Appendix 4
g. Use the simulator velocity truth data (𝑉𝑎𝑣𝑒𝑎𝑒𝑎𝑣𝑎𝑣_𝑒𝑎𝑡𝑒ℎ) and the GNSS receiver velocity data (𝑉𝑎𝑣𝑒𝑎𝑒𝑎𝑣𝑎𝑣) to determine the vertical velocity error (𝑉𝑎) after the GNSS receiver has entered the desired navigation mode with the specified signal and RFI conditions:
𝑣𝑒𝑎𝑒𝑎𝑣𝑎𝑣_𝑒𝑎𝑡𝑒ℎ − 𝑉𝑎𝑣𝑒𝑎𝑒𝑎𝑣𝑎𝑣ห𝑉𝑎 = ห𝑉𝑎 A4-7. Vertical Velocity Accuracy Pass/Fail Determination.
a. The 95% vertical velocity accuracy statistic shall be computed using the formula given below. The equipment shall be considered pass only if the statistic is less than or equal to 50-LSB ft/s.
2 𝑁 ൬ 3(𝑉𝑎) ൰𝑎=1 𝑉𝐻𝐻𝑅𝑅𝑎2 ∗ ඩ∑ 𝑅𝑅 Where:
vi = vertical velocity error (ft/sec).
VDOPi = vertical dilution of precision at epoch i.
N = number of sample points used.
b. For this test, the number of samples shall include all samples where the receiver is in the desired navigation mode.
Note: The minimum number of samples is 420 for a 1 Hz solution and 2100 for a 5 Hz solution.
A4-8. Vertical Velocity Figure of Merit Pass/Fail Determination.
The receiver velocity data and the vertical figure of merit - velocity (VFOMV) data shall be used to determine the percentage of samples bounded by the VFOMV as shown below. The test passes if TSv,b is greater than or equal to 0.95.
𝑁 𝑇𝐴𝑣,𝑏 1 𝑏𝑣,𝑎= 𝑅𝑅 𝑎=1 N = number of samples = ൜1 𝑣𝑎 ≤ 𝑉𝐻𝐻𝐻𝑣𝑏𝑣,𝑎 0 𝑉𝑎 > 𝑉𝐻𝐻𝐻𝑣 A4-7
Appendix 4 A4-9. Additional Tests to Demonstrate Accuracy Commensurate with NACV = 2.
The following procedure is one acceptable means for equipment capable of better accuracy performance to demonstrate compliance with the horizontal velocity error requirement of less than 3 m/s.
a. Run the scenario in Table 13 with all satellites set at high power and no RFI.
b. This accuracy evaluation shall only include those data samples collected during the acceleration period.
c. Find the particular ℎ𝑎 (noted as 𝑇𝑎𝑣𝑣) so that 95% of ℎ𝑎 samples are less than or equal to 𝑇𝑎𝑣𝑣.
d. Re-run the scenario in Table 13 with the same satellite and RFI conditions as the 10 m/s (NACV=1) test.
e. This time only the data samples during the non-acceleration period with the specified signal and RFI conditions are used.
f. Compute:
2 𝑁𝑛𝑛𝑛_𝑎𝑎𝑎 ቆ 1.5൫ℎ𝑎𝑛𝑛𝑛_𝑎𝑣𝑣൯ ඪ∑ 𝐻𝐻𝐻𝑅𝑅𝑎_𝑛𝑛𝑛_𝑎𝑣𝑣ቇ𝑎=1 𝑇𝑛𝑛𝑛_𝑎𝑣𝑣 = 2 ∗ 𝑅𝑅𝑛𝑛𝑛_𝑎𝑣𝑣 Where:
𝐻𝐻𝐻𝑅𝑅𝑛𝑛𝑛_𝑎𝑣𝑣 and 𝑅𝑅𝑛𝑛𝑛_𝑎𝑣𝑣 are the HDOP values for each sample i and the total number of samples (non-acceleration period), respectively.
g. The test passes only if Tacc + Tnon_acc is less than or equal to 3-LSB m/s.
h. The velocity figure of merit is evaluated in the same way as for the 10 m/s test, i.e., the samples during acceleration and non-acceleration periods of the above 2 runs are evaluated together against the 0.95 threshold.
i. The vertical velocity requirement of 15 ft/s should be tested using the exact same philosophy as the test of 3 m/s above but with the scenario in Table 13.
