What evidence is required to establish that an unsafe condition exists under AMC1 21L.B.23(b)?

Factual evidence from in-service experience, analysis, or tests is required to establish that an unsafe condition exists.

Does AMC1 21L.B.23(b) consider non-compliance with applicable certification specifications as an unsafe condition?

Yes, non-compliance with applicable certification specifications or technical specifications is generally considered an unsafe condition, unless it is shown that possible events resulting from this non-compliance do not constitute an unsafe condition as defined under points (a), (b), and (c).

What does point (b) of AMC1 21L.B.23(b) define as an unsafe condition regarding persons other than occupants?

Point (b) defines an unsafe condition as an unacceptable risk of serious or fatal injury to persons other than occupants.

What is the unsafe condition described in point (c) of AMC1 21L.B.23(b) related to survivable accidents?

Point (c) states that an unsafe condition exists if design features intended to minimise the effects of survivable accidents do not perform their intended function.

What examples of reduced capability or crew ability are given in Note 4 for events that occur too frequently?

Examples include a significant reduction in safety margins or functional capabilities, a significant increase in crew workload, conditions impairing crew efficiency, or discomfort to occupants, possibly including injuries.

AMC1 21L.B.23(b) Airworthiness directives

Q: According to AMC1 21L.B.23(b), what are the three specific consequences that define an unsafe condition under point (a)?

The three consequences are: (i) a large reduction in safety margins or functional capabilities; (ii) physical distress or excessive workload such that the flight crew cannot be relied upon to perform their tasks accurately or completely; or (iii) serious or fatal injury to one or more occupants.

Q: Under what condition is an event not considered an unsafe condition even if it could cause fatalities or reduce aircraft capability?

An event is not considered an unsafe condition if it is shown that the probability of such an event is within the limit defined by the applicable certification specifications.

Q: Can an unsafe condition exist even if the aircraft complies with all applicable airworthiness requirements?

Yes, an unsafe condition may exist even though applicable airworthiness requirements are complied with.

Q: According to Note 3, does the definition in points (a), (b), and (c) cover all cases where EASA considers an unsafe condition?

No, the definition covers the majority of cases, but there may be other cases where overriding safety considerations may lead EASA to issue an airworthiness directive.

Q: Under Note 4, when can events be considered an unsafe condition even if they have less severe immediate consequences than those listed in point (a)?

Events can be considered an unsafe condition if they occur too frequently (significantly beyond the applicable safety objectives) and could eventually lead to the consequences listed in point (a) in specific operating environments.

Navigate / EASA

Ask question Discover more Add to collection

AMC1 21L.B.23(b) Airworthiness directives

ED Decision 2023/013/R

UNSAFE CONDITION

An unsafe condition exists if there is factual evidence (from in-service experience, analysis or tests) that:

(a) an event may occur that would result in fatalities, usually with the loss of the aircraft, or reduce the capability of the aircraft or the ability of the crew to cope with adverse operating conditions to the extent that there would be:

(i) a large reduction in safety margins or functional capabilities; or

(ii) physical distress or excessive workload such that the flight crew cannot be relied upon to perform their tasks accurately or completely; or

(iii) serious or fatal injury to one or more occupants,

unless it is shown that the probability of such an event is within the limit defined by the applicable certification specifications; or

(b) there is an unacceptable risk of serious or fatal injury to persons other than occupants; or

Note 1: Non-compliance with the applicable certification specifications or technical specifications is generally considered as an unsafe condition, unless it is shown that possible events resulting from this non-compliance do not constitute an unsafe condition as defined under points (a), (b) and (c).

Note 2: An unsafe condition may exist even though applicable airworthiness requirements are complied with.

Note 3: The definition in points (a), (b) and (c) covers the majority of cases where EASA considers there is an unsafe condition. There may be other cases where overriding safety considerations may lead EASA to issue an airworthiness directive.

Note 4: There may be cases where events can be considered as an unsafe condition if they occur too frequently (significantly beyond the applicable safety objectives) and could eventually lead to the consequences listed in point (a) in specific operating environments. Although having less severe immediate consequences than those listed in point (a), the referenced events may reduce the capability of the aircraft or the ability of the crew to cope with adverse operating conditions to the extent that there would be, for example, a significant reduction in safety margins or functional capabilities, a significant increase in crew workload, or in conditions impairing crew efficiency, or discomfort to occupants, possibly including injuries.

Details

Source-Title: AMC1 21L.B.23(b) Airworthiness directives View latest amendments

Erulesid: ERULES-1963177438-22227 Compare versions

Domain: Initial airworthiness

Amendedby: Issue 1

Applicabilitydate: 21 October, 2023

Entryintoforcedate: 21 October, 2023

Regulatorysource: ED Decision 2023/013/R Navigate

Regulatorysubject: Part 21 Light

Typeofcontent: AMC to IR (Acceptable means of compliance to implementing rule)

Parentir: 21L.B.23 Airworthiness directives

Origin: EASA

Category: EAR