Abstract. The USAF and RAF C-17 and the Boeing-funded commercial derivative, the BC-17X, are aircraft with unique requirements. The C-17’s capabilities include austere airfield landing, short takeoff and landing capability, and benign loading and unloading. Systems engineering (SE) is applied to the customer-required Producibility Enhancement / Performance Improvement (PE/PI) and to Boeing- initiated projects, such as Must Cost projects to im- prove aircraft affordability. PE/PI projects include the Dual-Row Airdrop capability. Must Cost examples include the Wheel, Brakes, and Tires Alternate Con- figuration. Other Boeing-initiated projects include the Extended Range project. BC-17X efforts include commercial certification and the conversion to com- mercial missions. All of these changes have been accomplished through the fusion of SE and the expe- diting of changes through the Change Breakthrough Initiative (CBI). The final area of SE application is the development of the Flexible Sustainment system for aircraft support. INTRODUCTION The achievements of the C-17, named the Globemas- ter III, and BC-17X programs include, first, the de- velopment of an aircraft with takeoff, landing, load- ing and loading capabilities found on no other aircraft in the world, military or commercial. The second achievement is to create an SE–based change proc- ess, first, to incorporate customer initiated changes, and second, to reduce the cost of the aircraft. The challenge of this change process was to maintain SE principles while reducing the change cycle time by 50%. The third achievement was to create a commer- cial derivative for outsized cargo which required both Special Conditions for Airworthiness certification and at the same time converted the aircraft from its military mission capability to commercial use. Fi- nally, the C-17 took the initiative of applying SE to its Flexible Sustainment program in the development of aircraft support systems. THE C-17 The first flight of the C-17 occurred in 1991, and a rigorous flight test program followed to demonstrate achievement of system requirements. The USAF first demonstrated the C-17’s unique capabilities in Kos- ovo in 1996. Figure 1 is an artist’s depiction of the C- 17 in Kosovo by (Wavell-Smith 2000). The UK has also selected the C-17 for the Royal Air Force. The UK employed strong SE in their se- lection. To date, the USAF has ordered 120 C-17s and the UK has a lease arrangement for an additional four. The USAF is evaluating a proposal for an addi- tional sixty. Other nations have shown a strong inter- est. According to (Wheeler, et al 2000), the C-17 meets the following strategic and technical require- ments: • Mobility • Rapid deployment • Intra-theater, outsize, airdrop capabilities The key capabilities of the C-17, as documented in the (Technical Description 1996), are as follows: Austere Airfield Capability. While conventional cargo aircraft are required to fly equipment (tanks, helicopters, etc.) to a staging airfield for that equip- ment to be driven or trucked to the front, the C-17 has the capability of being landed on airfields near the front which require only minimal preparation. This capability provides the military with the quick- response capability not previously available. This capability also eliminates the considerable costs pre- viously encountered in staging operations. The C-17 and BC-17X: Systems Engineered Transport Aircraft for the World Scott Jackson The Boeing Company Long Beach, California USA Figure 1. "Kosovo Salute"