Army Test Results

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Army Test Results

• AN/ASN-128D Doppler GPS Navigation System use of
  DAFIF

Glen Vinson, PM Aviation Mission Equipment
(Aerodyne Inc.) Vern Daley, Aviation Technical
Test Center
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Agenda

• Background
• Overview of GPS P3I programs
• AN/ASN-128D Description
• Test Incidents
• Noted behavior
• Investigation
• Resolution
• Test Results
• Conclusion

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GPS P3I

• Program Phase Production/Deployment
• ORD GATM ORD APR 01
• APB 25 FEB 02
• Fielding
• Production Decision
• DGNS LRIP 27 FEB 04
• EGI SOA, JUL 04
• FUE DGNS MAY 05 EGI SOA, APR 05
• IOC DGNS AUG 05 EGI SOA, OCT 06
• Current Contracts
• DGNS B Kit NRE BAE
• DGNS A/C Integration PIF
• EGI B Kit NRE Honeywell

DGNS P3I
EGI P3I
GPS Module
Prime Contractor EGI Honeywell (Clearwater,
FL)
DGNS BAE (Wayne, NJ)

• System Description
• Protects GPS signal thru SAASM
• Civil en-route through non-precision approach
  capability
• Supports situational awareness on the battlefield
• Military P (Y) code Precise positioning,
  Security
• Precise location (16m accuracy)
• DGNS-100 waypoints - AMPS loaded-Tactical
• Non-corruptible database-AMPS loaded-IFR
• Universal timing Supports frequency-hopping
  radios

• Requirement
• Upgrades existing nav systems w/SAASM
• Meets GATM NAV Requirements
• Unit of Issue
• EGI- 2 per on Bussed Aircraft
• DGNS 1 per UH-60A/L and CH47D
• Logistics Support 2 Level EGI, 3 Level DGNS
• Quantity Required DGNS 1268 EGI - 1168
• Quantity Fielded 0

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AN/ASN-128D (DGNS)

• Protects GPS signal thru SAASM
• Civil en-route through non-precision approach
  capability
• Supports situational awareness on the battlefield
• Military P (Y) code Precise positioning,
  Security
• Precise location (16m accuracy)
• DGNS
• 100 waypoints, AMPS loaded
• Non-corruptible 12MB DAFIF database, AMPS loaded
• Universal timing Supports frequency-hopping
  radios

IAP DESTINATION
TYPE ARPT
IDEN KMOB
1)GET TYPE ok?
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Test Incident 1
Problem Inconsistent naming between ICAO and FAA identifiers Pilot could enter HSV or KHSV for Huntsville International but could only bring up Pryor Field by entering KDCU.
Investigation From one version of DAFIF to the next, the FAA identifier field was changed from DCU to KDCU. The ICAO identifier was KZ. Engineers noted that the naming change was inconsistent FAA identifiers were not changed if it had a valid ICAO identifier.
Resolution Train the pilots to always use the ICAO identifier, e.g. KHSV for Huntsville International Can the naming convention be standardized in DAFIF?
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Test Incident 2
Problem Display of non-GPS approaches The DGNS initially displayed all approaches at KOZR (Cairns Army Airfield). The DGNS should have displayed only the two GPS approaches.
Investigation The DGNS was not designed to handle non-GPS approaches.
Resolution Filter out all non-GPS approaches. The filter was implemented in the Aviation Mission Planning System (AMPS).
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Test Incident 2

• Approaches at KOZR
• I06 ILS RW06
• N06-1 NDB 1 RW06
• N06-3 NDB 2 RW06
• O06 GPS RW06(OVERLAY)
• O24 GPS RW24(OVERLAY)
• S06 VOR RW06
• S24 VOR RW24

