XV-15 litho - NASA's History Office

Navy Participation
For a period of about eight years, starting in the mid-1970s, the USA experienced
one of the longest sustained periods of high inflation of the century. This
occurred, unfortunately, while the TRRA project was in its most active phase
and required high levels of contractor labor and expenditures of large amounts
of funding for subcontractor work. The completion of the wind tunnel test of aircraft
N702NA, in June 1978, left it in a non-flightworthy configuration and a
considerable effort was required to refurbish it for flight. In addition, resolution
of technical problems in most of the aircraft-development WBSEs was taking a
toll on the project’s financial resources. The “joint” commitment to the TRRA
project by the Army and NASA had, on numerous occasions, served to maintain
the support of each of the parties. Throughout the early years of the project, neither
agency was prepared to be first to walk away from their funding obligation
while the other was seen to be preparing to step up to the challenge. However, by
early 1979 costs had grown to the point where the TRRA Project Office was
forced to reevaluate its plans for the completion of the project in light of its
resource limitations. Among the solutions considered was the reduction of the
contractor’s flight program, a reduction of the procurement of needed spare
parts, and the discontinuation of work on aircraft N702NA. Each of these
approaches could have serious adverse effects on the ability of the TRRA project
to complete its technical goals.
Meanwhile, starting in early 1978, the Naval Air Systems Command (NAVAIR)
had been engaged in a congressionally-authorized Sea Based Air-Master Study
(SBA-MS) 33 to assess the Navy’s technology requirements. The report to
Congress was to “evaluate the capabilities and cost effectiveness of current and
future platform, aircraft and weapon system combinations.” The aircraft to be
considered included VTOL and V/STOL types (and, in fact, the original stimulus
for the SBA-MS was the Navy’s need to establish a basis for, or against, a future
commitment to V/STOL aircraft). For the Navy’s V/STOL Type “A” low speed
application, including the ASW (Anti-Submarine Warfare), COD (Carrier
Onboard Delivery), tanker, and SAR (Search and Rescue) missions, the tilt rotor
under development in the NASA/Army TRRA project was a candidate aircraft
type that warranted serious consideration. The XV-15 was seen by some
33 The Navy’s SBA-MS evolved from the Sea Control Ship (SCS) initiative established by
Admiral Elmo Zumwalt after he became Chief of Naval Operations (CNO) in 1970. The SCS
was to employ high performance V/STOL aircraft to perform various elements of the sea control
mission. Subsequent NAVAIR studies indicated that the tilt rotor aircraft had significant
advantages over other V/STOL concepts when applied to several Navy mission scenarios. In
1976, two years after relieving Admiral Zumwalt, CNO Admiral James Holloway initiated a
new V/STOL aircraft study under which the fighter/attack missions were to be performed by the
V/STOL “B” aircraft, and the assault/support (helicopter replacement) vehicles were designated
V/STOL “A.” During this period the Marine Corps was also investigating replacement aircraft
for their aging fleet of CH-46 helicopters under a program called HMX. Lieutenant General
Thomas Miller, USMC Deputy Chief of Staff, and Rear Admiral C. P. Ekas, Naval Materiel
Command (NAVMAT) Chief of Naval Development directed their subordinates to explore and
demonstrate, if feasible, new aircraft technology that could have potential for future Marine
assault transport applications. This provided the impetus for the Navy’s participation in the
XV-15 project.
59