BMI (Body Mass Index) is a number calculated from your height and weight.

On the logic that pilots with BMI over 40 are likely to have Sleep Apnea and therefore more likely to fall asleep when piloting, the FAA is planning to require AMEs to use BMI to trigger evaluation for sleep apnea when airmen seek medical certificate.

http://www.npr.org/blogs/thetwo-way/...ts-controllers

This is unlikely to have immediate practical impact on soaring because most people with a BMI of 40 will be too heavy to fly a glider. But the threshold might later be lowered to 30 because Sleep Apnea is very common for people with BMI over 30. (BMI 30 is the threshold for obese classification).

A person who is 5'-8" would need to weigh 262 lbs to have BMI = 40.

A person who is 5'-8" would need to weight 197 lbs to have a BMI = 30.

Calculate your BMI (Body Mass Index) he http://www.nhlbi.nih.gov/guidelines/...MI/bmicalc.htm

Most of us know that BMI unfairly classifies some healthy body types (like weight lifters) as obese, but that discussion is old and boring. BMI shortcomings do not stop the FAA from using BMI as a trigger for screening.