Cruising at FL 430

In the early ’80’s we were having a rash of J-85 flameouts, engine failures, at altitudes above FL 390.  The J-85 is the engine in the T-38A.  So Command issued a directive stating that flights would not be conducted above FL 390 unless ‘absolutely necessary.’  And of course, they held the final vote on what was “absolutely necessary.”

The J85 is a good engine, and very reliable, but it does have its limitations.  Think about it; it was designed in the ’50s, and is still with us.  If you know and respect these limitations there really are no problems with it.

One of the idiosyncrasies it has is, it is very sensitive to ‘rapid’ throttle movement in higher altitudes.  Define rapid?  I can’t – but I know what they are when I see them…

In the early ’70s our IPs (instructor pilots) were guys who trained on the T-33, the T-Bird.  The T-Bird had a maybe a second or third generation engine and was susceptible to flameouts with a rapid throttle burst.  If you slammed the throttle from idle to Max, you had a 50-50 chance which way the engine was going to react.  One, good; one, not so good.  At any rate, pilots of my generation were taught, from the very beginning, to be cognizant of throttle movement.

In the late ’70’s we began taking more and more FAIPs into our instructor corps.   (A FAIP is a First Assignment Instructor Pilot – an individual who graduates from pilot training and is assigned as an IP with his or her, or gender to be determined assignment.)  Anyway, with so many new young kids coming back, some things got dropped – like J85 throttle considerations.  And we began seeing the consequenses.

If you experienced a J85 engine failure at altitude, it wasn’t (really) that big of a deal.  Yeah, you were going to go down, but more often that not, the engine would restart below FL 260 as designed, and you could continue on.  However regulations at the time, stated that pilots experiencing an engine failure would land “as soon as conditions permit.”  This often meant a divert to a base that didn’t support T-38 maintenance.  So, maintenance troops would have to be brought in for an engine inspection, and the dollars began to mount up.

With a rash of T-38 J85 engine failures the dollars really began to mount up, so Command attacked the ‘symptoms’ of the issue, and missed the cause.  There was no problem cruising in the 40s, if you didn’t fly the jet with “ham hands!”  So, I more or less, ignored the rule.  And I knew, if I and any problems, I would be held accountable.  I was willing to accept that proposition.

From when the edict was put on us until I retired in 1988 I must have had a half-dozen flights in the ’40’s – with no problems at all…

Aside:  Right after this ‘rule’ came into affect I was at the SOF (Supervisor of Flying) desk one afternoon when call came in from an inbound jet.  The pilot wanted to be sure we knew he was coming.  Then came the call, “Houston Center, Tonto XX back with you at FL 430.”

The SOF couldn’t risk the “free shot, “Reporting at FL 430 this is Copperhead, say call sign.”  Nothing!  LOL!

The pilot, a general from Headquarters, landed, got in his car and drove off with nary a word!



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