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Under The Cover of Darkness:  Is Helicopter Night
Training Keeping Pace With Technology?
CSC 1992
Title:  Under The Cover of Darkness:  Is Helicopter Night
Training Keeping Pace With Technology?
Author:  Major R. K. Read, United States Marine Corps
Thesis:  Rotary wing aircrews proficient with Night Vision
Goggles   (NVG's)   offer  a  commander  expanded  mission
capabilities and increased survivability rates, but does the
Corps train them to acceptable experience levels?
Background:  The United States' night vision and electro-optic
technology is among the most advanced in the world.   United
States Marine Corps Aviation relies heavily upon this night
imaging  technology  to  maximize  its  night  operations
capability. Night Vision Goggle (NVG) use in the Marine Corps
has increased 600% over the past five years.  But even with
this dramatic increase, NVG time still only accounts for 7.26%
of the total fiscal year 1991 helicopter flight time.  Night
hours flown for the same year equalled only 17.1% of total
helicopter flight hours.  When comparing NVG time to night
time, 42.4% of night time was flown with goggles.
Recommendation:  Although the percentage of night hours flown
with goggles is reasonable, the ratio of night flight time to
total flight time is little more than half what it should be.
The Marine Corps helicopter community should fly 30% of its
flight time during the hours of darkness.
Thesis Statement.  Rotary wing aircrews proficient with Night
Vision Goggles (NVG's) offer a commander expanded mission
capabilities and increased survivability rates, but does the
Corps train them to acceptable experience levels?
I.	Genesis of night flying equipment
II.	Night vision enhancement technology
	A.	The AN/PVS-5 NVG
		1.	Full face
		2.	Cutout
		3.	COOB
		1.	Characteristics
		2.	Advantages
		3.	NVG HUD
III.	Night training statistics
	A.	The 1988 ADPA Study
		1.	Tri-service organization
		2.	DOD-wide doctrine
		3.	Minimum night training of 30%
	B.	Five year flight time comparison
		1.	Night versus total time
		2.	NVG versus total time
		3.	NVG versus night time
	C.	Training environmental conditions
		1.	Featureless terrain
		2.	Poor visibility
          He had begun his career as a night fighter
     and still practiced the skills of that subphylum of
     aviator.   To him the most  feared soldier ever
     created was the pilot who came at night, hiding
     from the cast-eyed light of half moons,  coming
     winged and unannounced out of the black, out of the
     void.  (6:386)
     One would be hard-pressed to find a helicopter pilot to
disagree with the assertion that the only way to survive in
any modern conflict is to fly low at night.  Low-level flying
under the cover of darkness provides a haven from anti-
aircraft weapons reliant upon line-of-sight, electro-optic,
and electronic methods.   (12:1-1)   Rotary wing aircrews
proficient with Night Vision Goggles (NVG's) offer a commander
expanded mission capabilities and increased survivability
rates, but does the Corps train them to acceptable experience
     To optimize one's own capabilities while diminishing
those of  the enemy is  a primary secret of success  and
survival.    Our  capability  to  conduct  low  level  night
operations diminishes the chance of detection and increases
the probability of surprise.  USMC Aviation, in the recent
past, has come to rely upon night-imaging tools to maximize
its night operations capability.   (12:1-1)  "Darkness is a
double edged weapon, and like the terrain, favors the one who
best understands and uses it, while hindering the one who does
not."  (12:1-1)
     In the early 1920's, few aviators saw the need for night
flying.   Furthermore,  few thought of night flying as an
enjoyable experience; this is something that hasn't changed
much in the last 70 years.  In the early days, pyrotechnic
flares provided light during the landing phase.  The flares
were mounted on the wing tip and ignited by battery-powered
spark coils.  Once ignited, there was no way to turn the flare
off and there wasn't enough burn time to allow for wave offs.
If you couldn't get down on your first attempt you weren't
going to have light on subsequent ones.  Additionally, there
was a definite danger of igniting your own fuel or of setting
a dry field on fire upon landing.  (8)
     An Army Air Corps Lieutenant, Donald L. Bruner, lost a
good friend in a fire caused by one of these wing tip flares.
