ASTM F3526-21

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:F3526 −21
Standard Guide for
Aircraft Instrument Systems Technician Certification
This standard is issued under the fixed designation F3526; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 4. Significance and Use
1.1 The purpose of this guide is to address the basic 4.1 The guide is intended to be used to assess competencies
ofqualifiedindividualswhowishtobecomecertifiedasanAIS
fundamental subject knowledge activities and functions for
avionics professionals to be titled Aircraft Instrument Systems Technician through a certification program.
(AIS) Technician.
4.2 The guide is intended to be used in concert with a
certification provider’s structure and materials for
1.2 This guide is the basis for the Aircraft Instrument
management, exam delivery, and candidate preparation.
Systems certification, an endorsement to theAircraft Electron-
ics Technician (AET) certification. Candidates must be a
5. Test Knowledge Requirements
certifiedAETtotakethecertificationexamassociatedwiththis
guide.
5.1 Thefollowingsubjectknowledgeareasshallbeassessed
by levels (referenced in Table 1) of competency in the exam
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the items.
responsibility of the user of this standard to establish appro-
5.2 Risk Management – LEVEL 3—Can describe in detail
priate safety, health, and environmental practices and deter-
and perform tasks related to the following:
mine the applicability of regulatory limitations prior to use.
5.2.1 Safety:
1.4 This international standard was developed in accor-
5.2.1.1 See ASTM F3245, Standard Guide for Aircraft
dance with internationally recognized principles on standard-
ElectronicsTechnician Personnel Certification, Section 6, Core
ization established in the Decision on Principles for the
Competencies – Common Maintenance Practices, Fundamen-
Development of International Standards, Guides and Recom-
tals of On-Equipment Maintenance andAircraft Fundamentals,
mendations issued by the World Trade Organization Technical
Subsections 6.1, 6.2, 6.3, 6.6, and 6.13.
Barriers to Trade (TBT) Committee.
5.2.2 Operational Considerations:
5.2.2.1 Limitations related to testing pitot and static instru-
2. Referenced Documents
ments including maximum vertical speed indicator limits and
airspeed indicator differential pressure limits.
2.1 ASTM Standards:
5.2.2.2 Proper and secure connection of air data test equip-
F3060 Terminology for Aircraft
F3245 Guide for Aircraft Electronics Technician Personnel ment to the aircraft to avoid inadvertent separation and
subsequent damage to instruments.
Certification
5.2.2.3 Impact of using magnetic tools near magnetic sen-
3. Terminology sitive devices to include compasses and magnetometers.
5.2.2.4 Safe operation of aircraft controls and control sur-
3.1 See ASTM F3060, Standard Terminology for Aircraft.
faces while testing/operating autopilot systems.
3.2 See Table 1 for knowledge level definitions relating to
5.2.2.5 Proper operation of gyroscopic instruments to avoid
the education requirements for AIS professionals.
damage caused by precession or gimbal lock, or both.
5.3 General Aircraft Instrument System Theory of Opera-
tion – LEVEL 1—Understands and can describe the following:
This guide is under the jurisdiction of ASTM Committee F46 on Aerospace
5.3.1 The purpose and function of sensors and displays used
Personnel and is the direct responsibility of Subcommittee F46.02 on Avionics and
in aircraft instrument systems.
Information Technology Endorsements.
5.3.2 The theory of operation and the differences between
Current edition approved Oct. 15, 2021. Published December 2021. DOI:
10.1520/F3526-21.
direct-sensing instruments and remote-sensing instruments.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
5.3.3 The categorization of instruments based on their
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
function to include flight instruments, engine instruments,
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. navigation instruments, and miscellaneous instruments.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F3526−21
TABLE 1 Knowledge Level Definitions
Definition: Knowledge Level
LEVEL 1 A familiarization with the principal elements of the subject.
Objectives:
• The applicant should be familiar with the basic elements of the subject.
• The applicant should be able to give a simple description of the whole subject using common words and examples.
• The applicant should be able to locate methods, procedures, instructions, and reference material.
• The applicant should be able to use typical terms.
