AC 120-35B

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 6, 1990
Last reviewed
August 7, 2024
Cancelled by
AC120-35C
Family
AC 120-35 · 4 versions
Revision
B
14 CFR parts
121, 135

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

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AdVISory U.S. Department of Transportation Circular Federal Aviation Administration Subject: Date: 9/6/90 AC No: 120-35B Initiated by: AFS-210 Change:

LINE-ORIENTED FLIGHT TRAINING,

SPECIAL PURPOSE OPERATIONAL TRAINING,

LINE OPERATIONAL EVALUATION PURPOSE. This advisory circular (AC) presents guidelines for the design and implementation of Line Operational Simulations, including Line-Oriented Flight Training (LOFT), Special Purpose Operational Training, and Line Operational Flight Evaluation. This document does not interpret the regulations; interpretations are issued only under established agency procedures.

2. CANCELLATION. Advisory Circular 120-35A, Line-Oriented Flight Training Programs, dated August 11, 1981, is cancelled.

3. RELATED FEDERAL AVIATION REGULATIONS.

Part 121, Certification and Operations: Domestic, Flag, and Supplemental Air Carriers and Commercial Operators of Large Aircraft;

Subpart N - Training Program; Appendix F - Proficiency Check Requirements;

b. Part 135, Air Taxi Operators and Commercial Operators;

Subpart H - Training.

c. Special Federal Aviation Regulation (SFAR) No. 58, Advanced Qualification Program.

4. RELATED READING MATERIAL.

a. AC 120-51, Cockpit Resource Management Training.

b. AC 120-40, Airplane Simulator Qualification, as amended.

c. AC 120-45, Airplane Flight Training Device Qualification, as amended.

5. BACKGROUND.

a. Training which uses flight simulators and flight training devices is an important element for ensuring the qualification of flight crewmembers, both as individuals and as part of a crew. In the mid-1970's, the concept of

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LOFT was introduced as a form of simulator training for a complete crew. LOFT was later allowed to be substituted for alternate proficiency checks under recurrent training programs. In 1980, LOFT was allowed under an Advanced Simulation Plan as a means to provide most or all flight crewmember training in flight simulators.

b. Since the early 1980's, as the technology of flight simulators and flight training devices advanced, the number of training applications has increased. These training applications are now grouped under the general term of Line Operational Simulations. The increase in the number of individual training applications requires clarification and updating of applicable guidelines. These guidelines are presented in this AC and cover the following:

(1) Up-to-date details on implementing LOFT for a complete crew under both recurrent training programs and Advanced Simulation Plans;

(2) Guidelines on implementing other types of Line Operational Simulations (for purposes other than those in (1) above). These include:

Special Purpose Operational Training (e.g., training in cockpit resource management skills; differences training) and Line Operational Flight Evaluation (i.e., LOFT-like training which includes an evaluation component).

6. COMMENTS INVITED. Suggestions or comments on this AC should be addressed to the Director, Flight Standards Service, Federal Aviation Administration, 800 Independence Avenue, SW., Washington, DC 20591.

DBoratte D. C. Beaudette Director, Flight Standards Service Par 5

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CONTENTS Page No.

CHAPTER 1. INTRODUCTION

1. Purpose..

2. Background. ....

3. Summary.

4.-8. Reserved. 3 CHAPTER 2. DEFINITIONS

9. General. 5 CHAPTER 3. BASIC ELEMENTS OF LOFT

10. General.

11. Crew Composition and Participation

12. Real-World Situations. 7

13. No-Jeopardy Training.. 7

14. Uninterrupted Training. 7

15. Feedback.. 7

16. Phases of LOFT 8

17. Training Hours, Recurrent, and Qualification LOFT 8

18. LOFT Scenarios 9

19. Approvals of Scenarios 9

20. LOFT and CRM. 10

21. Critique of Crewmember Performance. 10

22.- Use of Audiovisual Equipment. 10

23. Additional Training/LOFT Completion. 10

24. Basic Elements of LOFT: Summary

25. FAA Philosophy Regarding LOFT

26.-30. Reserved CHAPTER 4. TYPES OF LOFT

31. General. 13

32. Recurrent LOFT. 13

33. Guidelines for Recurrent LOFT. 13 Table 4-1. Recurrent LOFT Substitution Table. 14

34. Qualification LOFT. 14

35. Guidelines for Qualification LOFT. 15 Table 4-2. Qualification LOFT Substitution Table. 15

36.-40. Reserved. 15 CHAPTER 5. SPECIAL PURPOSE OPERATIONAL TRAINING

41. General. 17

42. Elements Resembling LOFT. 17

43. Guidelines for Special Purpose Operational Training. 17

44.-50. Reserved 17 iii

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AC 120- 35B 06/9/6 CHAPTER 6. LINE OPERATIONAL EVALUATION

51. General. 6I

52. Elements Resembling LOFT 6I

53. Evaluation. 19

54. Evaluators. 19

55. Flight Simulators/Flight Training Devices. 6I

56.-60. Reserved 6I CHAPTER 7. THE ROLE OF INSTRUCTORS

61. Minimum Qualifications. 21

62. Instructor Responsibilities at Each

Stage of Line Operational Simulations.21

63.-70. Reserved................... ... 22 iv

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CHAPTER 1. INTRODUCTION

1. PURPOSE. The purpose of this advisory circular is to provide updated guidance in designing and implementing Line Operational Simulations, which includes: LOFT, Special Purpose Operational Training, and Line Operational Evaluation.

