference for collective inputs, and airspeed to be the reference for cyclic (pitch axis) inputs. As we cruised at 2000 ft, I kept my hand on the collective and noted that it was constantly working in very small inputs to maintain altitude. These collective movements could not be felt or sensed by pilots or passengers.
I squeezed the force trim release trigger on the collective and set 60% power on the power index (PI) display on the PFD. The PI display selects the limiting parameter, torque (TQ), gas generator rpm (NG) or internal turbine temperature (ITT), and shows a normalized value on a vertical scale along with an alpha designator of the parameter being shown. The PTC6-67C’s large power margin means that torque is nearly always the limiting factor, so I was setting 60% TQ.
The autopilot nudged the aircraft’s nose down and soon we were indicating 161 KIAS—only 6 kts less than Vne. The ride was vibration-free with a nose-down body angle of only 4°. Fuel flow was 360 pph per engine, so we could have flown almost 3 hours with ample reserves. Given the near standard day conditions, TAS was within a few knots of IAS.
We calculated that, with all seats full, Honeywell’s AW139 can carry 2300 lbs of fuel. With the speed and fuel flow data points we observed, we concluded that with that fuel and payload the AW139 could fly a comfortable 450 nm, giving the operator wide flexibility in mission tradeoffs.
We selected direct to the SAX (Sparta NJ) VOR and engaged NAV mode for lateral guidance. The MFD showed our course almost due north to SAX, then a right turn to MANEE intersection. We selected the ILS 27 approach at SWF on the FMS with vectors to the final approach course. New York vectored us on a downwind with a base turn just outside the FAF.
Varied approaches
As we were nearing the FAF we engaged approach (APP) mode. N139H captured the localizer and then the glideslope. I beeped the speed back to 100 KIAS using pitch trim, and the helicopter decelerated smoothly.
Crossing the runway threshold, we selected go-around (GA) mode. The autopilot pitched the AW139 to 10° nose-up and went into heading hold. We selected the GPS 27 approach on the FMS and activated it, then reselected LNAV as the nav source, NAV as the lateral FD mode and finally direct to GOKRE intersection.
As we turned final on the GPS 27 approach passing ETUGE intersection, the FMS showed that vertical guidance path (VGP) was available. VGP capture was indicated when the white-lettered VGP symbol on the top of the PFD changed to green. The VGP for this approach procedure as referenced in the navigation database was 3°, although the AW139 is certified for approaches up to 7.5°.
We wanted to look at DCL mode on this approach, so we selected it as we intercepted the VGP. DCL slows the aircraft to achieve pilot-selectable airspeeds at 2 preselectable distances from the runway—the preselects are programmed through the FMS with default settings at 80 KIAS and 1 nm from the runway.
McClendon hovers the Honeywell AW139 on the ramp at MMU. Rwy 5 is visible out the windshield. The wind was gusting to 26 kts from the left side—yet, as this photo shows, the cyclic is nearly centered, thanks to the full-time stability augmentation system (SAS).
Deceleration was smooth in all axes, and we crossed the end of the runway precisely at the programmed settings. I took the controls and slowed the helicopter to 40 kts, then pushed down on the cyclic trim button to engage hover mode.
Course guidance dropped off the HSI and was replaced by a hover display format. A green line extending from the helo symbol in the center of the hover display showed the current aircraft groundspeed (GS) vector. A magenta groundspeed reference, or hover target bug, appeared on the display. This can be controlled laterally and longitudinally with the cyclic trim button. At the pilot’s option, pressing the cyclic trim button “in” brings the magenta GS reference to the center of the circle, setting the velocity reference to zero.
With the helicopter again on autopilot we watched it fly the half mile or so to the magenta reference point, decelerate to 0 kts and establish a stable hover. Since we had a brisk wind about 20° off the right side, the AW139 moved a little to the left—we beeped the hover slightly right using the cyclic trim button to correct for the drift.
I took the controls again and we headed down the Hudson River to land at JRB (Wall Street Heliport, New York NY), demonstrating a Cat A approach. During the flight down the river, in pristine VFR conditions at about 900 ft agl, we selected ground map mode on the Honeywell P701 radar and brought it up on the MFD. Mapping was near-3D graphic. Under low-visibility conditions or at night we could have depended on the terrain depiction for safe separation.
Arriving at JRB, we found ourselves in intensely busy traffic from sightseeing helicopters. Lajeunesse flew a Cat A approach to a hover—the best we could manage given traffic volume. As Lajeunesse talked through the approach, it was clear at the landing decision point (LDP) that we had more than adequate power to either land or fly away safely.
Returning to MMU, Lajeunesse selected OEI training mode. At the time I was flying the helicopter and we were cruising at 145 KIAS. As we transitioned to OEI training mode, the PI indicated that we were operating in the amber 2.5-min engine limit region. Reducing collective a little brought engine torque back within OEI limits, and we were able to continue flight using an OEI power setting of 85%. In OEI condition we were still indicating 120 KIAS.
We set up a visual approach to Rwy 31 at MMU using a fairly steep angle. All the way to the ground we never needed more than 60% OEI torque, and could clearly have hovered with an engine offline if it had been necessary.
We reset things to normal, hover taxied to the Alpha ramp and then onto the Honeywell ramp on wheels.
Summary
One thing that is clear is that the AgustaWestland AW139’s blend of performance and economics can only result in more business flying where the destination is away from mainstream airports. Investment groups widening their search for opportunities around the world will recognize AgustaWestland as a provider of the kind of mobility never before available to them.
Woody McClendon is a sales executive with a major aircraft company. He flies jets and helicopters.