This may have been the driving force behind his experiments
and inventions of night  electrical  equipment during  the
1920's.  After WW I, Lt. Bruner was transferred to McCook
Field in Ohio where he worked as a test pilot for the U.S. Air
Service Engineering Division.  After repeated requests for
permission  to  work  on  night-flying  equipment,  he  was
eventually granted authorization to do so. (8)
     Bruner  developed  electrical  lighting  equipment  for
aircraft and ground installations.  He was the first person to
develop and install beacons at aerodromes to assist pilots in
identifying and locating airfields at night. Additionally, he
developed airfield boundary and obstruction lights.  Cockpit
instrument and floodlights, as well as electrical  landing
lights, were also his inventions.  Ironically, Lt. Bruner's
inventions had more of an immediate impact upon commercial
aviation than it did upon the military.   The Post Office
Department's Air Mail Service adopted many of his inventions
for transcontinental night flights.  (8)
     The development of night vision enhancement equipment
first began during WW II.  The earliest system tested utilized
active  infrared  which produced  images  by  sensing  heat.
Starlight scopes used in Vietnam are an example of the first
generation of passive night-vision systems.  Passive night-
vision  systems   magnify   available   light   with   image
intensifiers.  (9)  First generation systems were large and
long-wearing, yet produced a light gain of 40,000 to 60,000.
Second generation systems, by using micro-channel plates,
enabled a  reduction in size that provided compatibility with
headgear.  However, light gain for second generation systems
decreased to the 10,000 range.  The gain for third generation
systems, those in use today, is 25,000.  (12:2-8)
     The U.S. Army was one of the first organizations, if not
"the" first, to test and evaluate the use of Night Vision
Goggles (NVG) for night helicopter operations.  The Army's
tests  effectively  illustrated  that  NVG-aided  vision  for
helicopter pilots was possible.  However, this testing was
conducted in 1969 when the weapons threat in South East Asia
did not call for low level or Nap Of the Earth (NOE) flight.
Therefore,  continued  development  of  NVG's  for  aviation
purposes was not considered then.  (14)
     By 1971, the air defense threat in South East Asia had
become somewhat refined.   The concept of flying low for both
day and night operations began to take hold for the sake of
survivability.  The army needed a "stop gap" answer to the
problem of flying low at night.  The U.S. Army Land Warfare
Laboratory (LWL) was tasked with finding the answer to the
"stop gap" question.  LWL selected and tested the AN/PVS-5, a
second generation NVG, which was developed earlier by the U.S.
Army Night Vision Laboratory.   This system was originally
designed for ground troops and required many adjustments and
alterations before it could be used by helicopter pilots.
     LWL sought a method by which goggles could be mounted
to  the  pilot's  helmet.   Testers  selected  a  cushioned
bracket/faceplate developed by the U.S. Air Force.  Bright
instrument, secondary, flood, and caution lights, as well as
the reflective paint on the instrument panel, were all found
to handicap, even blind, the pilot's vision.  The full face
mask allowed no capability for peripheral vision and the
ability  to  find  light  switches  proved difficult.    LWL
developed a  single  light  switch to  totally blacken  the
cockpit, if desired, and painted instrument panels a dull
black to prevent light reflection.  In late 1972, after 700
hours of in-flight testing,  LWL recommended that the Army
sanction the use of the AN/PVS-5's for aviation service.  (13)
     In 1976, the Marine Corps began to use NVG's in fleet
units and borrowed the Army's tactics for low-level night
operations.  The Army's flight capability evaluations on the
AN/PVS-5's were accepted;  however,  the Marine Corps  did
perform its own flight suitability test and evaluation.  (4)
It was not until the 1980's that all Marine Corps helicopter
pilots and crews began to receive thorough goggle training.
In the late 1970's and early 1980's,  only a select  few
received benign training that was normally conducted under
ideal environmental conditions, commonly referred to as a
"field grade night."
     The AN/PVS-5 night vision goggles were to be a temporary
substitute  for  aviation  use  until  a  system  designed
specifically for aviation could be produced.  Ironically, the
first major modification for the PVS-5's was approved by the
Army in the same year (1982) that commercial production began
on the Aviation Night Vision Imaging System (ANVIS) goggles.
One of the primary drawbacks to the PVS-5's was their lack of
peripheral vision.   The full-face system did not permit
aviators unrestricted, unaided vision to the sides and down.