2. BACKGROUND.

a. The use of flight training devices and flight simulators has become increasingly important in training flight crewmembers. As the level of sophistication in simulators increased, air carriers have come to rely on simulators for part or all of their flight training programs. Since the mid-1970's, some FAR Part 121 and Part 135 operators have implemented alternative simulator training, which is now known as LOFT, to train crewmembers. LOFT is training in a simulator with a complete crew using representative flight segments which contain normal, abnormal, and emergency procedures that may be expected in line operations. FAR § 121.409(b) delineates the requirements of LOFT; FAR § 121.441 allows LOFT to substitute for alternate proficiency checks. In 1978 and 1981, AC's 120-35 and 120-35A, respectively, provided guidance for the use of LOFT in recurrent training programs and set forth guidelines for its design and implementation. This type of LOFT is now termed "Recurrent LOFT." In 1980, the FAA published the Advanced Simulation Plan in FAR Part 121, Appendix H. This plan provides the option of providing most or all crewmember flight training in flight simulators. Appendix H mandates LOFT to facilitate flight crewmember transition from training in advanced simulators to operational flying. This type of LOFT is now termed "Qualification LOFT.

b. 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 scripted real-time scenarios which include routine, abnormal, and emergency situations.

They also learn and practice cockpit resource management 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 1980's, new issues that are related to the requirements of FAR § 121.409, Part 121, Appendix H. and expanding opportunities for the use of LOFT or other Line Operational Simulations have emerged. Issues which require an updating of applicable guidelines are:

(1) Requirements of FAR § 121.409. Section 121.409(b) delineates the requirements of Recurrent LOFT, which may be substituted on an alternate basis for the proficiency check requirement as specified in FAR § 121.441.

Section 121.409(b) requires a complete crew to be utilized 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 which is Line Qualified.

(See definitions in Chapter 2.)

Chap 1 Par 1 1

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Requirements of FAR Part 121, Appendix H. Part 121, Appendix H, contains guidelines 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) Special Purpose Operational Training. New training concepts and training media have identified a need for other types of training in operational simulations called Special Purpose Operational Training. This type of operational simulation includes the concepts listed below. In addition, other types of Special Purpose Operational Training may evolve over

(i) Both the FAA and industry have recognized the importance of Cockpit Resource Management (CRM) in crewmember training. CRM training addresses human factors (e.g.. leadership, communication skills. time management, situational awareness, and attitudes in flight operations).

Training to improve performance in these areas has been identified as a factor in reducing the number of airline accidents and incidents. CRM training is designed for a complete crew environment. Application of CRM skills appears to be an integral part of safe and successful line operations. This AC addresses the relationship of CRM to Special Purpose Operational Training, as well as to LOFT.

Current regulations do not presently address the use of Special Purpose Operational Training for Differences Training. This AC presents guidelines in conducting Special Purpose Operational Training for Differences Training.

(4) Line Operational Evaluation. Recently, a new concept related to the training, qualification, and evaluation of flight crewmembers has emerged.

In February 1989, the FAA published a proposed Special Federal Aviation Regulation (SFAR) No. 58, which would authorize the establishment of an Advanced Qualification Program (AQP); i.e., a voluntary training and evaluation program as an alternative to meeting the training and qualification requirements of FAR Part 121 or Part 135. The proposed SFAR allows greater flexibility in designing training programs that reflect recent advancements in aircraft technology as well as the development of new training and evaluation techniques. Requirements of an AQP include training and evaluation in operationally accurate flight simulations using realistic line-oriented scenarios. Evaluation is a necessary element of this process to provide initial and subsequent assessments of flightcrew and individual flight crewmember competency. Simulations using realistic, line-oriented scenarios as a training and evaluation tool have been demonstrated to provide effective instruction. The element of evaluation in this new proposal is distinct from LOFT as a training vehicle because. unlike LOFT, the proposed simulations will now involve evaluation. Therefore, the term "Line Operational Evaluation" is used to describe operationally oriented simulations that involve evaluation.

(See chapter 6 for further detail.)

Chap 1 Par 2

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3. SUMMARY. This AC identifies four types of Line Operational Simulations:

(1) Recurrent LOFT (in reference to FAR $§ 121.409, 121.427, 121.433, 121.441, and Part 121, Appendix F), (2) Qualification LOFT (in reference to FAR 2 рене (2, (2) 0.

Part 121, Appendix H), (3) Special Purpose Operational Training, which is training that may be used for various unique purposes such as aircraft differences or CRM training, and (4) Line Operational Evaluation, which is designed for persons participating in an AQP, or for persons who meet the general training requirements of FAR § 121.401 or § 135.323 and wish to conduct operational evaluations. It defines the terms used in describing Line Operational Simulations. It provides guidance for designing and conducting LOFT, Special Purpose Operational Training, and Line Operational Evaluation.

