Q –   Wow – what a site. Really appreciate the opportunity to learn all this stuff in such a neat way with no sales pressure. My question has to do with the summer just past and all of the heat issues. As we will be flying out of New Orleans next July, we are wondering how heat can affect flights and if they cancel them when it gets near or over 100 degrees?

A – High temps make it necessary for planes to reach a higher than normal speed to take off in extremely hot weather.  This has to be accomplished even though their thrust performance is limited by the light air. So the thing to understand is that a plane’s ability to take off is a combination of several things which must be measured by the pilot mathematically. These include air density, the design of the particular aircraft being flown, the length of the runway and the flight’s weight at take-off. If you look at these factors you will see that only only can be controlled and that is weight. So in really hot weather, either fuel, cargo, or passengers must be removed from the plane. The first is a safety issue, the second is highly profitable, which leaves fewer passengers as the only viable alternative.  The number of flights that have been “heat restricted” has been steadily climbing at busy airports like LaGuardia in New York and Washington D.C.’s Reagan National. Both airports have rather short runways, a safety issue that should have been corrected years ago.

The airport with some of the most serious heat-related take-off issues are Phoenix and Denver in the States and Dubai, Hong Kong, and Bangkok overseas. Projections into the future see weight restrictions increasing by as much as 30% in the next two decades. Long distance aircraft like the new Boeing 787 Dreamliner will see the greatest number of passengers bumped for weight issues because the Dreamliner is used on longer routes requiring full fuel tanks. The single-aisle jets like the Boeing 737 or the Airbus A320 will be impacted less with the exception of the short runway airports mentioned above.