Monday, November 06, 2006
I was thinking today about how as my career progresses, certain things about the actual airplanes get easier. The big secret about corporate jets is they are really easy to fly. And to start.
Here are a few aircraft starting procedures, in order of my career progression.
To start a Cessna 152 or 172, I would make sure the fuel mixture was set to "rich", then turn the key in the ignition until the engine fired up. If the engine was cold, sometimes I'd add a little primer, which is essentially pushing on a little lever to pump a wee bit of raw gas into the engine.
The Beech Baron was fuel-injected. To start a Beech Baron, I'd make sure the fuel mixtures were set to "rich", then turn on the boost pumps for a few seconds, then turn the magneto switches to the "start" position until the engine caught. The engines would usually catch right away, which was good because if they didn't, sometimes the fuel pumped out by the boost pumps would drip out and form a big puddle of gasoline right under the engines, which seemed a little dangerous to me.
I kind of forget how to start a Navajo, but I think it was pretty much the same except that the throttles would be set to full throttle, the fuel mixtures would be in the "Cut-off" position, and as soon as the engine caught a little, I'd advance the mixtures to the "full rich" position while simultaneously pulling back on the throttle. I think. I'll be honest; I wasn't very good at starting the Navajos, especially when they were hot. I can remember more than 1 huge cloud of smoke billowing out the back of the engines as I sat on the ramp, draining the battery and causing the engine to backfire so hard I worried the exhaust system would blow off.
Starting the MU-2 was considerably more exciting. I had it written down for posterity, and I have reproduced it here:
1. Place your right hand on the condition lever in case it all goes to hell and you need to move it to "emergency stop". If you move your right hand at all during the process, you will be killed by the most senior pilot. If that's you, you are expected to commit suicide.
2. Take your left hand, and press the starter button, holding onto it until you get light-off, which is indicated by a rise in EGT and fine beads of sweat forming on your forehead.
3. Using your your third hand, hold the unfeathering pump button until the engine reaches roughly 40% and passes the NTS test.
4. Take your tail and use it to hold the fuel enrich button from start to light-off, then tap the fuel enrich button if the engine starts to hang, making sure you don't overtemp it in the process.
5. Take your left foot and use it to flick the batteries from parallel to series if the engine isn't accelerating quickly enough. Dont flick the switch the wrong way though, or you'll shear the starter motor, which is considered a 'bad thing' by most AME's.
You were expected to do all this simultaneously, and to also monitor critical engine parameters. If you messed up the order of any of these steps, or if you used the wrong appendages to do this, expect the engine to promptly melt, and you to enjoy a very, very extended holiday from work.
And now it's back to easy street. In the Citation II, to start the engines I have the throttles in the "cut-off position". I press the big white "start" button on the engine I want, and then I watch the rpm increase. When the rpm gets to around 10%, I move the throttle forward to the "Idle" position. When I do that, fuel is introduced into the engine, which turns and burns and quickly settles into a relaxed idle, terminating the start sequence. That's it.
I have never had an engine catch on fire while starting it, and I'm happy about that. I think it might also be due to the fact that I have never started a radial-engined aircraft. That's one regret I have in aviation but I can live without it in exchange for the simplicity and safety of my current setup.