Once I became convinced that we could teach T-38 stall and sink-rate recognition and recovery procedures better than we were, I began to dig deeper into things – and I made some interesting discoveries. I was able to access the ATC archives and found the first edition of ATCM 51-38, the manual used to teach flying the T-38. Out of curiosity, before I went any further, I also looked at a T-33 flight manual. The T-33 was the jet used before the T-38 became operational. It was a ‘straight-wing’ aircraft while the ’38 is a ‘swept-wing’ aircraft.
In reviewing the two flight manuals I was astounded to find that the paragraphs on “stall recovery” for both aircraft were virtually the same! It appeared that someone had just taken the paragraph on T-33 stall characteristics and recovery techniques, and transferred it to ATCM 51-38. They failed to fully realize that the stall characteristics and behaviors of the T-33 (straight wing) and the T-38 (swept wing) are remarkably different. In addition, the T-38 is prone to very high sink rates with low thrust settings, e.g. with the throttles retarded. It was at this point then that I began to shift my attention more on T-38 high sink rates than on their actual stall characteristics.
After extracting the 39 stall/sink rate-related accidents from the ATC Flight Safety database, I created a simple matrix that included the phase of flight (straight-in approach, final turn, short final), aircraft configuration (gear up or down, flap setting), pattern spacing (e.g. too ‘tight’ to the runway or too wide from the runway), solo or dual, and so forth. When it was complete it was very revealing. In all cases, the position of the throttles was the common denominator. In each accident, they were found to be at or near the Idle position just before the onset of either the stall and/or a high sink rate.
While the T-38 stall characteristics tend to be very obvious, the onset of a high sink rate is very insidious. Yes, these accidents were categorized as ‘stall’ related, but the real problem was the induced high sink rate. Now I had a problem. It wasn’t T-38 ” “stalls” per se that were leading to these mishaps, it was their high sink rates!
Now that I had a deeper understanding of the problem at hand, I began to work on the solution. As the Chief of the Wing Stan Eval Division at the time, I could get a jet just about any time I wanted or needed to. This greatly facilitated my project here. I then sought out the most experienced IPs (Instructor Pilots) we had on base at the time and with their inputs, the T-38 Stall/Sink Rate Ride began to take shape. Now it was time to take to the air.
We typically performed our stall maneuvers from 13,000 to 19,000 feet, with the Throttles set to 85%. We would typically begin with a simulated “Normal Final Turn” stall with the flaps at either Full or 60%. Once configured, we would roll into a Final Turn attitude and begin increasing back stick pressure. It wouldn’t take long before the aircraft would begin transitioning through its characteristic stall buffets (light, moderate, heavy) before developing into a fully developed stall. At that point, the sink rate would become “obvious.”
Then we took the exercise a step further; we reduced the throttles even more. In doing this we could show how we could induce a high sink rate without transitioning through the typical T-38 stall buffets! As a matter of fact, I could put the aircraft into a very high sink rate, and point out that the AOA (angle of attack) indicators (the windscreen colored “arrow” indicator, and the cockpit gauge indicator), were reflecting “Normal!” All the while the aircraft was sinking like a rock!
After I had the ride where I wanted it, I had to sell it. ATC in those days tended to be very ‘parochial’ in its thinking. I knew when I went to Command to present my idea, I would have to be very sensitive as to how I presented the idea. I was not only suggesting a new way to approach T-38 Stall/Sink Rate training, but I was also suggesting the ride be “ungraded!” This was not without precedence. The T-37 Spin Ride in T-37 Pilot Instructor Training was ungraded.
So I opened the proposal with a simple question: if our T-38 training of stalls and sink rate recognition and recovery is “adequate,” then why are we continuing to lose folks after 25 years of operational experience? As late as early 1986 two pilots were killed at Sheppard AFB, TX in a Final Turn sink rate mishap.