Airworthiness Directives: Fairchild Aircraft SA26, SA226, and SA227 Series Airplanes

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 93-CE-03-AD]

Airworthiness Directives: Fairchild Aircraft SA26, SA226, and

SA227 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to revise AD 93-19-06, which currently

requires repetitively inspecting acrylic cabin and cockpit windows for

cracks on certain Fairchild Aircraft SA26, SA226, and SA227 series

airplanes, and, if cracks are found that exceed certain limits,

replacing that window. The proposed action would more fully define the

crack limits and establish clearer repetitive inspection intervals

under those crack limits for the affected airplanes. The actions

specified by the proposed AD are intended to prevent acrylic cockpit or

cabin window failures, which could result in airframe damage and

decompression injuries.

DATES: Comments must be received on or before June 10, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Central Region, Office of the Assistant Chief

Counsel, Attention: Rules Docket No. 93-CE-03-AD, Room 1558, 601 E.

12th Street, Kansas City, Missouri 64106. Comments may be inspected at

this location between 8 a.m. and 4 p.m., Monday through Friday,

holidays excepted.

Service information that applies to the proposed AD may be obtained

from Fairchild Aircraft, P.O. Box 790490, San Antonio, Texas 78279-

0490; telephone (210) 824-9421. This information also may be examined

at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Mr. Hung Viet Nguyen, Aerospace

Engineer, FAA, Airplane Certification Office, 2601 Meacham Boulevard,

Fort Worth, Texas 76137-0150; telephone (817) 222-5150; facsimile (817)

222-5959.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the

proposed rule by submitting such written data, views, or arguments as

they may desire. Communications should identify the Rules Docket number

and be submitted in triplicate to the address specified above. All

communications received on or before the closing date for comments,

specified above, will be considered before taking action on the

proposed rule. The proposals contained in this notice may be changed in

light of the comments received.

Comments are specifically invited on the overall regulatory,

economic, environmental, and energy aspects of the proposed rule. All

comments submitted will be available, both before and after the closing

date for comments, in the Rules Docket for examination by interested

persons. A report that summarizes each FAA-public contact concerned

with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments

submitted in response to this notice must submit a self-addressed,

stamped postcard on which the following statement is made: ``Comments

to Docket No. 93-CE-03-AD.'' The postcard will be date stamped and

returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request

to the FAA, Central Region, Office of the Assistant Chief Counsel,

Attention: Rules Docket No. 93-CE-03-AD, Room 1558, 601 E. 12th Street,

Kansas City, Missouri 64106.

Discussion

AD 93-19-06, Amendment 39-8705 (58 FR 51771, October 5, 1993),

currently requires repetitively inspecting acrylic cabin and cockpit

windows for cracks on certain Fairchild Aircraft SA26, SA226, and SA227

series airplanes, and, if cracks are found that exceed certain limits,

replacing that window. The actions are accomplished in accordance with

the following service bulletins (SB), as applicable:

Fairchild SB 226-56-001, Issued: February 2, 1983; Revised: November

26, 1991.

Fairchild SB 227-56-001, Issued: February 2, 1983; Revised: November

26, 1991.

Fairchild SB 226-56-002, Issued: March 3, 1983; Revised: May 29,

1992.

Fairchild SB 227-56-002, Issued: January 5, 1984; Revised: May 29,

1992, and April 1, 1993.

Fairchild SB 226-56-003, Issued: September 13, 1984; Revised:

November 2, 1989.

Fairchild SB 227-56-003, Issued: September 13, 1984; Revised:

November 2, 1989.

Fairchild SB 26-56-10-038, Issued: October 8, 1984; Revised:

February 7, 1991.

Fairchild SB 26-56-20-042, Issued: November 28, 1988; Revised:

February 7, 1991.

Since issuance of that AD and after examining the circumstances and

reviewing all available information related to the action referenced

above, the FAA has determined that (1) the crack limits specified in AD

93-19-06 should coincide with the applicable service information to

more fully establish either replacement or repetitive inspection

interval requirements; and (2) AD action should be taken to continue to

prevent acrylic cockpit or cabin window failures, which could result in

airframe damage and decompression injuries.

