Why don’t airliners fly off into space?

February 2019

Q. If a pilot attempted to fly his plane in a straight line for thousands of kilometers, rather than flying on a path parallel to the curve of the Earth, what would happen and why? How do pilots navigate from point A to B on a curved surface?

From the January issue

Q. We asked you whether a balloon-tour company that has never had an accident in its 98-year history should be seen as due for an accident. Reviewer Dave Finkleman, an AIAA lifetime fellow, thought the following answer was the best, although there is no simple answer.

A. Using statistics to weigh your future chances is risky — (almost) every casino visitor knows that.

In the current case choosing the referred company is not hazardous. On the contrary, it is recommended.

If a company has legacy which break the industry odds by almost two-folds, it is probably a good sign. The company itself might use this fact as a promotion in its marketing efforts:

“While the entire balloon industry suffers from lethal accident once in 50 years, we did not suffer such catastrophe in its last 98 year.”

This is the main issue here, inferring future local possibilities while using global statistics is doomed to be wrong. The statistics refer to the entire balloon industry, while the current balloon firm is only a single player in this field. It is possible that the spotless legacy of such a company is based on excellence concerning safety which makes this firm a prominent candidate of balloon manufacturing.

On top of that, aerial accident probability can be referred as a memorylessness incident. In such cases the distribution of waiting time until a certain event, does not depend on how much time has elapsed already.

This is the reason why the man and his wife should favor the company in their quest of safe ballooning.

Ohad Gur, AIAA senior member; Shoham, Israel; Ohadg7@gmail.com

For a head start … find the AeroPuzzler online on the first of each month at aerospaceamerica.aiaa.org and @AeroAmMag.