A4-10. Test to Demonstrate HAE Output and Vertical Position Accuracy Metric.
a. The following procedure is one acceptable means for equipment to demonstrate compliance with the HAE and 95% vertical position accuracy output requirements needed to support ADS-B. This parameter is commonly called the vertical figure of merit (VFOM) and A4-8
Appendix 4 should not be confused with the vertical velocity figure of merit (VFOMV) from the velocity accuracy tests. All GNSS TSO equipment should use this test to demonstrate both HAE and 95% vertical position accuracy outputs.
b. The HAE output must be calculated using the general least squares position solution of DO-229D appendix J.1 (or any mathematically equivalent linear combination of range measurements). There is no restriction on the choice of the weight matrix W (including nonweighted solutions), and using the LNAV/VNAV, LP, LPV approach weight (wi = 1/σi2) is optional.
c. The HAE accuracy must be tested using the procedure of DO-229D section 2.5.8.3.
The σi2 used to compute the variance dU2 must be greater than or equal to those listed in appendix J when the equipment uses SBAS-provided integrity and greater than or equal to those listed as an acceptable means for FDE-provided integrity in section 2.1.2.2.2.2 when the equipment does not use SBAS-provided integrity. A fixed sigma of 33.3 m is considered a sufficient over-bound when using FDE-provided integrity. For equipment that uses SBAS- provided integrity, testing only in the highest mode attainable for its declared operational class as specified in the test itself is acceptable.
d. Performing the test described in paragraphs A4-10.a through A4-10.c confirms that the σi and dU used to compute the VFOM accuracy metric provides a sufficient error overbound. The vertical position accuracy metric must be greater than or equal to 1.96 dU where dU is computed using the same σi employed during the HAE accuracy test procedure. This VFOM calculation does not require any specific additional testing.
Note 1: The scaling factors for the vertical position accuracy metric can be rounded to 2 decimal places but there is no intention to prohibit the use of a more accurate number.
Note 2: The vertical position accuracy metric listed above is the standard metric used to provide a minimum of 95% containment under the assumption that a Gaussian distribution with a sigma of σi over-bounds the error of the range measurements. The use of a general least squares position solution (or mathematical equivalent) results in a jointly Gaussian distribution for the components (North, East, Up) of the position error. Any accuracy metric that can be mathematically demonstrated to provide a minimum 95% containment in the position domain under this Gaussian assumption is also acceptable.
A4-11. Test to Demonstrate Horizontal Position Accuracy Metric.
a. The following procedure is one acceptable means for equipment to demonstrate compliance with the 95% horizontal position accuracy output requirements needed to support ADS-B. This parameter is commonly called the horizontal figure of merit (HFOM) and should A4-9
Appendix 4 not be confused with the horizontal velocity figure of merit (HFOMV) from the velocity accuracy tests. TSO-C145/C146 revision ‘b/c’ and TSO-C196(AR) equipment already satisfy this parameter by meeting the TSO requirements. TSO-C145a/C146a and TSO-C129(AR) equipment should use this test to demonstrate the HFOM output.
b. The horizontal position output must be calculated using the general least squares position solution of DO-229D appendix J.1 (or any mathematically equivalent linear combination of range measurements). There is no restriction on the choice of the weight matrix W (including non-weighted solutions), and using the LNAV/VNAV, LP, LPV approach weight (wi = 1/σi2) is optional.
c. The horizontal position accuracy must be tested using the procedure of DO-229D section 2.5.8.3. The σi2 used to compute the variance d2major must be greater than or equal to those listed in appendix J when the equipment uses SBAS-provided integrity and greater than or equal to those listed as an acceptable means for FDE-provided integrity in section 2.1.2.2.2.2 when the equipment does not use SBAS-provided integrity. A fixed sigma of 33.3 m is considered a sufficient over-bound when using FDE-provided integrity. For equipment that uses SBAS-provided integrity, testing only in the highest mode attainable for its declared Operational Class as specified in the test itself is acceptable.
d. Performing the test described in paragraphs A4-11.a through A4-11.c confirms that the σi and dmajor, deast, and dnorth used to compute the HFOM accuracy metric provide a sufficient error over-bound. The accuracy metric must be greater than or equal to 1.96 sqrt(d2east + d2north) or 2.45 dmajor where dmajor, deast, and dnorth are computed using the same σi employed during the horizontal accuracy test procedure. This HFOM calculation does not require any spec ific additional testing.
