Smart general aviation pilots won’t fly if they are taking a prescription that says Do not drive or operate machinery while taking this medication. But sometimes it’s not that clear cut. Other prescription drugs and even some over-the-counter medicines can affect a pilot’s performance.

That’s why Administrator Huerta and the heads of 11 aviation associations today sent a letter to all U.S.-registered pilots urging them to be more aware of the effect both prescribed medicines and non-prescription drugs containing antihistamines can have on their skills and judgment.

The letter tells pilots to read prescription labels carefully, talk with their doctors, and then decide if the drugs they’re taking could impair their performance in the cockpit. It also advises pilots to use a personal “IM SAFE” checklist to ensure they are not impaired by Illness, Medication, Stress, Alcohol, Fatigue or Emotion – any of which could affect their flying abilities. The letter counsels pilots who have recovered from an illness and have taken a medication with impairing side effects not to fly until at least five maximum dosage intervals have passed.

While the FAA works closely with many aviation advocacy groups, the letter represents an unprecedented joint effort. “In all of my years of practicing aerospace medicine, I am not aware of any time in which so many aviation organizations have collaborated to get out the same message at the same time,” said Dr. James Fraser, the FAA’s Deputy Federal Air Surgeon. “We hope this collaborative educational effort will put a dent in pilots’ usage of impairing medications and help lower the general aviation fatal accident rate.

Besides Administrator Huerta, signatories to the letter include executives from the Aircraft Electronics Association, Aircraft Owners and Pilots Association, Experimental Aircraft Association, American Bonanza Association, General Aviation Manufacturers Association, Helicopter Association International, National Association of Flight Instructors, National Air Transport Association, National Business Aviation Association, Society of Aviation Flight Educators and the U.S. Parachute Association.