PVS-5 goggles had to be manually focused in order to read the
instrument panel  or maps.   Full  face goggles  were  not
compatible with eyeglasses and tubes easily fogged due to the
lack of air circulation.  (11)
     This first major modification to the PVS-5's was called
"cutouts," or modified faceplate, and provided pilots and crew
the capability to view objects peripherally.  This ability to
see unaided to the sides of the goggles allowed aircrews to
identify aircraft by discerning the color and location of
position and anti-collision lights.   It also permitted the
convenience of reading a map with the naked eye rather than
through the goggles.  (11)
     ANVIS,  a  third-generation NVG,  received  input  from
aviators during its development and was the first of its kind
to be designed for aviation purposes.  Production began in
1982, although initial deliveries did not begin until 1985.
(10) A difference in perf ormance between the PVS-5 and ANVIS
goggles is not significant when operating in high light
levels. While it is nearly impossible to operate in low light
levels with the PVS-5's, the ANVIS goggles are operationally
efficient under starlight conditions.   This increased low
light level capability is considered one of its most notable
features.  ANVIS also out performs the PVS goggles in poor
visibility.   (14)
     Additional benefits of the ANVIS include:  flip-up and
break-away  capability,  enhanced  peripheral  vision,  dual
battery pack, and improved weight and balance characteristics.
The flip-up capability greatly improved goggle and de-goggle
difficulties.   The single mount  location  on the  helmet
precluded any need for the frame or face mask, thereby making
peripheral vision almost normal.  The backup battery in the
dual battery pack simplified the problem of changing batteries
in flight, and weight and balance improvements reduced crew
     Deliveries of  the ANVIS goggles did not proceed as
scheduled, therefore,  continued use of the PVS goggles was
necessary.   Technical  improvements  to  the  PVS  goggles
continued;  following the "cutouts," the next major upgrade
for the PVS-5's was the Crew member's Optional Breakaway
Bracket (COOB).  (3)  The COOB modification offered all the
advantages of the ANVIS except for the low light level and
increased resolution that characterize the ANVIS-6 goggles.
Upon reaching desired inventories of the ANVIS-6 goggles, a
phase out of the AN/PVS-5's, for general use in the Marine
Corps, was planned.  (4)
     Survival in a sophisticated threat environment forced the
development of night vision-imaging devices.    Because of
increased mission requirements, aircrew survival mandates the
need for research and development to keep abreast.  Today,
helicopter crews are required to perform roles and missions
that require the majority of their visual scan to be focused
outside the cockpit.   Obviously,  the requirement to scan
inside the cockpit for needed references reduces the time
spent scanning outside for terrain clearance and navigation
purposes.  Obviously also is that this problem is magnified
when flying at low altitudes and in  formation.  (2)
     Heads Up Display (HUD) technology for the fixed-wing
community   has   heightened   both   safety   and   mission
accomplishment for many years.  Incorporation of the NVG HUD
will be the next major development to benefit Marine Corps
assault support aircraft and crews.  The Marine Corps Combat
Development   Command's   (MCCDC)   Tentative   Operational
Requirement  (TOR)  for  the  NVG  HUD  lists  11  desired
capabilities.  A sample of these capabilities include:
     . . . The image should be easily switched on or off
     with a switch. . . . Removing  the hands  from the
     controls should not be required to accomplish this
     task.   HUD displays at a minimum will include:
     aircraft attitude,  airspeed,  altitude  (MSL  and
     AGL),  vertical  speed,   torque  setting,   trim,
     heading; warning system (master caution warning
     light); armament system (armament status); threat
     warning system symbology;  and navigation system
     (navigation data/status).  The cockpit control unit
     should allow the crew to select/deselect  (push
     button) each option system/individual symbology. . . .
     The Air Force already uses the NVG HUD with its special
operations helicopters and the Army is presently in the
process of equipping theirs similarly.  (2) Marine Helicopter
Squadron One (HMX-1) began evaluating the NVG HUD in 1986 and
determined that the HUD would enhance any task associated with
NVG's.   From November 1988 to April 1989, HMX-1 evaluated
three  NVG  HUD  systems  with  some  80  pilots  flying
demonstrations.  They concluded that the reduction in pilot
workload by suspending the need for outside-to-inside scan
greatly enhanced flight safety.  The HUD was determined to be
of the most benefit in terrain flying and while performing
shipboard landings during low-light-level conditions.  (5)
     The American Defense Preparedness Association (ADPA) was
tasked, in late 1987, to examine the capabilities of U. S.
Forces to conduct night operations.   The purpose for this
examination  was  to  improve  capabilities  by  identifying
deficient  areas  and  recommending  appropriate  solutions.
