Issue 2/95
In 1991 two respected institutions of modern aviation joined forces to establish
one of the world's best pilot training academies. Located in Tamworth, Australia,
and owned by British Aerospace and Ansett Transport Industries, the Australian
Air Academy benefits from the experience and professionalism of the British
Aerospace Flying College at Prestwick in Scotland together with over 50
years of air transport operations by Ansett in Australia.
This combination of experience and know-how has no doubt a great effect
on the young men and women preparing to cope with the rigours and discipline
of flying. Candidates with varied flying experience come to the Australian
Air Academy from a number of airlines, including Ansett Australia, Air Nippon
Co., Cathay Pacific, Vietnam Airlines, several carriers from the People's
Republic of China, the Australian Defense Forces and the Papua New Guinea
Defense Force.
Chief Instructor Captain Warren Gengos explains: "We consider the selection
process extremely important. If you choose the correct cadets, you should
have very few failures in your training system. Recently, Ansett Australia
have asked us to conduct the entire selection process for their cadets,
with the exception of the final stage (interview) which is conducted by
three senior Ansett captains and myself." The Academy's selection criteria
include: age, academic qualifications, medical exam, personality traits
and the U$32,000 WOMBAT-CS Situational Awareness and Stress Tolerance Test.
Gengos continues: "We use WOMBAT-CS and recommend it for several reasons
including:
· It does not matter whether an applicant has prior flying experience (this is important in Australia, as many of the applicants have already undertaken quite significant amounts of flying training.) Past flying experience does not affect the WOMBAT assessment.
· You cannot train someone to be better at WOMBAT. Unlike other tests, a candidate that already attempted a WOMBAT test will not perform better the second time.
· WOMBAT-CS appears to measure the ability of the candidate to see the 'big picture', known as Situational Awareness.
· WOMBAT-CS makes the candidate prioritize his tasks depending
on the value of the task."
The Academy is known for its ability to supply airlines with highly trained,
qualified pilots. "We tailor each curriculum to the specific need of
the sponsoring airline, including corporate culture and advanced cockpit
resource management."
The Academy evaluated several testing systems before deciding on WOMBAT-CS.
The ideal selection process has to be reliable, valid, comprehensive, discriminative
and objective. WOMBAT was designed to meet these requirements. Experiments
to date have shown no evidence of cultural or sexual biases. "We did
consider other tests available on the market, including the British MICROPAT
system. Although this is the system Qantas uses, so did we for some time
however we did not favour it for all the reasons that led us to adopt WOMBAT."
David O'Hare, Ph.D., a senior lecturer at the University of Otago (NZ),
in his Cognitive Ability Determinants of Elite Pilot Performance study,
states: "[Our] results support the claims that the WOMBAT test measures
individual ability to maintain situational awareness and that this ability
is found in high levels in elite pilots."
Consider the following seemingly unrelated activities: making landing approaches over water on a dark night toward a brightly lighted city; looking for intruding airplanes from the flight engineer's seat; sitting inside a screened porch and trying to read a NO FISHING sign down by the lake; projecting afterimages onto the walls of a football stadium; and watching the moon rise over the Wabash River. In fact, these activities all have something in common: visual illusions -systematic misjudgments of size and distance relationships, departures by varying amounts from the so-called "size-distance invariance hypothesis."
These illusions have implications for the selection and training of pilots
and for the design and use of imaging flight displays and visual systems
for contact flight simulators. When pilots make approaches and landings
with any type of imaging flight display projected at unity magnification,
they tend to come in fast and long, round out high, and touch down hard.
On the final approach the runway appears smaller, farther away, and higher
in the visual field than when viewed directly from the same flight path
on a clear day. This finding has been obtained independently with both flight
periscopes and simulated contact visual systems (Roscoe, Hasler, and Dougherty,
1966; Palmer and Cronn, 1973; Randle, Roscoe, and Petitt, 1980).
In stark and tragic contrast, when pilots make approaches to landings over
the water on a dark night toward a brightly lighted city, the runway appears
larger, nearer, and lower in the visual field than when viewed directly
from the same flight path on a clear day. On several occasions a commercial
airliner has landed in the water short of the airport when making an approach
at night. At the Boeing Aerospace Company, Kraft and Elworth (1968) and
Kraft (1978) have shown that pilots will systematically misjudge the height
and "tilt" of the runway and make low approaches under these conditions.
In another experiment by Kraft, Farrell, and Boucek (1970), a group of pilots
judged the threat of midair collisions with intruding airplanes at varying
distances and angles, none of which represented an actual collision threat.
The pilots were presented a series of pictures projected onto a screen viewed
from a mocked up Boeing 737 cab. When the judgments were made from the flight
engineer's seat, as opposed to the pilot's seat, the same pilots consistently
judged the intruders to be a greater threat at all ranges out to 1070 meters.
From the rear seat the intruders appeared larger and closer than from the
front seat.
In addition to misjudgments of size and distance with flight periscopes,
bias errors in depth discrimination have been discovered independently by
designers of submarine periscopes, tank periscopes, laboratory microscopes,
"one-power" scopes for shotguns, and helmet-mounted CRT displays.
