(1)
Proper useis made of seats, safety belts, and shoulderharnessesprovidedfor in the design; and
(2)
The occupantis exposed totheloads resulting fromthe conditionsprescribed in this section.
(b)
Except for those seat/restraint systems that are required to meet paragraph (d) of this section, each seat/restraint system for crew or passenger occupancy in a normal, utility, or acrobatic category airplane, must successfully completedynamic tests orbedemonstratedby rational analysis supportedbydynamic tests,in accor-dance with each of the following conditions. These tests must be conducted with an occupant simulatedby an anthropomorphictestdummy(ATD) de.nedby49 CFR Part 572, subpart B, or an FAA-approved equivalent, with a nominal weight of170pounds and seatedinthe normal uprightposition.
(1)
For the .rst test, the change in velocity may not be less than 31 feet per second. The seat/restraint system must be oriented in its nominal position with respect to the airplane and with the horizontal plane of the airplane pitched up 60', with no yaw, relative to the impact vector. For seat/restraint systemstobeinstalledinthe .rstrowof theairplane,peakdecelerationmust occur in not more than 0.05 seconds after impact and must reach a minimum of 19g. For all other seat/restraint systems, peak deceleration must occur in not more than 0.06 seconds after impact and must reach a minimum of 15g.
(2)
For the second test, the change in velocity may not be less than 42 feet per second. The seat/restraint system must be oriented in its nominal position with respecttothe airplane and with the verticalplane of the airplaneyawed 10', with no pitch, relative to the impact vector in a direction that results in the greatest load on the shoulder harness. For seat/restraint systems to be installed in the .rst row of the airplane, peak deceleration must occur in not more than0.05 seconds afterimpact and must reach a minimum of26g.For all other seat/restraint systems, peak deceleration must occur in not more than
0.06 seconds after impact and must reach a minimum of 21g.
(3)
To account for .oor warpage, the .oor rails or attachment devices used to attach the seat/restraint system to the airframe structure must be preloaded to misalign with respect to each other by at least 10'vertically (i.e., pitch out of parallel) and one of the rails or attachment devices must be preloaded to misalign by 10'in roll prior to conducting the test de.ned by paragraph (b)(2)of this section.
(c)
Compliance with thefollowing requirements mustbe shownduring thedynamic tests conductedin accordance withparagraph(b) of this section:
(1)
The seat/restraint system must restrain the ATD although seat/restraint sys-tem components may experience deformation, elongation, displacement, or crushing intended as part of the design.
(2)
The attachment between the seat/restraint system and the test .xture must remain intact, although the seat structure may have deformed.
(3)
Each shoulder harness strap must remain on the ATD’s shoulder during the impact.
(4)
The safety belt must remain on the ATD’s pelvis during the impact.
(5)
The results of the dynamic tests must show that the occupant is protected from serious head injury.
(i)
When contact with adjacent seats, structure, or other items in the cabin can occur,protection mustbeprovided sothattheheadimpactdoes not exceed aheadinjury criteria(HIC) of1,000.
(ii)
The value of HIC is de.ned as–
42.5
t2
1
HIC =(t2 .t1) a(t)dt
(t2 .t1)t1
max
where-t1 :is the initial integration time, expressed in seconds, t2 :is the .nal integration time, expressed in seconds,
(t2 .t1):is the time duration of the major head impact, expressed in seconds, and a(t) :is the resultant deceleration at the center of gravity of the headform expressed as a multiple ofg(units ofgravity).
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本文链接地址：FAA规章 美国联邦航空规章 Federal Aviation Regulations 2(17)
