AIG takes advantage of Global Express speed

 - May 8, 2008, 10:43 AM

The 73-year-old New York-based insurance company had interests and offices in nearly 130 countries and Canada’s Bombardier at the time had just introduced an airplane–the Global Express–that seemed to meet AIG’s requirements.

The Montreal-based company was projecting an NBAA/eight-pax range for the twinjet in excess of 6,500 nm, which would, under most conditions, allow nonstop travel from New York to Tokyo. At that time, the company was regularly traveling between city pairs separated by 6,000 nm or more. Range was a major consideration, and with that in mind, AIG placed an order for what was then little more than “a paper airplane.”

The following year, according to AIG director of corporate aviation Franklin Davis, “we were concerned that the max range for the Global might fall short and we ordered a Gulfstream V as a backup.” With a year head start over Bombardier and a max range also projected to exceed 6,500 nm, the GV appeared to be the front-runner.

But Davis doubted whether either aircraft would deliver the desired range. “In 1997 we were faced with deciding which position to sell,” said Davis, who started with AIG in 1978 as chief pilot. “We weren’t interested in holding a [delivery] position on a $40 million airplane we weren’t going to buy.”

Until then the company had been flying a GIV on its long-range missions, and Davis admitted, “it was a superb airplane for ten years with a 99.9-percent dispatch rate.” So Davis asked Gulfstream for a demonstration flight that would test the GV’s range. The attempt to fly nonstop from New York to Tokyo ended with a refueling stop in Anchorage, Alaska.

Convinced by then that neither airplane would really meet AIG’s max-range requirements, particularly since both OEMs had already revised their forecasts downward to about 6,400 nm, “We made a final decision based on cabin size and high-speed cruise,” said Davis. The Global cabin offered an additional inch of headroom, 10 in. more width and an additional 471 cu ft of volume. The max cruise was listed at Mach 0.88, barely five knots faster than the GV, but nevertheless faster.

By 1999 the Global Express was certified and AIG leased one for an around-the-world proving flight. “We did Teterboro-Dubai in 13 hours and landed with 3,200 pounds of fuel, then did Shanghai to Mexico’s Cabo San Lucas in 13 hours and five minutes and landed with 3,100 lb of fuel, so we knew we had a thirteen-and-a-half-hour airplane,” said AIG chief pilot Charles Couture.

Better Late Than Never
In January last year, a year late, an unhappy Davis took delivery of the finished Global Express.  Now that the big airplane has been in service for 18 months, and some 500 flight hours have passed over its wings, the flight department chief and the chairman are for the most part quite pleased with the decision.

In the spring last year, AIG quickly set three certified speed records in rapid succession.

However, Bombardier’s 1997 max-range forecast of 6,700 nm (with eight passengers, four crew and full fuel) remains elusive. Couture told AIN that while Teterboro to Tokyo remains a matter of wishful thinking, “Tokyo to Teterboro is an easy one, thanks to the prevailing westerly winds.”

In fact, even before AIG took delivery, a Global Express had set a new speed record from Tokyo to Teterboro, averaging 493 kt on the 11 hr 52 min 15 sec flight. The record this crew broke on May 9, 1999, had been held by a Gulfstream V, set March 8, 1998, with an average speed of 485.3 kt and an elapsed time of 12 hr 0 min 57 sec.

But if the max range has remained a major disappointment, the speed and performance have been more than expected.

The company makes at least one trip a year from Teterboro to Zurich, 3,407 nm, and the numbers are impressive. The crew typically leaves the flight department base at Teterboro with 30,000 lb of fuel, about 13,000 lb less than max. The flight profile typically calls for a direct climb to 41,000 ft and a cruise speed of Mach 0.87, then a climb to 51,000 ft and max cruise of Mach 0.88 for the last two hours. And, said Couture, “We still get in with about 8,000 to 10,000 pounds of fuel in reserve.”
The bottom line, added Davis with a broad smile, is that “we have an airplane that will go more than 5,000 nautical miles at Mach 0.88.”

How Slow Can You Go?
Bombardier designed the supercritical wing for the Global Express, to accommodate slower landing speeds yet clean up and allow better high-speed cruise numbers without a substantial loss in efficiency. Critics who once described the wing as too complex, with too many moving parts, are now remarkably silent. AIG’s five Global pilots, however, are very vocal about their appreciation of the wing.

Loafing in on approach at about 120 kt (Vref+10), they have often been asked by ATC to increase their speed. “Especially in Europe,” said Davis, “where they want you at about 180 knots to the outer marker.”

Landing light, with 1,800 lb of fuel remaining, the Global is typically touching down at about 108 kt and AIG’s Global Express pilots have learned that the ideal touchdown speed under most conditions is 110 kt.

Davis has also been gratified to learn that the ideal long-range cruise speed of the Global is Mach 0.81, rather than the Mach 0.80 forecast by Bombardier. It only amounts to about a five-knot difference, but “it’s a lot better than finding out it’s five knots slower than advertised.”

