Nozzle Failure at 70,000’    by Jim Flemming,  Canberra

In 1958, being the first TAC squadron to be re-equipped with the F104C Starfighter, the 476^th TFS  had to do a lot of operational testing of tactics, procedures and capabilities. These included Phase 2 nozzle tests and  high altitude operations.

There had been a spate of nozzle failures in the J79 engine fitted to the F104C. It was found that the nozzles, being operated by the engine oil system, were failing to open or close due to sludge on the oil filters, The  system was changed so that the nozzles were controlled by the engine fuel system and the problem was solved. The aircraft were being  modified at the next major inspection so some squadron aircraft continued to operate with without the oil system control being modified..

For the high altitude tests we were fitted with the early “Moonsuit” pressure suit which was based on the same principle as the “G Suit”but with a full body fitting.  Prior to donning the pressure suit you were required to be powdered all over with talcum powder and then don long underwear, inside out, so that the seams would not cause irritation points which could not be reached while wearing the “Moonsuit”. Sitting for an hour in the crewroom  pre-breathing oxygen was a most boring experience

I was scheduled for a  high zoom flight to 65.000’, and after the required  pre-breathing  I carried my portable oxygen unit out to my F104C, 56-899, strapped in, converted to the aircraft oxygen system and departed for the  high speed area “Stovepipe” up over Death Valley .

My scheduled profile was to climb to 36,000’ a level, run out to Mach 1.7  in full AB and a pull to 1.5 G. When the machmeter showed Mach 2 or better, I was to then increase to 3G for the zoom. At 38,000’ the machmeter was indicating Mach 2.1 with about 35 degrees nose up. The airplane was zooming like an angel and we rapidly passed 50.000’ where all indications were normal.

As the airplane neared 60.000’ I had to throttle back to keep the EGT within limits. The AB blew out and when the throttle was near idle I heard slight “thump” down the back end but all seemed normal. The Starfighter was still climbing but at a reduced angle of attack, about 20 degrees. As  65,000’ was reached I stop-cocked the throttle to prevent an overspeed over temp. and eased the stick forward to about level attitude. The cockpit de-pressurised and I felt the suit pressure come on. It was like being in in an all-over G suit and it was difficult to move my arms or legs. The outside light was poor due to the blue/black sky and I had to pull out the instrument panel shades to help the cockpit lighting.

I thought that the aircraft would start to descend but, to my amazement, the we kept climbing in a level flight attitude. As we reached  70.000’, I eased the stick forward to get a more nose down attitude. The airspeed was about 155 knots and the attitude changed but the Starfighter kept slowly climbing until it peaked at 72,300’ when it started to pitch down and descend with wings level. As the speed increased I popped the speed brakes, slowly increased the dive angle, and commenced a glorious high speed dive down to lower levels.

At 40.000’ I tried a relight without success. At 35,00’ I tried another relight procedure with same result. At 33,000’ I managed to get a relight  and was delighted to see the RPM and EGT started to rise. With everything appearing normal I turned towards George passing over the base at 30,000’ prior to entering the pattern. At this stage I knew something was wrong, as an increased throttle movement produced the desired RPM but no apparent increase in thrust.

Fortunately, I was aware of the nozzle failure problem where the nozzles remain open and you have a perfectly good engine but no thrust. This was my situation then.  The book indicated that level flight could be maintained at 2000’ above sea level in this configuration. With the altitude at George at 1800’ I was not about to test this theory. At 25,000’and descending I declared an emergency and requested a straight-in to Muroc Lake which was almost right in front of me. I turned so that the approach would be to the North East and at 15.000’ commenced a high key-low key dead stick approach, which I had practised many times, on to the world’s longest runway marked out on the lake bed.

On final approach the engine was developing a little thrust but I continued the deadstick approach, dropping the gear at 250 knots and touching down well into the lake bed at about 185 knots. When I came to a stop, Edwards Tower told me to vacate the airplane and await pick-up. I shut down the engine and when I descended, by hanging over the side of the airplane, I saw that the nozzles were stuck wide open. On looking around I could have been on the Moon; nothing but desert to all horizons.  After about fifteen minutes, I was pleased to see a chopper coming over the horizon from the West. The rescue crew took me back to civilization and I had a pleasant time in the Officers Club before being returned to George by car that evening.

After the maintenance crew at the Test Pilot’s School had completed the engine oil/fuel nozzle control modification 56-899 flew on for some years before being destroyed in an accident in Spain in the early sixties.

 -  Jim Flemming