In the design of a HH-65A helicopter cockpit, advanced integrated electronics systems technology was employed to achieve several important goals for this multimission aircraft. They were: (1) integrated systems operation with consistent and simplified cockpit procedures; (2) mission-task-related cockpit displays and controls, and (3) reduced pilot instrument scan effort with excellent outside visibility. The integrated avionics system was implemented to depend heavily upon distributed but complementary processing, multiplex digital bus technology, and multifunction CRT controls and displays. This avionics system was completely flight tested and will soon enter operational service with the Coast Guard

Castleberry, D. E.

Mcelreath, M. Y.

English

NASA Technical Reports Server

STATE-OF-THE-ART COCKPIT DESIGN FOR THE HH-65A HELICOPTER 
Daniel E. Castleberry 
HX Program Manager 
and 
Marsha Y. McElreath 
Avionics Pilot Instructor 
Collins Government Avionics Division of Rockwell International 
Cedar Rapids, Iowa 
Abstract 
The design of the US Coast Guard HH-65A “Dolphin” cock- 
pit employs advanced integrated electronics systems technology 
to achieve several important goals in this multimission 
aircraft: 
1) Integrated systems operation with consistent, simplified 
cockpit procedures 
2) Mission-task-related cockpit displays and controls 
3) Reduced pilot instrument scan effort with excellent 
outside visibility 
In order to meet these goals, Rockwell-Collins has imple- 
mented the integrated avionics system to depend heavily upon 
distributed but complementary processing, multiplex digital 
bus technology, and multifunction CRT controls and displays. 
This avionics system has been completely flight tested and will 
soon enter operational service with the Coast Guard. 
Introduction 
“On weekend duty, I always expected to be awakened in the 
middle of the night,” recounts a veteran pilot of the USCG, 
“and when flying search and rescue (SAR) off San Francisco 
Bay in summer, I always expected fog.” So it came as no sur- 
prise when an early morning call interrupted his sleep. Tasked 
with finding an overdue sailboat and two-man crew, the pilot 
and copilot strapped themselves in their HH-52 and lifted off. 
Passing over the harbor lights, they soon disappeared into the 
night. Searching amidst dense fog, the pilot contacted the har- 
bor radar control and asked for position confirmation plus 
advisories of nearby objects or vessels. The controller quickly 
warned him of a ship at his twleve o’clock position and asked 
if he could see it. “I don’t see anything,” responded the pilot. 
Suddenly, the drone of a fog horn cut through the night fog. 
Max power! Positive climb! Forward airspeed! With reflex 
action, the pilot executed an instrument take off, a Coast 
Guard maneuver which transitioned the helicopter up into San 
Francisco’s terminal control area-also, a less than desirable 
flight situation, but in the pilot’s judgment, the better option. 
Communication, navigation, flight control, and search sensor 
management are classical avionics functions which constitute 
every SAR operation. In theory, however, communication, navi- 
gation, and flight control are merely handmaids to the search 
effort-the sole reason for the mission. Yet, how much atten- 
tion could the pilot in this account devote to finding the miss- 
ing sailboat? Because routine cockpit duties often monopolize 
crew attention during SAR operations and thus impair crew 
effectiveness, the United States Coast Guard presented indus- 
try with a challenge: Build an avionics system that automates 
the routine tasks of communication, navigation, mission man- 
agement, and flight control, and therefore, frees the crew to 
focus on the mission tasks which only they can perform-the 
visual search and FLIR or RADAR interpretation.* 
’ On 14 June 19’79, the USCG awarded Aerospatiale Helicopter 
Corporation (AHC) a contract for a Short Range Recovery 
(SRR) helicopter, the HH-65A. Teamed with AHC, Collins Gov- 
ernment Avionics Division of Rockwell International designed 
the avionics system for the SRR helicopter. 
Integrated Cockpit Design 
The Rockwell solution to the Coast Guard design mandate 
exceeds mere automation. The HH-65A cockpit design achieves 
three additional goals: (1) integrated systems operation with 
consistent, simplified cockpit procedures, (2) mission-task- 
related cockpit displays and controls, and (3) reduced pilot 
instrument scan effort with excellent outside visibility. 