Since an unsafe condition has been identified that is likely to

exist or develop in other Fairchild Aircraft SA26, SA226, and SA227

series airplanes of the same type design, the proposed AD would revise

AD 93-19-06 to more fully define the crack limits and establish clearer

repetitive inspection intervals under those crack limits for the

affected airplanes. The proposed action would continue to be

accomplished in accordance with the previously referenced service

information.

The compliance time for the proposed AD is presented in both hours

time-in-service (TIS) and calendar time. The referenced acrylic cabin

and cockpit windows are affected by those conditions present while the

airplane is in flight and while the airplane is on the ground. In

addition, the utilization rates of the affected airplanes vary among

operators. For example, operators in unscheduled service utilize their

airplanes an average of approximately 300 to 400 hours TIS annually,

while those in commuter service (scheduled) utilize their airplanes an

average of approximately 2,000 hours TIS annually. Based on this wide

utilization rate variance and the fact that these windows are affected

when the airplane is in flight and on the ground, the FAA has

determined that the affected acrylic cabin and cockpit windows should

be repetitively inspected every 1,000 hours TIS, or every 12 calendar

months, whichever occurs first.

The FAA estimates that 633 airplanes in the U.S. registry would be

affected by the proposed AD, that it would take approximately 3

workhours per airplane to accomplish the proposed action, and that the

average labor rate is approximately $55 an hour. Based on these

figures, the total cost impact of the proposed AD on U.S. operators is

estimated to be $104,445. AD 93-19-06 currently requires the same

inspections as the proposed AD for all of the affected airplanes.

Therefore, the cost impact of the proposed AD on U.S. operators of all

affected airplanes is the same as AD 93-19-06.

The regulations proposed herein would not have substantial direct

effects on the States, on the relationship between the national

government and the States, or on the distribution of power and

responsibilities among the various levels of government. Therefore, in

accordance with Executive Order 12612, it is determined that this

proposal would not have sufficient federalism implications to warrant

the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (1) is

not a ``significant regulatory action'' under Executive Order 12866;

(2) is not a ``significant rule'' under DOT Regulatory Policies and

Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated,

will not have a significant economic impact, positive or negative, on a

substantial number of small entities under the criteria of the

Regulatory Flexibility Act. A copy of the draft regulatory evaluation

prepared for this action has been placed in the Rules Docket. A copy of

it may be obtained by contacting the Rules Docket at the location

provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the

Administrator, the Federal Aviation Administration proposes to amend 14

CFR part 39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by removing AD 93-19-06, Amendment 39-

8705 (58 FR 51771, October 5, 1993), and by adding the following new

airworthiness directive to read as follows:

Fairchild Aircraft: Docket No. 93-CE-03-AD. Revises AD 93-19-06,

Amendment 39-8705.

Applicability: Models SA26-T, SA26-AT, SA226-T, SA226-T(B),

SA226-AT, SA226-TC, SA227-AT, SA227-AC, and SA227-TT airplanes (all

serial numbers for all models), certificated in any category.

Note 1: The applicability of this AD takes precedence over that

specified in the service information.

Compliance: Required initially within the next 50 hours time-in-

service (TIS) after the effective date of this AD, unless already

accomplished within the last 1,000 hours TIS or 12 calendar months

(compliance with AD 89-06-02 or AD 93-19-06), and thereafter as

indicated in the body of this AD.

To prevent acrylic cockpit or cabin window failures, which could

result in airframe damage and decompression injuries, accomplish the

following:

Note 2: The paragraph structure of this AD is as follows:

Level 1: (a), (b), (c), etc.

Level 2: (1), (2), (3), etc.

Level 3: (i), (ii), (iii), etc.

Level 2 and Level 3 structures are designations of the Level 1

paragraph they immediately follow.

(a) Visually inspect all acrylic cabin side windows and all

acrylic cockpit windows for cracks in accordance with the following

service bulletins (SB), as applicable:

(1) For acrylic cabin side windows:

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Model Service bulletin

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SA26-T.......... 26-56-20-042, Issued: November 28, 1988, Revised:

November 26, 1991.

SA26-AT......... 26-56-20-042, Issued: November 28, 1988, Revised:

November 26, 1991.

SA226-T......... 226-56-001, Issued: February 2, 1983, Revised:

February 7, 1991.

SA226-T(B)...... 226-56-001, Issued: February 2, 1983, Revised:

February 7, 1991.

SA226-AT........ 226-56-002, Issued: March 3, 1983, Revised: May 29,

1992.