All require some optical magnification to cause objects to appear at the
same distances as when viewed by the naked eye, and all involve reductions
in the field of view and in the textural gradient to which the eye normally
accommodates. These biased perceptions of size and distance are not fully
explained, at least not sufficiently to give comfort to the pilots and passengers
of airplanes.
The mystery manifests itself in many forms that have puzzled psychologists
from Ptolemy, who tried to explain the "moon illusion," to Young
(1952), who had subjects project visual afterimages onto the walls of the
Ohio State football stadium from various distances across an open field.
The farther the afterimage is projected, the larger it appears, but not
in direct proportion as would be predicted by the size-distance invariance
hypothesis. The "size" of the moon also varies with the extent
of the visible textural gradient, appearing larger over a distant horizon
than it does over a near horizon, as shown experimentally by Kaufman and
Rock (1962).
The literature of vision research contains additional examples of unexplained
experimental findings and assorted optical illusions that may be related
to the observations by Wheatstone (1852) and Helmholtz (1887/1962), and
more recently verified experimentally by Biersdorf and Baird (1966); Leibowitz,
Shiina, and Hennessy (1972); and Roscoe, Olzak, and Randle (1976), that
the apparent size of an object changes with shifts in the distance to which
the eye is accommodated. The phenomenon can be illustrated by any one of
several simple experiments.
For example, close one eye, focus your open eye on your thumb held at arm's
length, observe a more distant object such as a window or a picture on the
wall, and while continuing to focus on your thumb, draw it toward you and
observe the change in the size of the window or picture. Better yet, look
at the moon through a peephole through your fist, alternately closing and
opening the other eye. Not only can the moon on the horizon be made smaller,
but also the moon overhead can be made to vary in apparent size by a surprising
amount.
Now reconsider the experiment by Kraft, Farrell, and Boucek (1970). The
viewpoint from the flight engineer's seat is nearly 2 meters from the windshield
aperture; from the pilot's seat it is less than 1 meter. Furthermore, the
view from the flight engineer's seat when searching for intruders includes
much of the instrument panel. When searching head-up from the pilot's seat,
the instrument panel appears in the dim periphery; the pilot sees mainly
empty space through a windshield that reflects glare and may be dirty or
scratched. These conditions suggest that pilots can unknowingly be subject
to the "Mandelbaum effect."
In 1960 Mandelbaum reported an informal experiment in which he asked subjects
to read a distant sign from a screen-enclosed porch. For each observer he
found a critical distance from the screen at which the sign could not be
read, although it was clearly legible from the other distances, either nearer
or farther. Upon questioning, the subjects realized that they could not
avoid focusing on the screen from the critical distance but could readily
focus on the sign by moving either nearer or farther from the screen or
by quick movements of the head from side to side. Mandelbaum concluded that
the "effect" was due to involuntary accommodation.
It was noted that the critical distance from the screen varied from person
to person, with an average distance of about 1 meter. In an ingenious series
of experiments at Pennsylvania State University, Owens (1979) has subsequently
determined that the critical distance is the individual's dark focus point
or resting accommodation distance. For the young, healthy eyeball that distance
on average is slightly less than 1 meter (slightly more than 1 diopter in
optical terms), the distance of the dirty windshield from the pilot. Almost
any textured visual stimulus at that distance is a powerful involuntary
"accommodation trap."
Such experiments cover a wide range of traditionally unrelated research
areas. The numerous threads of inquiry wind in and out and are hard to follow
to a point of convergence. Nevertheless, the following statements appear
defendable: (1) the accommodation of the eye can be forced or misled by
several phenomena that can occur in flight, and (2) when accommodation is
so disturbed, relative to the true distances of external reference objects,
both size and distance perception are distorted and the pilot's controlling
responses can be correspondingly biased.
What can be done to reduce or overcome these effects?
For years, Kraft, Hennessy, and several other investigators have recommended
that pilots routinely wear bifocal lenses at night and when making instrument
approaches in daylight conditions. The lower section would optimize their
vision for instrument panel and chart viewing distances. The upper section
would provide suitable correction to aid accommodation for outside viewing
(and in planes with overhead switches, a "third window" at the
top would be needed). Owens and Leibowitz (1976) have shown that if night
drivers with normal vision are asked to select the lenses that allow them
to see best, they will choose those with a negative correction halfway between
their dark focus distances and optical infinity.
To combat the possible underaccommodation experienced by some pilots while
making "black hole" approaches over water at night, lead-in light
buoys should be considered and tested for use at major airports. Although
no specific data are available, it would be expected that in the absence
of visible texture in the near field, pilots with extremely distant dark
foci would be the ones who tend to make low approaches at night and occasionally
land in the ocean. Perhaps they should wear positive corrective lenses at
night, but evidently no such tests have been made.