Membership of this ADPA team included "high rollers" from both
industry and the Department of Defense  (DOD).   The team
concluded that the U. S., as a whole, does not capitalize on
its technological edge; the individual service's stand on
night doctrine and training varied considerably. (1:3)  The
team also determined that "night vision and electro-optics
thrusts within DOD are poorly focused."  (1:3) Consequently,
they recommended that the Office of the Secretary of Defense
supervise a tri-service organization designed to manage the
research and development of night vision and electro-optic
technology.    This  organization  would  standardize  night
fighting  equipment  within  the  DOD,   reduce   resource
expenditures, and advance our present technological advantage.
     This study was conducted on the heels of the Goldwater
Nickols Act; thus, its joint flavor was both understandable
and warranted.   We do need a standardized DOD-wide night
vision  doctrine  as  well  as  research  and  development.
"Jointness" in this area would help to reduce research and
development costs, capitalize on superior U.S. technology of
both present and future systems, and ensure interoperability
between services.  (1:4) The ANVIS-6 NVG's  are a superb aid
for night flying.  Once accustomed to their use, there isn't
a single pilot who would choose the naked eye over the
goggles.  We still cannot change night into day, but with the
advent of the NVG HUD, and possibly the Forward Looking
Infrared (FLIR) for USMC helicopters, we are getting closer.
     The Marine Corps has, in the recent past, developed an
aggressive NVG training program;  but does this  training
program take full advantage of existing technology?  One of
the four objectives the ADPA recommended for a tri-service
"night operations doctrine" is "A commitment to train as we
fight while emphasizing an increase in combined arms night
training."  (1:5)
     In 1988, when the ADPA study was completed, the Marine
Corps, as well as the other services, were found to be lacking
in night training.  It was suggested that a minimum of "30% of
training be devoted to night operational training." (1:16) In
a flying squadron, technically not every flight is considered
a training flight.   A sizeable portion of their allocated
flight time is devoted to supporting ground operations, but
Pilot Training Officers in many cases are able to combine the
FRAG mission with worthwhile aviation-related training.  We
could argue that every flight is a training flight, but did
the study team mean 30% of all flight time for a squadron or
just 30% of that flight time allocated to training?   In any
case, devoting 30% of an individual's or squadron's monthly
flight time to night training is certainly both an admirable
and desirable goal.
     Fiscal Year (FY) 1991 total USMC Helicopter Flight Time
equalled 296,526.8 pilot hours.  Of the total, 245,770.4 hours
were day-flight time and 50,756.4 hours were night-flight
time.  Of the 50,756.4 night hours, 21,537.3 were flown on
NVG's.  (7)  Some 1,877 pilots were processed, resulting in an
average of 158 flight hours per pilot.  The average pilot flew
131 day hours and 27 night hours.  The average annual NVG time
per pilot was only 11.5 hours.  The 50,756.4 night hours flown
for FY91 account for 17.1% of the total time.  The 21,537.3
hours flown on NVG's account for 7.26% of the total time.
When comparing NVG time to night time, 42.4% of night time was
flown with goggles.
     Upon investigating annual USMC helicopter flight time for
fiscal years 1987 through 1990, total time and night time did
not  fluctuated to any great degree.   However,  NVG time
increased dramatically.  The following data was obtained from
HQMC (Code ASA-3) and lists  helicopter aircraft flight time
for Fiscal Years 1987 through 1990:
Click here to view image
When comparing night time to total time, night time equalled
roughly 14.5% of the total time for fiscal years 87-90.  NVG
time compared to total time increased from 1% in FY87 to 6.9%
in FY90.   The percentage of night time flown on goggles
increased from 7.2% in FY87 to 47.7% in FY90.
     Not  only  is  the  amount  and  frequency  of  training
important, but the environmental conditions that the training
is conducted in may be equally as important.  The challenging
night flying conditions experienced in South West Asia (SWA)
during Desert Shield and Desert Storm highlighted the need for
NVG training in featureless terrain.   Desert training areas
at MCAS Yuma and Twenty-nine Palms are excellent for training,
but they could not completely prepare aircrews for the flat,
non-vegetated,  featureless  terrain  experienced  in  SWA.
Flights along the eastern coastline, with its well-defined
roads, presented few problems for NVG operations.  But upon
leaving the eastern coast and flying westward, the lack of
terrain contrast visible through the goggles prevented pilots
from using the normal visual cues they had become accustomed
to and dependent upon.
