Some other things to keep an eye on, make sure hydro light goes out on motor (or else engine hydro pumps will cavitate). Call out "40/60", meaning you've reached 40% N2 under 600 degrees EGT, and if you're feeling froggy, call out "30/40", for 30% EGT under 400 degrees EGT. If the engine doesn't achieve this, it is not necessarily grounds to terminate the start, however, if it exceeds 600 degrees under 40%, pay EXTRA attention to your EGT, because failing 40/60 is an indication an overtemp may be coming. Make sure "LOP" (low oil pressure) light goes out by idle, and make sure the starter light goes out. It should go out automatically by the time you turn the starter switch off. If it doesn't, turn the starter switch off... If it STILL doesn't go out, you can save me some troubleshooting headaches by closing the overhead bleed air valve closed within 10 seconds of start, that should finally force the starter to disconnect and the light to go out... That greatly reduces the risk of shredding a starter. Oil pressure at idle should be above 11 PSI, and oil temp below 175, the oil temp gauge has a selector and will automatically show the highest temp. And if you're a pilot watching this, do jet troops a favor and never... NEVER... make an issue out of "fuel flow flux"... Unless the other indications are fluctuating too (N1, N2, EGT), or the fuel flow indication is clearly broken somehow (like showing 0PPH at cruise, for example), then don't complain the fuel flow is fluctuating. Fuel scheduling on the F108 is an old system, it's clunky, not really an exact science, and the fuel flow meter is literally just a turbine on the fuel line coming off the MEC. It's not particularly accurate. So long as the engine is making the correct power settings, and isn't fluctuating a bunch in N1, N2, and EGT, then fuel flow fluctuation isn't an issue.
As a flying crew chief, that was one of the qualification that was need to be on fly status with your jet on Tdy;s. It;s been over 21 years since I started an engine. some of it came back, other steps I forgot. I always love running engines. on fuel xfers, or off load, that was rare. Pressure check for environmental, or system check. I just love running engines. Ask any crew chief.
When/where did you serve? All the APUs are old hot garbage now. Occasionally we get a nice one that max motors at 25%, or a little higher if you wait. But most of ours technically reach max motor at 22-24% and need a while past that to reach 25, or struggle to get above 20% and can't even reach 25%. Also a gamble anymore whether they'll start right at all, most of our redballs are APU. Every now and again, we have to do a wave of back to back APU changes because several jets started getting 1 or 2 really bad APUs and simply don't get to 20% in a reasonable amount of time.
@@hatman4818 wow, thats just crazy. I was stationed at Grand Forks from 95-99 with the 912 ARS, then they combined all maintainers under the 319th AGS. I was in white flight working 912th jets. Our big issue was start nozzles clogging. Usually carried a stash in my backpack. If it was a #2, usually could change the nozzle thru the fire door. We did have APUs that would get to 22% and then lag. Adjusting the guide vane actuator on the apu sometimes gave you a couple more percent when starting the 108, but if not we replaced it. Big apu issues we had were when the jets would come back from Mildenhall. They were good and taking our ESCUs from the apu cabinet and giving us their broken ones.
Somebody in the know feel free to correct me, but based on my experience with many other Boeings, he -R model can't start more than a single engine at a time. You may be referring to the turbojet powered A-models, where you could gang bar the start switches when and if the J-57's had the black powder start cartridges installed, starting all four motors at once. Quite a bit of black smoke involved. On the new airplanes, the 747-400's can start two at a time using on-board (APU) pneumatics, and the 787 can start both engines together, as long as the ramp is dry. Engage one, count to three or five (Can't remember) and engage the other.
The wind can turn the fan backward with a tailwind. I have a hard time imagining a situation where the N2 is up to speed with the fan rotating the wrong way though. It's also possible for no fan rotation if there is ice frozen at the bottom of the duct.
Out in Grand Forks, the winds coming across the prairie always caused the fans to spin counter clockwise depending on which way the jet was parked on the ramp. The fan is not mechanically connected to any other part of the engine and can free spin.