121 North Henry Street

Alexandria, VA 22314-2903

T: 703 739 9543 F: 703 739 9488

arsa@arsa.org www.arsa.org

December 13, 2010

BY E-MAIL TO: rebecca.macpherson@faa.gov

Original by Certified Mail;

Return Receipt Requested

Receipt No: 7009 1410 0001 8878 6727

Rebecca B. MacPherson,

Assistant Chief Counsel for Regulations (AGC-200)

Office of the Chief Counsel

Federal Aviation Administration

800 Independence Avenue, S.W.

Washington, DC 20591-0001

RE: Legal Interpretation of 14 CFR § 121.377 – Maintenance and preventive 

maintenance personnel duty time limitations, dated May 18, 2010

Dear Ms. MacPherson:

The Aeronautical Repair Station Association (ARSA) is extremely disturbed by the Federal 

Aviation Administration (FAA) legal interpretation dated May 18, 2010 to Alexandra M. McHugh 

regarding the provisions of 14 CFR § 121.377. In particular, we contest the FAA’s assertion 

that:

Today, we would not view as compliant a schedule that provides over the course 

of eight weeks for four days off followed by 48 straight days of duty followed by 

four more days off. Such a work schedule that generally provides for an average 

of one day off over several weeks cannot be said to be “equivalent” to the more 

specific standard requiring one day off out of every seven days. (Emphasis 

added)

At best, that “interpretation” overlooks the plain language of the rule; otherwise, it

impermissibly represents a clear deviation from longstanding FAA construction and application 

of its regulation.

As a result, ARSA respectfully asks the FAA to retract its May 18, 2010 interpretation.

The basis for our request

First, ARSA looks to the regulation itself, which provides that:

Within the United States, each certificate holder (or person performing 

maintenance or preventive maintenance functions for it) shall relieve each person 

performing maintenance or preventive maintenance from duty for a period of at 
Ms. Rebecca MacPherson

December 13, 2010

Page 2

RE: Legal Interpretation of 14 CFR § 121.377 – Maintenance and preventive 

maintenance personnel duty time limitations, dated May 18, 2010

least 24 consecutive hours during any seven consecutive days, or the equivalent 

thereof within any one calendar month. (Emphasis added)

Despite the clarity of the underlined phrase, the FAA’s interpretation relies upon the specious 

contention that “[t]he tenants [sic] of statutory and regulatory interpretation suggest that the 

specific standard of one day off every week cannot be rendered completely inoperative by the 

more general equivalent standard”. That argument flies in the face of the most basic tenet of 

statutory construction: that language is not superfluous and one must give effect to every 

clause and word.

1

 This is not an instance of one specific rule being controlled or nullified by a 

general one; rather, it involves clear language within the same rule.

Previous FAA interpretations

In an attempt to avoid completely reading the phrase “or the equivalent thereof” right out of the 

rule, the May 18 interpretation claims that “[t]he FAA intended that the regulation allow 

employees to work in excess of six consecutive days in the event of a national emergency or 

unusual occurrence in the air carrier industry”. Although a previous FAA interpretation is cited 

as the source of that position,2

The clause “or equivalent thereof within any one calendar month” provides 

flexibility in the rule. It is intended to provide coverage for situations involving 

national emergencies as well as those unusual conditions that arise within the air 

carrier industry. Basically, it permits maintenance personnel to work 

continuously in any one calendar month, provided they are given time off and 

away from work in that month equal to the actual hours they would have been 

relieved from duty, had they worked six days with the seventh day off throughout 

the specific calendar month under consideration. This relief from duty must be 

given in increments of not less than 24 consecutive hours. (Emphasis added)

it is taken out of context; the full statement provided that:

The FAA’s earlier position does not limit application of equivalent days off to a particular 

circumstance and is therefore at odds with its latest interpretation.

In addition, the May 18, 2010 letter acknowledged “[a] previous interpretation allowed that a 

work schedule that provides for personnel to have a group of 4 days off followed by up to 24 

days of work, or vice versa, would still meet the standard of being ‘equivalent’ to one day off in 

every seven within a month”.3

 1 See, e.g., Duncan v. Walker, 533 US 167 (2001).

 In arguing against the continued validity of that plain assertion, 

the FAA stated that the earlier interpretation “was issued prior to the findings relating fatigue to 

2 Legal Interpretation 1987-15 (June 14, 1987). 3 Legal Interpretation 1991-40 (June 21, 1991).
Ms. Rebecca MacPherson

December 13, 2010

Page 3

RE: Legal Interpretation of 14 CFR § 121.377 – Maintenance and preventive 

maintenance personnel duty time limitations, dated May 18, 2010

maintenance related errors in the air carrier industry discussed in AC 120-72”.4 We fail to 

grasp the significance of updated guidance material in relation to an existing rule and 

interpretations of that rule. If the content of AC 120-72 revolutionized maintenance duty time 

limitations in the eyes of the FAA, then a change to 14 CFR § 121.377 was required to effect 

that view.

