During the next several years, U.S. Army special operations helicopters will
be upgraded with modern avionics, designed to improve the capabilities of the
aircraft, while making them easier to maintain, officials said.
The technology is called common avionics architecture system—or CAAS—and
will be installed on special operations MH-47G Chinooks, MH-60M Black Hawks,
and MH/AH-6M Little Birds cockpits. If the program goes as planned, more than
140 helicopters could be upgraded by 2010.
U.S. Special Operations Command officials said that common hardware and software
in all three aircraft should reduce the logistics demands on aviation units
and simplify training. The open avionics architecture also will make it easier
to upgrade the aircraft with software from third-party vendors.
Most important to special operations aircrews, the CAAS will help manage cockpit
workload and enhance situational awareness.
Rockwell Collins received a contract in April—worth up to $40 million—for
the avionics upgrade. Plans call for CAAS flight tests to begin in the summer
of 2003 and first production deliveries are scheduled for fiscal year 2004.
The aircraft of the Army’s 160th Special Operations Aviation Regiment
(SOAR) are uniquely equipped to fly long missions in hostile airspace at night
and in adverse weather. In one typical mission early in Operation Enduring Freedom
last year, an MH-47E carried a Special Forces A-team from a forward support
base in Uzbekistan to a rendezvous with anti-Taliban forces in Afghanistan.
The Chinook crew used multi-mode radar to find a way through mountains in zero
visibility, refueled at low altitude from an Air Force MC-130P tanker and exercised
aircraft survivability equipment to counter an apparent air defense threat.
The MH-47E then penetrated a dust storm before climbing over mountains into
From 16,500 feet, the Chinook crew again used terrain following radar to let
down into the target area and deliver the special operators. On the return,
they descended from altitudes near 20,000 feet in zero visibility, refueled
once more from an MC-130, and again used radar to negotiate the mountains. Overall,
the mission lasted 8.3 hours, including 6.3 hours in adverse weather over hostile
Long, high-workload missions are commonplace for the highly trained aviators
of the 160th SOAR. However, the fleet is suffering from age and attrition. The
MH-47E with its extra fuel and multi-mode radar is the most requested platform
in the special operations community, but two of the helicopters were lost and
another severely damaged in 2001. Despite incremental improvements, all the
helicopters of the 160th are due for recapitalization.
The 160th SOAR currently operates 23 MH-47Es, 11 MH-47Ds, 23 MH-60Ks, approximately
45 MH-60Ls, and 40-odd AH/MH-6s. The mixed fleet uses two proprietary avionics
systems, both integrated on MIL STD 1553B databuses. They are costly to maintain,
as a result of obsolescent hardware and monolithic code software.
The Lockheed Martin integrated avionics system of the MH-47E and MH-60K is
programmed in Jovial. The Rockwell Collins cockpit management system in the
MH-47D, MH-60L, and MH-6/AH-6 uses ADA 83. Fleet upgrades must be written in
both languages, and the proprietary architectures require costly regression
testing when functions are changed or capabilities are added.
Integrated or ‘glass’ cockpits enable helicopter crews to access
aircraft systems, thermal and radar imagery, navigation/communication functions
and aircraft survivability equipment through the multifunction displays and
center console control/display units. But much of the hardware in the special
operations fleet is out of production. The technology has been surpassed by
The MH-47E and MH-60K were fielded in 1995 with monochrome cathode ray tube
displays, about 6 inches square. The most recent cockpit upgrades for the older,
less-integrated MH-47D and MH-60L introduced color active matrix liquid crystal
displays 4.2 inches square only for flight instrument symbology. The forward-looking
infrared (FLIR) imagery on the MH-47D and MH-60L appears on a separate 6 by
5 inch display. Communications and navigation settings can be keyed in only
through the control/display units, pulling eyes down into the cockpit for mission
changes on the fly.
Simpler than the Chinook and Black Hawk, the convertible AH-6 attack and MH-6
utility helicopters recently received electronic flight instruments like those
in the MH-47D and MH-60L. Though the Little Bird now has flight management and
digital weapons management systems, it too could benefit from more capable processors
and state-of-the-art displays.
The Special Operation Command requires that every aircraft improvement enhance
safety, provide critical mission capability, reduce crew workload, improve reliability
and maintainability, increase standardization and allow for growth.
The development of a common avionics architecture began in September 2000,
when Rockwell Collins received a software task order to rehost the MH-47D/MH-60L
cockpit management system on a more modern processor. The effort also began
a move toward modular software that can be upgraded readily to accommodate new
functions and equipment.
Rockwell Collins is the software integrator for CAAS and also will provide
multi-function displays, control display units, and general processing units
shared by all three helicopters. Sanmina-SCI won the competition to supply the
CAAS data concentrator system.
The assembly work will be done at the Blue Grass Army Depot Special Operations
Forces Support Activity and at the Boeing and Sikorsky plants, as part of the
broader MH-47G and MH-60M recapitalization.
