I’ve been thinking a lot lately about aircraft innovation and how different airlines have reacted to new developments in different ways, but I was having trouble figuring out how to put this into something coherent. I had plenty of data thanks to SkyGo and Cirium schedules, but it took collaborating with Claude on ideas before I settled on a good way to display it. Artificial intelligence (AI) as a thought partner is pretty useful in that it helps me to crystalize my ideas into something useful, but let’s see if you agree.
First, how do you even define aircraft innovation? Sure, there are new composite materials that made the B787 a marvel, and there are winglets and other aerodynamic features as well as avionics. But in the end, I think it’s really the engines that drive a step change. And because of that, I decided to break aircraft down into seven categories. I only categorized jets flown by the big US airlines, and I skipped the no-bypass early jets since none of those were still flying at the airlines I looked at once SkyGo’s 1980 OAG schedule data started.
So, here’s how I’ve categorized them:
It is unquestionably imperfect, so I’ll give you a minute to decide what bothers you the most….
Ok, we good now? I think the categorizations are pretty self-explanatory. Category 5 is a very crowded place, and I thought about splitting even further, but this is where I settled based on the aircraft being flown by the US carriers. I have some of my own quibbles, but this gets my point across.
With the categorizations set, I took the schedule data and counted departures by aircraft type. No, I did not measure to the actual tail, so while there may have been some variations in aircraft types in split fleets, again I decided it was good enough for this purpose.
Then, I had Claude create a heat map. The lighter colors are the earlier generations and the darker colors are the newer generations. This looked at the percent of fleet in each type to determine the overall adoption of more efficient aircraft.
Data via SkyGo and Cirium, map via Claude
What does this tell us? So much. I want to roll through each airline, but first I want to show another chart that looks at this differently. This chart shows the percent of departures in the newest category. So when a new category rolls out, it will reset. This helps show which airlines were early adopters.
Data via SkyGo and Cirium, map via Claude
So, with all that, let’s just talk through each airline, starting with the ones that went out of business earliest.
Pan Am – This is confusing to think of Pan Am as a leader in efficiency, but this is really a quirk of being a long-haul carrier. The bulk of that airline’s flying was on the B747 which sits in category 2. The domestic-focused airlines were still primarily using B727/737s or DC-9s, and those were in category 1. So this wasn’t really indicative of Pan Am being a leader. It just skewed to big airplanes for its largely international network. Of course, it failed so early that it never got out of category 4, something it had just started to fly with the A310 in 1985.
Eastern – Eastern was full of those B727s and DC-9s I mentioned. Sure it had A300s, but those were dwarfed by the massive narrowbody fleet. That didn’t start to turn until 1983 when the first B757 arrived, but of course, Eastern also failed in 1991 before it could make much of a change.
TWA – TWA was most definitely not an early adopter at all. Heck, it was flying its B707s until 1983. Then when it acquired Ozark in 1986, it took a step back even further with that flood of DC-9s. It did take on the MD-80 in the early 1980s, but that was always a ‘tweener… better than the early generation aircraft but not as efficient as the high bypass B737 classics. It had moved to the B757/767s in the 1980s, and that was gaining steam, but it was generally broke and behind the curve until it was merged into American in 2001.
Northwest – I find it fascinating that in 1980, Northwest was actually slightly ahead of the curve. After all, Northwest is an airline that I always think of flying airplanes forever and not keeping up with the times. I mean, Delta had been out of category 1 aircraft at the time of the Northwest merger for four years, but Northwest’s ancient DC-9s brought them right back in. Northwest received a similar but less pronounced benefit as Pan Am by skewing more toward international than other airlines in the 1980s. It was an early adopter of the B747-400, and then in the 1990s is started taking Airbus narrowbodies very early. This kept it ahead of some failed dinosaurs, but those DC-9s just kept flying so it was always a little behind.
Continental – At the beginning of my data, Continental was a small airline flying B727s and DC-10s and nothing else. But as airline after airline folder into Continental, that fleet shifted dramatically. First there was Texas International, then New York Air, and lastly PeoplExpress (including Frontier which that airline had bought). By 1990, the fleet was a mess. The airline was even flying around old B737-100s until 1998. But that miracle management team led by Gordon Bethune and Greg Brenneman came in and started to rebuild. The fleet was replaced mostly with B737NGs along with B767/777s. Remarkably, it had become one of the more forward-looking airlines by 2000, a not-insignificant feat.
US Airways – I realize putting US Airways in here is a challenge, because so much of its fleet was made up of small props. Even with jets, the biggest airplane it flew in 1980 was a small fleet of B727-200s. Most of the flying was on the DC-9 with a big portion on the BAC 1-11. In the 1980s it took on Piedmont and a bunch of old Boeings and even Fokker F28s along with PSA with its B727s alongside MD-80s and BAe 146s. What a jumble. But in the 1990s under Stephen Wolf, the reinvention began and USAir became US Airways. A massive order for A320 family aircraft was placed, and bankruptcy helped the airline walk away from from older airplanes. When it was taken over by America West, it had become an airline with a modern fleet, and it would carry that until the merger with American.
American – And speaking of the American merger, let’s talk about the three airlines in my chart that still exist. This won’t come as a surprise, but American was very slow to adopt new tech. Unlike its competitors which filed for bankruptcy, came out, and placed orders to refresh the fleet… American did not do any of that. It stayed out of bankruptcy and clung to those old aircraft, especially the MD-80s. It was a late adopter of everything. The re-fleeting began in the early 2010s when it filed for bankruptcy and placed a big order of its own. There was a further cleansing during the pandemic when several old types were retired.
Delta – Of the three airlines that remain, Delta was actually the slowest to adopt newer technology, not American, thanks to the Northwest merger and philosophy for opportunistic aircraft purchases. It flew those old Northwest DC-9s until 2014. The ancient B757s and B767s continue to soldier on. Even new orders were regularly for old tech, including the end-of-line order of B737-900ERs was came as a great deal since the MAXs were arriving. But it is now going big on A220s and A321neos. It will have MAXs coming as well. Meanwhile, the widebodies are still split, but those B767s will finally disappear at some point in the not-too-distant future. Delta’s decision to stick with old technology was strategic whereas American’s was more by financial necessity in the 2000s.
United – Of the three remaining carriers, United is the quickest to adopt new aircraft. It had A320s in 1993 and B777s in 1995. Then in the Continental merger, the older generation aircraft were all gone within a couple years, by 2013. Though United was late to take on the B777-300ER, it has been very quick to buy new airplanes in the last decade. Just look at the number of MAXs, A321neos, and B787s that have been pouring into the fleet. Today, it’s just the B757/767/777s that are the last of an old generation, and the B757s/767s will likely be gone fairly soon. The B757 replacement — the A321XLR — has just started arriving, and there are a lot more deliveries coming throughout the fleet.
What does all this mean? There aren’t any key takeaways to crystallize what we’re looking at into a pithy one-liner. Having newer technology doesn’t have to mean it’s a better airline. As Delta has shown, you take care of old aircraft, and they can be a great option. But this is just a useful way to help think about the evolution of airlines over time.
