I place my hand between the speed brake and exhaust nozzle on either side to check for ECS (Environmental Control System) air flow. The F-16C needs this air to help cool the engine. Next, I check inside the JFS / brake accumulator door to make sure the JFS has pumped both accumulators back up to 3000 psi. These accumulators need proper pressure for braking or in case of an air start if the engine dies in flight. Then up to the right side hydraulic door to check pressure and quantity. Good to go, close the doors. I lean down to look inside the LOX (Liquid Oxygen) door where the fuel feed lights are located.
“Everything looks good up here Chief, you’re cleared to pull the EPU pin.”
“Copy that sir, you have six green lights (fuel feed) and I’m pulling the pin.”
I pull the EPU pin and walk towards the rear of the plane, standing on the right side of the wing so the pilot can see me.
“I have the pin (I always show the pin to the pilot). You’re clear for your test.”
Pilot bumps up the throttle a bit and runs a bleed test on the EPU. A shot of white moisture blows out of the EPU exhaust port. It runs for a few seconds, and quits as the test is done.
“EPU test good, okay to check for flow.”
I walk up to the EPU exhaust port and wave my hand past it checking for air flow… there shouldn’t be any.
“No flow sir.”
I walk to the rear of the jet.
“You’re clear for SEC.”
“Roger Chief, going to SEC.”
The exhaust nozzle closes as he hits the switch.
“Nozzle fully closed sir”
I look around making sure nobody is near.
“Clear for run up.”
The pilot runs the engine up to about 75% throttle and then takes it back to idle. He hits the switch for PRI.
“Back to PRI.”
The exhaust nozzle opens again.
“Your nozzle is fully open sir, speed brakes and flight controls are clear.”
The pilot goes through the full range of motions with all flight controls and opens the speed brakes as I observe each motion.
“Boards (the speed brakes) are fully open sir.”
“Copy that Chief, coming closed.”
“Boards are fully closed.”
“FLCS self test is all yours.”