Airplane models designed for consistency

Question: Owners of cars, trucks and motorcycles, especially older models, learn the quirks of their vehicles and how to safely compensate for them while driving. Do flight crews recognize individual planes when their airlines own dozens or hundreds of the same model? – John, West Lafayette, Indiana Answer: Pilots fly many different airplanes of the same model within a fleet. While there are some differences, they fly pretty much the same. Manufacturers strive to produce airplanes that are very similar. Pilots can tell individual characteristics of a particular airplane within a fleet if it has sustained damage and been rebuilt.

Q: Why do some airlines have similar planes? I believe Delta is buying both the A321 and the 737-900 ER, both with similar capability for 180 passengers and 2,500 miles.

– Peter Higgins, Melbourne, Florida

A: There are several reasons why airlines will fly similar airplanes. When negotiating the purchase price, the airline can often get better pricing by pitting one manufacturer against another.

Often a large airline will want to introduce a new airplane more rapidly than a manufacturer can produce it. If the airline is receiving new airplanes from more than one source, it can introduce them faster, allowing for retirement of older, less efficient models.

Finally, there are nuances between similar models that airlines can use to their advantage. For example, one type may have more payload capability at sea level and another have more payload capability at a high mountainous airport. Careful scheduling allows an airline to maximize those benefits.

John Cox is a retired airline captain with US Airways.