Jump to content
Sign in to follow this  
chiswick72

N2 & <?> Variations.. You don't say?

Recommended Posts

Thought you were going to ....................................................................................See a picture did'nt you? Well you asked for [h3]N1[/h3] Variations and guess what? Pictures coming but not now I'm at work hehe..[h4]Randy J. Smith[/h4]

Share this post


Link to post
Guest Babubhai

Bill at least get the name of the person right LOL. How can we take you seriously, when you dont even know who you are talking to...And if you are going to criticise then do it a constructive manner. Instead of making provoking comments.

Share this post


Link to post
Guest Boaz

I think he got the message guys, don't have to go on...He hasn't replied so...Boaz.

Share this post


Link to post

>"On approach, with flaps extended you get a rather higher>idle setting to that the engines can spool up quicker in case>of a go around or windshear.....">>I sincerley hope no one believed what was written in that>post. Flight idle being higher than ground idle has nothing>at all to do with spool time in case of go around/windshear. >Where on earth did you get that gem from. It's more to do>with the angle of the air entering the inlet interacting with>the blades on the compressor stages. Without getting too>technical - although if you want me too I can - if the blades>are spinning too slowly they will have the effect of slowing>the aircraft down (the interaction of blades and incoming air>producing a braking pitch - no not a negative pitch and not>reverse thrust).Directly from the 744 AOM"EEC Idle SelectionThe EEC selects minimum idle or approach idle. Minimum idle is a lower thrust than approach idle. Approach idle is selected in flight when:*nacelle anti-ice is ON*flaps are in landing position*Continuous Ignition switch is ONApproach idle decreases acceleration time for go-around. Approach idle is maintained until five seconds after touchdown, when minimum idle is selected. Approach idle is selected during thrust reverser operation."As a licensed aircraft mechanic, I can confirm that this is what approach idle(flight idle) is for. The high rotating mass of a large high bypass engine means that the acceleration times are slower and for certification purposes, approach or flight idle is used. The previous explanation would mean that the engine has some physical way of slowing the N1 down to create a braking action. This just can't be done as the N1 is a free running spool and it's speed is dependant on airspeed, air density and N2 speed.Cheers,JohnBoeing 727/737 & Lockheed C-130/L-100 Mechanichttp://www.precisionmanuals.com/images/forum/ng_driver.jpg

Share this post


Link to post
Guest Skiff

Good point. The only comparison I will draw to other sims, including the PMDG 737 for that matter, is how much they have been able to work around (or abuse) the limitations of MSFS. Given the history of addon aircraft in general, and PMDG specifically, I expect nothing less than for them to push these limits again.Jon (KSEA)

Share this post


Link to post

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  
  • Tom Allensworth,
    Founder of AVSIM Online


  • Flight Simulation's Premier Resource!

    AVSIM is a free service to the flight simulation community. AVSIM is staffed completely by volunteers and all funds donated to AVSIM go directly back to supporting the community. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. Thank you for your support!

    Click here for more information and to see all donations year to date.
×
×
  • Create New...