PBN.3.2 PBN Components - Navigation Specifications Flashcards
1
Q
Phases of Flight and PBN
What are the different phases of flight and PBN?
A
En-route:
- Oceanic/Remote
- Continental
Terminal Airspace:
- Arrival/Departure
- SIDs/STARs
- Approach
- simple, non-complex (RNP APCH) with or without vertical guidance, which every operator certified and operationally approved can fly
- complex, demanding (RNP (AR) APCH) requiring specific approval, functionality and training
2
Q
What are RNAV specifications?
A
Oceanic/Remote RNAV 10
En-route/Terminal/Approach RNAV 5, RNAV2, RNAV 1
3
Q
What are RNP* Specifications?
A
Oceanic/Remote RNP 4
En-route/ Basic RNP 1, RNP APCH,
Terminal/Approach RNP (AR) APCH
4
Q
PBN Performance Requirements
What does navigation accuracy define?
A
Defines the Estimation Error on the computed aircraft position: Real aircraft position remains within a determined area 95% of the flight time
5
Q
What’s navigation accuracy?
A
It is the radius of this determined area
6
Q
How much must it be?
A
Less than 1 x RNP value
7
Q
What’s integrity?
A
Ensures a high level of trust in the acft navigation computation
8
Q
At what percentage does the real acft position remain within a determined area?
A
99.99% of Flight time
9
Q
What’s considered in this 99.99%?
A
Undetected navigation systems malfunctions
10
Q
Navigation integrity is then…
A
the radius of this determined area
11
Q
What are the specific navigation specification parameters determining the integrity?
A
- Alert Limit
- Time to Alert
- Integrity Risk
- Protection Level
12
Q
What’s the Alert timit?
A
Error tolerance not to be exceeded without issuing an alert
- Region (horizontal & vertical) which is required to contain the indicated position with the required probability for a particular navigation mode
- Required ALs depend on the type of operation
13
Q
What’s Time to Alert?
A
Maximum allowable time elapsed from the onset of the navigation system being out of tolerance until the equipment enunciates the alert
14
Q
What’s integrity risk?
A
Probability that, at any moment, the position error exceeds the Alert Limit
15
Q
What’s Protection Level?
A
Statistical bound error computed so as to guarantee that the probability of the absolute position error exceeding said number is smaller than or equal to the target integrity risk
- The region (horizontal & vertical) assured to contain the indicated position. It defines the region where the missed alert requirement can be met
- PLs are computed by the on-board receiver
16
Q
What happens if during an operation the PLs exceed the required ALs?
A
The operation cannot continue
17
Q
What’s VPL only used for?
A
Operations with vertical guidance (e.g. LPV)
18
Q
What’s xAL?
A
Fixed value during operation
19
Q
What’s xPL?
A
Value calculated by on-board receiver (varies depending on aircraft and satellite geometry and SBAS corrections)
20
Q
What’s Navigation Continuity? What does this definition include?
A
Ensures the computation of navigation information all along the flight.
It includes GNSS services
21
Q
What documents emerged from the several local initiatives that defined their own requirements to fly some RNAV or RNP concepts?
A
PBN Manual (ICAO Doc 9613) and
PANS-OPS amendment (ICAO Doc 8168) in order to standarize the PBN concept for area navigation
22
Q
What’s the diference between the requirements for RNAV and RNP?
A
Both have the same requirements, but RNP requires to monitor navigation performance in addition, and to alert the non-conformance with the navigation performance criteria.
23
Q
What’s RNP’s requierement referred as?
A
On-board Performance Monitoring and Alerting (OBPMA)
24
Q
What does this differentiation enable aircraft without monitoring function to access?
A
Several PBN environments
25
By whom are RNAV operations monitored?
Mainly by ATC
26
What's availability?
Percentage of time that the services of the system are usable by the navigator.
Proportion of time during which reliable navigation information is presented to the crew, autopilot, or other system managing the flight of the aircraft
27
What are other requirements to Achieve Desired Perofrmance Levels?
- Navigation functionalities of the RNAV system: detailed capability of the nav system (such as execution of leg transitions, parallel offset capabilities, holding patterns, navigational databases)
- Choice of navigation sensors
- Aircrew knowledge and training requirements
28
What's the Monitoring and Alerting System?
RNP = requirement for the acft avionics to provide on-board performance monitoring and alerting
RNAV does not require this
29
What are the acft systems that are capable of performance monitoring and alerting called?
RNP systems
30
What does the on-board performance monitoring and alerting provide to the flight crew when the required lateral track accuracy limiti stipulated for the ATS route leg is exceeded?
Unable RNP
31
What's the historical difference between RNAV and RNP capable aircraft?
On-board performance monitoring and alerting (OBPMA)
32
What's this difference in reality?
Airframe
Aircraft built in the 1980s and 1990s have less functionality and are considered RNAV acft, whereas acft built after 2000, have significantly more functionality and are considered RNP capable
33
Where can we find the details of OPMA?
