A Type Certificate (sometimes called Airworthiness Certificate), is awarded by aviation regulating bodies (such as FAA in US and EASA in EU) to aerospace firms after it has been established that the particular design of aircraft, engines or propeller submitted has fulfilled the regulating bodies' current prevailing airworthiness requirements for the safe conduct of flights under all normally conceivable conditions. Military types are exempted. The Federal Aviation Administration is the entity of the United States government which regulates and oversees all aspects of civil aviation in the U.S. // Activities Along with the European Joint Aviation Authorities, the FAA is one of the two main agencies worldwide responsible for the certification of new aircraft. ... European Aviation Safety Agency (EASA) is an agency of the European Union which has been given specific regulatory and executive tasks in the field of aviation safety. ...

Prototype

Initially, the applicant aerospace firm shall submit documents to the aviation regulating body (initially of the firms' home country) detailing how the proposed design would fulfill the airworthiness requirements. After investigations by the regulator, the final approval of such documents (after the required comments and amendments in order to fulfill the laws), becomes the basis of the certification. The firm follows it and draw a proposed timetable of actions required for certification tests.

An initial design sample known as a prototype is built. This refers to either the aircraft, engines or propeller, depending on the basis of the certification. For the purpose of illustration, the discussions shall be limited to aircraft. Normally a few prototypes are built, each subjected to different tests. The prototypes initially is submitted to ground and system tests. One of them (known as the 'static airframe') is subjected to destructive testing i.e. the prototype is subjected to stresses beyond normal and abnormal operations until destruction and readings taken and compared with initial submitted calculations to establish ultimate structural strength.

Other prototypes will undergo other systems tests until the satisfaction of the regulators. With all ground tests completed, prototypes are readied for flight tests. The flight tests are flown by specially approved flight test pilots who will fly the prototypes to establish the ultimate flight limits which should be within the airworthiness rules. If a long range airliner is tested, the flight tests may cover the whole world. ETOPS testing may require tests over oceans or remote areas. ETOPS (Extended Twin-engine OPerationS) is an acronym for an International Civil Aviation Organization (ICAO) rule permitting newer twin-engined commercial air transports to fly routes that, at some points, are further than a distance of 60 minutes flying time from an emergency or diversion airport. ...

In tandem with aircraft testing, the applicant firm also draws up maintenance program to support continuous airworthiness after approval of the design. The program is drawn with inputs from tests results and also from initial customers' engineering departments. The proposed maintenance program is submitted to the regulators for comment and approval.

After successful completion of ground and flight tests along with an approved maintenance program, the prototype is approved, the firm is granted the type certificate for the prototype (as understood that it should include all furnished equipment for its intended role). The legal term for the firm is now the "type certificate holder". Subsequently the prototype now serves a template for aircraft production. Hence the aircraft rolling out of the factory should be identical to the prototype, and each given a serial number (a "series aircraft").

Continuous Airworthiness

As the aircraft enters service, it is subjected to operational wear and tear which may cause performance degradations. The approved maintenance program serves to maintain the aircraft airworthiness. Users have to comply in order to maintain their aircraft's airworthiness certificate. The maintenance may be light or heavy (such as overhauls) as dictated by the schedules and tasks in the aircraft's maintenance program.

Airworthiness Directives

Sometimes during service the aircraft may encounter problems that may compromise the aircraft's safety which are not anticipated or detected in prototype testing stages. The aircraft design is thus compromised. The regulators will now issue an airworthiness directives to the type certificate holder and to all owners globally. The directives normally consists of additional maintenance or design actions that are necessary to restore the type's airworthiness. Compliance is mandatory. Airworthiness directives may also be raised with changes of the local or global aviation rules and requirements, e.g. requirement to fit armored cockpit doors for all airliners post 9-11.

Service Bulletins

With increasing in-service experience, the type certificate holder may find ways to improve the original design resulting in either lower maintenace costs or performance increases. These improvements (normally involving some alterations) are suggested through service bulletins to their customers as optional (and may be extra cost) items. The customers may exercise their discretion whether or not to incorporate the bulletins.

Changes to Type Certificate

Often the basic design is enhanced further by the type certificate holder. Major changes beyond the authority of the service bulletins require amendments to the type certificate. For example, increasing (or decreasing) an aircraft's flight performance, range and load carrying capacity by altering its systems, fuselage, wings or engines resulting in a new variant may require re-certification. Again the basic process of type certifications is repeated (including maintenance programs). However, unaltered items from the basic design need not be retested. Normally, one or two of the original prototype fleet are remanufactured to the new proposed design. As long as the new design does not deviate too much from the original, static airframes need not be built. The resultant new prototypes are again subjected to flight tests.