SA226-TC........ 226-56-002, Issued: March 3, 1983, Revised: May 29,

1992.

SA227-AT........ 227-56-002, Issued: January 5, 1984, Revised: May 29,

1992, and April 1, 1993.

SA227-AC........ 227-56-002, Issued January 5, 1984, Revised: May 29,

1992, and April 1, 1993.

SA227-TT........ 227-56-001, Issued February 2, 1983, Revised: November

26, 1991.

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(2) For acrylic cockpit windows:

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Model Service Bulletin

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SA26-T.......... 26-56-10-038, Issued: October 8, 1984, Revised:

February 7, 1991.

SA26-AT......... 26-56-10-038, Issued: October 8, 1984, Revised:

February 7, 1991.

SA226-T......... 226-56-003, Issued: September 13, 1984, Revised:

November 2, 1989.

SA226-T(B)...... 226-56-003, Issued: September 13, 1984, Revised:

November 2, 1989.

SA226-AT........ 226-56-003, Issued: September 13, 1984, Revised:

November 2, 1989.

SA226-TC........ 226-56-003, Issued: September 13, 1984, Revised:

November 2, 1989.

SA227-AT........ 227-56-003, Issued: September 13, 1984, Revised:

November 2, 1989.

SA227-AC........ 227-56-003, Issued: September 13, 1984, Revised:

November 2, 1989.

SA227-TT........ 227-56-003, Issued: September 13, 1984, Revised:

November 2, 1989.

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(b) If cracks are found that meet or exceed 4.3 inches in

combined length, prior to further flight, replace the window with a

new or serviceable window, and reinspect thereafter at intervals not

to exceed 1,000 hours TIS or 12 calendar months, whichever occurs

first.

(c) If cracks are found that are less than 4.3 inches in

combined length but that meet or exceed .30 inch as specified in the

Crack Limits section of the service information referenced in

paragraphs (a)(1) and (a)(2) of this AD, prior to further flight,

accomplish one of the following:

(1) Replace the window with a new or serviceable window and

reinspect thereafter at intervals not to exceed 1,000 hours TIS or

12 calendar months, whichever occurs first; or

(2) Fabricate a placard with the following words in letters at

least 0.10-inch in height and install this placard within the

pilot's clear view close to the pressurization controls: ``AIRPLANE

MUST BE OPERATED UNPRESSURIZED'', and accomplish both of the

following:

(i) Insert a copy of this AD into the Limitations Section of the

FAA-approved Airplane Flight Manual (AFM); and

(ii) Within the next 25 hours TIS or 30 calendar days, whichever

occurs first, reinspect the cracked window for crack progression in

accordance with the inspections specified in paragraph (a) of this

AD, as applicable, and accomplish either paragraph (b), (c) or (d)

of this AD, as applicable.

(d) If cracks are found that are less than .30 inches as

specified in the Crack Limits section of the applicable service

information referenced in paragraphs (a)(1) and (a)(2) of this AD,

within the next 25 hours TIS or 30 calendar days, whichever occurs

first, reinspect the cracked window for crack progression in

accordance with the applicable service information specified in

paragraphs (a)(1) and (a)(2) of this AD, and accomplish either

paragraph (b), (c), or (d) of this AD, as applicable.

Note 3: The repetitive inspections required by this AD are also

referenced in the FAA-approved Fairchild Airframe Airworthiness

Limitations Manual, ST-UN-M001.

(e) Special flight permits may be issued in accordance with 14

CFR 21.197 and 21.199 to operate the airplane to a location where

the requirements of this AD can be accomplished.

(f) An alternative method of compliance or adjustment of the

initial or repetitive compliance times that provides an equivalent

level of safety may be approved by the Manager, Airplane

Certification Office, FAA, 2601 Meacham Boulevard, Fort Worth, Texas

76137. The request shall be forwarded through an appropriate FAA

Maintenance Inspector, who may add comments and then send it to the

Manager, Fort Worth Airplane Certification Office.

Note 4: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the Fort Worth Airplane Certification Office.

(g) This amendment revises AD 93-19-06, Amendment 39-8705.

Issued in Kansas City, Missouri, on March 24, 1994.

Bobby W. Sexton,

Acting Manager, Small Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-7496 Filed 3-29-94; 8:45 am]

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