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TECHNICAL REPORT STANDARD TITLE PAGE

T. Report No, Z. Government Accession No. 3, Recipient's Cotelog No. |
FAA AM- 72-7
Title and Subtitle 3. Report Date
EVALUATION OF A FIBERGLASS INSTRUMENT February 1972
GLARE SHIELD FOR PROTECTION AGAINST 6. Performing Organization Code
HEAD INJURY
7._Auther’s) 8. Performing Organization Report No.

E. D. Langston
John J, Swearingen, D. Av. T

9. Performing Organization Name ond Address 10. Work Unit No.
FAA Civil Aeromedical Institute
P. O. Box 25082 TT. Contract or Grant No.

Oklahoma City, Oklahoma 73125

13. Type of Report and Period Covered

12. Sponsoring Agency Name ond Address
Office of Aviation Medicine
Federal Aviation Administration

800 Independence Avenue, S. W.
Washington, D. C, 20591

15. Supplementary Notes
Research leading to preparation of this report was performed under Project
NO, AM-A-71-PRS-47.

16. Abstract
An all fiberglass prototype glare shield has been evaluated in terms of head injury
protection. In 30-ft. /sec., head impacts, the 9-1/2-inch protrusion folded down
over the heavy instruments, offering significant improvement in head injury
protection when compared to current aircraft instrument panel design, However,
in this particular design the fiberglass broke, allowing the forehead to contact a
thin, sharp edge with sufficient force to produce fatal head injuries. Design
changes to eliminate this fracture point and incorporation of fiberglass glare
shields of similar design in future general aviation aircraft could lead to a
significant reduction of head injuries during crash decelerations,

OAM

14. Sponsoring Agency Code

17. Key Words 18. Distribution Statement
Availability is unlimited. Document may
Crash safety, engineering design, be released to the National Technical
crashworthiness Information Service, Springfield, Virginia,
22151, for sale to the public.
19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages | 22. Price
Unclassified Unclassified 10 $3.00

Form DOT F 1700.7 (8-69)



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nose producing an initial deceleration peak of
10 G's followed by a second peak of 30 G's as the
shield began to collapse. Chalk deposited on the
head form from the edge of the glare shield
during this phase of the impact was lifted by
means of masking tape and the area of facial
contact determined to be 3.75 square inches.
Based on previous research,’ it appears unlikely
that major facial fractures would occur during
this initial head impact. From 0.025 seconds
to 0.04 seconds, the glare shield folded down
over the instruments and prevented head contact
with them. However, beginning at about 0.04
seconds, the fiberglass broke about 614 inches
from the edge of the glare shield. The thin edge
of the shield, supported by the instrument panel
flange penetrated the 14-inch padding and cut
the rubber head form covering, as shown in
Figures 5 through 8. A peak head form de-
celeration of 60 G’s was produced as the rigid
head form contacted this thin edge. In Refer-
ence 7 it is stated that the forehead cam tolerate
80 G’s on one square inch without bone fracture.
Tf we assume that the forehead contacted a four-
inch length of this 0.035-inch-thick fiberglass
edge, we can calculate a contact area of 0.14
square inch and any impact deceleration in ex-
cess of 12 G’s would be expected to produce

injuries. The impact of 60 G's in this test would
produce severe lacerations (Figure 8) and ex-
tensive fracture of the anterior cranium.

The results of this test were confirmed by a
second test which produced almost identical
failure patterns and head form decelerations.

V. Conclusions.

Since the fiberglass glare shield folded down
over the heavy instruments and sharp knobs and
edges and produced a maximum deceleration
force on the head of only 60 G’s while distribut-
ing the load over large facial areas, as com-
pared to 300-G forees produced on small areas
of the head in similar impact tests of conven-
tional light aircraft instrument panels without
the glare shield (Reference 2), it must be con-
cluded that a glare shield constructed of fiberglass
or of some similar material could substantially
reduce the large number of severe head injuries
now occurring in general aviation crashes. The
failure of the glare shield in these tests exposing
a relatively rigid sharp edge to the head could
cause fatal injuries, even in the relatively low
impact velocities represented by these tests.
Correction of this fault by a minor design modi-
fication could lead to a significant improvement
in crashworthiness.

