15 Principles of PBN Flashcards
RNAV ‘X’ and RNP ‘X’ ?
RNAV ‘X’ and RNP ‘X’ – lateral system accuracy requirement where ‘X’ indicates required LNAV accuracy in nautical miles, for 95% of the flight time.
The difference between Conventional Nav and PBN?
- Conventional Nav - (Sensor based, raw data, little perf monitoring)
- PBN - (Perf based, computed Data, perf monitoring)
RNP?
Required Navigational Performance (RNP) has a required navigational accuracy plus an on-board monitoring and alerting system, for operations within a confined airspace.
Basic functional requirements of RNAV/RNP are:
- Continuous indication of lateral deviation in pilot’s primary field of view.
- In multi-pilot aircraft, it must be available in second pilot’s primary field of view.
- Distance / bearing to active (TO) waypoint.
- GS or time to active (TO) waypoint.
- Storage of a minimum of four waypoints.
- Appropriate failure indication of the RNAV system and its sensors.
RNAV / RNP system performance requirements, necessary to optimize the utilization of available airspace, defined by:
- Accuracy – the conformance of the true position and the required position.
- Integrity – measure of the trust that can be placed in the system.
- Continuity – capability of the system to perform its function without interruption.
- Functionality
- Avaliability
Accuracy and containment?
Accuracy Limit: The aircraft must remain within the defined lateral and longitudinal accuracy limit for 95% of flight time. The maximum TSE for the accuracy limit must be equal to or less than 1 × RNP. 95% of the time (Prob you may exceed)
Containment Limit: The maximum TSE for the containment limit must be equal to or less than 2 × RNP. 99.99%
Integrity risk?
The probability that the position error exceeds the acceptable limit of operation.
Time to alert?
Maximum time between the equipment going out of tolerance and an alert being provided.
Availability?
Availability – percentage of time system it is available for use.
Components of PBN:
- Navigational aid (NAVAID) infrastructure.
- Navigation specification.
- Navigational application.
Guidance may be:
- Linear: Reduces a cross-track or along-track error.
- Angular: Reduces the angle of error between required and actual paths.
Valid Nav infrastructure?
No NBDs.
PBN scope?
PBN scope defines which phases of flight use which guidance:
* Oceanic/remote, en-route and terminal – linear and time constraints.
* Approach – linear and angular.
Continuity?
The capability of a totoal system to perfrom its fucntion in the event of lack or loss of nav data, without unscheduled interuption during the intended operation.
Key difference between RNP and RNAV?
RNP specs include the requirement for onboard system monitoring
PDE?
Occurs when the path defined in the RNAV system does not correspond to the desired path, the expected path to the flown over the ground.
NSE?
The differnece between the aircrafts estimated position and actual position.
FTE
The ability of the crew or autopilot to follow a pescribed route.
TSE
Components include PDE, FTE and NSE.
TSE is the sum of FTE and NSE.
Never greater then 1xRNP
ARINC 424
- ARINC 424 path terminators set standards for coding flight procedures.
- Path terminators define the termination of the previous flight path.
Radius to Fix?
Radius to Fix – path defined by radius and arc length, centered on a fix.
Fixed Radius Transition?
Fixed Radius Transition – used in en-route procedures, with two possible radii:
* 22.5 NM – high altitude routes (> FL195 in Europe).
* 15 NM – low altitude routes.
Fly-By Turn?
Fly-By Turn – turn before the waypoint to intercept new track without delay.
Fly Over – overfly the waypoint before turning onto the new course.
