Flight Test: Bell 407GXP
10:38 05 January 2017
keith wilson (c) single use pilot mag only
This refined seven-seater has the load-carrying capacity, speed and comfort to shake up the helicopter market
Words: Pat Malone; Photos: Keith Wilson
Ask a potential buyer what they want in a helicopter and there will be a few basic must-haves − full fuel, all seats filled, long legs it has to be faster than the next guy’s aircraft. But in the real world we’re always trading something off – fuel sacrificed for load, speed for fuel, range for load and fuel. Every serious journey begins with the hard sums.
So it comes as a pleasant surprise to find that the Bell 407GXP is virtually impossible to load out of limits. Fill the tanks, put a bum on every one of the seven seats, load the boot with duty-free, blast off and maintain 150mph until your bladder forces you down. It’ll take it!
The GXP is the latest incarnation of Bell’s best-selling civilian single (pending arrival of the 505, one presumes). It is the most refined version of an aircraft that has been around for twenty years and originally grew out of the LongRanger, itself a development of the much-loved B206 JetRanger.
The most visible departure from tradition was the four-bladed rotor, which gave a much smoother ride than the teetering system on the 206 range. While the design shouted ‘JetRanger’, the 407 was all-new in most departments, and with the Rolls-Royce-Allison 250-C47 engine it offered performance that left the 206 in the weeds. Over the years, it’s been developed further through the GX to the GXP, which comes with FADEC and whizz-bang avionics − to wit, a Garmin G1000H glass panel.
As a card-carrying technophobe who liked the panel layout of the Hiller 12C, I look askance at these newfangled contraptions, but my fear was misplaced. You can learn the basics in five minutes and if you can get the Met on your iPad, you can handle the rest standing on your head. It really is logical and simple. So resist the urge to sneak a peek at the standby instruments and get your information off the telly−you’ll wonder why you ever fretted about glass. Clocks are so 20th century!
This is a serious issue for the private owner-pilot with a limit to how much time they can invest in mastering new skills, which could be considered optional. No problem for the professional, but a businessperson with a company to run, a life to lead and a JetRanger or an Squirrel to get around in may consider it to be too big a step to upgrade to a 407 with a glass panel.
Don’t give it a second thought – one steps through the glass into a whole new world of easy flying, and every minute spent in study will be rewarded a hundredfold. What’s more, you don’t have to go to Mirabel or Forth Worth to learn the drill, you can now do the job in Kent.
I went down to the Bell dealers, Heli Charter at Manston, to fly the 407GXP with their Commercial Director Gary Slater. I was a hot day so I was pleased our helicopter, G-TOPI, boasted the air conditioning option. This was one of many add-ons, such as the two-axis autopilot and the high-visibility doors with convex Perspex down to ankle height in the club cabin. They provide stupendous views even by helicopter standards, boosting the price from the basic model’s £2.8m to £3.4m. The interior has been done out in leather and looks like something a Russian gentleman might select to enhance his yacht.
A walk around the 407 is fairly short and sweet. The aircraft is an order of magnitude larger than the 206, fully 12.61 metres long and 3.3 metres tall at the fin. Of course, the four blades make hangarage requirements different as the doors need to be over 7.7 metres wide.
You can get an optional blade-folding kit if you don’t have the width to play with, and this would fit the helicopter into any slot able to accommodate the 2.64 metre skid width. Failing that, as Robert Shaw said in the movie, I think you’re going to need a bigger boat.
Pitot on the nose, ni-cad batteries under the flap − you can get lead-acid if you prefer − and it’s so far, so JetRanger. But there are no dipsticks any more. All the oils, engine and transmission can be checked via sight glasses and each one has a cut-out so you don’t need to open any cowls. But you do, of course, for the usual: both sides of the engine and transmission, and check for oil stains or streaks, pinching of cables or lines.
There’s a baffling amount of wire and pipe around the engine to facilitate the smart stuff the FADEC does. The nodal beam that reduces head vibrations in the 206 series has been replaced by live transmission mounts, saving a lot of weight. One stand-out fact is the cleanliness of the engine − there was neither soot stains around the jetpipe nor filth on the tail rotor shaft fairing. Gary assured me the aircraft had not been cleaned in honour of my visit. The helicopter had 42 hours on it, and the Rolls-Royce 250-C47B/8 (good for 862 shp) really is a remarkably clean-burning engine.