Note 1: The scaling factors for the horizontal position accuracy metric can be rounded to 2 decimal places but there is no intention to prohibit the use of a more accurate number.
Note 2: The horizontal position accuracy metric listed above is the standard metric used to provide a minimum of 95% containment (varying from 95% to approximately
98.5%) under the assumption that a Gaussian distribution with a sigma of σi over-bounds the error of the range measurements. The use of a general least squares position solution (or mathematical equivalent) results in a jointly Gaussian distribution for the components (North, East, Up) of the position error. Any accuracy metric that can be mathematically demonstrated to provide a minimum 95% containment in the position domain under this Gaussian assumption is also acceptable.
A4-10
Appendix 4 A4-12. Demonstrat ing True Track Angle/True Track Angle Validity.
a. The true track angle/true track validity parameter is intended as a non-critical, optional parameter for airport surface operations. Since most GNSS position sources output some type of track information even during ground operations, it is recommended that GNSS manufacturers output ground track angle as the information can be useful for non-critical ADS B surface applications. The concern is that below a certain velocity the ground track information becomes invalid, and the velocity at which this occurs is dependent upon the specific GNSS equipment design. GNSS/ADS-B integrations at the aircraft level must stop broadcasting ground track when the GNSS ground track information becomes invalid.
Note: It is possible that future ADS-B surface applications may be defined for critical functions. More stringent GNSS performance requirements and tests than what is described below will have to be developed if and when these new surface applications are defined.
b. GNSS equipment not providing a valid ground track.
GNSS manufacturers may choose to not have their equipment provide a ground track output acceptable for the ADS-B true track angle/true track validity parameter. GNSS manufacturers choosing this option need to include a statement within the equipment limitations section that the ground track information must not be used for ADS-B surface applications.
c. GNSS equipment providing a valid ground track for the true track angle/true track validity parameter.
(1) Appendix H in both RTCA/DO-229D and RTCA/DO-316 provides a recommended output for true ground track angle (ARINC 743 all revisions label 103) for those using ARINC 429 characteristics.
(2) GNSS manufacturers must indicate at what velocity the GNSS track angle 95% accuracy (derived from north/east velocity) exceeds eight degrees variance from the aircraft’s actual ground track. GNSS manufacturers must provide this data within the equipment installation instructions for the GNSS/ADS-B integrator.
(3) Optimally, the GNSS equipment will either invalidate or stop outputting the ground track information when it is no longer valid. If the sensor outputs a validity indicator for the velocity, it is sufficient to simply flag the output as invalid if the track accuracy exceeds eight degrees (95%). The GNSS manufacturer must provide information in the installation instructions describing how the sensor outputs the validity indicator if one is provided.
Alternately, it is acceptable for the GNSS manufacturer to state in the installation instructions that the track angle does not meet the required accuracy below a specified velocity and indicate the minimum acceptable velocity.
(4) GNSS manufacturers developing data for the minimum valid velocity should consider the following assumptions:
A4-11
Appendix 4
• Surface message is used during taxi, takeoff, and landing ground applications.
• Surface taxi speed is less than 50 knots.
• No turns; only along-track acceleration (0.58g) and jerk (0.25 g/sec).
• Track angle validity is only an issue at taxi speeds.
• Use the GNSS noise environment defined in the velocity test (paragraphs A4-3 through A4-8), or for sensors not originally certified to the latest noise environment standards, use a reduced environmental noise level as described in paragraphs A4-2.d(3) and A4-2d.(4).
A4-12
Appendix 5 Appendix 5. Sample Airplane/Rotorcraft Flight Manual Supplement.
