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Petition for Amendment to Exemption No. 6425B which permits relief from 14 

CFR 25.562(b)(2) Amendment 25-64 from floor warpage testing requirement for 

flight deck seats 

Name and Address of the Petitioner 

Douglas Lane, Deputy Lead Administrator 

The Boeing Company 

PO Box 3707, M/S 03-56 

Seattle, Washington, 98124 

Section(s) of the Regulation(s) to which an Amendment is sought: 

Section 25.562(b)(2), as amended by Amendment 25-64, requires the floor tracks 

used to attach the seat to the floor to be misaligned with respect to the adjacent seat 

tracks by at least 10 degrees vertically (i.e. out of parallel), with one rolled 10 

degrees. The misalignment is used during the forward loading dynamic test 

condition and applies to both crew and passenger seats. 

Extent of Amendment Sought and Reason(s) 

Boeing hereby petitions for an exemption from the floor warpage testing 

requirements of FAR 25.562 Amendment 25-64, for flight deck seats on Boeing 

Airplane Model 737 MAX (737-7/-8/-9). The 737 MAX models (737-7/-8/-9) are 

derivatives of corresponding 737NG models (737-700/-800/-900ER). The significant 

product level change for the 737 MAX models is the new engine and related 

changes. With respect to FAR 25.562(b)(2), the 737 MAX flight deck seats are 

unchanged relative to the 737NG model airplanes, which were granted an 

exemption. 

Description of Issue 

Boeing 737-600/-700/-700C/-800/-900/-900ER, 757-300, 767-200C/-400ER, 777 

series/-200, and 787 models were exempt from this requirement based on the 

following justification: 

FAR 25.562 states that “... where floor rails or floor fittings are used to attach the 

seating devices to the test fixture, the rails or fittings must be misaligned with respect 

to the adjacent set of rails or fittings by at least 10 degrees vertically (i.e., out of 

parallel) with one rolled 10 degrees.” 

The preamble to Amendment 25-64 states: “Crash investigations have shown that 

localized cabin floor deformation can occur in survivable crashes. This has been 
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confirmed by the controlled impact demonstration and drop tests involving transport 

category airplanes. The inability of some seats to accommodate such deformations, 

remain in place, and restrain the occupants can contribute significantly to [the] 

degree of injury during a crash. The simulated floor deformation used in the 

dynamic tests...will demonstrate the tolerance of the seat and its attachments to 

deformations that could occur in an actual crash. 

The preamble also states the benefit of this amendment is believed to be that “... 

some lives are expected to be saved that otherwise may not have been.” 

This test requirement makes no distinction between passenger and crew seats, 

while the evidence mentioned in the preamble is believed to be based on passenger 

seats only. There is evidence to suggest that floor warpage has not been a 

significant factor in flight deck seat failures during survivable crash conditions. 

The FAA acknowledged in the preamble to Amendment 25-64 that the likelihood of 

seats designed to meet this amendment costing more to manufacture and therefore 

to purchase, as well as increasing the airplane operating cost due to a weight 

increase. In order to justify the increased costs, it must be expected that some lives 

will be saved that otherwise may not have been. This does not appear to be the 

case for flight deck seats. These increased costs will create an economic 

disadvantage for the 737-7/-8/-9 without a commensurate expectation of saving lives 

that otherwise may have been lost. 

 

Statement of Public Interest 

Granting of this exemption is in the public interest because it will: 

 Not adversely affect flight safety; 

 Improve the efficiency of the Model 737-7/-8/-9; 

 Tend to reduce air transportation fares; 

 Improve the potential for sales to foreign operators, which in turn improves 

the U.S. balance of payments;

Statement of No Adverse Effect on Safety 

This test requirement makes no distinction between passenger and crew seats, 

while the evidence mentioned in the preamble is believed to be based on passenger 

seats only. There is evidence to suggest that floor warpage has not been a 

significant factor in flight deck seat failures during survivable crash conditions. In 

Exemption No. 6425, the FAA noted, “Although some cockpit floor distortion have 

been observed after accidents, there has not been a problem with flight deck seat 

separations due to floor buckling on narrow body and larger airplanes which have a 

minimum of 40 inches of frangible structure between the flight deck floor and the 
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lower fuselage contour. The FAA now considers that requiring testing of pilot seats 

with floor warpage cannot be justified on narrow body and larger airplanes.” 

Summary to be Published in the Federal Register 

PETITIONER: Boeing Commercial Airplanes 

SECTION OF 14 CFR AFFECTED: 14 CFR 25.562(b)(2) 

DESCRIPTION OF RELIEF SOUGHT: Exemption to permit relief from the 14CFR 

Part 25.562(b)(2) Amendment 25-64 compliance with the 10 degrees of track 

misalignment and roll test requirements for flight deck seats installed on Boeing 

Model 737-7/ -8/-9 series airplanes.

Request to “Waive Publication and Comment” 

The petitioner would like to request waiving the requirement for Federal Register 

publication because the exemption, if granted, would not set a precedent. This is 

not a new exemption but rather a revision to the existing ones to add additional 

model series aircraft. This request is based on the rationale of similarity to the 737-

600/-700/-700C/-800/-900/-900ER and exemptions granted on other Boeing models.

Privileges of the Exemption Outside of the United States 

The petitioner would like to extend the privilege of the exemption outside of the 

United States. The same flight deck seats are applicable to all 737NG and 737 MAX 

airplanes. 

 

Conclusion 

With reference to the FAA position when granting the exemptions for previous 

Boeing models, Boeing petitions for an exemption from the floor warpage testing 

requirement of 14 CFR Part 25.562(b)(2) Amendment 25-64 for flight deck seats 

installed on Boeing 737 MAX Models (737-7/-8/-9).