AC 120-35C

Historical

Advisory circular · Line Operational Simulations: Line Oriented Flight Training, Special Purpose Operational Training, Line Operational Evaluation

A newer version is currentThis is a historical version. AC 120-35D Ed Update is the version in force, approved May 1, 2020.
Approved
September 27, 2004
Last reviewed
August 7, 2024
Cancels
AC120-35B
Cancelled by
AC120-35D
Family
AC 120-35 · 4 versions
Revision
C
14 CFR parts
121, 135, 142

Guidance, not mandatory unless a rule or AD requires it. DRS record last changed November 22, 2025.

AC 120-35C Date: 9/27/04 Initiated By: AFS-230

ADVISORY CIRCULAR

Line Operational Simulations: Line Oriented Flight Training, Special Purpose Operational Training, Line Operational Evaluation

U.S. DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Flight Standards Service

Subject: LINE OPERATIONAL SIMULATIONS: LINE ORIENTED

FLIGHT TRAINING, SPECIAL

PURPOSE OPERATIONAL

TRAINING, LINE OPERATIONAL

EVALUATION Date: 9/27/04 Initiated By: AFS-230 AC No: 120-35C Change:

1. PURPOSE. This advisory circular (AC) presents guidelines for the design and implementation of line operational simulations (LOS), including line-oriented flight training (LOFT), special purpose operational training (SPOT), and line operational evaluation (LOE).

This document does not interpret the regulations; interpretations are issued only under established agency guidelines. As operators develop LOS, they should develop an interdependent relationship between their Human Factors, crew resource management (CRM), flight operations, and safety initiatives since they are linked to a common safety goal.

2. CANCELLATION. AC 120-35B, Line Operational Simulations: Line Oriented Flight Training, Special Purpose Operational Training, Line Operational Evaluation, dated September 6, 1990, is canceled.

3. RELATED REGULATIONS.

a. Title 14 of the Code of Federal Regulations (14 CFR) part 121, Operating Requirements:

Domestic, Flag, and Supplemental Operations; Subpart N - Training Program; Appendix F - Proficiency Check Requirements; Appendix H - Advanced Simulation Plan.

b. Title 14 CFR part 135, Operating Requirements: Commuter and On Demand Operations and Rules Governing Persons on Board Such Aircraft; Subpart H - Training.

c. Title 14 CFR part 142, Training Centers.

d. Special Federal Aviation Regulation 58 (SFAR 58), Advanced Qualification Program.

4. DEFINITIONS. The following terms are used throughout this AC and are defined as follows:

a. Advanced Qualification Program (AQP). AQP provides an alternate method of qualifying and certifying, if required, pilots, flight engineers, flight attendants, aircraft dispatchers, instructors, evaluators, and other operations personnel subject to the training and evaluation requirements of parts 121 and 135. AQP is a systematic methodology for developing the content of training programs. AQP incorporates data-driven quality control processes for validating and maintaining the effectiveness of curriculum content. AQP encourages innovation in the methods and technology that are used during instruction and evaluation, and efficient management of training systems.

b. Aviation Safety Action Program (ASAP). ASAP provides a vehicle whereby employees of participating air carriers and repair station certificate holders can identify and report safety issues for resolution, without fear that the Federal Aviation Administration (FAA) will use reports accepted under the program to take legal enforcement action against them, or that companies will use such information to take disciplinary action. These programs are designed to encourage participation from various employee groups, such as flight crewmembers, mechanics, flight attendants, and dispatchers.

c. Aviation Safety Reporting System (ASRS). National Aeronautics and Space Administration (NASA)-administered program that provides for the receipt, analysis, and deidentification of aviation safety reports; in addition, periodic reports of findings obtained through the reporting program are published and distributed to the public, the aviation community, and FAA.

d. Evaluator. A person who has satisfactorily completed training and evaluation that qualifies that person to evaluate the performance of crewmembers, instructors, other evaluators, aircraft dispatchers, and other operations personnel in an approved AQP.

e. Event. An integral part of training or evaluation that is task-oriented and requires the use of specific procedures.

