US Air Force C-17 Flight Test
AeroNavData assisted the US Air Force in the C-17 Flight test at Edwards Air Force Base (KEDW). The flight test required AeroNavData to design a number of custom procedures that could provide navigation data in a tab-delimited format that matches DAFIF Edition 8.1. Our provided navigation procedure design also incorporated aircraft maneuvering speeds, bank angle, and the capabilities of the aircraft’s upgraded Flight Management System (FMS). The navigation file was also useable by Jacobs Engineering, the team responsible for creating the Nav Images used by the C-17.
The purpose of the flight tests are to assess for certification of the C-17’s ability to successfully fly these ARINC Path terminators, using the aircraft’s upgraded FMS.
- Standalone PI legs
- RF – CF leg combinations
- RF – TF leg combinations
- RF – RF leg combinations (alternating turn directions)
- TF – RF leg combinations
- DF – RF leg combinations
- FM legs
AeroNavData hosted technical meetings with Jacobs Engineering, the USAF C-17 Program Office, Hanscom AFB CNS/ATM auditors, and Boeing to discuss certification requirements, aircraft characteristics, the airspace in which the fight test would take place, and to define which aircraft and FMS capability was being tested.
This joint team agreed that these constraints must be met:
- The Aircraft must remain within Restricted Airspace R-2515 corridor, located inside R-2508
- The Instrument Approach Procedure using the stand alone Procedure Turn (PI) should be designed into Edwards AFB (KEDW)
- All other tailored Standard Terminal Arrival Route (STAR) procedures should include a direction of flight from East to West
- All procedures should use 200 KT TAS and a max bank angle of 30° when doing design calculations.
- STAR procedures will contain no altitude constraints within the provided navigation file.
- AeroNavData will coordinate with AFMC TERPs at Wright Patterson AFB to determine a safe procedure turn altitude at KEDW.
AeroNavData utilized the L-7 IFR Enroute Low Altitude FAA Publication, Google Earth imagery, the currently published Restricted Area R-2515, and currently published approaches into KEDW to:
- Determine airspace constraints and the size of the approved flight test area
- Evaluate possible terrain limitations
- Evaluate any airspace restrictions such as operating altitudes
- Assess the availability of any usable currently published waypoints or navigation aids
Instrument Approach (PI) Path Terminator
After analyzing the Instrument Procedures that serve KEDW we discovered that none of the approaches were currently published with a Procedure Turn (PI). In the interest of time and safety AeroNavData decided it would be much more efficient to use an existing approach and add the Procedure Turn leg in a manner that would satisfy the flight test. Using the currently published VOR/DME or TACAN RWY 22L approach, AeroNavData contacted AFMC TERPs to determine if a procedure turn, considering the current published design, could be added to the approach in a safe manner. AFMC TERPs affirmed that the AeroNavData Procedure Turn could be added to either the north or south side of the approach course as long as the altitude constraint in the procedure turn was at or above 5900 FT MSL.
Standard Terminal Arrival Routes (STAR)
While designing the STARs, the main focus was to test all of the necessary path terminator combinations on a path that was both safe, cost effective, and allowed adequate time for analysis by the crew. All necessary leg combinations except for the DF-RF were included in a single STAR design. Additionally, we determined it necessary to design a separate STAR to test the DF-RF combination in the event that the combination would cause errors during the creation of the Nav Image.
All fixes used for the FLTPN6 & FLTPN7 STARs were created outside the KEDW Class D airspace in order to reduce interference with the remaining traffic at Edwards AFB. The STARs were kept at least 2 NM inside the edges of R-2515 to ensure compliance with restricted airspace requirement and the RF legs were calculated to have a radius of 6.00 NM. All of the RF legs were designed with proper turns to remain with restricted airspace.
Both STAR designs and the D22LT approach were designed and coded using our certified navigation data procedure coding processes and practices. Once the design and coding passed all stringent integrity checks, a tab-delimited navigation file was created and delivered to Jacobs and the USAF.
On April 9, 2015, the Program Office at Wright Patterson Air Force Base reported back that the C-17 RF, FM, PI leg testing at Edwards Air Force Base was 100% successful. All 26 testpoints that were provided were attempted and reported as Effective during the thorough 3.5 hour flight test mission.
AeroNavData is pleased to have been a part of this successful flight test mission!