Missed Approaches and GPS

Flashcards about Missed Approaches and GPS

Missed Approach

Breaking off the approach without landing

Reasons for Going Missed

Visibility below minimums, poor runway conditions, inoperative equipment, inability to see runway at MAP, runway incursion, any time pilot deems landing unsafe

Other Reasons for Going Missed

Unstable approach, not properly configured, not in position to make a normal descent to landing at MAP, ATC instructions

Types of Approaches

ILS, RNAV, LPV – DA, LNAV/VNAV – DA, LNAV – Runway threshold, Non-precision

Non-Precision MAP Locating Methods

Time, Crossing the NAVAID, DME fix, Crossing a radial

Pilot Requirements to Land (91.175)

Continuously in a position to make a normal rate of descent using normal maneuvers, have the required minimum flight visibility, one of 10 visual references distinctly visible and identifiable

Visual References for Landing (91.175)

Approach Lighting System, Threshold, Threshold markings, Threshold lights, REIL, VGSI, Touchdown Zone or Touchdown Zone markings, Touchdown Zone lights, Runway or runway markings, Runway lights

Actions if Approach is Compromised Before MAP

Begin the climbing portion of the missed approach procedure, Remain on or rejoin the FAC, Continue on the FAC until reaching the MAP

GPS Segments

Space, Ground/Control, User

Space Segment Components

31 Operational Satellites (27 Active, 4 Reserve)

Ground/Control Segment Function

Global network of ground facilities that track the GPS satellites and monitor their transmissions

User Segment

GPS unit in the plane

GPS Receiver Function

Computes location and makes adjustments for positioning using data from satellite signals

Contents of GPS Database

Airport information, navigational fixes, and instrument approaches

Using Expired GPS Database

Can still be used for IFR flights and instrument approaches but must be in VFR conditions

Data Computed with Four Satellites

Latitude, Longitude, Altitude, and Time

Baro-Aiding

GPS uses the static system to provide a vertical reference and reduce the number of satellites required

Reason for Manual Altimeter Setting Input in Baro-Aiding

Because GPS is using the transponder pressure altitude

RAIM (Receiver Autonomous Integrity Monitoring)

Tests for corrupted data and sufficient number of satellites

Satellites Required for RAIM

A minimum of 5 satellites (or 4 with Baro-aiding)

Consequence of No RAIM

No assurance of position integrity

Potential Delay in Correcting Erroneous Satellite Signal

Up to a two-hour delay before erroneous satellite signal is detected and corrected

Types of RAIM Fault Messages

Indicates not enough satellites for RAIM, indicates potential error detected in navigation solution

Fault Detection and Exclusion (FDE)

GPS unit excludes a failed satellite, while still producing an integrity-assured position

Requirements for GPS Approach to Go Active

Within 2 NM from the FAF and approach mode is armed, suspend mode is deactivated, aircraft is heading towards FAF, FAF is the active waypoint, RAIM available at FAF and MAP