IATA Aircraft Lease Guidance

Guidance Material and Best Practices for Aircraft Leases
standards are issued by ICAO. There are about seven states that have developed more detailed design
standards, or airworthiness codes, such as US FAR-25 and EASA CS-25. For aircraft, these codes form
the basis for Type Certification and are reflected in the Type Certification Data Sheets (TCDS).
Certifying an aircraft type design is a complex and demanding effort that requires a high level of expertise
and resources. States without OEMs typically adopt one or more of the airworthiness codes of other
states. These states usually have limited knowledge, or have not yet established airworthiness
requirements of their own.
The options that are recognized for acceptance of airworthiness codes are displayed in Table 2. Please
note that this is a non-comprehensive list of states, and serves as an example only.
For any product,
use of its own
airworthiness
code
For any
product, use
airworthiness
code of state of
design
For any product,
airworthiness
code of one or
more specified
other state(s)
For any
product, use
any
airworthiness
code
State
example
Major design
states:
●
●
●
●
●
●
US
EU
Canada
Brazil
China
Russian
Federation
Pakistan
Saudi Arabia:
●
Qatar:
●
●
US, except
where no US
TC is issued,
then validation
State of design
or
EU or US
Sri Lanka
●
Japan
Table 2.
Acceptance of Airworthiness Codes (example)
●
Airworthiness directives
An AD is a regulatory enforceable rule which is issued to correct unsafe conditions in products, and
restore the airworthiness of the aircraft. ADs are commonly issued by the state of design. However, each
state of registry has the right to issue its own ADs.
States of registry have several options in respect to issuing ADs:
o
o
o
Blanket adoption of the AD of the state of design
Re-issuing the AD of the state of design
Issuing additional ADs of its own
●
Modifications and repairs
Traditionally, modifications were designed by the TC holder. Presently, in many cases, modifications to
type designs are developed by another organization and certified separately by means of an STC. Most
34 4 th Edition 2017