Flight Management and Nav Flashcards
During climb out on the RAMBL6 from DAL departing departing runway 31L, ATC issues a climb and maintain 17000’. How do you delete the hold down over NNOLN without using the FMC?
Each selection of ALT INTV deletes the next altitude restriction if the MCP altitude is beyond the next altitude restriction. (Speed restrictions on the FMC LEGs page are not affected).
You are in VNAV cruise at FL380 100 miles from the TOD and ATC issues a descent clearance to FL240. How would you initiate an early descent.
The use of early descent on the FMC is recommended for VNAV PATH descents prior to the TOD. TO initiate an early descent, use the following procedure on the FMC:
-set the clearance limit in the MCP
-select the DES page
-select the DES NOW prompt key
-press the EXEC function key. the MOD DES page changes to ACT and the descent is initiated.
How would you initiate a cruise descent when greater than 50 miles from TOD?
Use ALT INTV (when greater than 50 NM from TOD point and MCP altitude is at or above an FMC altitude constraint).
When you initiate a cruise descent, the FMC calculates ECON speed for the new altitude.
CAUTION: a cruise descent may result in a new ECON speed that is unacceptably low for the current altitude. Avoid the use of cruise descent for large changes in altitude
What additional considerations regarding VNAV descents in the MAX are there?????
There are some VNAV descent prediction anomalies.
-FMC performance predictions are periodically recalculated automatically to better account for changing environmental conditions. This may result in additional computing time. Updated preditions can provide a new path when the aircraft is already in descent.
this can result in a 600-800 foot VNAV path discrepancy where the aircraft can find itself below or above idle descent path.
If below the idle path descent, the FMC provides guidance to the enhanced Digital Flight Control System to command 1000 FPM until VNAV path intercept. If above, the FMC may find itself in late descent where it switches to VNAV speed to attempt to recapture path. Flight deck intervention may be required to re establish path tracking (speed brake, increase speed, Etc)
What does the illumination of a flashing IRS ALIGN light indicate?
Alignment cannot be completed because the IRS detection of:
-no present position entered in FMC
- significant difference between previous and entered position or unreasonable present position entry
-excessive motion of aircraft during alignment period.
If two consecutive entries of the same position do not pass teh second internal position test, the fault light will illuminate
What are the costs/benefits of a derated thrust takeoff and climb?
Reduced thrust takeoffs lower EGT and extend engine life. They are used whenever performance limits and noise abatement procedures permit. Use of derated climb thrust reduced engine MX costs but increases total trip fuel.
What speed does VNAV command at the all engine acceleration heigh if the VNAV CLIMB page is not manually programmed (L2 L3) and speed intervention is not selected?
With VNAV armed for the climb phase, VNAV commands acceleration to the following:
- Last MCP speed (V2) plus 20 until acceleration height
- The flap placard speed minus 5 kt
- 230 knots are less when Leading-edge flaps are not fully retracted
- 250 with all flaps retracted
- the active target speed
- the speed restriction associated with the origin airport, whichever is more restrictive
You are on arrival and given holding instructions due to WX at destination.
How does entering EFC on the FMC hold page affect arrival fuel?
-entry of EFC time will help optimize FMC performance computations. Computation of destination fuel assumes that departure from the holding fix will occur at EFC time.
How does FMC calculate hold available time?
Displays available holding time in hours plus minutes remaining if destination is to be reached with planned fuel reserves as entered on PERF INIT page