Davis is also enthusiastic about the Global’s autobraking system. Without autobraking, right and left brake temperatures are inevitably uneven and often reach the upper tolerance levels. When the system is engaged, said pilot Chip Abbott, the aircraft comes to a halt, temperatures on all four brakes are identical “and it works great on runways that are wet or in snow and icing conditions.”

Five of the company’s fixed-wing pilots are type rated in the Global Express and a sixth will receive his rating by early 2002. But the flight schedule for the Global Express has created a situation in which proficiency flights are common. The big airplane typically remains continuously on the road for two weeks to a month when it is being used. But these trips are rare enough, and a month of inactivity is not unusual. So a couple of days before each trip, the scheduled pilots will take the Global up for an hour or so, often making two or three approaches and turnarounds at Stewart International Airport in Newburgh, N.Y., where there’s little congestion and an IFR approach. At least one of the landings during a proficiency hop includes an ILS coupled approach.

Mission profiles for the Global Express vary greatly. Some trips may be only for a week, others for a month or more and involve a variety of stage lengths. A month-long journey this summer included stops in Helsinki, Kuala Lumpur, Hong Kong, Manila, Shanghai and Beijing. For it, AIG carried three pilots and made use of the forward crew-rest area.

For other trips, the Global may carry two pilots and arrange for a crew change partway through the itinerary. A crew-rest area in the forward cabin, just aft of the cockpit, provides privacy and a fully reclining seat. Each flight carries a mechanic who also handles flight-attendant duties.

Some Squawks
While AIG’s pilots are enthusiastic about the Global Express, they don’t hesitate to offer critical opinions where they feel they are warranted.

There have been some 200 Global Express service changes by Bombardier since the airplane entered service in 1999, “which is actually not a lot for a new airplane,” said Couture. Most of the changes, he said, have been software upgrades and tweaking of the FMS and other avionics components.

An obvious and somewhat mysterious problem came early while the airplane was still under Canadian registration. Flying out of Kuala Lumpur with full fuel and flaps at six degrees, Davis and his Bombardier copilot were suprised when the nosegear refused to retract, automatically blocking retraction of the main gear. They diverted to Singapore, a 45-min flight, and landed over gross but safely after a visual check confirmed that the “three-green” was indeed an accurate visual. An extensive check of the landing gear system revealed nothing amiss and Davis continued home without incident.

On a subsequent flight to Zurich, also with full fuel and six degrees of flaps, the nosegear again balked. A Bombardier test pilot on board suggested changing the aircraft configuration and when 16 deg of flaps was called for, the gear came up normally. It was later found that with full fuel and six degrees of flaps, the attitude of the aircraft caused airflow around the nose to force the nosegear doors further apart. A mechanical connection between the starboard door and landing gear then forced the squat switch to remain in the position required to stop any accidental retraction of the landing gear while on the ground. The solution was the addition of a tiny shim to ensure that the switch would disengage normally and there has since been no recurrence of the problem.

The most recent problem has come with the optional cabin humidifier system. Bombardier, following up on complaints of excess cabin moisture, last fall issued an advisory to Global Express owners to cease use of the French-made Liebherr-Aerospace humidifier system. And for the time being Bombardier is not offering the system as an option.

“We’re very distressed that the humidifier is not operational,” said Davis. He noted that the AIG Global has had no previous problems with excess moisture. “We had some problems with our GIV humidifier and cured it by waiting until an hour into each flight to turn it on, and by turning it off an hour before arrival. We did the same thing with the Global and our humidifier worked fine.”

Meanwhile, a fix for the system has been created by Bombardier and tested, but not yet approved.

AIG is already planning some upgrades to its early delivery (S/N 00012) Global. Among them are engine modifications and software upgrades to the FMS and Honeywell Primus 2000XP avionics suite.

An earlier mod involved the lavatories. Originally, AIG had opted for two vacuum toilets, one aft and one forward. After numerous complaints from passengers about the noise, the aft vacuum toilet was changed for a quieter chemical toilet.

Bombardier’s new performance enhancement package (PEP) was recently installed. Tighter seals around the vertical and horizontal stabilizers and thrust reversers, and a fuel-scavenging system that draws 140 lb more fuel from the tanks, is supposed to add 100 nm to the range. While it brings the Global closer to its projected max range, Davis considers it both “long overdue and inadequate.”

AIG has also had a new fuel heating system put in to cure a problem with fuel gelling at high altitudes where the temperature often falls below -35 deg F.

However, pointed out Davis, they have experienced only one AOG problem and dispatch reliability continues to be 100 percent. Eighteen months after taking delivery of its Global Express, AIG’s flight department is convinced it has a winner.

There was a time, said Davis, when an AIG crew would find itself at 41,000 ft on a transatlantic crossing, watching as commercial airliners passed them en route to Europe. “Now,” said Davis, with a chuckle, “we’re cruising at Mach 0.88 and watching the 747s disappear behind us. We even get calls on 123.45 from airline pilots who’ve heard us talking to Shannon [Control] and want to know what kind of airplane we’re flying. It’s a great feeling.”