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designed to enhance reliability. Specifically, the MQ-9 will have actuators with an MTBF of 2,000 hours,
which is over an order of magnitude improvement over the actuator MTBF of 150 hours on the earlier
Predator models. There will be a triplex (double redundant) flight control system, and the control
surfaces survivability will increase with two rudders, four ailerons, and four elevators. The overall
objective failure rate for the MQ-9 is on the order of 10-5, or 1 in 100,000 hours of flight, a value equal to
UAS ROADMAP 2005
APPENDIX H – RELIABILITY
Page H-7
that for a number of mature manned aircraft. For a typical 15 hour flight, this translates to an operational
reliability of over 99.99 percent.
RQ-2/Pioneer
RQ-2A. The reliability analysis for early-model Pioneers is based on statistical data gathered between
September 1990 and April 1991 from three Marine, two Navy, and one Army Pioneer unit (total of six
systems) while deployed in the Persian Gulf theater in support of Operations Desert Shield and Desert
Storm. Although known as the Option II+ version of Pioneer at that time, this model was subsequently
designated as the RQ-2A. At the time of this data, it had been in service with the Navy for four years, the
Marines for three, and the Army for one. By this time, it had already incorporated a number of reliability
improvements to its original, imported version.
With respect to its Operational Requirements Document, the early model Pioneer achieved less than
desired reliability metrics. This could be due to one of several factors. First, the Pioneer was purchased
from Israel as a non-developmental system in an accelerated procurement. Once in operation, Navy and
Marine users quickly identified several deficiencies that contributed to unreliability. General Charles C.
Krulak, then Commandant of the U.S. Marine Corps noted “the Pioneer does not have an automatic takeoff,
landing, or mission execution capability and that has led to a high accident rate.” Shipboard
electromagnetic interference caused several crashes, and the engines were thought to be too small and
easily overstressed. In addition to the need for a more reliable engine, the Marine Corps users also felt
that the system needed a smaller logistical footprint and a longer endurance.
RQ2-B. The currently fielded version of Pioneer, the RQ-2B, is essentially a digital version of its analog
predecessor, with the major distinction being the replacement of the analog air data system with the
digital Modular Integrated Avionics Group (MIAG). RQ-2Bs are modifications of the existing RQ-2A
airframes, rather than new production. All twenty-five operational (out of 49 existing) RQ-2As have been
converted to RQ-2Bs.
The reliability analysis for later model Pioneers is based primarily on the Marine Pioneer squadrons’
(VMU-1 and VMU-2) operations in the late 1990’s. The reliability data for the RQ-2B is derived from
two sources: maintenance aborts and in-flight aborts. Each offers a somewhat different perspective on
the reliability of the overall aircraft. In a distribution closely resembling that of the Predator RQ-1A data,
the majority of the failures (66 percent) are attributable to the combination of malfunctions in flight
control, power, and propulsion. The breakout in the flight critical systems is roughly 25 percent flight
control failures and 75 percent power and propulsion failures. (Recall the corresponding RQ-2A data
showed failures due to power and propulsion and flight control equally divided.) This suggests an
improvement in the flight control system of the Pioneer over time, or perhaps a shift in emphasis from
power and propulsion concerns. The latter is unlikely, however, given that the planned (1997) conversion
from the Sachs to the more reliable Quattra engine was never accomplished.
RQ-5/Hunter
Following three crashes in close succession in August-September 1995, OSD terminated the RQ-5/Hunter
program after LRIP completion by deciding to not award a full rate production contract. Seven systems
of eight aircraft each were delivered between April 1995, and December 1996. A total of 62 aircraft were
built by IAI/Malat and assembled by TRW, now Northrop Grumman Corporation. Since that redirection,
however, the Hunter program has made numerous component quality related improvements and been
used to demonstrate a wide variety of payloads including SIGINT, chemical agent detection, and
communication relay for UA use. It has supported National Training Center exercises and NATO
operations in Kosovo, and it recently served as the surrogate TUA for the Interim Brigade Combat Team
at Ft Lewis, Washington.
The acquisition of the Hunter system by the Army presents a case study in the peril of ignoring, and the
　
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