To achieve these goals, Collins Division of Rockwell has 
designed the avionics system to rely heavily upon distributed 
but complementary processing, multiplex digital bus technol- 
ogy, and multifunction CRT controls and displays. 
Distributed but complementary processing is an important 
integration concept used in the HH-65A. Its architecture does 
not hinge on one centralized computer for processing all navi- 
gation signals, displays, control inputs, etc. Instead, distributed 
processors perform specialized functions. The system coupler 
unit (SCU) manages communications between the boxes and 
controls radio tuning. The control display unit (CDU) provides 
pilot access to all flight management operations. The horizon- 
tal situation video display (HSVD) driver unit generates the 
navigation displays, and the mission computer (MCU) acts as 
both navigator and flight engineer. Without pilot action, the 
MCU calculates a “best estimate” of present position and veloc- 
ity, automatically tunes the navigation sensors, enables flight 
planning, RNAV-style (including the generation of special 
USCG patterns), monitors fuel consumption, and records the 
engine and transmission condition (Fig. 1). 
These specialized processors perform distinctive tasks; yet, 
they cooperate as a single integrated system to accomplish 
mission objectives. A high-speed mvltiplex digital data bus 
enables uninterrupted communication between the avionics. 
Using discrete addresses, any two boxes can communicate with 
each other on the bus. To fly to a point, for example, the pilot 
indicates his intent on the CDU, which in turn communicates 
that intent to the mission computer. The MCU computes and 
displays the aircraft’s navigational situation on the HSVD and 
CDU, then, sends roll commands to the flight director (FD), 
which executes the commands through the automatic flight 
control system. 
Although centralized versus distributed processing does not 
necessarily alter cockpit operation, system survivability argues 
for distributed processing. A mission computer failure, for 
instance, impacts only RNAV capability; automatic navigation 
via TACAN, VOR, or localizer is not impacted. LORAN, con- 
trolled through the system coupler unit, also remains valid; 
and since the HSVD display drivers process all VOR and 
TACAN signals plus generate the navigation displays, the crew 
retains display guidance. 
139 
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Fig. 1. Distributed but complementary processing. 
Another important integration tool is using one device to do 
the work of many. Four multifunctional CRT devices, dual con- 
trol display units (CDU’s) and dual horizontal situation video 
displays (HSVD’s), inhabit the HH-65A cockpit (Fig. 2). 
HSVD f 
(COPILOT) 
1 
r ’ HSVD 
(PILOT) 
Fig. 2. HH-65A panel and console layout. 
Fig. 3. Control display unit (COMM radio control display). 
The CDU is a single-point control for all flight management 
operations. By incorporating “function keys,” the CDU controls 
numerous mission tasks: For example, pushing the COMM or 
NAV button dedicates the CDU to COMM or NAV radio tun- 
ing. Selecting FPLN dedicates the CDU to flight planning. 
Likewise, pushing the PROG or STAT keys transforms the 
CDU into a flight progress or status reporting device. Having 
assigned the control display unit to a particular function, the 
crew uses the “line select keys” adjacent software labels to 
(1) tune individual radios, (2) set transponder codes and modes, 
(3) insert waypoints, plus a host of other functions (Fig. 3). 
Because the CDU centralizes all operational inputs, it simpli- 
fies pilot procedures. He communicates, navigates, flight plans, 
etc, without having to manage dedicated controls scattered 
throughout the cockpit. Furthermore, CDU pilot procedures are 
uniform. Whether the pilot tunes a COMM/NAV radio, 
changes the transponder code, or enters a waypoint, he uses 
identical procedures. 
As the CDU is a central point of avionics control, so the 
horizontal situation video display (HSVD) is a central point for 
flight situation displays. The HSVD supplants several dedi- 
cated instruments: the conventional HSI, projected map, 
RADAR and FLIR displays, as well as a hover indicator 
(Fig. 4). 
Nonetheless, merely replacing conventional instruments is 
not the purpose of the HSVD. Rather, it organizes data into 
“task-related“ modes which not only present the pilot informa- 
tion needed for specific mission phases but also eliminate 
