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Advisory Circular 23.1523, Minimum Flightcrew

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Federal Aviation Administration (FAA), DOT.


Notice of availability of proposed advisory circular (AC) and request for comments.


This notice announces the availability of and requests comments on a proposed advisory circular, AC 23.1523. This guidance sets forth one method that may be used to show compliance with the requirements contained in 14 CFR, part 23 and § 23.1523, which prescribes certification requirements for minimum flight crew. Most part 23 airplanes are certified for single pilot operations, therefore, the major focus of this guidance is to address cockpit workload considerations that are described in this rule. We are proposing that this guidance be used to improve cockpit safety by addressing pilot workload which has been impacted through the development on newer and novel technologies available in general aviation cockpits along with increased complexity of operations. This AC is one method that can be utilized to determine workload factors and issues for normal, utility, aerobatic and commuter category airplanes. Material in this AC is neither mandatory nor regulatory in nature and does not constitute a regulation. This material is intended to be a ready reference for part 23 airplane manufacturers, modifiers, Federal Aviation Administration (FAA) design evaluation engineers, flight test engineers, engineering flight test pilots [Aircraft Certification Office (ACO), Flight Standards, and Manufacturers] as well as human factors engineering evaluators. This material may also be used by FAA authorized designees in the performance of workload evaluations.


Comments must be received on or before August 31, 2004.


Copies of the proposed Minimum Flight Crew, AC 23.1523, may be requested from the following: Small Airplane Directorate, Standards Office (ACE-110), Aircraft Certification Service, Federal Aviation Administration, 901 Locust Street, Room 301, Kansas City, MO 64106. Proposed advisory circulars are posted on the RGL at​AC.

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Mr. Frank Bick, Standards Office, Small Airplane Directorate, Aircraft Certification Service, Kansas City, Missouri 64106, telephone (816) 329-4119, fax (816) 329-4090,

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Any person may obtain a copy of this proposed AC by contacting the person named above under FOR FURTHER INFORMATION CONTACT. A copy of the AC will also be available on the Internet at​AC within a few days.

Comments Invited: We invite interested parties to submit comments on the proposed AC. Commenters must identify AC 23.1523 and submit comments to the address specified above. The FAA will consider all communications received on or before the closing date for comments before Start Printed Page 40452issuing the final AC. The proposed AC and comments received may be inspected at the Standards Office (ACE-110), 901 Locust, Room 301, Kansas City, Missouri, between the hours of 8:30 and 4 p.m. weekdays, except Federal holidays by making an appointment in advance with the person listed under FOR FURTHER INFORMATION CONTACT.

Background: In the early 1980s, a move to reduce the crew size of the new generation of commercial jet transport airplanes from three to two caused the FAA to develop additional criteria and guidance for minimum crew determination for part 25 airplanes. AC 25.1523 was developed to provide manufacturers and certification personnel a means of demonstrating compliance to 14 CFR, part 25, § 25.1523. Most part 23 airplanes are single pilot, none require a crew of three, and only a few require a crew of two; therefore, there was no desire to address crew complement in these airplanes and no parallel effort was initiated at that time for part 23 airplanes. For many years, part 23 airplane cockpits were relatively simple in design and utilized instruments and systems that were also quite similar in operation. This made it relatively easy for pilots to safely transition from one part 23 airplane to another. However, in recent years due to the growth of modern technology and the reduced cost of electronic components, novel and more complex integrated avionic systems are increasingly being installed in part 23 airplanes. These new systems have changed the appearance, operation, and usability of the pilot-vehicle interface. There is also much variation between manufacturers in terms of the design and operational characteristics of these systems. Consequently, there is a concern that pilot(s) familiar and proficient with one system may not be able to sufficiently understand and operate another system. Although many of these systems can greatly improve pilot situational awareness and safety, poorly designed systems can increase pilot workload, and increase the potential for pilot error.

Additionally, the lack of standardization in the design and operation of these systems can negatively affect pilot training and impact performance and safety. Accordingly, there is a need to more closely examine pilot workload and error potential in these highly complex, integrated cockpits.

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Issued in Kansas City, Missouri on June 16, 2004.

William J. Timberlake,

Acting Manager, Small Airplane Directorate, Aircraft Certification Office.

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[FR Doc. 04-15038 Filed 7-1-04; 8:45 am]