Train qualified volunteer civil service employees from other agencies/components who already travel frequently. Many flights already carry civilian federal government employees cleared at or above the level required for Air Marshalls. Many of those frequent traveling feds are capable and willing of serving as a public safety officer on flights that they are already traveling.
I recommend a process that would allow current federal government employees who travel frequently to volunteer (with home agency/supervisor approval) for a specialized FLETC training course that would equip these existing employees as Air Marshals. Once trained the employees would attend reoccurring training as required by the program.
These trained and credentialed flying feds could report into a secure web site or an Air Marshal Field office X number of days/hours in advance of their scheduled travel to notify TSA that a certified volunteer will be on certain flights. TSA could then divert their full-time Air Marshals to other flights that might not otherwise have coverage or they could simply reduce their Air Marshal work force.
A program like this could be modeled after state constable programs to some degree where a volunteer is required to have professional training and the volunteer has to serve so many hours per year/month to remain current in the program.
This program would increase security and reduce cost by using personnel who are already in place on flights as required by their home agency duties. This would save on airline, hotel, and per diem already being paid by the home agency. This would safe on the number of background investigations and other suitability screenings by using personnel who have already completed screening for other duties. The number of flights protected by trained Air Marshals would increase without increasing the size of the federal Air Marshal workforce.
A modified version of this recommendation (if not already in place) would be at least cross-train current frequently traveling federal law enforcement officers from other agencies to serve in an Air Marshal capacity on flights they travel on and divert planned Air Marshals from flights to others.