The CAAS can be described as a flexible software architecture built on lessons
from the personal computer industry. Multiple isolated applications can run
on a single processor, and the open system architecture with a Windows-based
operating system simplifies connectivity and support. CAAS software is written
in ADA 95 and partitioned into logical modules that can be modified with less
expensive regression testing. The Army retains the rights to seek competitive
upgrades from third-party vendors, and changes would be made with a standard
The avionics suite takes advantage of modern commercial processors and databuses.
While the MH-47D now has a single Intel 486 processor in each control display
unit, CAAS draws on one Power PC 750 processor in each control display unit
and two Power PC 750 processors in each multi-function display. Compared to
the MH-47E and MH-60K integrated avionics system, the CAAS avionics will provide
about 50 percent more reserve memory and throughput for growth, said Rockwell
officials. A MIL-STD-155B bus still carries data around the avionics suite,
but a new 100 baseT Ethernet bus links all the processors.
The hardware and software architecture make the entire system scaleable for
different air vehicles. More display area means more information. The CAAS common
cockpit for the recapitalized MH-47G and MH-60M has five 6 by 8 inch multi-function
displays. The MH/AH-6M uses just two displays. CAAS itself is a variation of
the Rockwell Collins Flight2 avionics architecture used in military and commercial
The cockpit displays are readily readable in direct sunlight and cross-cockpit,
and they are compatible with night vision goggles, according to Rockwell. Primary
flight symbology, thermal and radar imagery, digital maps and aircraft systems
information can be posted on any display, and each portrait panel can be split
to customize the information. In addition, essential flight symbology will be
duplicated on two Goodrich electronic standby instruments.
Among the features that help reduce the crew workload is a “precision
flight director” with an altitude-hold function for long transits. An
automatic approach to hover function sets descent rates in desert brownouts
or other adverse conditions. A ground speed-select function helps synchronize
the arrival of the aircraft with other events to better coordinate assaults.
The CAAS displays help improve the crews’ situational awareness by providing
data from both on-board and external sensors, Rockwell officials said. The CAAS
general-purpose processor can merge two video inputs into one display. Imagery
from an unmanned drone may be injected into a map display to help identify targets.
Through the improved data modem, near real-time intelligence data downloaded
from orbiting JSTARS (Joint Surveillance and Target Attack Radar System) or
other sources should help pilots avoid threats or weather and adapt to changing
battlefield situations. While the cockpit still has two control/display units,
pilots will be able to change flight plans and radio presets through the multi-function
displays, without going head-down to the control/display units.
CAAS deliveries are scheduled to begin in fiscal year 2004 and continue through
2009 for the MH-47G, from 2006 through 2010 for the MH-60M, and from 2005 through
2009 for the AH/MH-6M.
However, the Army’s 2004-2009 budget plan, called the Program Objective
Memorandum, has “unfunded” requirements for another 10 MH-60Ms and
25 MH-47Gs. SOCOM said it needs up to 72 MH-47Gs and 96 MH-60Ms.
The conventional Army expects to upgrade 300 CH-47Ds to CH-47Fs, from 2003
to 2013. The 34 surviving special operations Chinooks will become MH-47Gs on
the F-model line in Philadelphia. Some of their special equipment will be installed
at the Blue Grass Army Depot in Kentucky. The plan is for one of the first seven
Chinooks on the CH-47F line to emerge as an MH-47G. The G-model improvements
for the MH-47D and E have yet to be finalized. CASS will integrate an improved
multi-mode radar, digital map, dual embedded global positioning system/inertial
navigation units, the improved data modem and new aircraft survivability equipment.
The upgraded CH-47Gs would take three years to build, and with a pressing near-term
requirement for additional aircraft, the Army is negotiating with the British
Royal Air Force for the purchase of eight Chinook HC.3 helicopters. The helicopters
could be modified to current MH-47D/E standards in about 18 months, officials
The RAF special operations aircraft were delivered with Rockwell Collins integrated
cockpits, but their fielding has been delayed, pending additional equipment
integration in the United Kingdom. In October 2002, the Defense Security Cooperation
Agency notified Congress of the intent to sell the Royal Air Force eight makeup
MH-47Gs should the deal come to pass.
The Army’s Block I Black Hawk recapitalization plan calls for a mix of
remanufactured UH-60As and Ls and new-build UH-60Ms. Production should transition
from the current UH-60L to the new UH-60M in 2007.
SOCOM intends to maximize commonality with the MH-47G and plans to complete
a special operations Black Hawk upgrade with CAAS avionics by fiscal year 2010.
While the special operations MH-60M configuration is not yet finalized, the
cockpit of the Black Hawk should differ from that in the MH-47G only in the
engine instrument crew alerting system data on the displays. The Army has a
reported requirement for up to 96 special operations Black Hawks and could extend
the run with new-build MH-60Ms.
The smaller special-operations birds, the AH-6J and MH-6J, provide night reconnaissance,
fire support, and resupply for special forces. The MH-6M and AH-6M modernization
is underway, giving the Little Birds more powerful engines and transmissions,
six-bladed main rotors, and larger cabin doors. The concurrent weapons and digitization
management upgrade includes a 1553 databus and single-point data entry for navigation,
flight plans and weapons management.
The CAAS upgrade will introduce new, larger displays and the processing power
for a digital map, next-generation FLIR and other improvements.