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Tuesday, January 1, 2013

Bridge to Somewhere

By Lee Benson

We have all heard about “the bridge to nowhere.” What about a bridge to somewhere? Somewhere can be improved aviation capabilities en route to the U.S. Army’s Aim Point 2030. The challenge is with aviation leadership’s willingness to actually be the honest broker and analyze the benefits of the bridging technology available to them. A 200-plus-knot cruise speed for a Black Hawk helicopter will go a long way as a bridge to the Army’s Aim Point 2030.

The U.S. military faces challenges from sequestration, budget deficit, and the need to maintain a strong military. It will take more than a big cut in defense spending to balance the budget this time. If Congress does its job, this will greatly affect the defense budget and might delay aviation leadership’s ability to meet the Aim Point 30 goal for Future Vertical Lift (FVL) integration into the Army. With the focus by Congress and DoD, Black Hawk operators would not have to wait for FVL for improved capability. Sequencing particular technologies into the existing Black Hawk fleet, would demonstrate technologies prior to incorporation into subsequent FVL programs, resulting in cost and risk reduction. These modifications would increase near-term capability, safety and survivability. Improvements can be obtained as early as 2020—200+ knot cruise speed, improved agility, maneuverability and survivability, and operational range. Improved maintainability/reliability, reduced fuel and maintenance costs can be attained.

This is a way to bridge capability gaps identified by the joint services in the August 2010 Report to Congress: “A Strategic Plan for U.S. Department of Defense Vertical Lift Aircraft.”

Piasecki Aircraft Corp. pioneered compound helicopter flight. A compound helicopter is a helicopter augmented with auxiliary lift and thrust. Piasecki modified a preproduction UH-60 Seahawk with wings and a ducted fan. The modification is about a 30 percent modification of the existing Black Hawk. The pilot controls the fan in a similar manner as controlling the tail rotor. The fan replaces the need for a tail rotor and provides thrust for faster flight and improved lift. Phase l test confirmed increased performance, survivability and affordability. The test aircraft cruised at 180 knots (maximum based upon NATOPS regulation), has twice the range of the current UH-60 and 50 percent less vibration than the test UH-60 did prior to the mods. The addition of wings provides for additional fuel and enables the aircraft to fly in a flat mode versus nose down at high speeds.

Phase ll—if or when funded—will confirm Phase l projections that the aircraft can meet or exceed the key performance objectives. Phase ll program objectives include the addition of a supplemental power unit (SPU) to power the ducted fan. This modification removes the need for 500-700 SHP from the main engines to drive the tail rotor and essentially frees up the additional horsepower to provide lift for the aircraft. The SPU provides power for the ducted fan. The reduction in power needed to drive the tail rotor is now used for lift, greatly improving hover performance and airspeed. The cost of such an effort can be mitigated if leadership allows itself to be innovative.

There is potentially a way to mitigate development costs. The Army gave priority to the Improved Turbine Engine Program (ITEP). This improvement requires a new transmission and a new tail rotor. Improved speed is not a benefit of the modification. The benefit is improved lift.

Objectives of FVL came from various studies conducted by the joint services and rolled into the August 2010 report. Aviation leadership set the year 2030 to begin operational flights for FVL aircraft. This is approximately 17 years from today. If one looks at the lessons learned, this cannot happen with the government bureaucracy involved—Comanche and V-22 both exceeded 20 years in development. Sikorsky and EADS/Eurocopter—using their own funds—developed the X2 and the X3 (X-cubed), respectively, and mitigated many of the capability gaps identified in the Report to Congress. The development times will be less but still will take time. The large and cumbersome military development system slows fielding of even the simplest equipment item when the equipment requires attachment to the aircraft structure.

Black Hawk production is expected to run through 2025. This could be decreased or increased by the funding provided by Congress. The compound modification can be certified rapidly with the correct attention of leadership and the modification integrated into the production and the rebuild lines. Both would save on cost while the bridge to the future vertical lift provides the joint forces improved capability in speed, range, survivability, maintainability and reliability. The Compound Black Hawk should be combined with the improved turbine engine effort to provide more than just improved lift. The speed can compensate for a smaller military force.

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