light and weather conditions, one sees that as
flight conditions deteriorate, the total number
of accidents decreases. This can be explained
in part as indicating that the exposure rate is
lower during the more severe light and: weather
conditions. The Aircraft Owners and Pilots
Association (AOPA) found, in a survey con-
ducted in 1961, that only 5 percent of flying is
done at night and less than 4 percent by Instru-
ment Flight Rules (IFR). However, IFR total
hours were about 50% higher than night total
hours flown’.

The point to be made, however, is that even
though fewer flights occur under increasingly
difficult flying conditions, the percentage of both
non-fatal and fatal accidents rises sharply. Re-
view of the accident records shows that pilots
involved in accidents where severe light, and
weather conditions existed were, in most cases,
those pilots who were least prepared for the con-
ditions they encountered: student pilots with
only a minimum of instrument understanding
and very little night time; private and commer-
cial pilots who were aware of the conditions but
pushed into weather such as ice, thunderstorms,
snowstorms and severe turbulence; pilots with
very little current time, low time in the aircraft
being flown, flying over unfamiliar ‘territory,
and poor preflight preparation. The ATR (non-
airline) pilots, for the most part, were victims
of instrument failures, fatigue from long flights,
and “pushing their luck”. Table #5 shows the
results of such actions graphically. Students
were involved in six accidents at night under
IFR conditions. Of these, four were fatal. In
these four, only the students and ¢legal passen-
gers were aboard. The two non-fatals were ac-
cidents in which flight instructors were aboard.
The presence of the flight instructor might well
have saved the two non-fatals from being fatal.

It was reported during the time this study
was made that in general aviation there was a
high percentage of cases in which alcohol was
involved as shown by a blood alcohol test. Medi-
cal investigators were successful in obtaining
specimens for the testing of blood alcohol in 42
percent of all fatal accidents; of these 39 percent
showed positive alcohol levels 10mg% and above.
The percentage of alcohol involvement within
the ratings based on Total Fatal accidents was
23 percent for students, 16 percent for privates,
and 17+ percent for both commercial and ATR

pilots. Approximately three-fourths of all pilots
known to be involved with alcohol (39 percent
of those tested), had a level greater than 50mg%.
Dr. Herman Heise’s report to the Flying Physi-
cians Association indicated “that individuals
tested for judgment, sensory and motor func-
tions, prior to and shortly after consumption of
alcohol, showed deterioration at blood alcohol
levels in the range of 50mg% and above”. Dr.
Heise feels that such levels causing degeneration
of performance may be judged to have been con-
tributory to the accident rate by resulting in a
decrease of pilot proficiency. It is interesting
to note that previously unpublished data on
alcohol involvement (1964) verifies the results
of “Alcohol and General Aviation Accidents”.
reported by Albers and Harper (1963)‘, and
“Recent Findings on the Impairment of Airman-
ship by Alcohol” by Stanley R. Mohler, M.D.°.

As the various light and weather factors were
analyzed, it was found that 88 percent of all
accidents occurred during the day under Visual
Flight Rule (VFR) conditions and accounted
for 59 percent of the fatal accidents. The re-
maining 12 percent occurred during Day IFR,
Night VFR and Night IFR conditions and ac-
counted for 41 percent of the fatal accidents.
Here we can see that the percentage of fatal
accidents increases sharply over the total acci-
dents as flight conditions become more hazardous.
See Table #5.

A review of the fatal accidents by type of cer-
tificate and their representation in the total
population indicates that there is what could be
defined as a fatal base rate. That is a percentage
of fatal accidents which will occur regardless
of the number of accidents. The average base
rate is 9.31 percent of the total accidents. See
Chart #1. If one checks the percentage of fatal
accidents in relation to the total number of acci-
dents over the last 10 years, they will find that
approximately 10 percent of all accidents are
fatal.

IV. Summary and Conclusions.

The analysis of 1964 accidents reveals:

1. Students generally were involved less fre-
quently in accidents than any other class of air-
men. However, the high percentage of fatal
accidents for students flying when light and
weather conditions were marginal points up



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limits of their ability under such conditions.

2. Generally, all airman certification groups
showed a high percentage of accidents as flying
conditions became more demanding, i.e., as visi-
bility decreased because of light and/or weather
conditions (see Table #5). Here we see the
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ing flight conditions.

8. Eighty-eight percent of all accidents oc-
curred during the day under VFR conditions
and accounted for 59 percent of all fatal acci-
dents. ‘(Ninety percent of all flights take place
during day VFR conditions.) Only 12 percent
of the accidents occurred under less favorable
conditions but accounted for 41 percent of all

fatalities. It is quite evident that as exposure
goes down (10 percent of all flying occurs dur-
ing Day IFR, Night VFR, IFR conditions) and
light and weather conditions become more haz-
ardous, the percentage of fatal accidents in-
creases. However, the percentage of fatal acci-
dents decreases as the type of certification is
upgraded.

