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Tuesday, September 1, 2009

The Bell 429: A New Hope

By Ernie Stephens, Editor-at-Large

It’s a big deal when a manufacturer introduces a new helicopter model. It’s the culmination of years of designing, engineering, testing and tweaking, interspersed with artist conception drawings, full-scale mock-ups, flying prototypes and then a number of fully-functioning machines that are available for aviation journalists and a few potential customers to fly.

It’s during the early months of the demonstration flights that the breath-holding really begins. Will the company’s new helicopter be a hit or a miss out in the real world?

Bell Helicopter has been on a bit of a rollercoaster ride with its helicopter designs. The bubble-canopied Bell 47 enjoyed wide acceptance on both the battlefield and the private sector, followed by the wildly popular Jet Ranger, the first helicopter designed with the corporate executive in mind.

Then came the dark days at Bell.

First, it was the Bell 419, a new, single-engine design that never got out of the starting gate. Next, a militarized version of the much-loved 407, dubbed the Armed Reconnaissance Helicopter, was cancelled by the Pentagon for running behind schedule and over budget, leaving the company with little to show for the millions of dollars it had invested in an aircraft that was never delivered. And there was also the twin-engine 427, a design that was expected to capture the corporate and emergency medical service market with its wide cabin and high-end avionics, but customer interest was lackluster.

429 Specifications
Speeds at Maximum Gross Weight
V n 155 kts.
V h Cruise 150 kts.
Service Ceiling 20,000 ft.
HIGE (Max GW SL ISA) 14,130 ft.
HOGE (Max GW SL ISA) 11,280 ft.
Maximum Range 390 n.m.
Maximum Endurance 4.2 hrs.
Accommodations
Place 7
Minimum Crew 1
Passengers 6
Capacity
Standard Fuel 215 U.S. gals.
Aux. Fuel (Optional) 40 U.S. gals.
Cabin Floor Space 32.7 sq. ft.
Cabin Volume 204 cu. ft.
Baggage Compartment Volume 74 cu. ft.
Weights
Min. Empty Weight (SPIFR) 4,245 lbs.
Empty Weight (Standard Config.) 4,425 lbs.
Max. Useful Load (Internal, SPIFR) 2,755 lbs.
Useful Load (Standard Config.) 2,575 lbs.
Max. Gross Weight (Internal) 7,000 lbs.
Max. Gross Weight (External) 7,500 lbs.
Cargo Hook Capacity 3,000 lbs.
Powerplant
Transmission Rating 1,100 shp.

Source: Bell Helicopter

Bell Helicopter is now showing off several flying examples of its new model 429, "The only intermediate twin designed in the 21st century for your evolving mission requirements," according to the company’s color brochure. It’s been shown off at factory open house events, the Paris Air Show and several private sessions. Rotor & Wing was granted one of those private "get acquainted" sessions while one of its three, fully operational frames was in Paris. I went to fly it.

Bell Helicopter brought one of its 429 demonstrators to the Heliport de Paris, a fairly busy facility buried in the middle of a densely populated part of the city. I was there when it landed.

Meeting the Bell 429

As I walked out onto the apron, the first thing I noticed was the skid assembly. I had seen artist conception renderings, mock-ups and action photos of the Bell 429 before I arrived in Paris, and these skids were not the same. Originally, the forward portion of the tubes gently curved up and inboard, disappearing into the fuselage just behind the chin windows. Basically, it looked like the design used by Eurocopter on the EC120 and EC130. The skids on the 429 demo that sat in front of me, however, curved up and terminated inches above the ground. (I later discovered that Eurocopter didn’t appreciate those similarities, resulting in Bell’s decision to make the alteration I was seeing.)

To me, the Bell 429 looked like a chubby 407, with its wide fuselage, slightly bulging windows and thick engine housing. In the back was a tall, notched, shark’s tail-shaped fin that looked remarkably like the vertical stabilizer found on the Schweizer 333, and a horizontal stabilizer akin to its own 407 and 430 cousins.

C-FTNB was a light blue over dark blue 429 outfitted with an executive transport interior that made solid use of its relatively cavernous 204 cu. ft. cabin volume, while leaving room for a separate but generous 74 cu. ft. baggage compartment. For customers who want to put the aircraft to work as an air medical transport platform, the forward wall of the baggage compartment can be removed, using the space to make an even larger EMS suite with a set of aft-facing clamshell doors for stretcher loading and unloading. Headroom in any configuration is excellent, as is ingress and egress through the double doors set in the port and starboard sides. (Sliding doors are available.)

Up front, Bell rejected analog instruments and installed a single-pilot IFR-certified glass cockpit in a low panel that doesn’t obstruct the pilot’s field of view. Digital information includes IGO, OGE and Cat-A profiles, weight and balance calculations, exceedance monitoring and a primary limit indicator; a specific spot on the primary multi-function display that shows whichever engine or rotor parameter is closest to being exceeded at any given time.

Cockpit seating is comfortable, even for me, a 5-ft, 10-in, 240-lb pilot. Switches, circuit breakers and flight controls were appropriately positioned, with further adjustments available from the seats and pedals. As in the aft cabin, shoulder room was plentiful and there was enough headroom for pilots who choose to wear helmets and night vision goggles when flying.

But while exterior design, interior ergonomics and overall beauty are things to admire in a helicopter, how the aircraft handles in the sky is where "the rubber meets the road," if you will.