LEVEL 2 A general knowledge of the theoretical and practical aspects of the subject, and an ability to apply that knowledge in a practical manner.
Objectives:
• The applicant should be able to understand the theoretical fundamentals of the subject.
• The applicant should be able to find and interpret maintenance data and information.
• The applicant should be able to give a general description of the subject using, as appropriate, typical examples.
• The applicant should be able to use mathematical formulae in conjunction with physical laws describing the subject.
• The applicant should be able to read and understand sketches, drawings, and schematics describing the subject.
• The applicant should be able to apply their knowledge in a practical manner using detailed procedures.
LEVEL 3 A detailed knowledge of the theoretical and practical aspects of the subject. To know, understand, and apply facts, principles, theories, and concepts.
A capacity to combine and apply the separate elements of knowledge in a logical and comprehensive manner.
Objectives:
• The applicant should know the theory of the subject and interrelationships with other subjects.
• The applicant should be able to give a detailed description of the subject using theoretical fundamentals and specific examples.
• The applicant should understand and be able to use mathematical formulae related to the subject.
• The applicant should be able to read, understand, and prepare sketches, simple drawings, and schematics describing the subject.
• The applicant should be able to apply their knowledge in a practical manner using manufacturer’s instructions or other acceptable data.
• The applicant should be able to interpret results from various sources and measurements and apply corrective action where appropriate.
• The applicant should be able to perform all skill operations to a return-to-service standard using appropriate data, tools, and equipment.
• The applicant should be able to perform inspections in accordance with acceptable or approved data.
5.3.3.1 The typical location and purpose of flight instru- 5.4.8 The theory of operation of pitot-static systems.
mentstoincludethosethatmakeupthebasic“T”configuration
5.4.8.1 The purpose and function of the pitot system and the
and the common “six-pack” configuration.
basic instruments that use pitot pressure.
5.3.3.2 The typical location and purpose of engine instru-
5.4.8.2 The purpose and function of the static system and
ments.
the basic instruments that use static pressure.
5.3.3.3 The types and purpose of navigation instruments.
5.4.8.3 The purpose and function of an alternate static
5.3.3.4 The types and purpose of miscellaneous instru-
system.
ments.
5.4.8.4 The basic flow of pressures in the pitot and static
5.4 Pressure Measuring Instruments – LEVEL
systems.
2—Understands and can apply the theory related to the
5.4.9 The purpose, function, and theory of operation of an
following:
Altimeter.
5.4.1 The theory of operation of pressure measuring instru-
5.4.10 The purpose, function, and theory of operation of a
ments to include both direct-sensing and remote-sensing in-
struments. Vertical Speed Indicator (VSI) and an Instantaneous Vertical
5.4.2 Thetheoryofoperationofbourdontubesusedtosense Speed Indicator (IVSI).
and measure pressure.
5.4.11 The purpose, function, and theory of operation of a
5.4.3 The theory of operation of diaphragm/bellows used to
Variometer.
sense and measure pressure.
5.4.12 The purpose, function, and theory of operation of an
5.4.4 The theory of operation of solid-state pressure sensing
Airspeed Indicator and a True Airspeed Indicator.
and measuring devices.
5.4.13 The purpose, function, and theory of operation of a
5.4.5 Thevarioustypesofpressuressensedandmeasuredin
Machmeter.
an aircraft to include absolute, gauge, differential, and standard
reference atmospheric pressure.
5.5 Remote Sensing and Indication – LEVEL
5.4.6 The purpose, types, theory of operation, and markings
2—Understands and can apply the theory related to the
of the following pressure measuring instruments:
following:
5.4.6.1 Oil Pressure
5.5.1 The theory of operation of d’Arsonval meter move-
5.4.6.2 Manifold Pressure
ments.
5.4.6.3 Engine Pressure Ratio
5.5.2 The theory of operation of various types of DC and
5.4.6.4 Fuel Pressure
AC synchro systems to include AutoSyns, Selsyns, and Mag-
5.4.6.5 Hydraulic Pressure
nesyns.
5.4.6.6 Vacuum Pressure
5.5.3 The application of remote sensing indication systems
5.4.7 The theory of operation and applications for pressure
switches
...