We are also skeptical of the agency’s new fatigue study rationale when there is no regulation 

prohibiting maintenance workers from being on duty for several days at a time without any 

minimum daily rest period. Indeed, prohibiting a certificate holder from providing four

consecutive days off at the end of a calendar month does nothing to address this glaring

omission in the existing rule.

The “new” interpretation required notice and comment under the APA

The May 18, 2010 letter is effectively an attempt by the FAA to make a rule change without 

following the notice and comment requirements of the Administrative Procedure Act (APA). 

Existing case law prohibits such actions. As made clear by the U.S. Court of Appeals for the 

D.C. circuit in a case involving the agency:

Once an agency gives its regulation an interpretation, it can only change that 

interpretation as it would formally modify the regulation itself: through the process 

of notice and comment rulemaking...’[r]ule making,’ as defined in the APA, 

includes not only the agency’s process of formulating a rule, but also the 

agency’s process of modifying a rule.

5

In a similar case, that same court stated that:

The phenomenon we see in this case is familiar. Congress passes a broadly 

worded statute. The agency follows with regulations containing broad language, 

open-ended phrases, ambiguous standards and the like. Then as years pass, the 

agency issues circulars or guidance or memoranda, explaining, interpreting, 

defining and often expanding the commands in the regulations. One guidance 

document may yield another and then another and so on. Several words in a 

regulation may spawn hundreds of pages of text as the agency offers more and 

more detail regarding what its regulations demand of regulated entities. Law is 

made, without notice and comment, without public participation, and without 

publication in the Federal Register or the Code of Federal Regulations. With the 

advent of the Internet, the agency does not need these official publications to 

ensure widespread circulation; it can inform those affected simply by posting its 

 4 Advisory Circular (AC) 120-72 titled “Maintenance Resource Management Training”, is dated September 28, 

2000.

5 Alaska Professional Hunters v. FAA, 177 F.3d 1030 (1999) at 1033 citing Paralyzed Veterans v. D.C. Arena, 

117 F.3d 579, 586 (D.C.Cir. 1997).
Ms. Rebecca MacPherson

December 13, 2010

Page 4

RE: Legal Interpretation of 14 CFR § 121.377 – Maintenance and preventive 

maintenance personnel duty time limitations, dated May 18, 2010

new guidance or memoranda or policy statement on its web site. An agency 

operating in this way gains a large advantage. ‘It can issue or amend its real 

rules, i.e., its interpretative rules and policy statements, quickly and inexpensively 

without following any statutorily prescribed procedures.’6

In line with the court’s directives, we feel strongly that the May 18, 2010 interpretation is 

contrary to the APA because it changes the plain language of the existing rule and 

longstanding agency interpretations without providing the public with notice and an opportunity 

to comment. We are aware of at least one major U.S. air carrier that has been informed by the 

FAA that, based upon the new interpretation, it must immediately change its maintenance 

staffing policies that have been in effect for many years. Without notice of the new 

requirement, such immediate changes wreak havoc on schedules, operations and result in 

dramatically increased costs. The APA provides industry the ability to plan for, and participate 

in, regulatory changes of this magnitude to alleviate those ill effects. In accord with existing 

case law, if the FAA desires to change a rule it must follow APA requirements.

Conclusion

The FAA’s May 18, 2010 interpretation should be withdrawn immediately.

We look forward to your favorable response, and we appreciate your assistance in handling

this matter.

Respectfully submitted,

Craig L. Fabian

Vice President Regulatory Affairs and

 Assistant General Counsel

cc: Anne Bechdolt anne.bechdolt@faa.gov

Carol E. Giles carol.e.giles@faa.gov

Neil Eisner neil.eisner@ost.dot.gov

 6 Appalachian Power v. EPA, 208 F.3d 1015 (2000) at 1020 citing 47 ADMIN. L. REV. 59 (1995).