question on N1 gauge being too low

DennisM · Post by **DennisM** » Mon Dec 27, 2004 2:03 am

"Hi Fellow pilots, maybe a simple question but, When I descend I notice my N1 warning light goes on saying n1 too low and the gauge needle does go below the green area, Is this due to going too slow(engine thrust) while descending? If so, what is the corrective action? Thanks and best regards, [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img] Dennis [img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img] 1050"

nharwood · Post by **nharwood** » Mon Dec 27, 2004 11:06 pm

What rate of decent are you using? Do you use auto thrust? Do you simply cut the throttle to idle and push the nose over? I usually set N1 at somewhere above 50% then alter my decent rate to maintain 290kts. I'm not sure what proper procedure would be.

DennisM · Post by **DennisM** » Tue Dec 28, 2004 3:58 am

"<div class='quotetop'>QUOTE(nharwood @ Dec 28 2004, 03:06 AM)</div><div class='quotemain'>What rate of decent are you using? Do you use auto thrust? Do you simply cut the throttle to idle and push the nose over? I usually set N1 at somewhere above 50% then alter my decent rate to maintain 290kts. I'm not sure what proper procedure would be. [right][snapback]2603[/snapback][/right] </div> Thanks for your response and feedback. I decent Manually at 2000 ft per min, I do use auto thrust at set it at 290 initially, then decrease to 280 at 25000 ft, 270 at 18000 ft, 260 at 15000 ft till 250 at 10000. No reason, just a pattern I used. Maybe I am deaccellerating too fast! Will try to keep the speed up more and see if it helps. Of course, not sure if N1 being too low is a problem or not. Best regards, Dennis [img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img]"

FlyQXCRJ · Post by **FlyQXCRJ** » Tue Dec 28, 2004 1:26 pm

"Hello- - I don't know about the 742, but this is usually a result of the nacelle anti-ice or/or wing anti-ice being on. It is taking air from the engines and if the engines are below a certain power setting (in this case a N1 setting), you will get a warning light due to the engines inability to supply proper airflow. The light being on does not hurt the engine, but it is just an indication of not having enough air to keep the ice out/off of the aircraft - remember, ice is bad - espescially inside the engine cowl. Again, I don't know if this is true with the 742 - I'm a former EMB-145 pilot and current CRJ-700 pilot and that's what happens in those airplanes. Blue Side Up, Matt [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]"

DennisM · Post by **DennisM** » Wed Dec 29, 2004 2:25 am

"<div class='quotetop'>QUOTE(FlyQXCRJ @ Dec 28 2004, 05:26 PM)</div><div class='quotemain'>Hello- - I don't know about the 742, but this is usually a result of the nacelle anti-ice or/or wing anti-ice being on. It is taking air from the engines and if the engines are below a certain power setting (in this case a N1 setting), you will get a warning light due to the engines inability to supply proper airflow. The light being on does not hurt the engine, but it is just an indication of not having enough air to keep the ice out/off of the aircraft - remember, ice is bad - espescially inside the engine cowl. Again, I don't know if this is true with the 742 - I'm a former EMB-145 pilot and current CRJ-700 pilot and that's what happens in those airplanes. Blue Side Up, Matt [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img] [right][snapback]2615[/snapback][/right] </div> Hi Matt, Thanks for your feedback. Yes, I tried it just now, I turned off my Nacelle and anti ice switches, I usually turn them off after 15000 ft, but I turned them off right before descent. And results was no N1 Low warning light. Use the same descent pattern as I use always as listed and no N1 light. Wow, very interesting. Thanks for your real life experience. Best regards, Dennis [img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img] "

globecar · Post by **globecar** » Wed Dec 29, 2004 3:00 pm

Matt nailed it correctly.