The G150, Gulfstream’s Baby



Gulfstream demonstrator aircraft have been regular visitors to New Zealand skies in the past year. The latest to visit was the company’s “baby”—the G150. Pacific Wings’ Airline and Business Aviation correspondent, Graeme Mollison, checked out the evolutionary aircraft.

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Business is booming for the manufacturers of business jets following the slowdown after “September 11”. In the United States, 2005 saw orders for business jets increase by almost 30% over the previous year, and 2006 saw a further 16% increase. These figures are reflected worldwide and are seen by many analysts as indicators of the overall state of the global business economy.

One company riding the crest of the wave and stamping its mark in our region (and around the world) is Gulfstream. The name—synonymous with quality and style in the business jet industry—has been strengthening its presence in the region, and in the last twelve months, the company has brought its G550, G450, G200 and now its G150 demonstrators into New Zealand.

Competing for business in the mid-size market against Cessna’s Sovereign, Bombardier’s Learjet 60XR and Raytheon’s Hawker 850XP (Pacific Wings, May 2006), Gulfstream’s G150, like the larger G200 (Pacific Wings, March 2007), can trace its lineage back to Israel and the design team at IAI (Israel Aircraft Industries).

Astra production began in 1985 and the improved “SP” model, which shared the same fuselage and wing, followed five years later. A total of 68 examples of both models were produced before production ceased in 1995. The Astra SPX rolled out of the IAI factory in 1996. This was a vast improvement over the previous model, utilising new engines and avionics, and a new supercritical wing with winglets.

Capable of Mach 0.87, the SPX was quite a “hot rod” in the business jet arena at the time.

When Gulfstream’s parent, General Dynamics, acquired the joint Israeli/US business jet company Galaxy Aerospace in 2001, the SPX was re-branded the Gulfstream G100. Although the aircraft continued to sell reasonably well, the market was changing, as customers were demanding more space and comfort. The G100’s cosy 1.70 m x 1.45 m cabin was a carry over from the IAI Westwind days and meant that it was at risk of being left behind by the competition…even at M0.87!

Gulfstream headed back into the design room and the G150 was born. Having entered service in 2006, the G150 may look similar to its predecessor, but believe me, it is not. This aircraft has had some serious attention from the team at Gulfstream. It is longer, wider, flies further and uses less runway.

“The G150 is bringing the Gulfstream experience in at a whole new price point,” commented Gulfstream’s Regional Vice President Asia/Pacific, Jason Akovenko. There was no hiding the enthusiasm of Akovenko and the two Gulfstream pilots who brought the aircraft to Auckland in March. They know they have a winner in the G150.

Joined by Air National Corporate’s Marketing Manager, Richard Bagnall, the group made time available to chat with Pacific Wings about Gulfstream’s latest “pride and joy”.

List price of the G150 is $US14.2 million—significantly cheaper than the company’s $US22 million super-midsized G200. Richard Bagnall, who had calculated some operating figures for the G200 for Pacific Wings previously, again went to work on the G150 for us.

For a New Zealand-based G150 flying 400 hours per year, Richard calculates the direct hourly cost to be approximately $US1,000. This figure takes into account such items as fuel and maintenance. When the fixed hourly cost—which includes such items as salaries, insurance and training—of $US900 is added, the total cost works out to be approximately $US1,900 per hour. When this is compared with the super-midsized G200’s total operating costs of approximately $US2,800 per hour, the importance of establishing mission and size requirements becomes apparent.

What does a G150 owner get for his or her $US14.2 million?

While it is still powered by two Honeywell TFE-731-40AR-200G engines (thrust has been increased to 4,420 lb per side), the G150’s engine pylons have been redesigned to significantly reduce interference drag.

The wing is essentially the same, with the addition of four new stiffened airbrakes and the deletion of the inboard leading edge fuel tank. However, total fuel capacity has been increased.

