Watching the Blue Angles last year reminded me of another incident that occurred during USAF flight training.
Midway through our T-38 training, we were introduced to formation flying beginning with two-ship formations and then four-ship groups (sometimes they were actual formations).
I enjoyed formation flying. It was a challenge to maintain position only a foot or so from the lead aircraft traveling at 450 knots. It was work, and I was pretty well beat after an hour of formation flight. On advanced two-ship formation flights, one instructor had two students. He rode with one student, while the other was solo, but under the guidance of the flight instructor.
Supersonic flight was one of the coolest things in two-ship formations. The T-38 is a slick airplane. In the aircraft, the only indication of achieving supersonic flight is a slight hesitation in the movement of the Mach indicator; then it bumped up to Mach 1.1.
Shock waves form around a T-38 as it accelerates to Mach 1.1. Under the right conditions,
these shock waves are visible. This is a dramatic NASA research photo.
In formation flight, as we crept up on supersonic speeds, a visible compression wave formed over the nose of the lead aircraft. The wave, visible to the wingman, was a wedge of denser compressed air over the top and bottom of the aircraft.
Incidentally, we were restricted to high altitudes for intentional supersonic flight to reduce the effect of the sonic boom at ground level over the high plains of West Texas. We were told that there were mink ranches in the area, and that a sonic boom made female minks lose interest in mating. Apparently, mink ranchers were quick to complain about sonic booms! (I have no idea if this was true, but that is what we were told.)
On one two-ship flight, our exercise was for the formation so split up and then the lead aircraft would, in effect, try to lose the wingman. The objective was for the wingman to maneuver so that he always kept the lead aircraft ahead of him and in sight. If lead turned left, the wingman would turn hard left and cut across the arc of lead’s turn. Of course, lead would reverse his turn, and then the flight would be turning right, or climbing, rolling, or diving. It was the nearest thing to a dogfight we did. It was fun, but then, no one was trying to shoot us down.
There I was…
It was my turn to lead. I was in the solo aircraft and I decided I was going to lead them on a high energy, hard turning, climbing and diving chase. I had it in my mind that as long as I did not exceed 360 knots indicated airspeed I would stay below Mach 1.0. I did not want to upset the mink ranchers!
I initiated a series of hard turns, added a climb and came up and over the top inverted and pulled hard into a dive. Looking up, I could see them cutting inside the arc of my path, keeping up with me nicely. I reversed course hard, pulling Gs and then again up and over the top, rolling as I climbed. I could not shake them. Again I pulled hard down, checking my airspeed indicator, pegged on 360. As I leveled before another turn our instructor came on the radio. “Okay guys, time to go back to the base. Two, lead us back.”
I hit my mike button, “Roger.” They pulled up on my wing in a nice tight two-ship formation and I contacted approach control requesting a penetration approach (a steep descent approach from high altitude, used to allow aircraft to stay at a high altitude until close to the base).
The Tactical “Overhead” Pattern
We were cleared to descend and started down. Approach control guided us to the “initial point” for a visual approach, and the tower cleared us for a tactical or “overhead” traffic pattern.
We flew directly over the runway at traffic pattern altitude—about 1000 feet. At the midpoint of the runway we rolled left into a hard left turn, or “pitch out,” at the break point to the downwind leg of the pattern. In a formation, the lead aircraft would pitch out at the break point. The wingman would count to three and then pitch out. This provided adequate spacing between the aircraft for landing.
On downwind, we reduced power and configured the aircraft for landing (landing gear and flaps down!). As the approach end of the runway passed by the wing, we ease back on the power and begin a wide descending arc and rolled out lined up with, and descending toward, the runway. The next few seconds were about not embarrassing myself with a poor landing.
We taxied in as a formation, pulled into our parking spots, and shutdown the aircraft.
We climbed out of our aircraft and, as we came together in front of my plane, the instructor said, “Well you did it, Lieutenant.”
“Did what, Sir?” I asked.
“Lieutenant, you boomed Muleshoe.”
Changes in altitude change the relationship between indicated airspeed and Mach 1. As it was, 360 knots indicated airspeed, was in excess of Mach 1.0 during the higher altitudes of our maneuvering, creating a sonic boom over the town of Muleshoe, Texas.
But, to my knowledge, no mink rancher registered a complaint.
The Day that I Boomed Muleshoe was the day I was leading a two-ship formation in a high speed chase over the high plains of west Texas.