A5-1. Introduction.
a. The intent of this appendix is to provide general guidance for creating an AFM(S)/RFM(S). The information and structure below are not intended to cover all possible aircraft integrations or equipment capabilities and should not be construed to limit the content included in an AFM(S)/RFM(S). Actual AFM(S)/RFM(S) language and structure must be tailored to the actual installation, equipment capabilities, and limitations. AC 25.1581-1 provides flight manual guidance information for transport category airplanes.
b. Section A5-2 contains an example AFM(S)/RFM(S) entry describing operations limitations for the aircraft PBN capabilities and qualification basis that provides easy reference for flightcrews. This is just an example and is not intended as a required format. But, the example could be used as a general template by applicants, modified as needed, when constructing their AFM(S)/RFM(S).
A5-1
_____________________ Appendix 5 Installation Center/Repair Station Model XXX 123 Fourth Street Navigation System Anytown, USA
FAA APPROVED AIRPLANE FLIGHT MANUAL SUPPLEMENT
ABC MODEL XXX NAVIGATION AND/OR BARO-VNAV SYSTEM
AIRPLANE MAKE:
AIRPLANE MODEL:
AIRPLANE SERIAL NO.:
REGISTRATION NO.:
This document must be carried in the airplane at all times. It describes the operating proced ures for the ABC Model XXX navigation and/or baro-VNAV system when it has been installed in accordance with <manufacturer's installation manual number and date>.
For airplanes with an FAA approved airplane flight manual, this document serves as the FAA approved ABC Model XXX GPS, RNAV multi-sensor system, and/or baro-VNAV flight manual supplement. For airplanes that do not have an approved flight manual, this document serves as the FAA approved ABC Model XXX supplemental flight manual.
The information contained herein supplements or supersedes the basic airplane flight manual dated <insert date> only in those areas listed herein. For limitations, procedures, and performance information not contained in this document, consult the basic airplane flight manual.
FAA APPROVED Title Office Federal Aviation Administration City, State FAA Approved Page <> of <> Date: ________ A5-2
Appendix 5 Sample Airplane/Rotorcraft Flight Manual (Continued) Installation Center/Repair Station Model XXX 123 Fourth Street Navigation System Anytown, USA Table of Contents
SectionPage
1 General.............................................< > 2 Limitations........................................< > 3 Emergency/Abnormal Procedures....< > 4 Normal Procedures...........................< > 5 Performance......................................< > 6 Weight and Balance..........................< > 7 System Description...........................< > FAA Approved Page <> of <> Date: ________ A5-3
Appendix 5 Sample Airplane/Rotorcraft Flight Manual (Continued) Installation Center/Repair Station Model XXX 123 Fourth Street Navigation System Anytown, USA SECTION 1 - GENERAL <Include the appropriate statement to describe the equipment capability:> TSO-C115<revision b or later>: The installed ABC system complies with AC 20-138D for IFR navigation using multi-sensor inputs including GPS for enroute, terminal area, and approach RNP operations (as appropriate). <include appropriate GPS TSO statement below as applicable> GPS TSO-C129<appropriate revision>: The installed ABC system complies with AC 20-138D for IFR navigation using GPS for enroute, terminal area, and non-precision approach operations. Non-precision approach operations include those based on conventional navigation aids with “or GPS” in the title and those with “GPS” and “RNAV(GPS)” in the title to “LNAV” minimums.
GPS/SBAS TSO-C145 or C146<appropriate revision> Class 3: The installed ABC equipment complies with AC 20-138D for navigation using GPS and GPS/SBAS (within the coverage of a satellite-based augmentation system complying with ICAO Annex 10) for enroute, terminal area, non-precision approach, and approach procedures with vertical guidance operations.
Non-precision approach operations include those based on conventional navigation aids with “or GPS” in the title and those with “GPS” and “RNAV(GPS)” in the title to “LNAV” and “LP” minimums. Approach procedures with vertical guidance includes “RNAV(GPS) to “LNAV/VNAV” and “LPV” minimums.
Note 1: TSO-C145a/C146a Class 3 equipment is not required to perform LP approaches.
Note 2: Functional Class Delta equipment is an “ILS look-alike” that only provides LP/LPV capability on the final approach segment.
GPS/SBAS TSO-C145 or C146<appropriate revision> Class 2: The installed ABC equipment complies with AC 20-138D for navigation using GPS and GPS/SBAS (within the coverage of a satellite-based augmentation system complying with ICAO Annex 10) for enroute, terminal area, non-precision approach, and approach procedures with vertical guidance operations.
