Source: Various (listed below)

Let me first start off, I was extremely board sitting at Andrews AFB when I found the following information out.  Although it only applies to handful of people in the entire DoD it is a good to piece of information to tuck away in your grey matter.

 When it comes to aviation , each service has special "requirements" to get pay and/or wings.  Regardless, if you fly Department of Defense (DOD) Pay Regulation, Volume 7A (Active Duty & Reserve Pay), Chapter 22 highlights both Hazardous Duty Incentive Pay (HDIP) for Flying Duty and Aviation Career Incentive Pay (ACIP) for Rated or Designated Officers, Aviation Cadets And Warrant Officers.

For those of you that are not Career Aviators, the HDIP discuss a $150 a month pay if you fly at least 4 hours a month.

The Air Force as well has special "requirements" to receive the incentive pay.  AFI 11-402, Aviation And Parachutist Service, Aeronautical Ratings And Badges chapter 8, Aviation Service Of Operational Support Fliers discuss what the rules of a Operations Support flier.