"Turn the heat off!!!! O.F.F, OFF, turn it OFF!!"
Ah yes, students....
IP didn't help himself out at all with that screaming session, probably clammed up the student. Some context for the uninitiated: the environmental system in the 38 is your 1959 cadillac frost-o-matic special. All major controls and switches are on the front cockpit only. You heard that right, I cannot even shut down engines from the back without the student raising the finger lifts in the front throttles under my verbal command. Like the commercial says:
It's not science fiction, it's what we do every day...
At any rate, the system collects a hell of a lot of moisture on the ground which then freezes at altitude, since in the middle of the summer there's really one setting to use, and that's thermostat all the way CCW. Might as well safety wire it to that setting for 3/4 of the year down here.
So when the water freezes in the ducting, it starts coughing at high pressure, eventually breaking the ice and literally snowing in the cockpit. it's the most hilarious thing you've ever witnessed. Snow in the cockpit, pelting your visor, and it's 105F on the ground. This quickly turns to liquid, and now all your inflight pubs are soaked. A real peach of a setup.
So the "technique-procedure" is to purge the system on the climbout when the bleed air pressure is at its highest (MIL power) in order to eject the water through the A/C vent in liquid form until nothing more comes out. At that point the system is dry and you can safely go back to a cold temperature for the rest of the sortie without re-enacting Disney on Ice on the recovery. This is accomplished by moving the thermostat all the way to the 100F stop, which basically moves the valve to all bleed-air and away from the mixer flow in the A/C turbine. That's high pressure hot air coming from the vent, which forces all that water out.
Problem is that the panel is NOT labeled ON and OFF like he was screaming at the student. You have a knob for the defog upper ducting, then you have a thermostat knob in degrees F, then you have a 3-position spring loaded switch.
AUTO,
MAN COLD,
MAN HOT. The AUTO is top position, there the system auto moves the mixer valve to match the thermostat knob selection you have in place. Moving the thermostat to a different value, it auto moves the mixer valve to give ya the target value you selected.
If you move the switch out of AUTO, you're now in MANUAL mode. Now you need to hold the spring loaded switch left or right into MAN COLD or MAN HOT. That action of holding the switch, manually moves the mixer valve, so you can get the right flow temperature,
and disregards the position of the thermostat knob. This is most often used when the auto selection doesn't work.
The problem is that if you scream at a student to turn the heat OFF, and he's in manual, he won't see anything labeled OFF so he'll improvise and turn the thermostat all the way to 40F (full CCW). Except, with the switch out of AUTO, that action won't do anything for you. It'll keep blowing that breath from Hades LOL. And to be clear, it can become a safety of flight issue real quick, to include loss of consciousness and incapacitation, maybe even burns, if you don't de-pressurize (which de-energizes the A/C system), worst case maybe even jettison the canopy in flight. A real bad day for you over something so seemingly simple.
So that's what happened here. Of course, it bears noting that the student was a
Japanese national. Soo, you do the math. Also recognize, even if the student went manual, if he didn't hold down the switch in manual cold until the high pressure hot air quit (the valve moves slowwww), then he may have thought he had accomplished what was requested of him. That video was a c-fk of CRM breakdown. But funny in hindsight.
To tie it to the theme of this thread, this job can be repetitive and frustrating. Not every good pilot makes a good instructor, and we deal with many a great mil pilots roll through these halls and are completely s---ty instructors because they don't have the temperance nor the communication skills to handle a myriad of student learning gradients and learning styles, and so frustrations like this one are the end result. Then there's others who can rate a good jet, but absolutely cannot do it while teaching and demo'ing what they're doing, which can be a bit ego-bruising to type-As. The problem is exacerbated when some pilots consider the assignment second-class, something that's taking them from "hacking the mish" and putting warheads on foreheads. Like having a crappy CA on a 4-day, that can make for a loonnng assignment, having to deal and witness that kind of impetuous and pointless student berating, and the kid doesn't get better (shocking).