f. Event Set. A relatively independent segment of a scenario made up of several events, including an event trigger, possible distracters, and supporting events.

g. Flight Operational Quality Assurance (FOQA). A program to improve flight safety by providing more information about, and greater insight into, the total flight operations environment through routine recording and analysis of digital flight data generated during flight operations. Analysis of FOQA data can reveal situations that require improved operating, training, and maintenance procedures, practices, equipment, and infrastructure.

h. Line Operational Evaluation (LOE). LOE is an evaluation of individual and crew performance in a flight simulation device conducted during real-time (LOS). LOE is primarily designed in accordance with an approved design methodology for crewmember evaluation under an AQP.

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i. Line Oriented Flight Training (LOFT). LOFT is conducted as a line operation and allows for no interruption by the instructor during the session except for a non-disruptive acceleration of uneventful enroute segments. There are two types of LOFT:

(1) Qualification LOFT. Qualification LOFT is a simulator training session to facilitate the transition from flight simulation to operational flying by integrating technical knowledge, flying skills, procedural knowledge and CRM into the operational environment. The session allows the crew to practice those technical skills presented in previous training in a real-world “line” environment. The primary objective of qualification LOFT is to meet the requirements of initial qualification within part 121, appendix H, and will be conducted in a simulator approved under part 121, appendix H.

(2) Recurrent LOFT. Recurrent LOFT is a simulator training session conducted during any phase of recurrent training and allows the crew to practice both technical and CRM skills in an uninterrupted real world “line” environment. The design of recurrent LOFT scenarios centers on CRM objectives as defined in AC 120-51, Crew Resource Management Training, current edition. Recurrent LOFT may be used to meet recurrent flight training requirements and it also meets the requirements of part 121, section 121.409, as allowed by section 121.441.

j. Line Operational Simulation (LOS). LOS is a training or evaluation session conducted in a “line environment” setting. LOS includes LOFT, Special Purpose Operational Training (SPOT), and LOE. Instruction and training is based on learning objectives, behavioral observation, and assessment of performance progress and instructor or check airman debriefing or critique (feedback). The training objectives under AQP are proficiency objectives that include both technical and CRM issues identified by a task analysis. In an LOE, aircrew technical and CRM performance are formally evaluated.

k. LOS Facilitator. For LOFT or SPOT, an instructor who administers the training session.

For an AQP LOE, a check airman who administers the evaluation session.

l. Proficiency Objective. An objective containing the criteria for a required level of performance.

m. Seat Dependent-Task Familiar. Describes a flight crewmember who is familiar with and can satisfactorily accomplish the duties of a particular cockpit duty position, though not qualified for that duty position. For example, a second-in-command (SIC) candidate who performs the duties of the pilot in command (PIC) during simulator training.

n. Special Purpose Operational Training (SPOT). SPOT is a simulator training session designed to address specific training objectives. Training objectives are based on technical and CRM requirements, and include specific training objectives to be critiqued and debriefed on both technical and CRM performance. SPOT may consist of full or partial flight segments depending on the training objectives for the flight.

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o. Task Familiar. Describes a flight crewmember who is familiar with and can satisfactorily accomplish the duties of a particular crew duty position, though not qualified for that duty position. For example, an SIC candidate who performs the duties of the PIC during simulator training.

5. RELATED READING MATERIAL.

a. AC 120-40, Airplane Simulator Qualification, current edition.

b. AC 120-45, Airplane Flight Training Device Qualification, current edition.

c. AC 120-51, Crew Resource Management Training, current edition.

d. AC 120-54, Advanced Qualification Program, current edition.

NOTE: These ACs may be dow nloaded free of charge from the follow ing FAA public Web site: www.faa.gov/avr/afs. Scroll dow n to Regulations and Guidance or Information Advisories.

