Airworthiness of Aircraft

The whole chapter sits on a single safety idea: an aircraft is only allowed to fly if it has been designed, constructed and operated in line with the proper airworthiness requirements. The authority that sets and enforces those requirements for a particular aircraft is the State of Registry of that aircraft.

In simple terms: compliance with airworthiness requirements ⟶ the aircraft earns a C of A ⟶ the C of A declares it fit to fly. Without that declaration, the machine is not permitted in the air.

Airworthiness does not live in isolation. The Standards of Annex 6, Part I — which deal with aeroplane performance operating limitations — are described as complementary to the airworthiness Standards of Annex 8. Both Annexes state broad objectives, but they look at the aircraft from two different angles.

Protecting Visiting Aeroplanes

The ICAO Council has urged Contracting States not to impose on visiting aeroplanes operational requirements other than those established by the State of Registry — provided those State-of-Registry requirements are not lower than the Standards of Annex 6, Part I.

Recognising a Foreign Airworthiness Certificate

To make it easy to import, export, lease, charter or interchange aircraft and to support international air navigation, ICAO places a duty on the State of Registry to recognise and render valid an airworthiness certificate issued by another Contracting State.

flowchart LR
    A["Aircraft holds a C of A
issued by another
Contracting State"] --> B{"State of Registry checks:
Are the airworthiness requirements
EQUAL TO or ABOVE the ICAO
minimum Standards?"}
    B -- "Yes" --> C["State of Registry
RECOGNISES & RENDERS
VALID the certificate"]
    B -- "No" --> D["Certificate NOT
automatically rendered valid"]
      

ICAO is realistic about its own limits. It is recognised that ICAO Standards would not replace national regulations. ICAO Standards set the broad framework; the fine, detailed work of certifying individual aircraft needs a fuller, more detailed national code.

Annex 8 includes broad Standards which define — for application by the national airworthiness authorities — the minimum basis for the recognition by States of Certificates of Airworthiness, so that aircraft of other States can fly into and over their territories.

While the C of A applies to an individual aircraft, the Type Certificate applies to the design of a whole type — and it is issued by a different authority.

Applicability of the Technical Standards

These technical Standards include requirements relating to:

• Performance and flying qualities
• Structural design and construction
• Engine and propeller design and installation
• Systems and equipment design and installation, and operating requirements

The Four Parts of Annex 8

Annex 8 is divided into four parts:

flowchart TD
    X["ICAO ANNEX 8
Airworthiness of Aircraft"]
    X --> P1["PART I
Definitions"]
    X --> P2["PART II
Procedures for Certification
& Continuing Airworthiness"]
    X --> P3["PART III
Technical Requirements —
Certification of New Large
Aeroplane Designs"]
    X --> P4["PART IV
Helicopters"]
      

Following the events of hijacking and terrorist acts on board aircraft, special security features have been built into aircraft design to improve the protection of the aircraft.

This part of the chapter moves from the international ICAO framework to the national rules administered by the Director-General (DGCA). It covers how a C of A is issued, modified, suspended, cancelled and revalidated.

9.1  Issue of C of A / Special C of A / Airworthiness Review Certificate

flowchart TD
    A["Owner / Operator of the aircraft"] -->|"Applies"| B["Director-General (DGCA)"]
    B --> C{"Both conditions checked"}
    C --> D["Condition (a)
Applicant furnishes documents /
evidence of airworthiness
as specified by the DG"]
    C --> E["Condition (b)
DG satisfied the aircraft is
airworthy OR in a condition
for safe operation"]
    D --> F{"Conditions (a) AND (b)
both satisfied?"}
    E --> F
    F -- "Yes" --> G["C of A / Special C of A
ISSUED"]
    F -- "No" --> H["Certificate NOT issued"]
      

9.2  Modification and Repairs

9.3  Suspension or Cancellation — When a C of A is "Deemed Suspended"

A C of A or special C of A is deemed to be suspended automatically when an aircraft falls into any one of the following four situations:

flowchart TD
    S["C of A is DEEMED SUSPENDED
when the aircraft..."]
    S --> A["(a) Ceases / fails to conform
with the rules — operation,
maintenance, modification, repair,
replacement, overhaul,
process or inspection"]
    S --> B["(b) Is modified or repaired
OTHERWISE THAN per
the provisions of the rules"]
    S --> C["(c) Suffers
MAJOR DAMAGE"]
    S --> D["(d) Develops a MAJOR DEFECT
affecting safety of the aircraft
/ occupants in subsequent flights"]
      

9.4  Director-General's Powers on "Reasonable Doubt"

If, at any time, the Director-General is satisfied that reasonable doubt exists as to the safety of an aircraft, or as to the safety of the type to which that aircraft belongs, he may take either of the following actions:

flowchart TD
    R["Director-General is satisfied
REASONABLE DOUBT exists
about safety of the aircraft
or of its type"]
    R --> O1["Option (a)
SUSPEND or CANCEL
the C of A / Special C of A"]
    R --> O2["Option (b)
REQUIRE modification, repair,
replacement, overhaul, inspection
(incl. flight tests & examination)
under an approved person"]
    O2 --> Y["Compliance becomes a CONDITION
of the C of A remaining in force"]
    O1 --> Z["Aircraft must NOT be flown
while the C of A is suspended"]
    Z --> SFP["On application by owner / operator,
the DG MAY issue a
SPECIAL FLIGHT PERMIT"]
      

9.5  Prohibition on Flying & the Special Flight Permit

9.6  Flight Manual

9.7  Instruments and Equipment

Self-Test   All five chapter questions, the correct option, and the reasoning behind each answer.