Certificate issued by the
Federal Aviation Administration that means a particular
aircraft design meets standard
critera for
production. A
type certificate does not authorize its holder to produce that
aircraft in any
numbers. It only proves that the aircraft meets
safety,
airworthiness, and
performance criteria. If
mass production is then desired a
production certificate must be obtained.
The typical
type certification process takes anywhere from
two to five years. All
airplanes made by a manufacturer for sale in the
U.S. must have a
type certificate, from the
Cessna 150 all the way up to the
Boeing 747.
The type certification process is
outlined in 14
CFR parts 21, 23 and 34.
Part 21 defines
certification procedures,
part 23 defines
airworthiness standards, and
part 34 defines
emissions and fuel venting requirements for turbine powered aircraft.
There are a few ways to change a type certificate in terms of modifications and flexibility within a design.
1.
Supplemental Type Certificate (
STC) - If a third party designs a
modification to an aircraft (
long range fuel tanks,
more powerful engine,
upgraded lighting,
etc.) with a type certificate they can apply for a supplemental type certificate, they must show that the modification does not adversely affect the airworthiness of the original design. The
STC describes methods of applying the modification and changes to
aircraft performance or operation and must be kept with the
aircraft maintenance logs.
2.
Ammended Type Certificate - Rather than having to
re-certify a design because of some relatively
minor changes the FAA allows you to re-certify only the changes and then
amends those changes to the original type certificate. Usually the same
model number is retained and some other means of identifying the changed design is used. For example: The
Piper PA-28-140,
PA-28-151, and
PA-28-235 all share the same type certificate, as do the
Cessna 172A-S models.
3.
Airworthiness Directive (
AD) - If the
NTSB recommends a change to an aircraft the
FAA can issue an
Airworthiness Directive. The aircraft's type certificate is then ammended to include the required
AD. The aircraft is considered
unairworthy until the
AD is
complied with.
A type certificate includes what is called a "
Type Certificate Data Sheet (
TCDS)." The
type certificate data sheet includes general information about the design such as
wingspan,
wing area,
wing loading,
limiting airspeeds and required
placards and markings,
control surface travel,
engine installations and
approved engine/propeller combinations.
Type certificates are generally held by the
manufacturer of a certain airplane although they can be
transferred and some type certificates are
purchased so that a company can produce aftermarket replacement parts for an out-of-production
airframe.