You can see everything you need to see from ground level apart from the rotor head, for which a stepladder is required. Up there you’ll find an uncluttered elastomeric arrangement, the GXP having dispensed with the Frahm damper and coolie hat because the composite head is deemed not to suffer from the ‘four-per’ that affected the original 407 without the damper. Flying along in the GXP, you’d have to agree. I’ve had rougher rides in hot air balloons.
The tail boom has the same horizontal stabiliser arrangement as the LongRanger, but with a leading-edge slat to improve effectiveness. The end plates are carbon fibre and they’re much taller. The vertical fin, skewed nine degrees to reduce the tail rotor power requirement in the cruise, has a full-height gurney flap above the tail rotor thrust line, which is instrumental in taking the never-exceed speed out to 140 knots, and reduces weight by sixty pounds. (Vne on the LongRanger is ten knots slower – so much reward for so little effort!)
There’s a sight glass to check for the bearingless tail rotor (two blades), then you’re coming back down the port side. Peeking under the engine cowling there’s the usual couple of pop-outs to check on the oil and fuel filters. Of interest is an auxiliary alternator, the PMA (permanent magnetic alternator), on the drive shaft to provide power to the FADEC if all else fails. On the rear of the bottom tub is a rear-view camera with a wide-angle lens, so you can check for Messerschmitts or something.
Hop in, strap in and the sticks will tell you you’re in a Bell – swan-neck cyclic, cork-handled collective with a big box of tricks on the end. If you’ve flown a JetRanger you’ll feel at home, glass panel notwithstanding. The binnacle is big, flat and blank-wall clean, just the two 10.4-inch flat screens with old-fashioned altitude and airspeed gauges above and a few buttons below.
Where is everything? The panel’s cut in such a way that visibility from both left and right seats is unimpaired, an important factor for a helicopter that spends a lot of time working off-airport (an air ambulance company in the USA has ordered 200 of these machines).
Flip the battery switch and the LED displays come to life. If at first acquaintance the data on the glass panel looks like hieroglyphics, do not despair. You can ignore almost all of it. After just half an hour of flying from the left seat, I reckon I could start her from cold, fly her away, land her and shut down, and they’d probably even be able to use her again. It’s that straightforward.
You can even start the engine manually, but why do that? The FADEC can do it better than you, and the risk (and expense) of a hot start is massively reduced.
The Multi Function Display, the left-hand screen, defaults to the weight and balance page when you turn the battery on – just confirm the system’s fuel state calculation, add occupied seats and Bob’s your uncle. Before starting you can switch on the rear view camera to check there’s nobody about to dent your tail rotor with his head.
Now choose the engine page, which gives you a big round dial with a single pointer. This is your Power Situation Indicator (PSI) and it displays whichever parameter is limited first. The twelve o’clock position is 100% of something, either torque, MGT (turbine outlet temperature) or Ng (gas producer). Collective down and power at idle, cyclic central and pedals neutral, hit the starter and let the FADEC do the rest. Not only does it start you safely, but it maintains precise rotor speed control, restarts automatically, monitors engine health and grasses you up to your engineer when you exceed limits.
If the battery’s too feeble, the FADEC won’t let you do any damage. But all being well, the needle (representing MGT at this point) sweeps around the dial, wavers a little near the top and falls back to the start-breathing-again value, untouched by human hand. The PSI takes up station at the bottom left of the Primary Flight Display (PFD) in front of the right-seater, with three digital values next to it for torque, MGT and Ng.
The MFD has a caution/warning/advisory panel, including a light that illuminates when the cyclic is not perfectly centred when you’re on the ground. This saves stress on the rotor mast, and it’s not very forgiving − or perhaps I’ve always been a bit cavalier with stick position. Cautions come up when you’re approaching a power limit, together with a chirpy little audio alert, so you can back off before the helicopter makes a black mark against your name in the ‘exceedences’ directory. FADEC malfunction warnings are to be found here, and much else besides, but that’s day two of your week-long factory course so we’ll skip the details here.
On the PFD you’ve got a big HSI with DI beneath and ribbon strips on either side for speed (left) and altitude (right). Underlying the whole picture is Bell’s synthetic vision display, a representation of what the ground would look like in unlimited visibility. Joy of joys, how reassuring is that!
It’s coupled with a terrain warning system called HTAWS, which can even alert you to masts and other barely-visible obstacles, and a ‘go-around’ button that levels the aircraft and allows you to escape from inadvertent IMC, so you need never have fog nightmares again. It displays your traffic, of course, and get this − if the potential conflict is on the right of the aircraft, you’ll hear a warning through the right cup of your headphones. Good thinking.