Volume II, Part A of the PBN Manual
34
Aircraft Functionality
What are all acft able to do when area navigation capable?
Flyover turn
35
How does the aircraft perform the flyover turn?
Acft starts to turn onto the next leg of the ATS route as it passes over the waypoint
36
What's the disadvantage with a flyover waypoint?
Acft must transit over wpt before turn is initiated and then recover onto the next desired track
Recovery back on to the intended path after the turn initiation may not be consistent due to different acft performance
37
How does an acft perform a fly-by?
Aircraft's RNAV system anticipates the turn
38
On what does the turn initiation depend?
Max bank angle
Speed
Altitude
Turn angle
39
By what are all turns affected?
TAS and wind velocity. Therefore, the performance of these turns will not be the same
40
What's the earliest the turn can be initiated?
20 NM prior to the waypoint
41
What are fixed radius used for?
To ensure predictable and reliable track keeping in the turn
42
What will the aircraft fly with a fixed radius?
Consistent, highly repeatable ground track
43
Which acft are highly likely to have this functionality today?
Newer generation, RNP capable, acft
44
How does the acft do a turn with a fixed radius?
Acft commences the turn at a defined point and then automatically adjusts the Angle of Bank to maintain a constant radius from a specified point
45
In which ways is fixed radius performance achieved?
Depending on the phase of the flight:
Radius to Fix (RF)
Fixed Radius Transitions (FRTs)
46
What are these functionalities associated to?
RNP Specifications
47
Where is RF used? What does the computer use?
RNP Specifications on Instrument Flight Procedures (IFPs)
Computer uses path terminators
48
What do IFPs include?
SIDs
STARs
RNP APCH / RNP (AR) APCH
49
Who uses this?
High percentage of the European Commercial Air Transport (CAT) fleet, it is a mature application
50
What does the PCP IR require to support SIDs and STARs?
RNP 1 with RF
51
What does PBN IR encourage to service providers?
Use of RNP 1 with RF
52
What should designers consider for IFP? Why?
Whether RF is necessary. To protect the size of the acft navigation database
53
What's the FRT? What are they used for?
An en-route functionality. They are used for ATS routes, usually at higher altitudes
54
To what can only FRTs be associated?
Wpts held in the Airways Record of the acft's database
55
What's the recommended turn radii for FRTs?
Industry standard, DOC 236C/ED75D
- 22.5 NM for airways above FL 200
- 15 NM for airways below FL 190
56
In which Navigation Specifications can FRT functionality be used?
RNP 4
RNP 2
A-RNP
57
Which acft have this functionality?
Few acft, its application is extremely limited today
58
Description of a Leg and How and Aircraft Flies it
En-route and Terminal
Path between two wpts is normally called a leg
59
How does an acft fly the leg with ATS routes?
Flies to the next waypoint in sequence, performing a fly-by turn where capable
60
What do we use for consisten ground track in the turn?
FRTs
61
What does a Path Terminator define in IFPs' legs?
how the path will be flown and how the leg will be terminated
62
Where are Path Terminators defined?
ARINC 424
63
What's a Path Terminator?
two-letter code, dfines a specific type of flight path along a segment of a procedure and a specific type of termination of that flight path
64
To what are path terminators assigned?
All RNAV SID, STAR and approach procedure segments in an airborne navigation database
65
What does this allow?
Translating the procedures designed for clock & compass manual flight into computer language (FMS)
66
Into what are charted procedures translated?
Sequence of ARINC 424 legs in the database
67
How many path terminators are defined in ARINC 424?
23
68
What are the path terminators that can be expected in RNAV or RNP charts?
Initial Fix (IF)
Track to a fix (TF)
Course to an altitude (CA)
Direct to a fix (DF)
Course to a Fix (CF)
Course from a fix to an altitude (FA)
69
What's the IF?
Defines a point in space
Coding of RNAV procedures starts at an IF
70
What's the TF?
Preferred type for straight legs
Geodesic path between two waypoints
71
What's the CA?
Course that terminates at an altitude with an unspecified position
For departures or Missed Approach
72
What's DF?
Segment from an unspecified position to a known waypoint
73
What's a CF?
Course that terminates at a waypoint
CF legs are subject to magnetic variation issues
74
What's a FA?
Begins at a fix and terminates when acft altitude is at, or above, a specified altitude
75
Aircraft RNAV System and Database
Do all RNAV systems have a database?
No
76
What will the Nav Specs identify?
If computer is required to have a database
77
How do database capacities vary?
According to the particular navigation computer system
78
How does the upload of AIRAC cycle work?
Where RNAV system has a database.
ATS routes and data required by that particular AO are stored as well as coordinates for all ground-based NAVAIDs
79
What's required of each State by ICAO?
To publish ATS routes, NAVAIDs, aerodromes and related procedures in the AIP
80
What does a data house produce?
Global dataset using the State's AIP as primary source of information
81
How are Data houses employed by AOs?