     The ability to see terrain features or man made objects
through the NVG's is, in a large part, dependent upon the
difference in the amount of light the terrain or object
reflects.  Sand, water, trees, and blacktop all absorb and
reflect varying degrees of light, providing contrast.  Except
for dry lake beds, SWA offered very little terrain contrast.
The lack of contrast in the terrain, coupled with the black
smoke caused by burning oil fires, presented aircrews with
some of the most demanding visual flight conditions they had
ever experienced.   Without normal visual cues, helicopter
aircrews experienced many cases of vertigo and inadvertent
Instrument Flight Rules (IFR), often resulting in the need for
unusual attitude recoveries.
     The training that aircrews receive at 29 Palms and Yuma
proved a tremendous asset in preparation for desert operations
in SWA.   Combined Arms Exercises (CAX)  at 29 Palms and
Squadron Weapons and Tactics Instructor (WTI) graduates from
MCAS Yuma have dramatically improved Squadron Combat Readiness
Percentiles (CRP).  The Marine Corps has aggressively pursued
NVG training producing an impressive 600% increase in NVG
flight time over the past five years.   Unfortunately, the
ratio of night flight time to total flight time is little more
than half what it should be.   Even though NVG time has
increased 600% over the past five years, it was still only
7.26% of the total helicopter flight time for FY91.
     In 1988, the ADPA claimed that "we spend to little time
training at night with our electro-optic systems" and gave the
following explanation as to why:
     Several factors contribute to our inadequate night
     training program.   Historically, military forces
     have used night to rest, resupply and reposition.
     Today, this tactical philosophy is largely still
     embraced by U.S. and NATO forces.  We have not yet
     recognized the advantage to be gained by using our
     night operations technology to conduct offensives
     after dark.  In some situations, there may be some
     validity in conducting some offensive operations
     exclusively at night, and using the day for rest
     and resupply.  (1:70)
Although we still spend too little time training at night, we
now recognize the significant tactical advantage to be gained
by conducting night operations.  As a matter of prudence, we
have no  choice  but  to  press on  and  capitalize  on  our
technological  capability to "turn night  into day"  while
performing all the missions modern warfare demands.  What an
advantage this will be!
1.	American Defense Preparedness Association.  Report
to the Deputy Under Secretary of Defense (Tactical Warfare
Programs).  Night Operations Study, 20 Sep 88.
2.	CG MCCDC ltr, Subj:  Tentative Operational Requirement
(TOR) For The Night Vision Goggle Head Up Display (NVG HUD),
dtd 1 Feb 91.
3.	CMC Msg, Subj:   Use Of The Guard Mount-6 (GM-6) With
AN\PVS-5 Night Vision Goggle (NVG) Image Tubes, DTG 020002Z
Nov 88.
4.	CMC Msg, Subj:  Public Affairs Guidance - Night Vision
Goggles (NVG), DTG 202004Z Dec 88.
5.	CO HMX-1 ltr to CMC, Subj:  Night Vision Goggle Head-Up
Display (NVG HUD) Assessment, dtd 20 Jul 89.
6.	Conroy, Pat.  The Great Santini.  New York:  Avon Books,
7.	Data received from Maj Ellis, Alfred W. III, HQMC (Code ASA-3).
8.	Downs, Eldon W., Col, USAF, and Sights, Albert P. Jr., Col,
USAF (Ret).  "Out of Darkness," Aerospace History, (Autumn 69),
16-17 and 31-35.
9.	Eshel,  Tamir.  "Night Warfare:  The New Challenge," Defense
Update, (1987), 50-62.
10.	Gourley,  Scott R.  "Piercing The Darkness," Defense Electronics,
(Jul 89), 85-89.
11.	Gunning, James A., CW2.  "Modified Face Plate Goggles," U.S.
Army Aviation Digest, (May 83), 2-6.
12.	MAWTS-1, USMC, Helicopter NVG Manual, Yuma, Az., 1 Sep 90.
13.	Moses, George W., Ltcol.   "Helicopter Low Level Night Operations,"
U.S. Army Aviation Digest, (May 73), 2-5.
14.	Neal, Tim.  "ANVIS, Now a System Designed For Aviators," U.S.
Army Aviation Digest, (May 83), 13-17.

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