The G150 is 30 cm wider than the G100 and although the fuselage aft of the cabin area is basically the same as in the G100, it has been stretched 40.6 cm to allow it to be smoothly contoured to blend with the new wider cabin. Thanks to a new redesigned nose, which is shorter and incorporates larger cockpit windows, the G150 is only 33 cm longer overall.

Composite material has been used for the elevator tab, which is longer by 50%.

As with the G200 and the larger Gulfstreams, an extensive drag reduction programme was undertaken as part of the G150 project. New improved seals have been installed over control surface gaps, and the wing leading edge where it attaches to the wing box has also received attention. A new reinforced and stiffened cover plate was installed to reduce the flexing under load that had been found to be destroying the laminar flow (the flexing causing airflow ripples).

Airflow research also revealed that drag was being generated by air “eddying” at the junction of the wing and winglet installation. Vortex generators were installed in this region of the wing to keep the boundary layer attached.

An exterior walk around of the G150 reveals that most things are easily accessible from ground level. The external heated luggage locker located at the rear of the aircraft has a capacity of 490 kg—no 20 kg-per-passenger limit here!

Climbing the forward airstair, you are left with no illusions that you are entering a Gulfstream. There is no denying that this is smaller than the G200 cabin, but this is a mid-size, not a super mid-size. At around 185 cm tall, I couldn’t quite stand up in the cabin that measures 175 cm (5’ 9”) in height. The cabin itself gives the perception of being wide for an aircraft in this class, but the numbers are deceptive; at 175 cm, the competition quote reasonably similar numbers. Where the G150 wins out is in the retention of its predecessor’s squarer cross section, whereas other aircraft in the same class have circular cabin cross sections, so that the G150’s shape provides an average seated passenger with 30 cm more head room.

The layout is fairly standard with a restroom and storage cupboard at the rear. Another storage cupboard and a small galley, which is equipped for cold meal service, are located at the front of the cabin. A microwave or high-temp oven is available as an option.

Typically seating six to eight passengers, the demonstration aircraft was configured in the “Universal 7” layout with fine leather upholstery covering a side facing divan on the forward port side and five individual chairs. Each seat had its own adjustable cabin monitor and individual headphones coupled to a DVD and audio system. The monitor may also be selected to display a moving map of the aircraft’s progress.

Each set of single seats has an ample sized pull-out table, and with three 110-volt power outlets and a dual channel Iridium Satcom system with three handsets, this is truly a mobile office.

One hundred percent fresh air is used in the cabin and the large G200 style windows contribute to a bright and airy feel.

Moving forward into the flight deck, you cannot help but be impressed. It is wider and roomier than its predecessor with large windows providing excellent visibility.

The G150 is fitted with a superb, highly customised Rockwell Collins Pro Line 21 integrated avionics system, whose four large (30 cm x 25.4 cm) LCD screens dominate the forward panel and make the G150 an office to be envied by any pilot. The primary flight display (PFD), with its speed and altitude tapes, and attitude direction indicator (ADI), is typically selected on the outboard screens. The size of these screens allows a 24 cm horizon line to be displayed! EICAS (engine indicating crew alerting system) is standard, as is the dual integrated digital FMS (flight management system) with integrated GPS.

This is a paperless flight deck; the only paper charts carried onboard are en-route charts. Approach plates or aerodrome plates can all be displayed on the inboard screens; no more squinting over miniscule caution notes on tiny pieces of paper in a dimly lit flight deck for G150 crews.

The pièce de résistance would have to be the incorporation of Gulfstream’s ‘PlaneView’ features into the G150 flight deck. Although lacking the full package of the G450 and G550 with their Enhanced Vision Systems (EVS) and head-up displays (HUD), the G150 is nevertheless fitted with the cursor control devices (CCD) mounted on the sidewalls outboard of each pilot. Designed to improve cockpit functionality, the CCD is used to select whatever function is desired on the PFD/MFD. It has a grip handle with a trigger for enter functions, a thumbwheel to scroll through ranges and menus, and thumb buttons for moving the cursor from one display to another. It sounds like an exercise in coordination, but having previously used the CCD in the G450, I found it intuitive to operate and within minutes, I was accessing the system’s many functions with ease.

