When Airbus compares the range of its different single-aisle aircraft, it takes the existing figures shared through media and print for each aircraft. A320neo and A321neo are presented with their Airbus numbers. The A220 with the numbers from Bombardier. But the measurement sticks in the two companies weren’t the same.
The smaller A220 was measured with a tougher ruleset than the one Airbus uses for their Single Aisle public data. I asked the then CSeries Program manager, Rob Dewar, (today A220 Head of Engineering and Customer support) why the tough ruleset? “Our first customer Lufthansa wanted us to measure the aircraft with airline rules. This is why we used 102.1kg (225lb) per passenger and our reserve calculations were made with 5% for the enroute reserve” answered Dewar.
Airbus measures with 90kg/passenger+bags for Single Aisle aircraft, and it uses an enroute reserve of 3%.
If we put all the data in our performance model and compare the aircraft with typical airline rules (100kg pax+bags, 5% enroute reserve, 200nm alternate and 30min circling) and configure the cabins for the same comfort, we get another picture than Airbus shows in Figure 1.
We have used our Normalized cabin ruleset to make each aircraft comparable in seating capacity. We have equipped all aircraft with standard rear lavatories as the SpacFlex rear lavatories and galleys are not yet an option for the A220.
The A220-100 then seats 111 seats with 8 36-inch Pitch Domestic first-class seats and 103 32-inch pitch Economy seats, the A220-300 132 seats (12/120), the A320neo 150 seats (12/138) and the A321neo 192 seats (16/176).
The A320neo then fly a 3,400nm maximum range compared with the A220-300’s 3,300nm, both loaded to a 100% load factor. This is a difference of 3%, far less than Airbus shows in Figure 1. The A319neo flies further but no-one is buying it as its operational economy is not competitive.
The comparison is made with both aircraft loaded to 100%. At the more normal 85%, the range is equalled as the A220 is not fuel limited. It has big enough tanks to replace the missing passenger weight with fuel whereas the A320neo can’t.
Its tanks are full at 3,400nm and it will not fly much further with a lower passenger load. Then an ACT (Additional Center Tank in the cargo bay) is needed. It’s not a popular option as it increases the empty weight and by it, the aircraft consumes more fuel in normal use.
The A320neo has about a 5% lower fuel cost per seat at 100% load factor but an 85% load factor this changes in the A220-300’s favour. The A220-300 then has a lower Empty and Take-Off Weight per passenger which gives it up to a 5% lower seat-mile fuel consumption dependant on the mission.
The smaller A220-100 is a straight cut-and-shut shrink of the A220-300. It also has an artificially low Maximum Take-Off Weight (MTOW) to limit its range to 3,100nm. It has the same wings and landing gear as the -300, with the same fuel capacity. The MTOW can therefore readily be increased and it would then fly further than both the A220-300 and A320neo.
But at 110 seats this has perhaps limited utility, except for a London City airport to New York mission as we described here. As a straight shrink and at 111 seats it can’t compete in per seat mile fuel economy with it’s larger brothers.
The A220 is the only clean sheet aircraft in the 100 to 220 seat segment. It’s made with state of the art aerodynamics and structures (Aluminum-Lithium fuselage and Carbon Composite wings and tail), a top modern engine (the Pratt & Whitney 1500G geared turbofan) and latest Fly-By-Wire (FBW) flight controls.
It’s not surprising the larger model, with only an 18 seat difference to the A320neo (measured like for like), can compete both in range and per seat fuel economy. The neo update of the A320 only changed the engine. Structures, wings and base FBW are now 30 years old, though with improvements over time. But PIPs (Product Improvement Packages) can only go so far to replace a fresh design.