Source: https://www.federalregister.gov/documents/2019/04/29/2019-08613/special-conditions-boeing-model-787-series-airplanes-seats-with-inertia-locking-devices
Timestamp: 2019-05-22 08:47:21
Document Index: 613122297

Matched Legal Cases: ['art 25', '§\u200921', 'art 34', 'art 36', '§\u200925', '§\u200925']

Federal Register :: Special Conditions: Boeing Model 787 Series Airplanes; Seats With Inertia Locking Devices
A Proposed Rule by the Federal Aviation Administration on 04/29/2019
This document has a comment period that ends in 7 days. (05/29/2019) Submit a formal comment
Send comments on or before May 29, 2019.
84 FR 17977
17977-17979 (3 pages)
Docket No. FAA-2019-0236
Notice No. 25-19-03-SC
2019-08613
https://www.federalregister.gov/d/2019-08613 https://www.federalregister.gov/d/2019-08613
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On February 14, 2019, Boeing applied for a change to Type Certificate No. T00021SE for seats with inertia locking devices in Model 787 series airplanes. The Model 787 series airplane is a twin-engine transport-category airplane with a maximum takeoff weight of 560,000 pounds and seating for 440 passengers.
Under the provisions of title 14, Code of Federal Regulations (14 CFR) 21.101, Boeing must show that the Model 787 series airplanes, as changed, continue to meet the applicable provisions of the regulations listed in Type Certificate No. T00021SE, or the applicable regulations in effect on the date of application for the change, except for earlier amendments as agreed upon by the FAA.
If the Administrator finds that the applicable airworthiness regulations (i.e., 14 CFR part 25) do not contain adequate or appropriate safety standards for Boeing Model 787 series airplanes because of a novel or unusual design feature, special conditions are prescribed under the provisions of § 21.16.
In addition to the applicable airworthiness regulations and special conditions, Boeing Model 787 series airplanes must comply with the fuel-vent and exhaust-emission requirements of 14 CFR part 34, and the noise-certification requirements of 14 CFR part 36.
Boeing Model 787 series airplanes will incorporate the following novel or unusual design features:
Seats with inertia locking devices (ILD).
Boeing has proposed to install, in Model 787 series airplanes, Thompson Aero Seating Ltd. passenger seats that can be translated in the fore and aft direction by an electrically powered motor (actuator) that is attached to the seat primary structure. Under typical service-loading conditions, the motor internal brake is able to translate the seat and hold the seat in the translated position. However, under the inertial loads of emergency-landing loading conditions specified in 14 CFR 25.562, the motor internal brake may not be able to maintain the seat in the required position. The ILD is an “active” device intended to control seat movement (i.e., a system that mechanically deploys during an impact event) to lock the gears of the motor assembly in place. The ILD mechanism is activated by the higher inertial load factors that could occur during an emergency landing event. Each seat place incorporates two ILDs; one on either side of the seat pan. Only one ILD is required to hold an occupied seat in position during worst-case dynamic loading specified in § 25.562.
The ideal triangular maximum severity pulse is defined in Advisory Circular (AC) 25.561-1B. For the evaluation and testing of less-severe pulses for purposes of assessing the effectiveness of the ILD deployment setting, a similar triangular pulse should be used with acceleration, rise time, and velocity change scaled accordingly. The magnitude of the required pulse should not deviate below the ideal pulse by more than 0.5g until 1.33 t1 is reached, where t1 represents the time interval between 0 and t1 on the referenced pulse shape as shown in AC 25.561-1B. This is an acceptable method of compliance to the test requirements of the special conditions.
The proposed special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.Start Printed Page 17979
As discussed above, these special conditions are applicable to Boeing Model 787 series airplanes. Should Boeing apply at a later date for a change to the type certificate to include another model incorporating the same novel or unusual design feature, these special conditions would apply to that model as well.
In addition to the requirements of § 25.562, passenger seats incorporating inertia locking device (ILD)s must meet the following:
Issued in Des Moines, Washington, on April 10, 2019.
[FR Doc. 2019-08613 Filed 4-26-19; 8:45 am]