6. BACKGROUND.

a. The use of gate-to-gate flight simulator scenarios, known as LOFT, began in the mid-1970s as a means to provide pilot training that is more representative of actual flight operations than is maneuver-based training alone. LOFT was soon recognized as a highly effective means of developing and practicing CRM skills. Due to the role of CRM issues in accident causation, it has become evident that training curriculums must develop pilot proficiency in both technical and CRM skills. While LOFT is designed to include all phases of flight, scenario-based training may also include limited portions of flight designed to focus on specific operational training needs, known as SPOT. Air carriers with an approved AQP must also conduct evaluated LOFTs, known as LOE, for jeopardy grading purposes. These three methodologies, LOFT, SPOT, and LOE, are now grouped under the general heading of LOS.

b. The introductory CRM training that many flight crewmembers have experienced is similar to the foundation of a building: It is an essential structural part, but by itself the foundation has limited operational use. If CRM training is to be operationally effective, it must be built into other training steps and activities in a systematic way. A structured LOS design process is employed to specify and integrate the required CRM and technical skills into line operational LOS scenarios.

c. LOS is an environment that is structured to allow and encourage the application of technical and CRM concepts to a situation that enables conceptual knowledge to become working knowledge. Instead of being programmed with a solution, the crew can manage the operational environment and process available information to learn its limits, properties, and operational relevance. LOS can be conducted in a simulator or flight training device (FTD), Page iv Par 4

depending on whether the LOS is for training or evaluation, and the requisite fidelity of the training/evaluation media.

d. Much of the information in this AC stems from a working paper developed by the Airline Transport Association Training Committee, AQP Subcommittee, LOFT Design Focus Group.

This AC provides a structured design process for LOS design and implementation and builds upon air carrier experience with developing and implementing scenarios to provide guidelines for LOS programs.

7. REQUIREMENTS AND CONCEPTS

a. LOFT is a useful training method because it gives crewmembers the opportunity to practice line operations (e.g., maneuvers, operating skills, systems operations, and the operator’s procedures) with a full crew in a realistic environment. Crewmembers learn to handle a variety of real-time scenarios that include routine, abnormal, and emergency situations. They also learn and practice CRM skills, including crew coordination, judgment, decisionmaking, and communication skills. The overall objective of LOFT is to improve total flightcrew performance, thereby preventing incidents and accidents during operational flying. Since the early 1980s, new issues that are related to the requirements of section 121.409, part 121, appendix H, and expanding opportunities for the use of LOFT or other LOS have emerged.

Requirements include:

(1) Section 121.409. Section 121.409(b) delineates the requirements of recurrent LOFT, which may be substituted on an alternate basis for the proficiency training requirement as specified in section 121.441. Section 121.409(b) requires a complete crew to be used in recurrent LOFT, but does not provide detail on what constitutes a complete crew. The guidance provided in this AC recognizes a complete crew as one that is line qualified or line familiar (see definitions in paragraph 4).

(2) Part 121, appendix H. Appendix H contains rules for operators who choose to provide flight crewmember training under an Advanced Simulation Plan. While appendix H provides a detailed description for implementing training, the specific LOFT components are not clearly described. This AC presents guidelines for implementing qualification LOFT as required under appendix H or as may be used within any other approved training program. This AC discusses how qualification LOFT is designed to help flight crewmembers transition from a training environment to operational flying.

(3) SFAR 58 AQP. AQP encourages the use of LOS in its qualification and continuing qualification (recurrent) curriculums.

b. SPOT. New training concepts and training media have provided the opportunity to creatively tailor training sessions to address specific training objectives. Training objectives are based on technical and CRM requirements. SPOT may consist of full or partial flight segments depending on the training objectives for the flight. This AC presents guidelines in conducting SPOT.

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c. LOE. The LOE is the primary means of proficiency evaluation under an AQP. This evaluation addresses the individual’s ability to demonstrate technical and CRM skills appropriate to fulfilling job requirements in a full mission scenario environment. The intent of an LOE is to evaluate and verify that an individual’s job knowledge, technical skills, and CRM skills are commensurate with AQP qualification standards. The LOE is conducted in a simulation device approved for its intended use in the AQP.

