Bryan Becker From United States of America, joined Mar 2001, 333 posts, RR: 0 Posted (12 years 7 months 1 week 3 days 2 hours ago) and read 850 times:
When starting a turbojet or turbofan,or any other kind of jet,and even home made or hoby gas turbines-What kind of things are you looking for or at to see if it is running properly.An if you see or hear anything that is wierd,is the engine always shut down?-And what are the most commen things that accure with the engines that are problems when the engines are started up?
Windshear From Denmark, joined Mar 2000, 2315 posts, RR: 11 Reply 3, posted (12 years 7 months 1 week 2 days 23 hours ago) and read 717 times:
Well I was a bit confused with the question, or which one WAS the question, but I agree with the others, EGT is the primary attention maker, then N1 RPM, OIl temp and fuel flow.
To stick to the topic, and not what you aksed in the above field. The engines are always shut down when the aircraft is no needed to taxi or ofcourse fly
The engines are shut down, simply by cutting off fuel flow to the engines, this is done by separating to valves in the engine and on the fuel line feeding the engine, when they transit and seperate, fuel is refused and restricted from the engines.
And as you can gues the engines die out...
"If you believe breaking is possible, believe in fixing also"-Rebbe Nachman
Buff From Australia, joined Mar 2007, 0 posts, RR: 1 Reply 5, posted (12 years 7 months 1 week 1 day 18 hours ago) and read 658 times:
Bryan: No, an engine is not always shut down for "weird" things happening. For instance, an erratic EGT unaccompanied by any other wandering parameter may simply be a failing/failed EGT guage. As far as sounds go, that's a tough one as many large aircraft have the pilots at a great distance from the noise-makers, especially with tail mounted engines (Remember the term "WhisperJet"?).
A pilot's philosophy is: Why shut an engine down if it is doing useful work?
Engines are shut down usually for one of two reasons:
1/ It has ceased working and is a detriment to flight aerodynamics/safety; and/or
2/ It is going to fail causing 1/ above (example: fire, seizure, stalling, bird/FOD ingestion).
Even given item #2 though, if continued operation of the engine will provide enhanced safety if even for a short duration, a pilot may elect to keep a failing engine running just to get him/her through "the rough parts" of an emergency. Even though continued operation may be the difference between a damaged engine and a destroyed engine.
JT-8D From United States of America, joined Dec 2000, 423 posts, RR: 3 Reply 6, posted (12 years 7 months 1 week 1 day ago) and read 631 times:
Bryan, I thing buff nailed it, but an understanding of an engines place in the whole system should be understood. An engine also powers a generator, hyd. pump, and provides a source of air to the air conditioning systen for pressurization. To shut down an engine because of an bad indication, would be a loss of more than just thrust. The crews generally know when "something really bad" just happened. If this is the case, they will refer to the checklist and accomplish the appropriate procedure. Most planes today fly just fine on one motor anyway, but its still not the first choice of any crew to shut down an engine.
JT-8D From United States of America, joined Dec 2000, 423 posts, RR: 3 Reply 7, posted (12 years 7 months 1 week 23 hours ago) and read 626 times:
Dont know what the checklist would say, but here we go.. Parking brake set. Ignition switch on, enough air pressure for the starter, (more than 35 psi for most engines), start switch to start. Watch for start valve open light. As soon as you see N2 rotation, (high pressure compressor), look for oil pressure rise(dont need full pressure yet, just making sure the pump is working). Then look for N1 rotation(low pressure compressor). We like to let the starter go as high as it will go, then turn on the fuel with the cutoff lever. Then you watch egt, to make sure it doesnt go above redline. Fuel flow indicator is your first indication. Should have said that first. If you have high fuel flow, chances are you are going to exceed max egt. Cut the starter off at the right speed, and make sure the start valve open light goes out, confirm by watching the duct pressure gauge, that the pressure returns to normal. As the engine accelerates, watch oil press to see that it goes to normal. Watch egt the whole time to make sure it doesnt go too high, or you might cook the engine. If you have a problem before fuel is turned on, just turn off the starter, if after fuel is added, turn off the fuel, and let the engine "motor" with the starter for about 15 seconds. Keep in mind, these are general procedures that do not apply to all engines. Turbo prop, and turbo shaft engines may be different, but I dont know why they would. Always follow the checklist..