Upon successful completion of the certification program, the original type certificate is amended to include the new variant (normally denoted by a new model number additional to the original type designation). Typical examples are; the Boeing 737NG (737-600, 737-700, 737-800 and 737-900) which replaced the 737 Classic family (737-100, 737-200, 737-300, 737-400 and 737-500) and the Airbus A340-500 and the A340-600 which is based on the Airbus A340-200 and the A340-300. The Boeing Company (NYSE: BA)(TYO: 7661 ) is the worlds leading aircraft and aerospace manufacturer, headquartered in Chicago, Illinois, with its largest production facilities in Everett, Washington, about 30 miles north of Seattle, Washington. ... Airbus S.A.S. better known as simply Airbus, based in Toulouse, France, is the worlds top commercial aircraft manufacturer measured by orders and deliveries for 2003 and 2004. ...

Supplementary/Supplemental Type Certificate (STC)

Any additions, omissions or alterations to the aircraft's certified layout, built-in equipment, airframe and engines initiated by any party other than the type certificate holder need an approved supplementary ("supplemental" in FAA terminology) type certificate, or STC. The scope of an STC can be extremely narrow or broad. It could include minor modifications to passenger cabin items or installed instruments. More substantial modifications may involve engine replacement, as in the Blackhawk modifications to Cessna Conquest and Beechcraft King Air turboprops, or a complete role change for the aircraft, such as converting a B-17 or Stearman into an agricultural aircraft. STCs are applied due to either the type certificate holder's refusal (frequently due to economics) or its inability to meet some owners' requirements. STCs are frequently raised for out-of-production aircraft types conversions to fit new roles. Before STCs are issued, procedures similar to type certificate changes for new variants are followed, likely including thorough flight tests. STCs belong to the STC holder and are generally more restrictive than type certificate changes. The Cessna 441 Conquest was the first turboprop designed by Cessna and was meant to fill the gap between their jets and piston-engined aircraft. ... King Air is the general name for a family of all-metal, twin-turboprop civilian aircraft produced by the Beech Aircraft Corporation (now Raytheon). ... A Turboprop or turboshaft engine is a type of gas turbine. ... A B-17 on a bombing run. ... PT-17 Stearman The Stearman model 75, widely known as the Stearman, Boeing Stearman (Stearman became a subsidiary of Boeing in 1934) or Kaydet was a biplane built in the United States during the 1930s as a military trainer aircraft. ...

Validity of Type Certificate

The type certificate holder keeps the type certificate valid by continuously following airworthiness directives, issuing service bulletins and as well as providing spares and technical support to keep the aircraft current with the prevailing rules. This is true even if the production of the type has stopped. This is what is meant by supporting the type and in this manner many out-of-production aircraft continue useful lives. Typical examples are old Boeings, Airbuses, McDonell Douglases, Lockheeds, Fokkers, Dorniers and many others. STCs are also bound by the same rules. When the holder decides to stop supporting the aircraft type (due to many reasons mainly economics), the type certificate is returned to the regulators and the remaining aircraft fleet permanently grounded. In this manner the whole Concorde fleet was finally grounded when Airbus SAS surrendered its type certificate. DC-10, retired from American Airlines fleet at gate McDonnell Douglas was a major American aerospace manufacturer, producing a number of famous commercial and military aircraft. ... The Lockheed SR-71, remarkably advanced for its time and unsurpassed in many areas of performance The Lockheed U-2 first flew in 1955 providing much needed intelligence on Soviet bloc countries Lockheed Corporation was an aerospace company founded in 1912 which merged with Martin Marietta in 1995 to form... Fokker 100 of British Midland Airways Fokker was a Dutch aircraft manufacturer named after its founder, Anthony Fokker. ... Dornier may refer to Claudius Dornier, original founder of Dornier GmbH Lindauer DORNIER GmbH FairchildDornier Dornier Medtech [1], maker of medical equipment e. ... The Aérospatiale-BAC Concorde supersonic transport (SST) was one of only two models of supersonic passenger airliners to have seen commercial service. ... Airbus S.A.S. better known as simply Airbus, based in Toulouse, France, is the worlds top commercial aircraft manufacturer measured by orders and deliveries for 2003 and 2004. ...

References

• Federal Aviation Administration - Certificate Types - Type Certificate Data Sheets
• List of US Approved Type Certificates; 1927 - 1958
• List of US Group 2 Memos; 1929 - 1947