8. SUMMARY. This AC identifies four types of LOS: (1) Recurrent LOFT (in reference to sections 121.409, 121.427, 121.433, and 121.441, SFAR 58 and part 121, appendix F); (2) Qualification LOFT (in reference to part 121, appendix H); (3) SPOT, which is line oriented training that addresses specific training objectives; and (4) LOE, which is a line-oriented evaluation designed for persons participating in an AQP. It defines the terms used in describing LOS. It provides guidance for conducting LOFT, SPOT and LOE. It defines the role of instructors and evaluators and provides guidance for designing LOS scenarios.

9. COMMENTS INVITED. Suggestions or comments on this AC should be addressed to the Federal Aviation Administration, Air Transportation Division, AFS-200, 800 Independence Avenue, SW., Washington, DC 20591.

James J. Ballough Director, Flight Standards Service Page vi Par 7

CONTENTS

Page CHAPTER 1. BASIC ELEMENTS OF LOS

100. General1

101. LOS Philosophy1

102. Crew Composition and Participation1

103. Real-World Situations1

104. No-Jeopardy Training2

105. Phases of LOS2

106. Training Hours, LOE, Recurrent LOFT and Qualification LOFT3

107. LOS Scenarios3

108. Approval of Scenarios4

109. Pre-LOS Briefing4

110. CRM Component of the Pre-LOS Briefing6

111. LOS CRM Briefing and Crew Orientation7

112. Preflight Activities8

113. Crewmember Responsibilities9

114. Debriefing the LOS9

115. LOE11

116. Use of Audiovisual Equipment and Animation Software12

117. Additional Training/LOFT Completion12

118. Basic Elements of LOS Summarized12

119. FAA Philosophy12

CHAPTER 2. TYPES OF LINE OPERATIONAL FLIGHT TRAINING

200. General15

201. Recurrent LOFT15

202. Guidelines For Recurrent LOFT15

Table 2-1. Recurrent LOFT Substitution Table16

203. Qualification LOFT16

Table 2-2. Qualification LOFT Substitution Table17

CHAPTER 3. SPECIAL PURPOSE OPERATIONAL TRAINING

300. General19

301. Guidelines for SPOT19

CHAPTER 4. LINE OPERATIONAL EVALUATION

400. General21

401. Elements Resembling Line Operational Flight Training (LOFT)21

402. Evaluation21

403. Evaluator21

404. LOE Media21

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Page CHAPTER 5. THE ROLE OF INSTRUCTORS

500. Minimum Qualifications23

501. Instructor Responsibilities23

CHAPTER 6. LINE OPERATIONAL SIMULATION SCENARIO DESIGN

600. Line Operational Simulation (LOS) Scenario Design Methodologies25

601. Philosophy of LOS Design and Conduct25

602. Scenario Design Process26

Table 6-1. LOS Design Methodology28

603. Identification of Primary CRM Training Objectives30

604. Identification of Primary Technical Objectives30

605. Developing LOS Scenarios With Automation Themes30

606. Identification of Possible Incidents That Will Produce the Training Objectives31

607. Event Set Solution Versus Management and Event Trigger Selection32

Table 6-2. Selected Scenario Event Set Index With Phase of Flight and Proficiency

Objectives35

608. The Event Set Matrix35

609. Integration And Validation of CRM Skills to Event Sets36

Table 6-3. Selected Scenario Event Set Index With Phase of Flight and CRM

Behaviors38

Table 6-4. The Event Set Matrix39

Table 6-5. The Event Set Assessment/Grade Sheet40

610. Scripting and Validating the LOS Scenario41

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CHAPTER 1. BASIC ELEMENTS OF LINE OPERATIONAL SIMULATION

100. GENERAL. Certain elements about line operational simulation (LOS) must be understood to ensure that its primary objective, to provide realistic line-oriented flight training (LOFT) and evaluation, are met. These elements apply to both recurrent and qualification LOFT, and are described in this chapter.

NOTE: Some or all of these elements may also apply to special purpose operational training (SPOT) and line operational evaluation (LOE). See chapters 5 and 6 of this AC for more information on how these concepts apply to these types of LOSs.