Air Manners

The brochures for the Bell 429 list its empty weight as 4,425 lbs and its maximum gross internal weight at an even 7,000 lbs. With myself and three Bell representatives onboard, the twin Pratt & Whitney Canada PW207D1 powerplants, rated at 572 SHP each, were able to launch somewhere in the neighborhood of 6,200 lbs of helicopter, fuel and people into the hot, mid-day sky with plenty of power to spare.

The smooth air found between Paris and our destination, a hospital landing pad 37 nm away in the city of Dreux, gave the 429 every opportunity to show off its flying manners. In a 100-kt cruise, the ship provided a smooth ride that was neither twitchy, nor aloof to my control inputs. Abrupt maneuvers, such as banks and dramatic speed changes were crisp and provided just enough control feedback to hint at where the envelope edge might be. Specific performance information was easy to find and interpret on the three big multi-function displays.

Cabin noise with headsets off was about normal for an intermediate twin-engine finished with an executive-class cabin.

A Closer Look

Although Dreux Hospital Center is one of the first medical facilities in Europe to have a helicopter GPS approach for IFR arrivals, ours was a visual landing at the trauma center’s elevated pad. The stop was part of a scheduled photo opportunity for a local television station who learned of the hospital system’s interest buying one or two 429s.

As the media people talked to the Bell representatives, I took a closer look at the 429’s two-piece composite tail boom, which Bell says is stronger, more fatigue tolerant and requires less maintenance at significant weight savings over other designs. The tail rotor system is designed with one two-bladed unit in front of another two-bladed unit. The addition of swept blade tips gives the system a more neighbor-friendly noise signature, and is more efficient.

I had to step aside from the aircraft as hospital staffers brought a stretcher out to stage an EMS arrival for the camera crew, but also to try to get a feel for working around the 429 had it been configured for medical transports. The results were positive. Flight nurses felt the floor height of the rear cabin was suitable for side entry, and envisioned an even easier ingress/egress scenario if the demonstrator had been equipped with the optional rear-facing clamshell doors.

The Sprint Home

En route back to Paris, I pushed C-FTNB into a 130-KIAS sprint across the French countryside in search of any unwanted cabin noise from ill-fitting doors or windows. None was detected. Meanwhile, the aircraft continued to handle smoothly with no unpleasant sensations.

While on approach back at Heliport de Paris, it occurred to me to look for something I discovered several years ago while flying Bell’s not-so popular intermediate twin, the 427. The problem was lateral instability, for lack of a better description, that felt like a cross between translating tendency — the sideways thrust caused by the tail rotor — and a Dutch roll that appeared at zero airspeed a few above the deck. It was very annoying in the 427, but completely absent when I held the 429 above the asphalt in a 4-foot hover. I was pleased.

Assessing the Aft Cabin

Even though my time at the controls of the Bell 429 had ended, the evaluation was not yet over. I wanted to see what the ride was like in the aft cabin where VIPs, aircrews and medical patients alike would be if the helicopter becomes the popular police, medical, offshore and executive transport platform Bell and parent company Textron hope it will be.

The aft cabin area is very spacious for a helicopter. An average size passenger won’t have to suffer the annoyance of their knees bumping into the knees of those seated across from them, or the cramped feeling of a low ceiling and tight shoulder room. The windows, which I had already noticed were fairly large, seemed even larger when seated in the back of the Bell model 429. Enjoying aerial views of the Eiffel Tower and the Cathedral of Notre Dame did not require a trunk-twist toward the door. Even the barely noticeable bulge that was engineered into the window played a role in enhancing visibility by allowing me to see slightly fore, aft and down while in straight and level flight. And even though I didn’t play with it, Bell offers a dual-zone climate control system for added passenger comfort.

Findings

All-in-all, the Bell 429 is a good aircraft. It flies well — not great, not remarkable — but well. It is, however, comfortable, has plenty of power and it even looks fairly nice. Its impressive list of manufacturer-offered features is, in my opinion, the helicopter’s biggest plus. With a little picking and choosing of options, it has the strong potential for being the right helicopter for a variety of purposes.

A lot of operators are looking for a good, strong, intermediate twin right now. The EMS market, which Bell unashamedly wants to grab control of with the 429, is especially interested in a ship with a large aft cabin for rendering in-flight medical assistance, the redundancy of two engines, and a single-pilot IFR avionics suite. The only thing left for Bell to do is to make the price and delivery times attractive. If the company can do that, they may have the hit they’ve been waiting for.

Bell 429 Features

  • Certified to meet or exceed the latest airworthiness and occupant safety requirements from the FAA, TCAA and EASA

  • Certified for single pilot IFR and all Category A profiles

  • Certified to 20,000 ft. maximum operating altitude with operating temperatures from -40° C to 51.7° C

  • Fully adjustable crew seats move fore and aft, up and down, and include adjustable lumbar support

  • Pedals adjust fore and aft

  • Track-mounted seats allows cabin seating to be reconfigured or removed in minutes for maximum utility

  • Optional clamshell doors open with minimum effort and hug the fuselage for operation in strong winds or while the aircraft is running

  • Fore and aft CG tolerances permit flexible load distribution without the need for added ballast

  • Lateral stability permits 600 lbs to be hoisted outside of skid gear

  • Wheeled landing gear option planned for 2011

Source: Bell Helicopter

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