Policy 

Statement

Subject: Risk Assessment Methodology 

for Transport Category Airplanes

Date: 11/4/2011

Initiated By: 

ANM-117 

Policy No: 

PS-ANM-25-05

Summary 

To support implementation of a Safety Management System (SMS) within the Aircraft 

Certification Service (AIR), AIR released Order 8110.107, Monitor Safety/Analyze Data 

(MSAD), on March 12, 2010. That order provides requirements and guidance for a standardized, 

SMS-based, continued-operational-safety process to be used across the service. 

The MSAD order requires each aircraft directorate to— 

Develop product-specific continued-operational-safety risk-analysis 

methodology and guidelines by which risk can be reported in terms of the 

statistical probability of a fatal accident. This methodology must be 

quantitative, or it must be structured in such a way that it can evolve into a 

quantitative methodology. 

An intra-directorate team was formed and chartered by the Transport Airplane Directorate in 

2002 to develop a transport-airplane-specific risk-analysis process. The result of that multi-year 

team development is the Transport Airplane Risk Assessment Methodology (TARAM). The 

TARAM has evolved significantly from lessons learned, and from comments and suggestions 

from many sources. The TARAM has also been reduced in scope to be compatible with, and to 

support, the MSAD process, which is described in the attached TARAM Handbook. 

The TARAM is to be used within the MSAD process for risk analysis and risk management. 

Aircraft-certification offices will use it to resolve issues of continued operational safety for 

transport-category airplanes.1

 This methodology may also be used by design-approval holders, in 

whole or in part, by agreement with the applicable aircraft-certification office. 

 

1

 Continued-operational-safety risk analyses for engine and propeller, small airplane, and rotorcraft issues will be 

accomplished using the applicable directorate-defined methodology. 
2

Current Regulatory and Advisory Material 

In general, the regulatory basis and roles and requirements for transport-airplane continued 

operational safety can be found throughout 14 CFR parts 21, 39, 91, 121, and 135. Mandatory 

corrective actions to address unsafe conditions are addressed by airworthiness directives as 

prescribed by 14 CFR part 39. Existing guidance for risk assessments for powerplant continued 

operational safety is contained in Advisory Circular (AC) 39-8, “Continued Airworthiness 

Assessments of Powerplant and Auxiliary Power Unit Installations of Transport Category 

Airplanes.”2 Order 8110.107 outlines a standardized process that aircraft-certification offices will 

use for safety decision-making and resulting airworthiness-directive action. 

Relevant Past Practice 

Previously, no formal process, guidance, or policy was in place for transport-airplane continuedoperational-safety risk analyses/management beyond that contained in AC 39-8 for powerplant 

continued operational safety. Transport-airplane continued-operational-safety risk determinations 

are currently based on engineering judgment and, to a lesser extent, derived very loosely from 

the certification guidance given in AC 25.1309-1A. 

To fill the need for such guidance, as part of AIR SMS development, the AIR SMS MSAD team 

has now created a standardized and documented continued-operational-safety process for each 

aircraft-certification office/directorate to use identifying and resolving safety issues. That process 

is contained in Order 8110.107. Integral to that process is the analysis of risk and the comparison 

of that risk to the product-specific risk guidelines that the directorates have developed. The riskassessment methodology and risk guidelines for transport category airplanes are found in the 

TARAM Handbook, attached. 

Policy 

The methodology in the attached TARAM Handbook is meant to be used by FAA aerospacesafety engineers within the MSAD process. It is important that the public and affected design 

approval holders also know how the risk associated with transport-airplane continuedoperational-safety issues will be analyzed and considered within that overall process. In addition, 

affected design-approval holders should know, in general, the data and information that could be 

requested from them when aircraft-certification offices are analyzing the risk associated with 

continued-operational-safety issues (failure rates, failure mode/physics of failure, root cause, 

potential accident sequence [causal chain], fault-trees, conditional probabilities, affected fleet 

size, etc.). Design-approval holders may request to perform, or be asked to perform, all or part of 

the TARAM process pursuant to an organization delegation approval or negotiated continuedoperational-safety-management agreement. In those cases, the design-approval holder will need 

to understand the details of the TARAM contained in the TARAM Handbook. 