To collate specific info from each State to support their client's required operations
82
What do the data houses do with this collated information?
They pass it in ARINC 424 format, on to the original equipment manufacturers (OEMs), referred to as data packers, to be coded and then uploaded into the appropriate target RNAV system
83
In accordance to what are databases updated and validated?
To the ICAO AIRAC cycle
84
What do AOs do for pilot ease?
They create company routes to enable quicker uploading of specific routes
85
What happens if the data is incorrect in the database? What can you do to avoid it?
The pilot may be unaware.
Ensure that the flightpath extracted from the database is checked for accuracy and consistency against the chart information
86
What happens if there are errors in the database?
Pilot cannot correct them
87
How does the pilot use the data?
Selecting the company route or waypoints in turn from the database to create an ATS route
88
What about for IFPs?
Pilot calls out the procedure by name
89
What can the pilot do for RNAV systems without a database?
Pilot is required to manually insert the waypoints. This functionality will limit the Navigation Specifications these aircraft can meet
90
Who creates the Path of SIDs, STARs and ATS routes? What do they use?
Airspace Planner and Procedure Designer
They use a sequence of waypoints, also known as the Desired Path
91
What's done with these waypoints?
Loaded into the aircraft's RNAV system
92
What does the computer do with these waypoints?
Links them together in order and creates a flightpath. This path is known as the Defined Path
93
What are the small computational errors?
Parth Definition Errors (PDE)
94
How do you fly the path?
Acft uses one or more sensors to estimate its position and the RNAV system calculates the deviation from the defined path and adjusts accordingly to maintain that path
95
On what depends how well actual and desired paths coincide and the ability to follow fixed path turns?
Coding of database
Navigation sensors
Capabilities and functionalities of the RNAV system and/or
How the acft is flown
- manually following a CDI
- manually with the aid of a FD
- by AP
96
Implications for PBN:
What do PBN operations require?
Lateral accuracy
Integrity
Continuity of acft systems together with
Particular RNAV system computer functionalities to meet specific requirements
97
Where are the requirements for a particular NAvigation Application defined?
In the associated Navigation Specification
98
How is lateral track accuracy defined?
Path that has been defined by the RNAV system
Nav sensor used to estimate the position, and
Ability of the pilot and/or the system to fly the defined path
99
What the Flight Technical Error (FTE)?
Unability of pilot or system to maintain the defined path
100
By whom are the performance limits for the FTE laid down?
By ICAO for each Nav Spec
101
When is an acft certified?
When it demonstrates the ability to fly at the required Nav Spec's specified lateral accuracy 95% of the flight time with all errors combined (TSE)
102
Continuity
what must both signals-in-space and aircraft systems meet to meet a specific navigation applicatoin?
Required accuracy, Integrity, Continuity for that operation
103
What must the probability of failure of being unable to compete an operation?
Acceptably low
104
What will some Nav Specs in the oceanic/remote continental phase of flight require?
A higher continuity for these operations
105
How is high continuity achieved?
By carrying a second, independent RNAV sytem and sensor to provide redundancy
106
On-Board Performance Monitoring and Alerting (OBPMA)
Do aircraft RNAV systems necessarily need to provide the pilot with a warning when the required lateral accuracy limits have been exceeded?
No
107
What can be done regarding this?
Some area nav computers have extra functionality to monitor the Navigation Sensor Error (NSE) and issue alerts
108
What capability do these area nav computers with extra functionality (OBPMA) have? what are they called?
RNP capable
RNP systems
Some nav applications will require RNP capable systems for their oprations
109
Navigation Specifications
By whom are ICAO Nav Specs used?
Individual States
Regions
as a basis for Certification & Operational Approval
110
How can an acft be certified to a particular Nav Spec?
With one or more of the required nav sensors identified in that Spec
111
Where are the criteria for the carriage of specific navigation sensors detailed?
In a Nav Spec, driven by the NAVAID infrastructure defined by the individual State or region
112
What is the possible outcome of this?
An acft that is certified to a particular Nav Spec cannot meet theneeds of the airspace because the navigation sensors do not match the NAVAID infrastructure
113
Hence, what do Nav Applications require in individual States?
Same Navigation Specification, which may be based on differing NAVAID infrastructures
114
Who must ensure that acft have the appropriate certification and navigation sensors to fly in that airspace?
Airspace users
115
Implications of cross Specifications Qualifications
What should be noted if an acft and crew are certified for a particular Nav Spec Designator?
It does not imply automatic qualification for a Nav Spec requiring less stringent accuracy
For example:
RNAV 5 approval does not imply RNAV 10 is satisfied
RNAV 5 approval may be based on VOR/DME, whereas RNAV 10 infrastructure is GNSS
116
Does it apply as well to RNP?
Yes, being qualified or certified for an RNP Specification does not imply automatic qualification for RNAV Specifications
Example:
RNP APCH approval based in GNSS
RNAV 1 infrastructure is based in DME/DME and in this example the State does not recognise the use of GNSS in terminal airspace
