CP-140 Block IV moves one step closer to Technical Airworthiness certification

November 24, 2021 -  Defence Stories

Caption

The Integrated Test Team poses with the CP-140 Block IV test aircraft CP140111, at 14 Wing Greenwood, NS. Photo: S2 Jeremy W. Morris

From November 2020 to April 2021, an Integrated Test Team conducted comprehensive flight testing on a Block IV-modified CP-140 Aurora. The team included personnel from the Aerospace Engineering Test Establishment (AETE) and 415 Long Range Patrol Force Development Squadron who conducted testing on the Aurora Incremental Modification Project (AIMP) aircraft. Flight tests were initially conducted from IMP Aerospace in Halifax and then the team relocated to 14 Wing in Greenwood in late December 2020.

Flight testing was required because the Block IV design added components to the external surface of the CP-140 which changed the aerodynamic characteristics of the aircraft and had the potential to affect the flying and handling qualities. These components included:

• a large Wideband Global SATCOM radome on the upper fuselage
• multiple smaller fairings as part of the Directed Infrared Counter Measures system
• antennas for the Tactical Data Link 16 system, and
• a new anti-collision light on top of the vertical stabilizer

The flight test program was developed by AETE using a build-up approach, which followed cumulative step by step testing to ensure safety. It covered a myriad of test points across a range of flap, landing gear, gross weight, and center of gravity conditions. In order to capture the necessary data to assess the aerodynamic effects of the modification, the aircraft was fully instrumented to capture multiple parameters such as:

• tri-axial body accelerations
• angles of attack and sideslip
• pilot control input positions and forces
• airspeed, and
• altitude

The CP-140 Block IV flight test was the culmination of a significant engineering effort to assess aircraft behavior prior to AETE flight testing, which included computational fluid dynamics (CFD) and wind tunnel test (WTT). WTT was conducted at the National Research Council 2m x 3m tunnel, with CFD and data analysis being conducted by L3 Harris and the Flight Sciences team of the Directorate of Technical Airworthiness and Engineering Support (DTAES).  Through the use of WTT data and CFD, the flight test requirements were developed to specifically target parameters which could not be fully assessed at the edges of the envelope without flight testing:

• air data system
• aircraft stall
• controllability
• performance, and
• stability and control

This project milestone was integral towards certifying the CP-140 Block IV aircraft for operational use. AETE flight test data will be used to support certification of the Block IV modification by comparing CP-140 Block IV aircraft to the original CP-140. DTAES is a primary finding authority for CP-140 Block IV: it will review the data analysis provided by L3 Harris, to determine if the aircraft is ready to enter operational service.