extraneous information. Consider the low altitude hover over 
water at night. Because the pilot generally faces a centrally 
Data 
Fig. 4. Horizontal situation video display modes. 
positioned HSI which provides virtually no hover information, 
he scans several other instruments to interpret his hover situ- 
ation. The HSVD’s hover mode integrates all hover data into 
one central display: omnidirectional airspeed, longitudinal/ 
lateral drift, radar altitude, computed wind, plus target posi- 
tion. 
Remaining HSVD modes, likewise, satisfy other flight phase 
requirements: The HSI mode is primarily an approach display. 
The MAP mode serves en route navigation, where the flight 
plan ahead may be viewed. The RADAR and FLIR modes dis- 
play the video images from these sources for searching. The 
RAD4R MAP mode relates radar returns (weather/ground) to 
the flight plan. And the DATA mode, a north-up chart presen- 
tation, facilitates impromptu flight planning. 
Besides suiting information to flight phases, task-related dis- 
plays denote “complementary formatting.” For example, 
because a pilot navigating cross-country uses wind information 
to plan the flight, the MAP mode incorporates a digital wind 
readout. By contrast, the pilot in a hover does not need wind 
information for flight planning; he needs to visualize wind 
velocity relative to the helicopter. Consequently, the hover 
mode incorporates a modified Beaufort wind arrow, which 
instantly pictures the changing wind velocity. Each pilot needs 
computed wind information but in a complementary for- 
mat-dictated by the flight situation. 
Typical SAR Operation 
Thus far, we have described technical features of the HH- 
65A avionics system. At this juncture, one might ask, “How 
does the integrated avionics system aid the pilot in the context 
41 
of the SAR environment?” The following scenario intends to 
demonstrate integrated system operation, specifically, as it 
impacts cockpit procedures and workload in the SRR helicop- 
ter. Assume that a pilot were flying a routine patrol when the 
rescue coordinator calls and instructs him to proceed directly 
to the site of a ditched aircraft, initiate a search and rescue 
reported survivors. 
To navigate to the downed aircraft, the pilot types in the 
LAT/LONG position on his CDU (the mission computer also 
recognizes LORAN TD’s, place-bearing-distance, or identifiers) 
and selects DIRECT TO. The mission computer creates a direct 
course to the point. It also continuously plots present position 
using dual LORAN, dual VOR, TACAN, dual compass systems, 
and precision omnidirectional airspeed sensor inputs; manages 
the navigation sensors (ie, automatically selects navigation sta- 
tions and tunes the LORAN, VOR and TACAN receivers); and 
flies the aircraft to the waypoint through the flight director. 
The HSVD MAP mode simultaneously displays the flight plan. 
This mode combines a tactical map presentation of flight plan 
waypoints and an abbreviated HSI, which the pilot uses with 
the progress and flight plan displays of the CDU to monitor en 
route progress. 
Meanwhile, the mission computer has already assessed the 
fuel situation. Accounting for wind, the MCU calculates the 
fuel required to fly to the search point, proceed to the destina- 
tion, and leave a 30-minute reserve. If on-board fuel is insuffi- 
cient, the system warns the crew by announcing FUEL ALERT 
on the CDU. If sufficient fuel exists, the STATUS display 
translates the fuel reserve (ie, fuel in excess of what’s needed 
to fly to the destination) into hours and minutes of flight time, 
labelled BINGO. MCU fuel management gives the pilot instant 
visibility of his fuel status, and thus, how long he can search. 
Fig. 5. Sector search entry into flight plan. 
While the mission computer monitors fuel consumption, the 
data link system reports en route progress to the search coor- 
dinator, relieving the pilot of routine position reporting. He 
merely designates the communication radio and transmission 
interval on the CDU DATA LINK display. At the specified 
time, the integrated system automatically downlinks 9 pieces 
of information regarding aircraft position, status, and flight 
progress. 
Eliminating routine flight management tasks frees the pilot 
to concentrate on system performance and flight progress. 
Pushing the PROG key on the CDU calls up the computed pre- 
sent position (LAT/LONG) and ground speed. Pushing the line 
key adjacent any flight plan waypoint provides instant access 
