Flight Management/Navagation Flashcards
Components of the Navigation System
- 2 GPS receivers (GPS L and GPS R)
- Inertial Reference System (IRS)
- 3 Inertial Reference Units (IRUs)
- IRS Mode Selector Panel
- 2 ADFs (L and R)
- 2 DMEs - 5Chs each (L and R)
- 3 ILSs (L, C, R)
- 2 VORs (L and R)
- 2 Transponders (L and R)
- 2 WX Radar units (L and R)
- Flight Management System (FMS)
- 2 Flight Management Computers
- 3 Control Display Units (CDUs)
Inertial Reference System
- gyros and accelerometers (acceleration sensors) are used to calculate:
- airplane position
- acceleration
- track
- vertical speed
- ground speed
- heading (T and M)
- attitude
- 3 Inertial Reference Units (IRUs) translate date to other aircraft systems
Normal and Fast Alignment times
Normal Alignment - 10 mins
*must be completed when arrival time since previous full alignment exceeds 18 hrs
Fast Alignment - 30 sec
When is ILS Approach tuning inhibited?
- AP on and LOC or GS captured
- Below 500 RA; FD engaged and LOC or GS captured
- On the Ground; LOC alive; within 45º of course; great than 40 knts GS
Data required in the FMS Preflight phase
- initial position
- routed of flight
- performance data
- takeoff data
How does FMC update/calculate position
On the Ground:
- IRS and/or GPS data
- with GPS inactive, TO/GA buttons update to runway threshold/position shift position
* with GPS active TO/GA update is inhibited
In Flight:
- IRS position updated by GPS/Nav Radio data (compensates for inertial ref errors)
ILS/LOC approach
- LOC signal updates FMC position
Priority source for FMC position data
1) GPS
2) Nav radio source
3) IRS(at lease 1 IRU required)
Standard Radio Navigation Performance (RNP) levels
RNP 0.15 - RNAV/RNP Approach RNP 0.3 - RNAV/GPS; RNAV/GNSS Approach RNP 1.0 - Terminal area RNP 2.0 - Enroute operation RNP 10 - Oceanic
What speed is commanded in VNAV at acceleration height?
At Accel height:
- flap speed -5 knts
After flap retraction:
- V2+100, or
- speed transition associated with departure airport
Databases contained in FMC
- navigation (2 sets, updated every 28 days)
- operation program configuration (OPC) -airplane manufacturer configurable data
- aero engine database (AEDB) - engine performance data
- MAGVAR tables
- airline modifiable information (AMI)
Reference Thrust setting options
- TO
- TO-1
- TO-2
- D-TO
- D-TO-1
- D-TO-2
- CLB
- CLB-1
- CLB-2
- CRZ
- CON
- GA
Reduced Thrust Takeoff options
Derated/Variable
- TO-1, TO-2
- thrust setting parameter is considered a limitation for Takeoff
- thrust levers should not be moved further forward except in an emergency
Assumed Temperature
- reduces takeoff thrust depending on assumed temperature entered
- max thrust reduction is 25%
- thrust setting is not considered a limitation
Derated Thrust Climb
CLB 1:
- 10% of climb thrust to 10,000’
- thrust increases to CLB thrust at 15,000’
CLB 2:
- 20% of climb thrust to 10,000’
- thrust increases to CLB thrust at 15,000’
When is FUEL USED value reset
- at each engine start
- after a long power interruption on the ground
What are fuel predictions based on
- the active route
- flaps, landing gear up during climb, cruise, and descent
What is unusable during DUAL FMC Failure?
- VNAV
- LNAV
- Autothrottle
IRS POS entry options during initialization
- LAST POS
- REF AIRPORT
- GATE
- GPS POS
- manual Lat/Long
When do LNAV/VNAV activate after being armed prior to takeoff?
- LNAV at 50’
- VNAV at 400’
What is Econ Cruise Speed based on?
Cost Index
What does DES NOW prompt command?
- descent guidance at approx 1250 fpm until established on planned descent path
- descent rate can be adjusted by manually repositioning thrust levers
How is information displayed with dual FMC failures?
- Alternate Navigation
- CDUs use internal computing and respective IRUs for performance calculations
- CDUs continuously memorize and copy FMC flight plan
- CDU L: provides info to CA
- CDU R: provides info to FO
- CDU C: backup based on selector
How are Radios tuned in Alternate Nav mode?
- CDU L tunes left radios
- CDU R tunes right radios
- CDU C tunes center ILS
*Autotune is not avail
What does VNAV command after takeoff?
V2 +10 to V2 + 25
How is speed controlled in VNAV SPD and VNAV PTH
VNAV SPD - speed controlled by pitch
VNAV PTH - speed controlled by thrust