101. LOS PHILOSOPHY.

a. The overall objective of LOS is to improve total flightcrew performance by combining crew resource management (CRM) and technical skills. CRM skills include techniques that allow and encourage crews to become better problem-solvers and resource managers. The LOS context must be structured to enable CRM behaviors to emerge and the crew to become aware of them; that is, the scenario must last long enough for crew traits to become evident and should require CRM skills to be displayed in response to specific circumstances. Similarly, scenario construction should focus on the CRM and technical objectives integrated into a training program.

b. LOFT and SPOT are training events in which crews can enhance their CRM and technical skills. LOE contains events in which CRM and technical skills are assessed. LOS learning and assessment should not be artificially stress-free; crewmembers should maintain performance parameters applicable to their phase of training. This will require crews to handle failures and their consequences. If the LOS instructor identifies crewmember performance deficiencies, additional training or instruction should be provided.

102. CREW COMPOSITION AND PARTICIPATION. LOS should take place in a line operational environment with a complete crew. A complete crew concept allows crewmembers to use their full resources and creativity to create a complete learning experience. A complete crew consists of crewmembers for each seat position who are line-qualified or in qualification training for their respective seat positions. During LOS, each crewmember performs both as an individual and as a member of a team, as is expected during line operations. Line crewmembers must be scheduled and paired together, as much as practical, in a standard crew configuration

(e.g., line captain with line first officer). Circumstances will occur where the initial composition of the schedule cannot be maintained. Hiring requirements, high first officer to captain ratios, illness or failure of a crewmember to progress, are all situations that would necessitate providing a seat substitute to complete the training. In all cases, the seat substitute must be task-familiar with the duty position.

103. REAL-WORLD SITUATIONS. LOS should contain scenarios of real world, line operational situations, which progress in real time. These scenarios should be representative of flight segments where an entire en route operation is completed. In cases of flights with flight Par 100 Page 1

segments involving repetitive events, the en route segments may be compressed. However, if the scenario is compressed, enough time should be allotted for crewmembers to resume or restart the scenario without confusion. In addition, the scenario compression method must be designed and executed to minimize degradation of scenario realism and enhance training or checking.

104. NO-JEOPARDY TRAINING. LOFT and SPOT are “no-jeopardy” training (i.e., there is no certificate action based on LOFT/SPOT performance). If the LOFT instructor identifies crewmember performance deficiencies, additional training or instruction will be provided. This training or instruction should be in a form most appropriate to correct the specific performance deficiency, including additional LOFT. Before the crewmember may return to line operations, the performance deficiencies will be corrected, and the instructor will document the training as satisfactorily completed. The “no-jeopardy” concept allows crewmembers to use their full resources and creativity. At the end of a LOFT session and after debriefing, the instructor certifies that the training has been completed.

105. PHASES OF LOS. LOS scenarios should contain the following phases

a. Briefing. Before the flight segment begins, the instructor should brief crewmembers on the LOS scenario, including the training objectives, and the role of the instructor (i.e., the instructor is considered “not present,” except as an air traffic controller (ATC) or as another ground base entity). The role of the flightcrew should be discussed in the briefing (i.e., flight crewmembers should perform their duties just as they would in line operations). Information about “the environmental setting of the scenario” should also be discussed.

b. Preflight Planning Documents and Activities. Preflight planning documents (e.g., weather reports and flight plans) should be prepared with the operator’s particular training objectives in mind. For example, the operator may choose to have crewmembers learn how to handle unfavorable weather conditions or how to correct improper fuel loads. Preflight activities include cockpit setup, computation of takeoff data, etc.

c. Flight Segment. The flight segment includes taxi, takeoff, climb, cruise, descent, and landing, as appropriate. It should also include the time in which communication with ATC and other ground agencies takes place.

d. Debriefing. Debriefing should include feedback to crewmembers on their performance.

Positive comments regarding crew performance should be emphasized in the debriefing as well as crew performance that needs improvement. The debriefing involves instructor critiques of individual crewmembers and of the crew as a team. Also, it is important that crewmembers be given the opportunity to critique and analyze their own performance and review key points of the video record, if used (see paragraphs 314 and 316 for further discussion of critiques, debriefing, and use of video records).

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