Weighing in

SHEPPARD AIR FORCE BASE, Texas -- Anyone with an inner ear infection can understand how important a center of gravity is as things seem to swirl about and maintaining balance becomes a survival skill. Now imagine piloting an aircraft that has no center of gravity and trying to land it. 

A three-day course here trains crew chiefs how to ensure those aircraft are weighed and balanced properly to ensure they don't lose their center of gravity. But, it still happens from time to time. 

Lt. Col. Sam Starkey, a 97th Flying Training Squadron instructor, has had his share of aft center of gravity problems in F-4's and an F-16's. 

"The airplane feels kind of weird with an aft center of gravity," he said. "It gets really pitch sensitive." 

In both incidents, he said he gently turned the plane around, took a straight approach to the runway and landed. He said in his cases, the problem was not severe enough to make him crash as long as he did not demand too much from the airplane, but it would have made it nearly impossible to complete his mission. 

That places more importance on the course here. 

"No matter how much gas you put in it; no matter how good the pilot is; no matter how well the crew chief has it maintained; if the (center of gravity) is bad, the aircraft can't leave the ground because it will return to the ground shortly," said Tech. Sgt. Tommie Schexnayder, an instructor of the weight and balance course. 

Sergeant Schexnayder said the course is comprised of two days of lecture and one day of practical experience. The fact that the course is so short and only covers one airplane, the F-16, won't affect the mission readiness of the students because the principles are universal, he said. Once the basic principles are understood, on-the-job training fills in the details of specific aircraft. 

He also said most of the students have seen or assisted with weighing an aircraft. All three of the students in the Aug. 8 class illustrated that point. 

Sergeant Schexnayder said there is more than just weighing the airplane, which during training takes about an hour. The process is abbreviated slightly because of time and feasibility he said. 

First the airplane undergoes an inventory inspection. Then it can be weighed. After it's weighed three times, plumb lines are used to mark the floor so measurements can be made. Those measurements are used to make sure the center of gravity is still where it should be. 

After all of that, Sergeant Schexnayder said, there are charts to compare and fill out and the hydraulics are leveled. 

Tech Sgt. Kevin Richmond and Master Sgt. Lewis Godfrey assisted the weight and balance crews at their home stations. Master Sgt. Chris Liszewski has not assisted in weighing an airplane, but he said he has watched the process once. 

All three said they look forward to learning more about the process and the certification that comes with completing the course. 

"(Weight and balance technicians) are really strapped all the time. There are so few of them, they are some of the busiest guys in our section," Sergeant Richmond said. "I look forward to helping them out and maybe taking a little bit of weight off their shoulders." 

The process of weighing, balancing and leveling - leveling is not covered on Sheppard for certification reasons - takes about four hours for an F-16, Sergeant Schexnayder said. But, he said the process can vary greatly from model to model. For example, it takes about 12 hours to weigh, balance and level a C-17.