Non-precision approach operations include those based on conventional navigation aids with “or GPS” in the title and those with “GPS” and “RNAV(GPS)” in the title to “LNAV” FAA Approved Page <> of <> Date: ________ A5-4
Appendix 5 Sample Airplane/Rotorcraft Flight Manual (Continued) Installation Center/Repair Station Model XXX 123 Fourth Street Navigation System Anytown, USA minimums. Approach procedures with vertical guidance includes “RNAV(GPS) to “LNAV/VNAV” minimums.
GPS/SBAS TSO-C145 or C146<appropriate revision Class 1: The installed ABC equipment complies with AC 20-138D for navigation using GPS and GPS/SBAS (within the coverage of a satellite-based augmentation system complying with ICAO Annex 10) for enroute, terminal area, and non-precision approach operations. Non-precision approach operations include those based on conventional navigation aids with “or GPS” in the title and those with “GPS” and “RNAV(GPS)” in the title to “LNAV” minimums.
GPS/GBAS TSO-C161<appropriate revision>: The installed ABC system complies with AC 20-138D for navigation using GPS and GPS/GBAS (within the coverage of a ground-based augmentation system complying with ICAO Annex 10) for GPS/GBAS precision approach procedures to “GLS” minimums.
GPS TSO-C196(AR): The installed ABC system complies with AC 20-138D for IFR navigation using GPS for enroute, terminal area, and non-precision approach operations. Non-precision approach operations include those based on conventional navigation aids with “or GPS” in the title and those with “GPS” and “RNAV(GPS)” in the title to “LNAV” minimums.
<The following statement applies to all types of GNSS stand-alone equipment>:
Navigation information is referenced to the WGS-84 reference system, and should only be used where the Aeronautical Information Publication (including electronic data and aeronautical charts) conform to WGS-84 or equivalent.
<For TSO-C129(AR), TSO-C145/C146(AR), and TSO-C196(AR) equipment that complies with the requirements in appendix 1 of this AC:> The ABC equipment as installed has been found to comply with the requirements for GPS oceanic/remote navigation, when used in conjunction with the ABC prediction program. This does not constitute an operational approval.
<For baro-VNAV equipment:> The ABC VNAV system has been demonstrated capable of and has been shown to meet the accuracy requirements of:
VFR/IFR enroute, terminal and approach (if applicable) VNAV operation within the conterminous U.S. and Alaska in accordance with the criteria in AC 20-138D.
FAA Approved Page <> of <> Date: ________ A5-5
Appendix 5 Sample Airplane/Rotorcraft Flight Manual (Continued) Installation Center/Repair Station Model XXX 123 Fourth Street Navigation System Anytown, USA SECTION 2 - LIMITATIONS
1. The system must use at least software version <insert version identification> as the minimum version.
2. A valid and compatible database must be installed and contain current data.
<Limitation for TSO-C129(AR) and TSO-C196(AR) equipment:>
3. The aircraft must have other operational, approved navigation equipment installed appropriate to the operation.
<Limitation for all GNSS equipment:>
4. The TSO-C<insert number and revision> equipment has a performance limitation necessitating an alternate airport flight planning operational mitigation. In the U.S., refer to sections 1-1-17, 1-1-18, 1-2-3 and 5-4-5 in the Aeronautical Information Manual for specific operational guidance. In other states, refer to their operational guidance for RNAV(GNSS) approaches.
5. The ABC Model XXX Quick Reference Guide, P/N <insert part number>, dated <insert date> (or later appropriate revision) must be immediately available to the flight crew whenever navigation is predicated on the use of the system.
<Limitation for baro-VNAV equipment:>
6. The ABC Model XXX VNAV system Pilot’s Guide, P/N <insert part number>, dated <insert date> must be immediately available to the flight crew whenever navigation is predicated on the use of the system.
7. When using the <insert name> VNAV system, the barometric altimeter must be used as the primary altitude reference for all operations; including instrument approach procedure stepdown fixes.
8. Minimum altitude for autopilot coupled VNAV operation is <insert number> feet above ground level.
9. <Specify any additional limitations applicable to the particular installation.> FAA Approved Page <> of <> Date: ________ A5-6