4, Regardless of the percentage of accidents
associated with a particular airman certification,
10 percent, on the average, were fatal. How-
ever, although student pilots accounted for 14.47
percent of all fatal accidents, only 7.36 percent
of the accidents involving students were fatal.
In the other three classes of pilots, the percent-
age of accidents which were fatal was somewhat
greater than for students.


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AM 67-23

TYPE AIRMAN CERTIFICATION AS RELATED
TO ACCIDENTS

Everett J. Veregge

Approved by Released by
fom ay x. Aland, é ad
James L. Harris P. V. Srecrn, M.D.
Crer, ArromepicaL Epucation Feperat Air Surcron
Division

October 1967

FEDERAL AVIATION ADMINISTRATION
Office of Aviation Medicine



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The Aviation Psychology Program? in the
Army Air Force showed, in studies conducted
on a controlled group of about 1,000 airmen,
that the higher stanine groups which produced
40 percent of the graduates had 25 percent of
the total accidents, none of which was fatal: the
lower stanine groups produced 60 percent of the
graduates and had 75 percent of the accidents,
which included 100 percent of the fatalities.
However, it must be pointed out that in this test
the stanine groups were based on AAF Qualify-
ing Examination scores, which are measures of
individual applications selected for flight train-
ing, while the airman certifications are levels of
training achieved by pilots.

The student certificate is the most elementary
and, as such, requires only that an individual
be at least 16 years old and medically fit. How-
ever, to achieve the higher certificate of private
pilot, an individual must pass a written test and
a flight test to demonstrate his proficiency; in
addition, he must have at least 40 hours of flight
experience. The commercial certificate requires
200 hours of flight experience and the ability to
perform more complicated flight maneuvers.
The pilot with an ATR certificate, the highest
airman certificate, is required to pass an instru-
ment flight test, handle larger and more complex
aircraft, and possess greater aeronautical knowl-
edge and skill, as well as have at least 1200
hours of flight time distributed over a range of
flight conditions such as night flying, instrument
time, and pilot-in-command. Based on these
differences in training and experience, the level
of proficiency should increase from one certifi-
cation to another as long as the type of flying
remains the same.

All figures relating to accidents and their
distribution by type of light and weather condi-
tions were furnished by the Civil Aeronautics
Board and represent only 1964 reports of acci-
dents received, reviewed, and coded as of Decem-
ber 10, 1965. In order to show the distribution
of certificate holders by qualification, Table #3
was constructed using 1964 data showing the
percentage each group represents in the total
population of 426,817 active pilots. Combined
with these data are the number and percentage
of accidents within each certification and their
proportion of the year’s total accident population.

Ill. Findings.

Individual pilots will react individually to the
same or changing conditions. Pilots with ad-
vanced airman certificates and more current
flight exposure will be better equipped to handle
these changes than those with lower ratings and
less current flight experience. Table #1 indi-
cates the exposure rates associated with each of
the airman certificates. It is apparent that there
are differences between certificate classes. How-
ever, here again the accident rate per se does not
address itself to the difference within the ele-
ments of exposure that account for these differ-
ences. It is only when the accident percentages
are calculated for airman certificates by increas-
ingly difficult light and weather conditions that
we begin to understand some of the components
associated with proficiency (see Table #2).

An examination of Table #3 also shows that
the accident percentage does not follow the popu-
lation percentage for students and commercially
rated pilots. Our first assumption would be that
students, based on their representation in the
pilot population, have fewer accidents, while the
commercial pilots have about 8 percent more
than would be expected based on their repre-
sentation in the total population. This would
seem to indicate that students are safer than
commercial pilots. If one looks at the makeup
of the four groups, he would find the type of
flying done is heterogeneous between them rather
than homogeneous. For example, students on
the average are required to fly with a flight in-
structor for the first 10 hours, in addition to
several hours of dual cross-country flying, dur-
ing which the flight instructor, who is a com-
mercially rated pilot, is charged with the stu-
dent’s accidents. Secondly, the commercial pilots
who fly as crop dusters (there were 4,500 regis-
tered as aerial applicators in 1964) fly under
conditions which are foreign to the ATR, pri-
vate, and student pilot. If we adjust the com-
mercially rated group by excluding from Table
#3 those pilots who are aerial applicators and
those accidents which occurred while crop dust-
ing, and by charging to the student group those
accidents which students caused during pre-solo
or dual flight time instruction, for which the
instructors are charged, we obtain the distribu-
tion shown in Table #4, which shows that acci-
dent numbers tend to follow the distribution of
the pilot population. If accidents are due to