REFERENCES

1. Swearingen, J. J.: General Aviation Structures Di-
rectly Responsible for Trauma in Crash Decelerations.
FAA-~AM-71-3, January 1971.

2. Swearingen, John J: Injury Potentials of Light-
Aircraft Instrument Panels. AM 66-12, April 1966.

3. Marrow, D. J.: Analysis of Injuries of 1942 Persons
in 1422 Light Plane Accidents. CAA Medical Serv-
ice Records, Washington, D.C., unpublished data, 1949.

4, Pearson, R. G.: Human Factors Aspects of Light
Plane Safety, OAM Report AM 63-35, 1963.

gt

. Boeing head impact tests against the 747 door slide
cases, Boeing Document D6-30667, October 1969.

6. Haley, J. L, Jv: Presentation at the ALPA 8rd
Annual Air Safety Forum, Steward and Stewardess
Division. J. L. Haley, Jr, Av. Ser Div., Flight
Safety Foundation, Ine.

. Swearingen, J. J.: Tolerances of the Human Face

to Crash Impact. OAM Report 65-20, July 1965.


EVALUATION OF A FIBERGLASS INSTRUMENT GLARE SHIELD FOR
PROTECTION AGAINST HEAD INJURY

I. Introduction.

In view of the large number of serious or fatal
head injuries resulting from head impact against
upper instrument panels during crashes of gen-
eral aviation aircraft,*** the Protection and
Survival Laboratory at CAMI maintains interest
in new design concepts which may offer protec-
tion against head trauma,

II. Test Equipment and Procedures.

Two fiberglass instrument panels (without in-
struments), along with their integrated glare
shields, were submitted to the laboratory for
evaluation. These were mounted at the end of
the CAMI crash decelerator (Figure 1). The
position of the glare shield was adjusted to con-
form with measurements provided by the manu-
facturer.. An instrumented dummy head, taken
from an Alderson F-50 anthropometric dummy,
was rigidly attached to a weighted arm which
was free to swing about a pivot on the decelera-
tor sled. The sled was braked prior to impact,
allowing the head to swing forward in an are,
impacting the protruding edge of the glare shield
in the orientation shown in Figure 2. Yellow
chalk applied to this protruding edge allowed
determination of maximum area of initial face
contact and strips of adhesive tape indicated
depth of head penetration, Sled decelerations
were calibrated to produce head impact velocities
of 380 and 35 ft./sec. since these head impact
velocities will occur in crashes of approximately
i-G magnitude as measured on the floor struc-
ure under the seat.°® Head impact deceleration
was measured by a single 250-G CEC Model
£202-0001 strain gage accelerometer mounted
n the dummy head with data recorded using a
Sanborn 550 M signal conditioning system and a
TEC Model 5-124A oscillographic recorder.
Time lines on the oscillograph paper, a sweep-
econd clock and time marks on all high-speed

motion picture film allowed synchronization of
deceleration peaks on the tracing with structural
collapse of the fiberglass glare shield. Motion
picture coverage was: provided by four cameras,
one operating at 24 fps, two at 400 fps, and one
at 2,000 fps.

III. Description of Glare Shield.

The glare shield shown in Figure 3 consisted
of a basic structure of a thin fiberglass layer
covered with a 14-inch thick layer of Ensolite
and a thin layer of plastic vinyl. It extended
914 inches from the instrument panel toward
the pilot and was elevated about 13 degrees
above the horizontal. On the protruding edge
nearest the pilot the shield was rolled down and
under with an inside radius of curvature of ap-
proximately 14-inch. After impact testing had
been completed, the covering was removed from
a portion of the shield so that the thickness of
the fiberglass could be measured. The first five
inches (nearest the pilot) were of a uniform
thickness of .020 inches, increasing to 0.025 inches
at six inches, to .050 inches at seven inches, and
.065 at eight. At nine inches the thickness
abruptly increased to 0.200 inches due to the lap
with the instrument panel.

It should be noted at this point that the glare
shield protruded only in front of the left pilot
and that the right side dropped back such that
the head impact area for the right seat occupant
consisted of a layer of the thin padding over a
rigid structure at the top of the instrument
panel (Figure 1).

IV. Results.

Figure 4 presents a pictorial sequence of
events correlated with deceleration measured dur-
ing Test One (30 ft./sec. head impact velocity).
The initial head contact with the edge of the
glare shield was with the maxilla just below the