It defines the role of instructors and evaluators.

4.-8. RESERVED.

Chap 1 Par 3 3 (and 4)

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CHAPTER 2. DEFINITIONS GENERAL. The following terms are used throughout this advisory circular and are defined as follows:

a. Line Qualified. Describes a flight crewmember or instructor who is current and qualified to conduct actual flight operations in an assigned aircraft and duty position.

Line Familiar. Describes a flight crewmember or instructor who is familiar with a certificate holder's line operations. This person is either line qualified or otherwise qualified by participation in an approved line observation program. (An acceptable line observation program would include observation from the cockpit jump seat of a line crew on at least two operational flight segments. This should be accomplished twice annually, and the line observation program should be included as a part of the approved training program.)

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.

d. Qualification LOFT. An approved flight simulator course of LOFT to facilitate transition from training using flight simulation to operational flying. Qualification LOFT meets the requirements of FAR Part 121, Appendix H.

e. Recurrent LOFT. An approved flight simulator course of LOFT which may be used to meet recurrent flight training requirements and to substitute for alternate proficiency checks. Recurrent LOFT meets the requirements of FAR § 121.409 as allowed under FAR § 121.441(a).

Line Operational Evaluation. An evaluation of crewmembers and crews in a flight training device or flight simulator during real-time Line Operational Simulations.

g. Special Purpose Operational Training. An approved course of operationally oriented flight training, conducted in a flight simulator or flight training device, which may be used to learn, practice, and accomplish specific training objectives; e.g., training in variant aircraft or special aircraft equipment.

Chap 2 Par 9 5 (and 6)

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CHAPTER 3. BASIC ELEMENTS OF LOFT GENERAL. Certain elements about LOFT must be understood to ensure that its primary objective, to provide realistic line-oriented training, is 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 and Line Operational Evaluation.

See chapters 5 and 6 for more information on how these concepts apply to these types of Line Operational Simulations.)

CREW COMPOSITION AND PARTICIPATION. LOFT should take place in a line operational environment with a complete crew. A complete crew will always be scheduled and every effort will be made to maintain crew integrity. During LOFT, each crewmember performs both as an individual and as a member of a team, as is expected during line operations.

REAL-WORLD SITUATIONS. LOFT 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 involving repetitive events, the en route segments may be compressed. However, enough time should be allotted to allow crewmembers to become sufficiently familiar with the scenario to ensure that if the scenario is compressed, crewmembers will be able to resume or restart the scenario without confusion.

13. NO-JEOPARDY TRAINING. LOFT is "no-jeopardy" training, i.e., the instructor does not issue a passing or failing grade to a participating crewmember. As a LOFT scenario progresses, it is allowed to continue without interruption so crewmembers may learn by experiencing the results of their decisions. Decisions which produce unwanted results do not indicate a training failure, but serve as a learning experience. If the LOFT instructor identifies crewmember performance deficiencies, additional training or instruction will be provided. This training or instruction may be in any form, 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 without instructor interference. At the end of a LOFT session and after debriefing,

14. UNINTERRUPTED TRAINING. LOFT scenarios run full-length, with no interruption by the instructor permitted. The effects of crewmember decisions are allowed to accrue and influence the rest of the flight. The concept is that crewmembers will learn more effectively if they are allowed to learn from their experiences, rather than being interrupted and corrected by an instructor. In rare cases, and only during Qualification LOFT, an instructor may choose to intervene if he determines negative learning is taking place.

15. FEEDBACK. LOFT includes feedback to crewmembers on their performance in the scenario. This takes place during the debriefing phase. (See the following paragraph for further detail on feedback and debriefing.)

Chap 3 Par 10 7

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16- PHASES OF LOFT. LOFT scenarios should contain the following phases:

briefing, preflight planning documents and activities, flight time, and debriefing. These are described in the following paragraphs.

a. Briefing. Before the flight segment begins, the instructor should brief crewmembers on the LOFT 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 taxiing, takeoff, flying, and landing. 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 Positive comments regarding crew performance should be emphasized in the debriefing as well as crew performance which 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 21 and 22 for further discussion of critiques, debriefing, and use of video records.)

TRAINING HOURS, RECURRENT AND QUALIFICATION LOFT. Both recurrent and qualification LOFT sessions should be based on at least 4 hours of total crewmember training activity, which should include at least 2 1/2 hours of LOFT scenarios. Reasonable amounts of time should be allowed for problem solving (e.g., consulting minimum equipment lists and operations manuals, preparing takeoff data, as well as other crew actions which are occasioned by the training scenario). For qualification LOFT, the 4 hours of crewmember training should include cockpit preparation, preflight activities, crew briefings, and interactions with flight dispatch and other ground agencies.

For Recurrent LOFT, any additional hours of training, beyond the 2 1/2 hours of LOFT scenarios necessary to comply with FAR § 121.409(b) may, subject to the approval of the FAA, be utilized for other specific training requirements.

All crewmembers participating in a LOFT session are credited with 4 hours of training time.

Chap 3 8 Par 16