Statistically speaking

Jun 29, 2017 - 3:30 PM

When numbers are in dispute, an oft-quoted complaint is “lies, damned lies, and statistics,” a phrase popularized by Mark Twain. But you’re not likely to hear that line with regard to aviation performance statistics, which are largely untainted by numerical sleight of hand and must be proven and documented. If you’re a pilot, you certainly don’t want to have to treat published stall speeds with any skepticism.

Even aircraft sales data is difficult to distort. Airframers must report sales numbers to the General Aviation Manufacturers Association and, in some cases, to  shareholders, and everything has to add up on the balance sheet. In the preowned market, data services like JetNet LLC and Aircraft Post have relentlessly tracked and revealed formerly opaque sale prices and residual values.

The tables we present with this column are an example of that transparency. We show sales data for 10 aircraft, usually a mix of in- and out-of-production models. (Our chart typically favors large-cabin jets over light ones, because there are more big models, and that’s where market activity is focused.)

These statistics don’t lie, and they can be illuminating, but they can also obfuscate. In this issue’s table, for example, the Citation Encore+ shows no average preowned asking price for March 2015, though at least one was for sale, or for March 2017, though three were available. Reason: the three Encore+ aircraft are all being sold on a “make offer” basis, so there is no average asking price. One or more sellers listed a dollar figure in March 2016, hence we indicate an average price for that time. Though this data doesn’t reveal whether more Encore+ models could have gone through the preowned market during this period, the information is available and, in fact, those are the only three, and all remain unsold.

What about Embraer’s Legacy 500, which shows no average asking price in 2015? Explanation: the Legacy 500 entered service in the fall of 2014, and none were yet up for resale the following March. No grounds here for invoking the line that Mark Twain cited.

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Nonetheless, there are statistical gaps in aviation that would be unthinkable in almost any other mature consumer market: How many passengers use a business aircraft at least once per year? How much does the average bizav traveler (or flight department, per passenger) spend annually on business aviation? What’s the approximate number of business aviation customer experiences per year? What’s the gender breakdown of business jet travelers? No data exists to answer such questions. These are statistical omissions worth complaining about.