RAPID DEVELOPMENT OF THE X-55A AND INITIAL FLIGHT TEST RESULTS

RAPID DEVELOPMENT OF THE X-55A AND INITIAL

FLIGHT TEST RESULTS

Robert A. Rowe (AF), Lockheed Martin

 

Even before the ACCA program was initiated, Lockheed Advanced Development Programs [ADP] was doing studies under another contract to look at the overall feasibility of building a large composite aircraft about the size of a C-27.  These estimates showed it would take about 3 years and over $150M to execute.  When the actual RFP from the Air Force Research Lab [AFRL] came out for ACCA at a cost of $50M and less than 18 months to complete, you can imagine there was a lot of headshaking and discussions about what, if anything could be built that quickly and for $50M dollars that would still meet the overall requirements of a large cargo aircraft.  This is when an idea, some would say a crazy idea came about:  This idea was to utilize an existing aircraft, namely a Do-328J and chop off the flight station, wing and horizontal tail to re-use on a brand new composite fuselage and vertical tail came about.

This program would not have started correctly had we not put together such a phenomenal proposal and program plan.  People like Steve Justice, Scott Burleson, Jeff Cramer, Ken Gousman, John Carter, and many others helped construct a plan that gave us a way to absorb schedule impacts due to unforeseen issues that may arise, which turned out to be exactly what happened.

We were awarded a Phase 1 contract in April 2007 to do preliminary design and risk reduction tasks in support of the Phase 2 effort to actually build the aircraft.  During the course of this initial 5 month Phase, the team had to become experts in the Dornier 328, even though it’s not made by Lockheed Martin.  This presented many challenges and without being able to obtain the original technical data on the aircraft or the assistance of AvCraft, who maintains Do-328’s.  We would have fallen way behind in the design effort right from the start without them.  People like Kevin Kelly, Derek Paige, Daren Kimura, Steve Burns, and Guy Rossi led the technical effort successfully through Phase 1 and were critical to us winning the Phase 2 contract [from AFRL] to build and fly the aircraft.

In October, 2007 we were awarded Phase 2 which was the actual build of the demonstrator.  The single biggest challenge at that time was the fact that we were developing new material processes and manufacturing methods at the same time we were building the aircraft.  It was up to folks like Brian Shoemaker, Steve Laveaux Craig Smith, and Tony Borgia to lead the production operations, and advanced prototyping center efforts to build aircraft structure with materials and processes that had to be developed on the fly.  In some ways, I think it was similar to what the team developing the SR-71 had to go through when they started using Titanium to build airframes.  We had a pretty high scrap rate initially and were conducting hundreds of coupon tests to better characterize the structural performance of the materials.  In the end, we were able to overcome these obstacles and get to the point where we were able to produce a composite airframe that passed all of structural tests and airworthiness certification process.

Finally it was actually time to test the aircraft that we built under the leadership of Jim Harris, our pilots Rob Rowe and Joe Biviano and the rest of the safety and flight test team.  We conducted a series of system checks on the aircraft, engine ground runs, and a series of taxi runs before taking to the air on June 2nd.  We flew for 1 hour, 29 minutes, achieved a maximum altitude of 12,000 ft. and a maximum speed of 162 kts.  We completed all 29 of our planned test points and brought the pilots and aircraft safely home.[1]

Our AFRL Customer has been elated with the program outcome and has said that the ACCA team was the finest team he has had the privilege to work with.

Interestingly for AFRL, ACCA is the first, new mold-line, manned technology demonstrator aircraft that the Air Vehicles’ Directorate has produced in over 20 years (the previous being the STOL F-15 in 1988).  As such, it represents the revival of a heritage that dates back to the formation of what is now known as AFRL.

In sum, AFRL met 4 of their 5 technical objectives:

  • We accomplished accurate, detail design of the aircraft concept in 5 months using advanced analysis methods
  • We advanced the state-of-the-art in composite materials technology by utilizing a material blend (MTM-45) on the largest (known) physical scale is the aerospace industry
  • We advanced  the state-of-the-art in manufacturing technology by successfully applying out-of autoclave curing at the largest (known) physical scale in the aerospace industry
  • From a “standing start”, we fabricated, certified and flew  the aircraft in 20 months versus the 12 month goal
  • We were able to complete the project within the $50M limit set for government investment. Key cost-saving features were order-of-magnitude reductions in both part count and mechanical fasteners relative to the metallic baseline. The compounding effect of these features enabled us to absorb an 8-month schedule slip and stay within budget, serving as testimony to the power of composites technology.[2]

The road to first flight started over a decade ago with industry and government laboratories collaborating in the AFRL-Led Composites Affordability Initiative (CAI), a series of critical development steps in both materials and manufacturing technologies designed to mature dramatic, cost-saving processes. Out-of-autoclave curing of large, unitized and co-bonded structures minimizes part count and mechanical fasteners.  The “ripple effect” of this approach spreads across every aspect of airframe production expense. Tooling, raw material, fabrication man-hours, quality control and floor space utilization efficiency are just a few of the factors that combine to create a compounding effect on cost when applied in a holistic manner. ACCA is the “capstone” test of integrating these CAI principles all the way from conceptual design through certification and flight. Despite its larger size, the materials and processes used for the fuselage reduced the number of parts by an order of magnitude relative to the original metallic design (approx 300 vs 3000) and drastically reduced the number of mechanical fasteners (approx 4000 vs 30000). [3]



[1] Mike Swanson, summary of flight test effort in Roll-Out ceremony

[2] ACCA Activity Summary, Barth Schenk

[3] ACCA Activity Summary, Barth Schenk