to “waypoint data” for that geographical point-time, distance 
and course to the waypoint via the flight plan or via direct. 
As the aircraft nears the search area, the pilot plans his 
search. He selects one of three available patterns (sector, lad- 
der, or expanding square) and then defines the pattern param- 
eters. For example, if he selects a sector search, the computer 
asks what track spacing is desired (Fig. 5). (NOTE: The pilot 
may request search advisories by entering the sea state, visi- 
bility, cloud cover, and altitude; the MCU will compute the 
optimum track spacing.) Selecting “INSERT -+” displays the 
flight plan, where inserting the pattern requires only pushing 
a line key at the desired datum point. The mission computer 
automatically plots the pattern waypoints and displays them 
on the HSVD. 
Upon reaching the target area, the aircraft automatically 
initiates the search while the crew concentrates on the search 
RADAR, FLIR (forward-looking infrared), and DF radio hom- 
ing, or they scan the white caps below. When the target is 
spotted, the integrated system, with minimal crew effort, aban- 
dons the search and expedites the rescue operation. Over-flying 
the target location, the pilot pushes two buttons: MARK - to 
mark the target’s location, and HOVER - to call up the 
approach-to-hover pattern. He inserts the approach-to-hover 
pattern into the flight plan and selects APPR on the flight 
director panel - triggering a chain of operational events. The 
system turns the aircraft downwind to ensure a final approach 
into the wind, directs a minimum time procedure turn, and 
computes a five degree descent to the hover transition point. 
Using the FD speed beep, the pilot. may vary the approach 
speed. At loo-feet radar altitude, the FD APPR mode drops; T- 
HOV mode captures and slows the helicopter to zero ground 
speed at 50 feet RA - just short of the target (Fig. 6). During 
the transition to hover, the HSVD automatically displays the 
HOVER mode. The computed wind, HOVER velocity com- 
mands, omnidirectional airspeed vector, and the marked target 
position enable the pilot to monitor the approach-to-hover 
maneuver as well as modify the hover conditions. If the pilot 
beeps either radar altitude or longitudinal/lateral airspeed, the 
indicators instantly verify his input. 
While the survivors are hoisted to safety, the pilot decides 
his next course of action. Should a victim require immediate 
medical attention, he may choose to fly to a medical center 
142 
MARK TURN 
A A L-l) 
-fh- “-=A -3 AUTOMATIC TRANSITION TO HOVER AT 50’ RADIO ALTITUDE 
f 
NOTE: Pilot selects Approach (APPR) and Transition to 
Hover (T-HOV) Flight Director Modes in order to 
fly entire maneuver automatically 
Fig. 6. Approach-to-hover maneuver. 
rather than home base. With the push of the DATA mode but- 
ton, the HSVD displays surrounding hospital locations in a 
north-up, chart presentation (Fig. 7). To examine direct dis- 
tance, time or course to any viable alternate, the pilot simply 
calls up waypoint data for the respective hospital through his 
CDU. If desired, the MCU will also compute the maximum 
range on that course. Once again, minimal pilot action acti- 
vates integrated system response, to enhance crew effective- 
ness. 
The technological tools of digital data bus communication, 
distributed but complementary processing, and multifunction 
CRT controls and displays have effected integrated cockpit 
operation in the HH-65A. Although this system has been 
implemented for a SAR application, these techniques and this 
approach to operational cockpit integration will adapt to any 
helicopter mission. A system coupler unit and CDU which cur- 
rently controls radios could as easily control weapons systems. 
A mission computer and HSVD might as easily display termi- 
nal area approach procedures or tactical combat command and 
control data. Meanwhile, the HH-65A with its integrated cock- 
pit operation, will benefit Coast Guard line pilots who under- 
take SAR despite adverse conditions. 
*Cdr. David A. Young, “Avionics System Design Requirements 
for the United States Coast Guard HH-65A Dolphin”: 
Presented at the Sixth European Rotorcraft and Powered Lift 
Aircraft Forum, Bristol, United Kingdom, September 16-19, 
1980. 
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Fig. 7. HSVD data mode. 
143 


State-of-the-art cockpit design for the HH-65A helicopters

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