Although the aircraft is not fitted with an auto-throttle system, the TFE731 engines have digital electronic engine computers (DEEC). These work like the full authority engine control (FADEC—as installed on the Lear 60XR) system except that the DEECs have a mechanical backup; FADEC systems use multiple electronic channels. As with FADEC, the DEEC system allows the pilot to move the thrust levers to a preset position for takeoff, climb and maximum cruise, and the system takes care of the power to suit the atmospheric conditions.

Redundancy is the key to the G150’s electrical and hydraulic systems. The Honeywell RE-100 APU is flight rated to 35,000 feet. There are two engine driven starter-generators, an APU generator, two 27 amp-hour nickel cadmium batteries and an auto load-shedding system in the event of an engine generator failure.

The two independent hydraulic systems have their respective engine driven pumps plus there is an electrically driven standby pump. In the event of total hydraulic systems loss, flight controls, landing gear, brakes, thrust reversers and flaps are still operational.

Gulfstream unashamedly claims the G150 has the best overall performance of any mid-size business jet, carrying four passengers 2,950 nm at M0.75, or 2,600 nm at M0.80. Taking another four passengers reduces the range by around 250 nm. Maximum operating Mach has been reduced to M0.85 for the G150.

At its maximum takeoff weight of 11,839 kg, the G150 requires 1,524 m of runway and just 878 m of landing distance at the aircraft’s maximum landing weight of 9,843 kg.

The Competition

Fitting squarely in the mid-size category, the G150’s closest competitors are seen as the Bombardier Learjet 60, Cessna’s Citation Sovereign and Raytheon’s Hawker 850XP.

Of the three competitors, Cessna’s Sovereign is probably the closest in the range and speed stakes; however, at best, it will still have to land a few hundred miles sooner than the G150.

If time is the governing factor then all the competition will see of the G150 is its contrail as it pulls away; it is capable of cruising at M0.83 for over 2,000 nm.

Figures published by Gulfstream based on a New York–Los Angeles journey (direct great circle distance between the two cities is 2,151 nm), using ISA conditions and assuming 85% annual winds, show that the G150 could make the trip nonstop in 5:44, cruising at M0.80 and burning around 3,800 kg of fuel—approximately 200 kg less than Cessna’s Sovereign, which would take 22 minutes longer to complete the journey. The Hawker 850XP could also make the journey nonstop, but cruising at M0.70, it would take 55 minutes longer than the G150 to reach Los Angeles, although it would burn around 180 kg less than G150 and almost 400 kg less than the Sovereign. Bombardier’s Learjet 60XR was the closest to matching the G150’s speed, cruising at M0.79, but in doing so would require a technical stop to refuel, adding significant time to the journey, and would arrive last. However, according to Gulfstream’s calculations, it would burn the least amount of fuel to complete the trans-continental journey.

Obviously, it would be prudent to use some caution when comparing figures because, as with any aircraft, there is a compromise, be it speed, range, performance, economy or comfort. Reduce the range requirement and the competition is liable to get a little tighter. The G150 uses more runway than some (less than others), but then it flies further, so if you don’t need those extra 300 miles, reduce the weight and the takeoff performance figures improve and the competition again is tighter. The Hawker 850XP’s cabin is some 1.11 m longer, but then on a longer range mission, you will also be spending more time sitting in it. The Lear 60XR is one of the least expensive midsize jets to purchase, “runs on the smell of an oily rag,” is reasonably quick and “climbs like a homesick angel”, which may come in handy if you have to do that twice to the competition’s once. If you are carrying seven or eight passengers and they’re all golfers, then Cessna’s Sovereign may be for you as it has huge luggage capacity. If you are in the Lear, pack your toothbrush and underarm deodorant!

It really does depend on what an individual or company’s requirement is, as to which jet would suit best. However, there is little doubt that no matter what that the mission profile may be, Gulfstream’s G150 is rattling the cages of the competition.