Surely if that were the case they would already have got it.

What advantage is there for the -100 compared with the -300 that's sufficient to justify having both?

The only one that comes to my mind is CASM is perhaps lower on shorter flights. That being said, I see the CS100 as a better option for Express/PAL and thus a I beleive a renegotiation of pilot scope clause would be required...

The question is
How much cheaper is it to fly a fully loaded A220-100 than an A220-300 with 20 empty seats.

The opportunity cost favour the potential revenue of the 20 extra seats on the -300 over the saving you get from operating an A220-100.

They had the opportunity to order the CS100 to replace their E190 fleet but ultimately they decided to up gauge to the CS300 to replace both E190 and A319 with a single variant.

Unless they can modify the scope clause to use cheaper labour in regional carriers, -100 remains unlikely.

Or in an alternate universe, A220-100 will find its niche when YTZ finally get their runway extended and allow jet ops, but that's more unlikely than any of us here marrying Anna Kendrick. Also, if they get the runway certified for A220-100, they might as well make it long enough for E2-195 and A220-300. (I was thinking about LCY when writing this, turns out A220-300 is not yet certified for LCY, so yeah. That'd be a reason AC may purchase the A220-100, but AC's pilots are easier to negotiate than those NIMBY.)

I suspect that AC views the A220-100 as having too much range for the missions that AC would deploy them on. Why does that matter? All the extra structure and engineering that went into the aircraft to support it's range is weight that AC would be carrying every flight despite not coming anywhere near the maximum range.

To put it simply the A220-300 has filled it's role exceptionally well as AC's primary transcon aircraft. The rest of the narrow bodies (319/320321/737's) in the fleet provide additional capacity for higher demand routes. The A221's range of 3600NM is much to far for AC regional operations where flights rarely surpass, I'm guessing, 500 NM (most flights from smaller communities simply fly one of the nearest hub airports, yyz, yul, yvr, yyc). And the capacity of 130 pax may be to high for some of AC's smaller routes where 60-80 seat aircraft are better suited.

That being said. I'll throw out my pipe dream again. What if AB were to shrink the 221 further. Removing 20-25 seats to a capacity of 80-100, and somehow reengineer the fuel tanks to bring range down to 1000'ish NM. Then maybe AC would be interested. Call it the 220-50 or 219. This plus a 225 stretch would make the 220 family an incredible force across multiple mission types.

I suspect there is a flight range where the CASM of the CS300 leapfrogs the CASM of the CS100. Same engine, same wing pushing less mass means significantly less cost to get a CS100 in the air. Once in the air, the difference is likely negligible thus every nautical mile cost is amortized over more seats, reflecting the advantage.

Thus why I think it�s a better plane for Express... if they were allowed to fly them.

Perhaps with the constant pressure for upguaging, a new agreement will bet set out and the sub brands could fly larger planes.

-300 outsold -100 8 to 1, the market has already spoken.

There are niches that suit the -100 (see LX and DL) but they are indeed niches. E2-195 is simply better optimised for that market and size (thus sold 4x more than A220-100, and LX is grounding the A220-100 and fly the E2 to LCY with 2L instead)

Can't imagine any plausible route where the CASM of the -100 is lower than the -300. Trip cost yes (slightly); CASM no.

A further shrink to the A220 would be even less competitive - it is over weight and over-engineered for an 80-100 seat aircraft. No way they can pull enough weight out without a full redesign. EMB has that market to itself for the foreseeable future.

Shrinks almost always struggle on unit economics. You�re carrying wings, tails, engines, landing gear, and structure sized for a much larger aircraft, so CASM tends to go the wrong way rather than improve. That�s why most successful families grow up, not down.Once you start meaningfully re-engineering things like fuel volume, wing sizing, control surfaces, and weights to make a shrink work properly, you�re no longer doing a derivative, you�re effectively designing a new aircraft, requiring recertification, and potentially lose the common type rating. At that point it�s hard to justify versus a clean-sheet design optimized from the outset for the 80-100 seat, ~1,000 nm mission.

I don't have the physics or engineering qualifications to do the exact math, but I�ll take the old Rapidair triangle as a probable route length. I suspect those 1-hour flights where the plane is at climb for 30 minutes, then cruise for like 5 minutes before starting descent are the ones where the lighter weight has the most benefit.

Both use the same wings and yes, the relationship between thrust requirements and weight are linear, but the relationship between fuel required for each additional unit of thrust ae not. Engines are designed to be most efficient at cruise and not a take off or climb thrust. The math associated with TSFC hurts my brain.

A CS300 will always require more fuel to operate a flight versus a CS100 assuming they are similarly/relatively loaded... that is basic physics. If we use LX as a base CS100 seats 125 versus CS300 145, the question becomes: does it require more than 16% more fuel (plus indirect costs like engine maintenance for using more thrust on the engines etc.) to get that additional 17k lbs (based on MTOW) from YUL-YYZ or YUL-YOW?

But most other costs are the same. So It would only be when you regularly cannot fill up the larger plane that this would become an advantage.

As an outsider/pax, I would rather see them immediately reconfigure the seats on the ex-Lynx aircraft (spacing only, leaving empty middle seats for the fake-J section), and not bother with the galleys or bins or whatever else they're doing to them.

Then, if they're going to keep them more than a few years, they could then schedule a seat replacement so that they can offer 12J + recline, but unless they plan to keep these aircraft in the fleet for 20+ years, I don't see the benefit to the rest of the overhaul.

If you can fill them, of course. And I wasn't suggesting you could not do so on Rapidair routes. Just an example of route length.

And basic economics dictate that even if a CS300 has a better CASM on most routes it still costs more to fly a CS300 than a CS100 so if you can't fill a CS300 then it's still more cost effective to use a CS100 net overall.

So there are routes that exist that are best suited for a CS100. For AC those are few and far between so there is zero reason for AC to get them.

Interesting comment regarding to the A320 leaving before 2030, although it was anticipated in pervious MD&A, we thought the 8 A320 getting refitted (originally the A320 were implied to be refitted into the current A321 "dream cabin/A220 experience" standard) will last at least another 10 years.

Not going to speculate too much here, if A220-500 were to launch this summer, and AC being one of its launch customer... 4 years to certify a new variant isn't exactly impossible ? Umm...

It would certainly make sense to have the narrow body fleet consist of A223/A225/A321CEO/A321XLR. Pretty efficient narrow body mainline fleet.