Flying for an airline is obviously different than flying general aviation. The airplanes themselves are much more complex, and even when they are the same…they are different.

You likely have some familiarity with this in the GA world. After all, there are multiple models of the 172. Some have flaps that go to 40 degrees, but most don’t, and a few didn’t require waiting for the white arc to extend the first 10 degrees of flaps. There are also as many radio combinations as there are pilots with money to spend on radios.

Airlines do what they can to maximize fleet commonality, because it’s cheaper and safer to do so. When I flew at the regionals, the airplanes were exactly the same for the most part. The differences that existed were more behind the panels, and the few that were not didn’t really matter.

But there were a few differences, notably in the max takeoff weight of two variants of the CRJ. It was hard to miss this, though, since it was on a (big) placard in the cockpit, and our flight release always noted the heavier airplanes. The landing weights were the same, which helped.

At the majors, the differences can be more stark. I fly the Boeing 737, and my airline has four basic variants: the -700, the -800, the -900, and the -900ER. Some of the differences are obvious: The -700 is smaller and the -900 and -900ER are much bigger; the wingspans vary a bit as well; and the -700 has much better overall performance. In the cockpit, the -700 has a different temperature control system than the larger airplanes. There are some significant details that must be committed to memory when it comes to the -900 autoland system, which isn’t something we use a lot—which makes remembering those details even more important. Further, every airline operates airplanes differently, which means that procedures in use at Southwest may not be common at United, and vice versa.

There are other, smaller differences, most of which are transparent to the pilots. During an emergency, it becomes important to read the notes in the quick reference handbook (QRH) checklist, because sometimes the checklist will stipulate different procedures based on the serial numbers of the airplane. This is especially common when the manufacturers have made significant changes or upgrades to the electronics or the avionics.

The introduction of the 737 MAX has added some new wrinkles. The MAX looks different (although it has the same shark-tooth engine cowling as the 787), and the cockpit has been drastically altered, so there is no mistaking which airplane you’re flying. The start procedure is different—it takes twice as long per engine, and it must be done correctly to prevent an auto-shutdown. There are some system changes and enhancements as well, all of which required some form of training. The airlines operating the MAX also provide cheat sheets that summarize the differences for the pilots, especially since the small fleet size of the MAX means opportunities to fly it will be rare.

Fortunately, there is a movement underway to eliminate the requirement that copious quantities of information be memorized, as was done in the past. Now, the FAA encourages airlines to provide written guides whenever possible. There are too many minor variables involved, especially after the round of mergers that took place in the past 15 years. Throw in airplanes purchased from airlines overseas, and it just makes sense to provide up-to-date guidance whenever possible.

However, none of this alleviates the pilots’ responsibility to be aware of those differences, even if they don’t have to memorize all of them. Limitations still need to be recognized and respected.—Chip Wright