The use of head-up displays for night and instrument approaches warrants
further investigation. It has been tacitly assumed by the advocates of such
displays that the collimated presentation prepares the eyes to resolve immediately
whatever is out there to be seen. Available experimental evidence does not
support that assumption. Landing approach studies at Ames Research Center
(Randle, Roscoe, and Petitt 1980) and moon-illusion studies at the University
of Illinois (Hull, Gill, and Roscoe, 1982; Iavecchia, Iavecchia, and Roscoe,
1988; Simonelli, 1979) clearly show that collimating bold symbology, whether
viewed directly or reflected from a combining glass, does not necessarily
call the eyes to a far accommodation distance. When the pilot breaks out
of the clouds, rapid negative accommodation is required, and the scene "explodes."
Studies suggest that dark focus, or resting accommodation distance, in addition
to basic visual acuity and color vision, should be taken into account in
pilot selection and assignment. Having a far resting accommodation distance
might be one basis for assigning military pilots to air combat duty; they
should be less troubled by empty-field myopia. Those with a nearer position
might benefit from negative lenses, as in the case of civilian pilots watching
for intruders. As pilots get older their resting accommodation may retreat
into the distance, occasionally to a point at which they could have serious
problems making "black hole" approaches.
There is ample empirical evidence that pilots learn to compensate for the
biased distance judgments they experience at night and with flight periscopes
and the visual systems used in flight simulators. Specific training in the
relationships between viewing conditions and the direction and magnitude
of visual biases would expedite learning the appropriate compensations.
Providing variable magnification in computer-generated night visual systems
as a function of the variations in simulated visibility and illumination
is a possible training feature that might be well worth its cost. (References
on request.)
In 1993, Canada's Ministry of Transport certificated the Hawker Pilot Trainer
as the first touch-screen-based pilot trainer in the world. This marked
an important event in the simulation industry, as many thought all-CRT aircraft
display and switching FTDs would never be accepted by any regulatory agency.
"Show me an aircraft with touch screens...", Paul Ray of FAA's
National Simulator Program said in September 1993 when asked if he would
accept virtual FTDs in the USA.
Transport Canada's Manager of Simulator Approval, Captain Bill Todd, did
not need very long to understand how the HPT technology could benefit all
levels of pilot training. Todd and Captain Ron MacEwen of the Licensing
Department flew the HPT and discovered a potent concept based on scientific
research demonstrating positive transfer of learning.
A few months later, after the appropriate test guide had been designed,
the Hawker Pilot Trainer received the Canadian FTD Level 2 Certification
with honors. This allowed operators to sell their candidates 20 hours of
instrument training on the HPT for IFR rating purposes.
The $210,000 (USD) Hawker Pilot Trainer (HPT) is manufactured by Australia's Hawker DeHavilland and sold worldwide by Montreal-based Aero Innovation Inc. The HPT is the first all-CRT aircraft display and switching control simulator and is approved FTD Level 2. It uses touch-sensitive screens to let the pilots operate the instruments, gauges and actuators where they are actually found in the cockpit, not where it is more convenient to locate them.
(Photo Aero Innovation ©1995)
Originally, the creators of the HPT designed a "teaching device"
answering the specific needs of ab initio training. Who else could ever
be attracted by a low-end, all-CRT FTD? The answer came quickly from Melbourne-based
Ansett Australia. The airline ordered 2 HPTs specially equipped with additional
Fokker 28 and Boeing 737 generic flight models. The intent of the airline
was to use the HPTs at all levels of training, from flight-naive cadets
to CRM requalification of line pilots.
The Australian certification was granted in October 1995 by the CAA who,
not unlike the Canadians, recognized the exceptional potential of the virtual
simulation technology. Both countries' officials found that virtual simulation
met their actual criteria of simulator acceptance. "The Hawker Pilot
Trainer was certificated in Canada because we are convinced that this technology
is the way of the future and, most importantly, the device met all our FTD
Level 2 criteria in every respect," said Capt. Todd when reached on
the phone in his Ottawa office.
Half-way around the globe, in Paris, Air Alizé Training acquired
two HPTs. They showed the device to the Direction générale
de l'aviation civile (DGAC) this month. Captain Marc Pasqualini, Chief Pilot
of the DGAC Training Schools Division also acknowledged the enormous capabilities
of the HPT. "I don't see why we should prevent anyone from using this
kind of device. I must admit it is surprising at first, but just a few minutes
at the controls and you really feel the same as in any conventional FTD.
French student pilots will be allowed to log the maximum credits on the
HPT for their IFR rating, no doubt about that".
Not only can the trainees experience training aids that have no real-world
counterparts, such as the Adaptive Augmentation or the Highway-in-the-sky,
but the HPT represents genuine cost reduction from any conventional device.
An unlimited number of generic aircraft at the touch of a button, from light
single airplane to complex "glass cockpit" airliner can be simulated
by the HPT. "It adds a flexibility that no other multi-crew device
offers", says Captain Paul Mathieu of the Centre
québécois de formation aéronautique (CQFA), the
largest pilot training college in Canada that has been operating 5 HPTs
since 1992.
Today, the HPT is in use in Australia, Canada, France, India, the Netherlands
and New Zealand.