Yesterday I talked about how Delta had lost its interisland partner in Hawaiʻi, but then I wondered just how much of a problem that would be. That took me down a rabbit hole where I looked at just how much the interisland market has changed in the past 30 years. That’s what we’ll look at today.
I dug into Cirium to look for answers. T-100 was my friend on this one, because it goes all the way back to 1990. Here is that chart I showed yesterday which looks at the number of seats from the mainland to both Honolulu and the Neighbor Islands (included Hilo, Kahului, Kona, and Līhuʻe):
Seats from US Mainland to Hawaiʻi
T-100 Data via Cirium
Talk about a clear picture here. Flights from the mainland to the Neighbor Islands were virtually non-existent in the early 1990s. In 1990 itself, flights operated only from LA and San Francisco to Kahului and from San Francisco to Kona. Delta and United did the heavy lifting while ATA also was in the mix. Hawaiian came in soon after, and that plus ATA made for the beginning of growth in the market. Still, service was primarily to Kahului, and Līhuʻe and its short runway didn’t even get their first mainland flight until 1998.
From that point on, Honolulu seats declined and Neighbor Island seats soared. It really changed gears before the pandemic when Southwest entered the market. That momentum carried the Neighbor Islands to being on par with Honolulu until 2024, when Southwest began to pull back.
What caused this huge change? It was the introduction of the B757 into longer, overwater flights, that’s what. Take a look at this evolution of the aircraft used on Honolulu and Neighbor Island routes.
T-100 Data via Cirium
First of all, yes, this goes back far enough that it still includes some of Hawaiian’s DC-8 flights. I love that, but in reality Honolulu was the domain of widebodies, mostly mighty three-holers plying the skies. It really didn’t change until about 2000 when the B767s took over. The B757s started in Honolulu en masse around the same time, but they never made a huge impact. It was in the last 10 years when narrowbodies took hold in Honolulu, much of that thanks to Southwest’s B737s and the introduction of the MAX and neo families.
The Neighbor Islands developed differently. They had a handful of widebodies, but there weren’t many markets that could support them. So when ATA started playing around with the B757s in the 1990s, it opened up whole new markets and ideas. Sure there were some B767s as well, but the B757 was the dominant force in Neighbor Island flying until the MAX and neo families came into the market and popularity exploded.
In 2024, Honolulu flights were split roughly 50/50 between widebodies and narrowbodies, but nearly 90 percent of Neighbor Island flying was on narrowbodies.
So, with a fleet better suited to these thinner routes, interisland flying became less important for airlines. I can remember plenty of trips as a kid where I flew to Honolulu and then connected over to Kahului. Sometimes it was on Hawaiian, Aloha, or even Mid-Pacific Air back in the 1980s. (Yeah, I flew a YS-11 once, and I’m pretty excited about that to this day.) But sometimes it was even on the airlines that got us to the islands in the first place. I remember flying an American DC-10 as a through flight from Honolulu to Kahului. All of that traffic could disappear with the ability to fly nonstop to the Neighbor Islands.
So what happened? Well, interisland flights declined. They really fell off after 9/11 when the hassle of security slowed short-haul flying. And the numbers tanked again in 2008 when Aloha failed. A handful of others tried to step in, but nobody has had a significant impact until Southwest.
Seats from Honolulu to Neighbor Islands
T-100 Data via Cirium
Even at Southwest’s peak, there were a third fewer seats in the market compared to 1990. And now, Southwest is pulling back again. In 2025, seats are currently showing as 8 percent below 2023 with more cuts entirely possible.
Which airlines are most impacted on the mainland flights? Interestingly, it’s been surprisingly stable with the exception of Southwest when it made its big entrance.
Seats from the Mainland US to Hawaiʻi by Airline
T-100 Data via Cirium
The big guys are, unsurprisingly, the mighty Alaska/Hawaiian combination and United which has historically been the leader between the mainland and the islands. Southwest is next followed by American, and then there’s little Delta which has less than half as many seats as United.
And since the focus was on Delta yesterday, let’s go even deeper and break down Delta’s routes:
Delta Hawaiʻi Routes by Type
T-100 Data via Cirium
What I find most interesting about Delta is that it hasn’t really changed much in the amount of service it has flying east of the Rockies. That’s been relatively flat except for a brief bump 20 years ago. What has really changed here is that the West Coast – Honolulu flying has declined dramatically while the Neighbor Island flying has increased. It’s a smaller version of the larger trends throughout the industry.
The interisland market has shrunk back down to its core function, primarily transporting people between the islands that need to go between them for work, school, and shopping. In addition, there is still a healthy amount of tourism that goes between islands, just as I did on spring break with the kids this year where we spent time both on Oʻahu and Kauaʻi. But Honolulu as a funnel for travel between the islands is really only truly important for international travel since Kona is the only other airport in the islands with a customs facility. For the mainland carriers, that’s not really an issue.