TYPE AIRMAN CERTIFICATION AS RELATED TO ACCIDENTS

I. Introduction.

Soon after the first flight at Kitty Hawk, acci-
dent rates were established, based on the number
of accidents in relation to the number of hours
spent in the air (exposure incident to flight),
as a measure of relative safety in aviation. Over
the last 63 years exposure has been considered
the common denominator of all accidents. While
this position is true, for without exposure there
would be no accident, it fails to account for
those factors or components which make up ex-
posure. Since accidents are chance phenomena,
the greater the exposure the greater the prob-
ability of an accident. Exposure is simply the
measure of the length of time during which a
condition or circumstance accumulates. Expo-
sure should be a qualitative measure of express-
ing conditions of flying, type of airman certifi-
cation, and hours of flying. While the general
term “exposure” is an overall expression of pro-
ficiency in flying, proficiency as measured by
conditions of exposure is a constantly changing
phenomenon which varies with circumstances of
the flight, such as varying light and weather
conditions, length of flight, altitude at which
flight is flown, and the physiological condition
of the pilot. With this in mind, the use of ex-
posure data as expressed in terms of flight hours
has been omitted from the analysis of accident
data for this paper.

II. Method.

Pilots are certificated as student, private, com-
mercial, or airline transport. This analysis
will deal only with general aviation accidents
and has no relation to air carrier operations.
Each type of pilot certification is distin-
guished by standards of training, medical fit-
ness, and experience, predetermined by the
Federal Aviation Administration, and is spe-
cifically so designated in the Federal Aviation
Regulations. As he progresses from a lower to
higher certificate, the pilot must demonstrate his
knowledge of aeronautics and his ability to ap-

ply this knowledge both by a written examina-
tion and a flight test. While a minimum
number of flight hours is required for a higher
certificate, this requirement covers the least
amount of time necessary during which the pilot
may be able to acquire the flight skills for the
next higher certificate. As the pilot advances
from one certificate to another, he gains new
skill and experience which contribute to his pro-
ficiency as a flyer. A relationship between pro-
ficiency and the probability of being involved
in an accident will exist as long as the type of
flying continues to be of low risk nature (exclud-
ing aerial applications, fire fighting, aerobatics,
coyote hunting, etc.).

To evaluate correctly the effect of airman
certification and accidents for this report, items
not common ‘to flying as practiced by the aver-
age pilot (e.g., aerial applications) were elimi-
nated from both the pilot and accident popula-
tion data. Additional adjustments in such data
were made to charge the student pilot with acci-
dents which he caused, but which had been
charged to his flight instructor.

The term “accident” can refer to a fatal acci-
dent, a serious injury, or an accident with sus-
tained damage:

1. “Fatal Accident” is any accident which
leads to death within seven (7) days.

2. “Serious Injury” is any injury which:

a. Requires hospitalization for more than 48
hours commencing within seven days from the
date the injury was received.

b. Results in a fracture of any bone (except
simple fractures of fingers, toes, or nose).

c. Involves lacerations which cause severe
hemorrhages, nerve, muscle, or tendon damage.

d. Involves injury to any internal organ.

e. Involves second or third degree burns
affecting more than 5 percent of the body surface.

3. “Substantial Damage” in aircraft of 12,500
pounds maximum certificated take-off weight or
less, means damage or structural failure reason-
ably estimated to cost $300 or more to repair.



ACKNOWLEDGMENTS

My appreciation goes to Rowland H. S. Bedell, M.D., Chief of the Acci-
dent Investigation Branch; 8. J. Gerathewohl, Ph.D., Chief of the Research
Planning Branch; H. L. Reighard, M.D., Deputy Federal Air Surgeon;
S. Anderson, M.D., Acting Chief of the Aeromedical Standards Division,
Federal Aviation Administration; and Alan Ross, Ph.D., Professor of Bio-
statistics, Johns Hopkins University, for their thought-provoking comments
and helpful suggestions in the writing of this report.

Qualified requestors may obtain Aviation Medical Reports from Defense Documentation
Center. The general public may purchase from Clearinghouse for Federal Scientific
and Technical Information, U.S. Dept. of Commerce, Springfield, Va. 22151


REFERENCES

1, Federal Aviation Regulations, Part 61: Subpart B, 4, Harper, Cnartes R., and ALsers, WILLIAM R.:

Student Pilots (61.61); Subpart C, Private Pilots “Aleohol and General Aviation Accidents”, Aerospace
(61.81); Subpart D, Commercial Pilots (61.111); Medicine, 35:5, May 1964, pp. 462-464,
Subpart E, Airline Transport Pilots (61.141). 5. Heise, Herman A.: “Drugs-Alcohol-and Flying”:

2, The Aviation Psychology Program in the Army Air ton en Phusician, Volume 8, Number 4, January

Forces, Report Number 1, 1948, p. 86.
6. Monten, Srantey R.: Recent Findings on the Im-
8, Aircraft Owners and Pilots Association: General pairment of Airmanship by Alcohol, AM Report 66-29,
Aviation Aircraft Operations, 1961, p. 8. 1966, pp. 9.

il