Filtered using AMPS
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Test Incident 3
Problem Seemingly valid approach would not load The DGNS displayed the GPS RWY 6 approach at OZR (Cairns Army Airfield). However, an error occurred when the pilot chose to load the approach.
Investigation Because the approach does not include a Final Approach Fix (FAF), the DGNS flagged an error. After discussions with USAASA, it was determined that GPS approaches are not approved without a valid FAF.
Resolution USAASA requested the removal of the GPS overlay approach in question.
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Test Incident 3
No FAF
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Test Incident 4
Problem Invalid approach (no FAF) was loaded with no errors The pilot was able to load and fly GPS RWY 17 at HUA (Redstone Army Airfield) with no errors from the DGNS.
Investigation The ARVES intersection was coded in DAFIF as the FAF even though the FLIP chart does not have a FAF.
Resolution USAASA requested the removal of the FAF from DAFIF to match the FLIP.
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Test Incident 4
ARVES Intersection Is not marked as the FAF
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Test Incident 5
Problem Waypoint names not on FLIP chart. The Missed Approach Point at KCHA is listed in DAFIF as MAKNP. However, MAKNP is not shown on the FLIP chart. The Procedure Turn Inbound point at KDHN is listed in DAFIF as RRS05. However, RRS05 is not shown on the FLIP chart.
Investigation Ongoing. Is there a naming convention that describes to the pilot the waypoint as related to a waypoint on the FLIP chart (runway marker, navaid, etc.)?
Resolution None.
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Test Incident 5
MAKNP is Missed Approach Point Instead of RW33
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Test Incident 6
Problem Valid approaches would not load. Several valid GPS approaches loaded were incorrect.
Investigation The DGNS encountered an E where there used to be a B in DAFIF and dropped the remainder of the approach. The DAFIF ICD changed as follows (1) Waypoint description code 2 B has been replaced by E (fly by vs. end of transition). (2) E used to indicate End of transition, none to follow
Resolution BAE Systems modified the DGNS software to handle the new definition DAFIF versions must be backwards compatible
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Test Results

• DAFIF database as loaded in the DGNS P3I has
  improved situational awareness, especially during
  IFR operations.
• Pilots are able to quickly grasp nuances of GPS
  approaches.
• Most test incidents relate to GPS Overlay
  approaches, not RNAV approaches.

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Conclusion

• As the DGNS and EGI are fielded, DAFIF data
  integrity and accuracy becomes even more
  essential to flight safety.
• Backwards compatibility between DAFIF ICD version
  is critical once we start fielding in FY05.
• USAASA has been very responsive during
  investigations.
• The DWG meetings seem to be a great way to keep
  communication flowing.

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End Result

• The AN/ASN-128D (DGNS) system will meet BRNAV
  requirements and be fielded on 1268
  aircraft.

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Backup
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AN/ASN-128D System Description

• The AN/ASN-128D consists of
• RT-1193A/ASN-128 Receiver-Transmitter-Antenna
  (RTA)
• CP-1252C/ASN-128 Computer Display Unit (CDU)
• CV-3338/ASN-128D Signal Data Converter (SDC)
• Ll/L2 GPS Antenna
• Pilot and Copilot Annunciator Light Panels
• PCMCIA Data Transfer Device (PDTD)

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DGNS P3I Description
The AN/ASN-128D (DGNS P3I) adds Wide Area GPS
Enhancement (WAGE) capable Selective Availability
and Anti-Spoofing Module (SAASM) GPS card Hot
Start capability twelve channel
receiver Integrates the VSI, HSI and CISP with
the DGNS adds a non-corruptible Digital
Aeronautical Flight Information File (DAFIF)
database for IFR navigation.
End Result The AN/ASN-128D meets BRNAV
requirements and will be used in United States'
airspace and Foreign National airspace in IFR,
IMC, VFR and VMC conditions.
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GPS P3I Features
FEATURES Position to 16m 1553 Capable Inertial
Nav(lt.8nm/hr), GPS Nav, or Both Doppler Nav, GPS
Nav, or Both Integrated w/Onboard Systems Target
Acquisition A/C Stabilization Systems Universal
Timing Flight Instruments P3I in FY03 Increased
security w/SAASM Box Level IFR Capabilities
Meets GATM Nav requirements
DGNS
EGI
CN-1689
AN/ASN-128B
SDC
RTA
UH-60A/L
CDU
CH-47D
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DGNS DAFIF Interface
1)VOR-A
2)ILS RW14

• Press the 3 key to select IAP LOOKUP.
• Press the KYBD key twice to select the
• IDEN data field.
• Type in the airport identifier.
• Press ENT to save changes.
• Press ENT to confirm.
• Press ENT to scroll to the next page.

3)ILS RW32
4)NDB RW14 more