Lifting off with the PSI now showing torque, I felt that the control harmonies are subtly different from the 206. The cyclic feels a little lighter, the pedals are hydraulically boosted, and there’s a lot more power available from a collective that travels an appreciable distance.
For flight, you’d probably want the moving map on the MFD. You can switch a smaller representation of it to the bottom right corner of the PDF. You can select a range ring to tell you where you’ll be when you have 100 lb of fuel left. The ring contracts as you pull more power. There’s a vast store of data in the MFD, almost all switchable to the PFD − flight planning tools, if you like, or the hover predictor, which takes OAT and altitude, matches it with weight, wind conditions and density altitude and lets you know if you can take off from your hot and high destination.
But me, I’m looking for the balance ball. Turns out it’s a little horizontal bar under the top arrow on the HSI, and it’s a little disconcerting to see it slide right while the arrow moves left while you’re trying to climb in a straight line at best rate, seventy knots. Looking across the cockpit from the left seat in strong sunlight it wasn’t as prominent as it might have been. With the boosted pedals, it’s sensitive, but by the end of the sortie everything was mostly in its proper place.
The over-riding impressions of cruise flight are of smoothness and quiet. The four rotor blades have obviously done away with the ‘two-per’ nod of the 407s predecessors, and in its fully soundproofed corporate clothing, G-TOPI is library-quiet.
Straight and level back at sixty knots we were pulling only 42% torque. We flew down the Kent coast past Walmer and Dover castles and the views were so spectacular I didn’t feel constrained to keep looking at the panel. This was one of my pre-flight concerns − how much time do you spend pushing buttons and watching the telly, instead of looking out of the window?
Well, even with my first-acquaintance fascination I wasn’t glued to the screen. And it’s a timely reminder of the basic fact that you don’t need any information at all to fly the helicopter, beyond what you can see out of the window and feel with your backside. Everything else just makes life better and easier. For some reason I’ve yet to fathom, I chose to get my speed indication from the clock above the panel, but my height from the ribbon on the PFD, where it’s presented as a number in a box. It just seemed easier, I don’t know why.
We rendezvoused with a B206 for pictures, before bombing off back towards Manston pulling max torque and dipping the nose to push out towards Vne. The horizontal stabiliser does a good job of levelling the fuselage at speed, but I still didn’t keep the nose down enough and when we were at 95% torque and 138 knots, Gary pointed out we were climbing at 200 fpm.
This is a very fast helicopter, and it’s easy to forget in helicopter terms, it’s at the heavy end of ‘light’ − empty weight of the basic aircraft is 1,191 kg, max gross is 2,722kg, and useful load is 1,160kg. We were two-up and half fuel, but seven-up and full she’ll still do the business.
At a takeoff weight in excess of 2,000kg, the 407 is said to be able to hover at over 18,000 feet out of ground effect. More numbers: cruise is 133kt, full fuel is 484 litres with a sixteen-gallon (72 lit) auxiliary option, range starting at MAUW is given as 322nm, and if you’re loitering you can string a tank out to over four hours.
Back at Manston, we set the timer for the two-minute warm-down, switched off the position lights, air conditioning and genny and let the FADEC complete the shut-down, applying rotor brake at 40% Nr and turning off the BATT with the Ng at zero. And there the fun stops.
For the technical, the systems can offer an encyclopaedia of data, but once you have the hang of the basics − comm and nav, fuel flow and suchlike − you can pick up the rest as you go along.
In recognition of the fact that it takes three hands to fly a helicopter there’s a voice recognition system for flipping frequencies so you don’t have to take a hand off the stick. The autopilot and stability system are no-brainers, the Iridium satphone kit is handy, and there’s an SD card slot for uploading flight plans or downloading trip data to the internet. And while the helicopter is not certified for instrument flight, in extremis you can make an instrument approach using a system called Pathways that will hold your hand down an ILS. Much easier than keeping those pesky needles centred.
The 407GXP is a stonking helicopter, but there are other positive factors to consider. Bell has won the top global customer service award for twenty years running, and given that the company is coming from behind in the UK market, Heli Charter is determined to build on that reputation.
They’ve got a giant stockpile of parts in Amsterdam and can get parts from the US in 24 hours. Bell has been playing second fiddle in Britain since the days of Alan Mann, and it’s only in the last four years since Heli Charter took over the dealership that they’ve started giving the competition headaches again. Complacency has crept in there, and with the 407GXP and upcoming new products, Bell has the opportunity to give the helicopter market an overdue shake-out.
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