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Chapter 4 - Approach to Space
click on the links below for more of the story...
i. Test Pilots & Operations - ii. Experimental Testing - iii. F5-A Freedom Fighter - iv. Variable Dynamics - NF-101A -
v. Anchors Aweigh - vi. Two Strakes - One Strike! - vii. Whirlybirds, Spinning Wings? - viii. The Rest of the Story

Two Strakes - One Strike!

I stumbled onto a brief but very interesting test on the basic F-104A airplane, even though the Starfighter had completed testing well before. 

 

Somehow the Test Pilot School had proposed to Lockheed adding a pair of strakes on standard F-104s, then in service around the world.  The school was by no means an authorized path for such modifications, in fact had no authority, but famous test pilot Chuck Yeager was the commandant.  Aided by Lockheed, supporters were in a process of pushing for the modification approval for the entire tactical fleet of the F-104, worldwide, including the German Air Force, then being equipped with the Starfighter. 

 

The modification mounted two aerodynamic surfaces (strakes) below the tailpipe and about 30-degrees angle-off the lower centerline.  I recall each as roughly 5 feet long jutting out about 12 to 14 inches from the fuselage.  One of the schools instrumented airplanes was modified for the strakes and an angle of attack gage in the cockpit.  The flight recorder included altitude, speed, and angle of attack, and the control positions.  The latter was important!

 

Col. Peterson, our director and the top dog in testing directed me to look into the school doing that testing.  A school instructor, Greg Neubeck, had been flying the test airplane, and he concluded that the strakes were significantly increasing the pitch-up angle of attack of the aircraft, thus giving improved turning performance as well as safety margin.  In talking to Greg he seemed to me overly intent on proving the value of strake even insisting that he had rat-raced in both configurations to get added confidence in his conclusion.  The idea of determining improved performance in a dogfight made me suspicious of the claims.  It was obvious that the only way to absolutely compare the effects of the strakes was to actually fly into pitch-up in the same, instrumented airplane, with and without the strakes installed, which he had not done.  And the data would be absolute:  But, only if my hands were not on the controls before entering pitch up, and if I stayed off the controls long enough to record the angle of attack when pitch up began.  At that point there would be a nose up acceleration without control inputs, induced entirely by the pitch up moments. I explained this and I asked for permission from to test it, which was granted. 

 

I had long before begun practicing low speed control and did loops in fighters starting pull up at normal landing approach speed.  In fighters of the era, which were not blessed with high thrust to weight of modern airplanes that was excellent practice for getting the most out of the airplane.  I had also flown the F-104 into and out of the edge of pitch-up with my hands on the controls and learned how to visually discern the pitch up with ample time to recover.  The rate at which you exceeded the pitch up angle and the degree of exceeding that angle determined the outcome.

 

That merely required smooth and gentle entry to see the pitch rate change in time to shove the stick forward and recover before too deep in pitch up.  I only needed to repeat this, except to do it hands off, which added very little complexity.  It was merely a matter of practicing a few times to establish trim and consistent nose-up (pitching) velocity to come almost to a stop at the pitch up angle of attack and then see the airplane begin an increasingly intense, self induced pitch up.  Staying off the controls as the rate decreased and then increased of its own volition recorded the exact angle of attack where pitch up occurred.  Repeated data points in flights with and without the strakes attached proved there was no change with the strakes, thus they added only drag, weight and cost to the F-104.  The large angle of attack display gave me the method to monitor the occurrence in real time, which was vital to success.

 

The only risks were approaching it with too great angular acceleration (nose-up, pitch rate) or delaying recovery after pitch-up commenced, after which recovery would be impossible, because of control limitations of the F-104.

 

Shortly after the tests, Col. Guy Townsend jumped me. He was furious that, in his words, I would risk an accident to get test data.  Nothing I said cooled him off one iota and it occurs to me, even today, that I received that ass-chewing for doing what a test pilot is supposed to, and doing it with the approval of a superior.  In fact, Col. Pete was Townsend’s boss, also.  I had no restrictions placed on me not to fly into pitch-up, and it was impossible to test conclusively with such restriction. Every real test flight by definition entails risk, with only the degree at question! I never mentioned this to our mutual boss, Col. Pete (because of my respect for him) until many years after retirement.  This was the first time I saw the real Guy Townsend, no longer the sugar-sweet voiced Southern Gentleman.

 

To confirm my recollections, I recently asked Bob Hoey, the premier engineer of the AFFTC at that time, if he recalled the tests and he not only did, but he gave me the following explanation for Neubeck’s incorrect conclusion:

 

Regarding Greg Neubecks "strakes" - I finally figured out what he did so

that his initial report showed the 0.2 to 0.4 g increase with the strakes. He had compared the max g's that were reported in the windup turns in Kinch (Iven Kincheloe)-and-my F-104A report with the numbers that he obtained during his qualitative flights with the strakes (which I think were done at Eglin). My report used oscillograph data and the max g was a line faired through the middle of the buffet trace.  Greg recorded the stop needles on his g meter that, of course, showed the top of the buffet boundary. At .9 Mn in heavy

buffet he would gain at least a half g!!  I could get his numbers by merely reading the TOP of the buffet trace on my charts.   

 

Being a test pilot at the AFFTC resulted in some memorable perks.  One weekend Danny Thomas joined a group of Hollywood entertainers at the base for a celebrity golf tournament.  Our base was unique and quite open and I happened to be driving home from the flight line and recognized Danny sitting in his auto, looking about rather puzzled. There weren’t any signs on base, so I pulled over, introduced myself, and gave him directions.  I was playing in the golf tournament and he mentioned something about it, but I knew he was surely scheduled to play with one of rank. 

 

The next day, my assigned celebrity was Danny and the guy who played the part of “Animal” in the William Holden movie Stalag 17. That evening we enjoyed an off-the-cuff floorshow by the group, including Ann Margret, which was outstanding.  Danny Thomas proved to be a gentle and gracious man and my respect, after that brief period with him is best shown in the fact that his St. Judes Childrens Hospital remains my primary charity for life and afterwards.

 

My affection for Ann Margaret, was rekindled very recently by a story on the email trail of her immense happiness in seeing a Vietnam infantry veteran at one of her book signings.  He brought in a picture he had with her and she stopped the crowd waiting in line to kiss and honor him, with sincere praise to the waiting crowd: for the performance of “Her Men”.  Little did I know at the time that a “Bob Hope, show for the troops” would not be very far off in my own future.