 

2

 The certification-guidance material for § 25.1309 (e.g., AC 25.1309-1A) contains no continued-operational-safety 

guidance 
3

Accordingly, for the purposes of public and design-approval-holder awareness, review, and 

comment, the TARAM Handbook is attached to this policy statement. The TARAM Handbook 

is intended as a job aid for FAA aerospace-safety engineers. It provides detailed instructions and 

guidance. Members of the public who want to understand the risk-analysis methodology and 

risk-level guidelines that support the MSAD process, without reviewing the entire handbook, 

will find an explanation of those concepts in these sections of the TARAM Handbook: 

 Section 5.0, Risk Analysis, including Appendix B, C, and D 

 Sections 6.1 and 6.2, Fail-Safe Design and Risk Level Guidance 

Effect of Policy 

This policy does not change or contravene the guidance in AC 39-8. For issues related to 

powerplant or auxiliary power unit (APU) continued operational safety, see AC 39-8. That AC 

describes the recommended methodology for identifying, analyzing, prioritizing, and resolving 

unsafe conditions on transport-category airplane power plants and APUs. 

FAA safety determinations, as described throughout 14 CFR parts 21 and 39, are an important 

function of the Administrator, yet the Administrator has a great deal of flexibility and latitude 

when making safety determinations. The TARAM Handbook provides guidance for considering 

risk as a factor when determining whether a condition found in the transport-airplane fleet is safe 

or unsafe. This guidance is only one thing to consider in the safety decision-making process and 

does not constitute the sole basis for unsafe-condition determination nor limit, in any way, the 

FAA prerogative to make such determinations. 

The TARAM Handbook, in conjunction with Order 8110.107, guides and standardizes transportairplane-related safety decision-making. Neither the TARAM Handbook nor Order 8110.107 

requires or obligates the FAA to perform any part of the TARAM process before issuing an 

airworthiness directive. 

The general policy stated in this document does not constitute a new regulation. The FAA 

individual who implements policy should follow this policy when it is applicable to a specific 

action. Whenever safety decision-making is outside this established policy, that individual must 

coordinate the decision-making with the policy-issuing office. Similarly, if an implementing 

office becomes aware of reasons that an applicant’s proposal that is based on the guidance in this 

policy should not be approved, that implementing office must coordinate its response with the 

policy-issuing office. 

Design-approval holders should expect that regulating officials will consider this policy when 

making safety findings and issuing airworthiness directives. In addition, as with all advisory 

material, this statement of policy identifies one means, but not the only means, of accomplishing 

safety decision-making. 
4

Implementation 

This policy discusses methods that should be applied during continued-operational-safety 

decision-making for transport-category airplanes certificated in the United States, except where 

the guidance of Advisory Circular 39-8 is applicable. 

Direct your questions or comments to Forrest Keller, Transport Directorate Standards Staff, 

Safety Management Branch, ANM-117, phone 425-227-2790. 

 /s/ Ali Bahrami 

Ali Bahrami 

Manager, Transport Airplane Directorate 

Aircraft Certification Service 

Attachments 
5

Attachment 1 

Terms 

Table A-1 defines the use of key terms in this policy statement. The table describes the intended 

functional impact. 

 

Table A-1 Definition of Key Terms 

 Regulatory 

Requirements 

Acceptable Methods of 

Compliance (MOC) 

Recommendations 

Term Must Should Recommend 

Meaning Refers to a regulatory 

requirement that is 

mandatory for design 

approval 

Refers to instructions for a 

particular MOC 

Refers to a 

recommended 

practice that is 

optional 

Functional 

Impact 

No Design Approval if 

not met 

Alternative MOC has to be 

approved by issue paper. 

None, because it is 

optional