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First Air’s ATR42 combi page 4

Story and photos by Raymon J. Kaduck

First Air purchased four Inter-Canadien aircraft for its Yellowknife operation. Another entire aircraft was acquired for parts from American Eagle, “allowing the same level of commitment to the ATR that we have to the Hawker, in terms of parts inventory,” says Orr.

Freight for fuel
First Air was certain it could build a compliant ATR42 combi, but not be able to replace the Hawker on a straight one-for-one basis. While the maximum payload of an HS 748 is 1,000 pounds greater than the ATR, its bulk capacity is 1,031 cubic feet compared to the ATR42’s 1,300 (Eight- and 10-passenger/combi configurations, respectively). This is very important in the north. For southern carriers, belly cargo is an additional source of revenue. For northern operators, however, cargo is of primary importance. It shapes their routes, aircraft types and even the location of bases.

“It was estimated that the company would have to do about 10% more flying, but that the operating economies of the ATR would be comparable to or lower than the Hawker’s,” says Orr.

One of the key considerations is the rate at which payload is traded for fuel as the length of the flight increases, according to Flight Operations Engineer Ken Rofe. “The Hawker has a maximum takeoff weight of 46,500 pounds and a zero fuel weight of 38,500. That means that 8,000 pounds of fuel can be carried before trading freight for fuel. With the Hawker engines burning 2,000 pounds of fuel an hour, you have four hours of fuel with max payload. Assuming an hour for IFR reserves, that’s three hours of flying with a full load.”

The tradeoffs of the ATR42 are not as favourable. Its maximum takeoff weight of 37,200 pounds and zero fuel weight of 34,200 allow 3,000 pounds of fuel with a full payload of 9,500 pounds. The engines are significantly more efficient, burning between 1,000 and 1,100 pounds of fuel per hour. With a reserve of one hour, however, freight is traded for fuel after two hours.

Higher airspeed is some compensation. The ATR42 cruises at 260 knots, while the Hawker flies at 220 knots in winter, 210 knots in summer. Higher power settings are possible in the winter without exceeding engine temps.

According to Rofe, the payload was important in choosing the airframe. While the ATR42 does not quite meet the Hawker’s freighting ability, the Dash 8-100 would have carried a payload of around 7,500 pounds. “It will fly for about two hours, but the fuel tanks are smaller, so even on lighter trips, you can’t add extra fuel. Using the Dash 8 means more technical stops.”

Orr adds that the ATR42 has better loading characteristics. Northern freight is close to unidirectional. Freight flows northward but the aircraft return empty, except for passengers. Making sure that the centre of gravity of the aircraft is correct can be a challenge. “With the ATR, there is both front and rear baggage storage. Baggage can be placed in front when only carrying passengers–no C of G problems.”

Gravel ops
One striking difference between the Hawker and the ATR is that the new aircraft fuselage sits much closer to the surface. This is a huge benefit in small communities because it means that the aircraft can be loaded from the back of a pickup truck without the use of a forklift and in a manner that is safer for the baggage handlers. But it also raises the issue of whether the airframe is suitable for operation on gravel runways.

“Prior to purchase, it was a key consideration,” according to Don Orr. “So we carefully examined what protection was available and studied previous operators’ experience. A composite tape is used that forms a skin on the aircraft belly. After one season of operation with reasonable success, we are still looking at other options.”

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