A hair-raising F-104 flying story!
Warren Hunt was to fly the F-104 with the 83rd FIS at Hamilton. Here is Warren Hunt's hair-raising F-104 story.
The F-104 was literally
a kick in the butt to fly in comparison to the old subsonic birds we had been
flying up until that time. When I say "that time" I am talking about 1957,
which is when I started flying the F-104. Going fast was no problem for the
F-104 but going slow was, so they installed a system, or Boundary Layer Control,
on the airplane. This system enhanced the boundary layer air flow over the
F-104's wings, allowing the 104 to be more easily controlled at lower airspeeds,
such as take-off and landing. But the new BLC system had its weaknesses.
On this day I had
picked up a new F-104 at the Lockheed factory located near Palmdale. Another
jock by the name of Don Dickman was also taking delivery of a new 104.
We were both delivering them to James Jabara's squadron
at Westover AFB, so we decided to fly across the country in formation.
Don and I took off and headed for our first fuel stop at Kirtland
AFB in Albuquerque. I was leading and Don was flying wing.
Even today that flight is clearly imprinted in my mind because
I came within a fraction of a second and only
a few feet from being killed during that base to final turn for landing at Kirtland.
I think I'd better explain
a bit about the BLC (Boundary Layer Control) system; how it worked in conjunction
with the F-104's wing flaps. The aircraft was built to go FAST and had very
small wings (7 feet in length each) and thus a very high approach
and landing speed. So Kelly Johnson, Lockheed's famous
chief engineer, and his "Skunk Works" guys
came up with something new to lower the F-104's approach speed
by about forty knots or so. They designed a
system which bled-off excess air from the jet
engine turbine's 9th stage high-pressure air compressor
***, re-routing this high-pressure air through
small metal tubes integrated into the wings ahead of the wing
flaps. These tubes had numerous holes
in them allowing high-pressure turbine bleed
air to flow out and over the 104's landing flaps
to improve lift, increasing the velocity of the wing's boundary-layer
air flow and basically "fooling" the wing into thinking it was going much
faster. As the F-104 slowed and its wings approached
a stall condition (loss of lift), the pilot lowered the flaps
to the fully extended LAND position with simultaneous high
air pressure from the BLC now delaying the stall and allowing lower
The 104 had three wing flap positions: UP, TAKE OFF & LAND (T.O. & L), and LAND. A military airfield's 360-degree* Overhead Traffic Pattern was normally entered at 1,500 feet AGL (Above Ground Level) and in the 104 you entered the Overhead at 325 knots indicated airspeed (fast). After passing mid-field over the runway you performed a 180-degree "pitch out" maneuver, then rolled the wings to straight and level after turning 180 degrees to the Downwind leg. The book (104 Flight Manual) said to lower the landing gear and T.O. & LAND flaps on downwind (opposite the direction of landing). Farther downwind, when the end of the runway is approximately 45 Degrees behind your shoulder, you start your descending Base-to-Final turn, pretty much one continuous descending turn, 180 degrees around to the short Final Approach leg to the runway. (*180-degree pitch-out plus 180-degree base-to-final turn = 360-degree overhead pattern!)
After approximately 90 degrees of the 180 degree Base-to-Final turn, the book said to select the LAND flaps position, where both leading edge and trailing edge flaps extend down to their full 45 degrees of extension, creating more lift at slow speeds, and the BLC air system cuts in, creating even more lift. I did all that.
But fate reared its ugly head.
With Don just 5 seconds behind me, I was turning onto final when I moved the flap lever to the LAND flaps position. The flaps neared full-down position while passing through 800-900 feet AGL with 30-40 degrees of left bank. As the flaps neared their full-down position the Boundary Layer Control air system "KICKED IN!"
Completely on its own, the aircraft ROLLED HARD LEFT turning me past the runway heading and rolling its wings well-past vertical.
Reacting instantly with full right rudder and as much right aileron as I dared use (due to adverse yaw) I could not stop the left roll. I was quickly going inverted. I thought about ejecting "upward" (the early F-104A had a downward ejection seat and my 104 was nearly upside-down) but the nose was too low...and getting lower.
I immediately knew the BLC had to be the problem. I slapped the flaps switch up one notch to T.O. & LAND position to cut off the BLC and simultaneously slammed the throttle into afterburner to give me all the thrust I could get. I'd instantly stopped fighting the left roll and used both rudder and ailerons to expedite the forced roll quickly back to wings-level (right-side up).
As the wings rolled level, I delicately started applying up elevator (pulling back on the stick gently to avoid a stall) until I felt a "burble" (near-stall buffet on the wings) while noticing that the pitot tube on the tip of the 104's nose cone appeared to be threading through the sage brush. Soon the nose began to rise a bit and the aircraft started accelerating and climbing out, away from the ground.
According to Kirtland's tower controller my afterburner blast was kicking up a terrible cloud of dust. They figured I was rolled up in a ball of fire out there and immediately dispatched crash and rescue crews.
Circling overhead, Don was amazed to see my beautiful new "Zipper" climb out of that horrible-looking mess down there.
Don joined up with me and we climbed up to 10,000 feet and took a few minutes to calm our nerves. I then asked for permission to enter the pattern for a straight in approach with T.O. & LAND flaps only, not full flaps, so as to prevent further use of the BLC system.
After landing and taxiing in to parking the maintenance folks came out and checked the BLC tubes in both wings. Sure enough, the tube in the trailing edge of the LEFT wing was badly warped while the remainder of the BLC air tubes were fine. That meant I was getting full BLC enhanced lift air blowing on the RIGHT wing while the LEFT BLC was not blowing air and this was destroying lift on the LEFT wing.
No wonder it had rolled hard left...
I got on the phone to Tony LeVier, Lockheed's famed chief test pilot, and I suggested (read: INSISTED) that Lockheed submit a change to the F-104 Flight Manual and immediately put out a RED LETTERED message to all users to go to LAND flaps (with BLC) while still at 1,500 feet AGL on DOWNWIND LEG, to check for any BLC rolling tendencies, and NEVER wait to select LAND flaps until down lower in the final turn.
Tony agreed and made the changes.
*** Boundary Layer Control (BLC) uses air from the engine compressors last stage, the 17th stage.
Copyright by Warren Hunt
The story may not be published by anyone without his personal approval.
update: March 16, 2017