Back to the Future: Return of the Turboprop?

Posted Tuesday, 3 June 2014, 09:30

Many travelers view turboprop aircraft as old-fashioned and uncomfortable compared to more passenger-friendly regional jets, which generally fly faster and farther. But the reality is that turboprops excel at fuel efficiency, and may make a comeback in this era of higher fuel prices. Simultaneously, airlines are moving away from 50-seat regional jets and shifting towards using larger aircraft to reduce seat-mile costs. With high fuel prices, a 70-seat turboprop can cost about as much to operate as a 50-seat jet.

Our recent U.S. airline fuel efficiency ranking found that the most fuel-efficient carrier on domestic operations from 2010 to 2012 was Alaska Airlines, due in part to the fact that its regional affiliate Horizon Air flies a lot of turboprops. In 2012, Horizon completely phased out its Bombardier CRJ-700 regional jets for the more efficient Bombardier Dash 8-Q400 turboprops. In contrast, the least fuel-efficient airline, American, had over 40% of its flights flown by its affiliate American Eagle on smaller regional jets (the CRJ-700 and Embraer ERJ-135/140/145). A 500-mile flight on an 80% full CRJ-700 burns about 28% more fuel than on a Q400 per passenger mile traveled. Differences between the fuel efficiency of regional airlines influenced the rankings of their mainline partners. The top-ranked airline, Alaska, would have lost to second-place Spirit in efficiency terms had fuel use by affiliates been excluded from the analysis.

The fuel efficiency of turboprops is even more striking when considered from the perspective of regional carriers. The frontier methodology used in our study is a flexible one, and can be used to rank regional airlines alone, independent of their mainline partners. The table below ranks their regional affiliates by their fuel efficiency score (FES) – a measure of transport service provided for a unit of fuel burn – in 2012. Only those carriers reporting their fuel consumption (and whose data was not found to be erroneous) were included here.

Fuel efficiency ranking on U.S. domestic operations for regional carriers and their fleet-average parameters, 2012

Rank Regional Carrier1 FES Excess
fuel burn
Turboprop
usage
Passenger
load factor
Aircraft age Aircraft gauge
1 Horizon 1.44 -- 100% 78% 5.9 76
2 Colgan 1.25 +15% 100% 67% 4.6 54
3 SkyWest 1.16 +24% 3% 82% 8.1 52
4 Mesa 1.07 +34% 0.5% 83% 8.2 71
5 GoJet 1.03 +39% -- 82% 7.0 66
6 Compass 1.02 +41% -- 80% 4.3 75
6 Republic 1.02 +41% 3% 79% 4.7 81
8 Pinnacle 0.98 +47% -- 79% 6.6 57
9 PSA 0.95 +51% -- 77% 8.1 55
10 American Eagle 0.92 +56% -- 76% 9.0 50
11 Air Wisconsin 0.90 +60% -- 74% 10.1 50
12 Shuttle America 0.87 +66% -- 76% 6.6 71
12 Comair 0.87 +66% -- 77% 9.1 60
14 Chautauqua 0.83 +73% -- 74% 10.3 48
  Average       79% 8.2 56

[1] FES of 1.00 corresponds to average in-use efficiency for the ranked carriers, with values above or below 1.00 representing carriers that fare better or worse, respectively, than the average carrier

Source: Bureau of Transportation Statistics Form 41 via Data Base Products, Inc. (2014); Ascend Online Fleets (2013)

Not surprisingly, regional carriers that fly a higher proportion of turboprops, Horizon and Colgan, are among the most efficient. The least efficient was Chautauqua, which flies smaller 44-seat ERJ-140 and 50-seat ERJ-145 regional jets. The gap between the most and least fuel-efficient regional affiliates is an alarming 73%.

Some of this gap can be explained by airline fleet characteristics. The best performer, Horizon, operated turboprops that were, on average, under six years old. The worst performer, Chautauqua, operated regional jets over ten years old. On an average flight, Chautauqua flew about 28 seats fewer with its Embraer regional jets than Horizon did with its Q400s. Horizon did not have stellar load factors, but airlines that did (above 80%) ranked closer to the top, though their turboprop usage was close to or at zero. Other factors (not shown here) that could explain the variation in efficiency include matching of flight length to aircraft optimum range for best fuel performance, routing, speed, engine utilization (e.g., singe-engine taxi), and fuel loading, among others.

The good news is that some major airlines are beginning to phase out smaller gas-guzzling jets. In December 2013, American made orders for 90 76-seat jets (CRJ-900 and ERJ-175) bought for its regional partners to replace smaller aircraft. That same year, Skywest became a launch customer of the 80-seat Embraer 175-E2 with a firm order of 100 expected to arrive sometime this year. Skywest also ordered 200 new 90-seat Mitsubishi regional jets, which can provide over 20% reduction in fuel consumption compared to current regional jets. However, even these next-generation jets are not expected to match the efficiency of current turboprops, and even less likely to match coming 90-seat turboprops with next-generation engines (Pratt & Whitney Canada)—also anticipated to deliver a 20% improvement in fuel burn, but from the engine alone. Already, five manufacturers have proposed 90-seat turboprops, with one, Avions de Transport Regional (ATR), actively pursuing them.

A move towards more efficient regional aircraft, namely larger turboprops, could significantly close that 73% gap in efficiency among regional carriers and help reduce both financial and environmental costs in the short-haul flight market.

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