As a pilot flying for the offshore oil & gas industry in India, I am fortunate to actively fly two different types of helicopters.
One is the venerable old workhorse, Bell Flight’s Bell 412EP. The other is Leonardo’s AW139, arguably the industry mascot today.
Old & New Nest Together!
Both are a generation apart. Bell Flight’s 412-family of light-twins with conventional cockpit, autopilot & flight director, twist-grip throttle and skid landing gear has been at sea for decades before the sleek, new-age AW139 with full glass cockpit, Flight Management System (FMS) with RNAV/RNP 0.3 specification, Electronic Engine Control & HOCAS-configured flight controls entered the fray.
A picture of these two helicopters parked cheek-by-jowl on a company’s flight line represents the delectable mix of old & new, spanning decades of rotary-wing technology. It also signals that good old days of ‘kick the tyre, light the fire’ may soon make way for ‘push the knob and turn the dial’, something oldies frown upon while transitioning (then soon get used to it!).
Offshore Operations – Cat A Performance & Easy Handling
The AW139 powered by two Pratt & Whitney Canada PT6C-67C turboshaft engines that deliver 1679 shaft horsepower (shp) per engine AEO at takeoff power (1872 shp in OEI) has been steadily chewing up competition in the ‘intermediate twin-engine’ category.
As per Leonardo, ‘the aircraft features leading edge technology, including a Honeywell Primus Epic fully integrated avionics system and 4-axis digital AFCS and benefits from the best-in-class power reserve and outstanding power to weight ratio, which provides Category A performance capabilities with no limitations in a wide range of operating conditions, including ‘hot and high’.
I have flown this machine in India and abroad, mostly from sea level to about 6000 feet density altitude. At sea level, the AW139 is certified for Cat A elevated deck ‘normal takeoff’ at its ‘increased max gross weight’ of 6.8 tons (limited by weight-altitude-temperature). That’s a notable capability, particularly with oil wells shifting deeper into the seas & stretching crew change sorties.
For certain profiles or to meet peculiar operating environments, a lower Regulated Takeoff Weight (RTOW) may apply. In India, offshore temperatures seldom cross 35°C where the AW139 delivers peak performance.
Full Automation, Reduced Workload
On a routine day, after departing from a runway or offshore helideck, the AW139 can transition to full automation within seconds. “Heading & altitude acquire please” is usually the first callout after accelerating beyond 60 knots. From here, the four-axis flight director and FMS combine can take over and fly you all the way to destination. Fully-coupled lateral, vertical & radio navigation, Standard Instrument Departure (SID), Standard Terminal Arrival Route (STARs) & IFR approaches (50-150 knots) can be flown with auto-level down to 50 feet.
But Never Forget Basics!
As recent accidents reveal, the broadsword of automation can cut both ways. Concepts such as Pilot Flying (PF), Pilot Monitoring (PM), ‘fly-attentive’ versus ‘fly-manually’, thorough systems knowledge, hand-flying skills under degraded modes, use of automation appropriate to phase of flight – all of this is crucial to safely operating modern machines such as the AW139.
Complaints? Hmm, Not Many
I haven’t too many complaints about the AW139; there’s the odd point for improvement, a couple of ‘irritants’ and some ‘highly desirable’ add-ons.
Oh, that Park Brake!
One irritant is the park brake system that requires the Captain to pull and rotate a lever through 90 degrees. Thereafter, the system has to be pressurized using rudder pedals. The rudder pedal design & height from cockpit floor doesn’t allow for feet to be anchored about a fixed pivot. The number of toe ‘jabs’ and quantum of force required to pressurize the system could be an irritant, particularly for pilots with low-percentile leg length. It requires careful crew coordination to ensure feet doesn’t slip on the pedals and cause sharp, undesirable yaw inputs, especially during the wet season and/or at high speeds.
A switch-operated electrical system is available as optional fit, I am told. But in an industry struggling to stay afloat, most operators make the obvious choice, leaving pilots to ‘please guard the pedals while I go a one, a two…and a three’! To testers like me with an interest in ‘control harmony’, this bites 😀
Leonardo, can you please make the optional a standard fit? Why this small disharmony in an otherwise carefree cockpit? Remember, in countries like India it pours cats and dogs for four months every year. Pilots sometimes have to wade through ankle-deep water to reach their aircraft.
‘External visibility’ is particularly important for offshore deck landings. The AW139 has a nose-up attitude at hover & low speeds (mitigated somewhat in the ‘long-nose’ Phase 7 by shifting the MAUs upfront). The large Main Instrument Panel (MIP) leaves plenty of spare space between pilot & co-pilot PFD/MFD set (why, one wonders; maybe to align with the broad interseat console). Although the vision plot is expansive under normal conditions, cross-cockpit external visibility at hover & low speeds can be an irritant.
As per standard safe practice, the pilot who has ‘obstructions’ (derricks, masts, exhaust stacks, superstructure, etc) on his side flies the offshore approach, landing & takeoff. VDP or Visual Descent Point for Cat A offshore approach is seldom greater than 0.7-0.8 Nm from the rig.
On the AW 139, the ‘Pilot Monitoring’ on disengaged side almost always loses sight of the platform / landing deck during the approach. This can be disconcerting while transitioning young, inexperienced crew into the offshore environment – a challenge best left to experienced instructors or check airmen. Some countries transition 200-hour pilots directly onto the AW139. Good luck to them!
Standardization and Commonality
Around 8-9 AW139 airframes I have flown thus far had as many types of door handles and baggage compartment locks. Some have handles that operate exactly opposite to others. Some baggage doors open upwards while others open sideways. This can give rise to confusion for helideck crew and baggage handlers, especially while operating in the dynamic, high-decibel environment around a helicopter. Hope Leonardo’s future rollouts have this covered.
Now Go Fly!
I can write reams about this machine! There is always room for improvement – in all walks of life. All in all, the AW139 provides top of the line capability, speed, ergonomics and cabin space. It stands tall among siblings like the AW169 & AW189 that are riding on its success.
Whenever I get tired of turning knobs and pushing buttons, I can always go back to good ol’ Bell 412, roll throttles & hand-pour AVCAT into the engines & fly in ‘SAS’ mode with ‘force trim’ off! That helps me stay grounded and in touch with basics. There is no flying skill higher than the ability to caress a helicopter back to terra firma with soft hands on a rough day. Aviate, navigate, communicate!
That said, the only competition for the AW139 in its category today could well be another AW 139.
What do you think, folks?
©KP Sanjeev Kumar, 2019. All rights reserved. An edited version of this article was published by Global Lifestyle Aviator, May 2019 edition.
Disclaimer: If you are a flight crew, please consult national regulations, Rotorcraft Flight Manual or Aircraft Flight Manual and your company’s Operations Manual as applicable to the type you fly. Views expressed in this article are entirely personal, does not represent that of my employer and have been written with no favours to / from Leonardo or its associates.
About the Author
Kaypius is an ex-navy experimental test pilot. He is dual ATP-rated on Bell412 & AW139 helicopters and flies for a leading helicopter services operator in India. Over 70 of his articles have been published in magazines, journals and news media in India and abroad, including Indian Navy’s flight safety journal ‘Meatball’, Rotor & Wing International, Shephard Media, Bloomberg Quint, Scroll.in, Times of India, The Print, LiveFist Defence, Global Aviator, Stratpost, Fauji India, Raksha Anirveda, etc. He enjoys being ‘full-time aviator, part-time writer’ and blogs at https://kaypius.com/. He can be reached at email@example.com. Views are personal.