Log inLog in    RegisterRegister       SearchSearch    ProfileProfile    ContactContact    FAQFAQ    Log in to check your private messagesLog in to check your private messages

FMC Cruise

 
Post new topic   Reply to topic    www.TheAirlinePilots.com Forum Index -> Boeing 777
View previous topic :: View next topic  
Author Message
K.Haroon
Site Admin


Joined: 11 Dec 2005
Posts: 1305

PostPosted: Tue Aug 14, 2012 8:58 pm    Post subject: FMC Cruise Reply with quote

Arrow VNAV Key

Shows Climb, Cruise and Descent Pages


Arrow Cruise Page



STEP TO

An altitude can be entered for a step climb evaluation. The FMC calculates the predicted step climb data and displays the results on this page and the PROGRESS page.

Line title displays STEP TO when all of the following are true:

an active route exists and there is no pending activation or flight plan modification

the airplane is more than 200 nm from the T/D

the airplane is more than 500 nm from the destination

However, on Legs Page the pilot decides the step point e.g. at point ABC for a step climb to FL390 enter 390S.


XXXX (Destination) ETA/FUEL, ETA/FUEL W/MOD

Displays estimated time of arrival and calculated fuel remaining at the destination.

Line Title displays "ETA/FUEL W/MOD" when a modified route is displayed.

Displays the same data for the alternate airport when a DIVERT NOW modification is selected from the ALTN page.

Calculations are based on optimum step climbs and cruise altitudes.


Optimum Altitude, Maximum Altitude, and Recommended Altitude (OPT, MAX, RECMD)


MAX:

Displays maximum sustainable altitude based on:

current gross weight

temperature

number of engines operating

cruise reference thrust limit default set by airline (CRZ or CLB)

speed (ECON, LRC, SEL, EO, or CO) option

residual rate of climb default set by airline (range: 100 to 999 feet per minute)

disregarding altitude or speed constraints

does not reflect the effect of speed if speed intervention (MCP IAS/MACH window) is selected.

maneuver margin limited altitude.


OPT:

with ECON speed selected, displays altitude which minimizes trip cost based on weight and cost index

with LRC, EO, CO, or SEL speed selected, displays altitude which minimizes trip fuel based on weight

does not reflect the effect of speed if speed intervention (MCP IAS/MACH window) is selected.

Penalty for being OFF Optimum Altitude (at LRC Speed) is:

2000 feet below - 1%
2000 feet above - 2%
4000 feet above - 3%
6000 feet above - 5%
8000 feet above - 7%


RECMD:

Displays the most economical altitude to fly for the next 500 nm based on gross weight; selected cruise speed, including specified cruise speed segments; and constant altitude cruise over a fixed distance taking into account the route of flight, entered winds, and temperature forecast.

The FMC evaluates altitudes up to 9,000 feet below the current CRZ ALT and up to less than MAX altitude.

Recommended altitudes are selected consistent with the step climb schedule and specified step size. If a step size of zero has been selected, the recommended cruise level is selected assuming a 2,000 feet step size. The recommended altitude is set to the CRZ ALT when within 500 nm of the T/D.

The recommended altitude may be above or below cruise altitude.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    www.TheAirlinePilots.com Forum Index -> Boeing 777 All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum