- Classification of Avionics Changes
- Extended model list
- Permits to Fly
- Orphan aircraft
- Execution of ground tests for compliance showing in a Minor Change Application
- EASA types and Annex II types
- Light Sport Aircraft
- Russian aircraft
- Grandfathered approvals
- Specific Airworthiness Specifications
- Classification of changes (non-avionics)
- Approval of Flight Conditions
- Validation of FAA STCs classified as Basic and limited to one serial number
How does EASA classify antenna installations?View
How does EASA classify single and dual GNS4xx/5xx installations?View
How does EASA classify Transponder Mode S Diversity and dual Transponder installations?View
How do I know whether my proposed change is Minor or STC?
Use of extended model list in case of minor changes for common replacements (box out - box in) of basic avionics equipment (e.g. transponder)
The replacement of avionics is a change to the type design that has to be approved in accordance with Part-21, and, for that, it has to be classified as major or minor, depending on the effect that the change has on the airworthiness of the A/C. The rules for the classification are identified in paragraph 21.A.91 and the guidance in the GM 21.A.91. Additional guidance can be found in the FAA AC 23.1309-1E and the “FAQ table of design change classification”.
Regarding the applicability of the change, each application need to include a reference to the TC and the eligible A/C type/model to be changed. As indicated on EASA website at the FAQ for Fees and Charges, one application for TC, RTC, STC, Major and Minor Change can cover several models but not more than one type per certificate.
There are, however, some exceptions where a list of models, applicable to aircraft covered by different TC’s, has been accepted. In such case, it has to be shown that the design change and the demonstration of compliance is valid, without relevant differences, on all the TC’s/models listed in the paragraph on the applicability of the modification.
Modifications consisting of a replacement (“box out – box in”) of basic avionics (e.g. transponder) represent one of such exceptions. In order for a design change to fall in this category, where an extended model list of A/C from different types can be accepted, the following criteria should be met:
- The design change is classified as minor according to Part 21.A.91;
- A proper and detailed model list is provided;
- A common certification basis in the Area of the change can be applied;
- Commuter category is excluded;
- The design change must be a pure replacement (“box out – box in”);
- For equipment located on the flight deck, it must be replaced by equipment which utilises the same location as the equipment which was removed;
- The validity of the modification design has been checked and justified in writing for all the models in the list;
- The minor classification is valid for all the models on the list. This means that the conditions that make the classification minor are valid for all the models (and categories) and no limitation is invalidated (example: installation of transponder on A/C with cruise TAS greater than 250 kts, is major);
The following conditions also apply:
- The mass of the new equipment is not significantly higher;
- Cables and Antennas have not changed (change of the mating electrical connector on the aircraft is accepted);
- The equipment does not add any new functionality.
Meeting all the above conditions typically allows acceptance of applications with extended model list. When one or more of the above conditions are not met, a case by case evaluation is possible. In both cases, acceptance will not constitute a precedent for any future change.
Who can issue a Permit to Fly?
In accordance with Part21A.711, the competent authority of the member state of registry is normally responsible for the issue of a Permit to Fly. Appropriately approved design or production or continuing airworthiness management organisations may also issue a Permit to Fly within limitations specified in Part 21.
When do I need a Permit to Fly?
When my aircraft does not meet, or has shown not to have met, applicable airworthiness requirements and as a result does not hold a valid certificate of airworthiness or restricted certificate of airworthiness, but is capable of a safe flight under defined conditions and for the purposes listed on point 4.2 of Form 37.
Note that the member State of Registry can also grant an exemption to allow an aircraft to fly without a valid C of A or R-C of A under the provisions of article 14.4 of the Basic Regulation if it finds that the conditions of this article are met.
How does EASA deal with aircraft without a Type Certificate holder?
An aircraft becomes orphan when:
- the legal person holding the Type Certificate (TC) has ceased to exist. The TC automatically becomes invalid by law because there is no one to be in compliance with the TC holders responsibilities (21A.51 (a) 1 and 21A.44); or
- The TC holder no longer complies with his regulatory obligations. A typical case is when the TC holder loses his DOA, or fails to comply with 21.A.14 before 28.09.05. This makes the TC invalid (21A.51 (a) 1)
- The TC holder has surrendered the TC. This also makes the TC invalid (21A.51(a)2).
Under the current Part 21, orphan aircraft cannot be issued a Certificate of Airworthiness, which requires that a TC holder takes responsibility for the continued oversight of the design. They can therefore only continue to be operated if they hold a restricted certificate of airworthiness or a permit to fly. These documents can only be issued on the basis of a design approved by the Agency.
How can I perform a ground test for showing of compliance (using “not yet approved” design data) in a Minor Change Application?
Preliminary remark: This FAQ is aimed to provide guidance on how to perform a ground test for a minor change application (Example: a minor change for the installation of a radio or transponder), and how the actions between the MC applicant and the installer shall be shared.
IMPORTANT: the following is valid only in cases where the ground test is needed to prove that the design change complies with the certification requirements. In many cases the ground tests are “post-installation tests” to check functionality and conformity for the release of the installation. In such cases the instructions below are not needed since the test would be done based on already approved data.
The following definitions and abbreviations will be used (limited to the scope of this FAQ):
- MC: minor change;
- MC Applicant: the Applicant (organisation or person) to EASA for the minor change approval and the owner of the design data that will be approved with the minor change;
- Installer: The organisation/person that will perform the modification of the aeroplane according to the MC design data and will release to service the aeroplane (note: According to part M.A.801 of EU regulation 1321/2014, this can be in some cases a person: certifying staff or the pilot owner). It is acknowledged that in most of the cases the MC applicant and the Installer are the same entity;
- Certified aircraft: the aircraft that is used for the ground test. Typically this is an aeroplane with its own CofA (Certificate of Airworthiness) that will be modified with the MC design data.
In cases, a certified aircraft is modified and used for the ground test to show compliance to the airworthiness requirements, the following shall be considered:
- Test plan: The MC applicant shall issue a test plan;
- Design data: the certified aircraft shall be modified using design data (drawing, specifications, procedures) provided by the MC applicant clearly identifiable as “not approved data”. IMPORTANT: Any instruction shall contain a statement like: “The approval status of the technical content of this document is limited to demonstration of compliance purposes only. Final approval is pending the approval of EASA minor change Project Nr. XXX. The aircraft shall not be released to flight before evidence of final approval is provided”;
- Aircraft modification: the installer modifies the aircraft using the design data provided by the MC applicant. The installer shall report all discrepancies (if any) to the MC applicant;
- Tests Configuration: The installer prepares the aircraft and the test equipment for test configuration. The conformity to the configuration required for tests should be checked together with the MC applicant;
- Test execution: The installer (or the MC applicant) performs the test and provides the test results. Tests can be also performed by a third party. Ultimately, it is the responsibility of the MC applicant to check the correctness of the test execution;
- Approval of modification: after test results have been received and accepted, and the rest of the compliance documents are also accepted, the approval is issued by EASA. Following issue of the approval, the MC applicant provides the installer with the final set of design data (in most cases they will be the same as the ones provided for test execution, but it could happen that the final set of design data provided for modification needs to be changed, in which case the installer shall be informed accordingly) and remove/replace the initial statement with the following statement: “the technical content of this document is approved with EASA approval XXXX).
- Flight tests for development / compliance demonstration: the above bullets can be considered in principle also for flight tests, with the difference that in this case, a Permit to Fly will be needed and corresponding rules of Part-21 Subpart P shall be followed.
A similar topic is treated in EASA document “GOOD PRACTICES ‐ First Installation of a Change to a Product” for DOA installing STC.
May I use Unleaded Aviation Gasoline (Avgas) UL 91 even if the airframe TCDS states that the minimum fuel octane is 100?
The use of Avgas UL 91, when this fuel grade has been approved for the particular engine types, is allowed even if the airframe TCDS specifies a higher minimum number of octane (e.g. Avgas 100LL). In this case, the Avgas UL 91 can be used with no approval required for the aeroplane, provided the aeroplane is already approved for operation with Avgas or Mogas and the engine is already approved to use unleaded Avgas UL 91. Avgas UL 91 may also be used in all engines and aeroplane types approved by the Type Certificate Holder for use with Mogas RON 95 (MON 85) in accordance with Standard EN228:2008.
The background of this special situation is that in the last decades many aeroplanes have been approved for 100LL only (because no other avgas grade was available) despite the fact that the engine is approved also for lower avgas grades (like 80/87).
SIB 2011-01R2 has been published to inform all owners and operators of aeroplanes powered by spark-ignited piston engines about the use of unleaded Avgas UL 91. The SIB clarifies the actions to be done to allow use of Avgas UL 91.
IMPORTANT: Use of unleaded Avgas UL 91 in engines that have not been approved for the use of these fuels may cause extensive damage or lead to in flight failure, due to the lower Motor Octane Number (MON) of the fuel, compared to Avgas 100LL.
How does EASA deal with STCs on Reims-built Cessna models?
STCs approved on US-built Cessnas and their applicability to Reims-Cessna models.
Reims-Cessna was a French company that manufactured US-designed Cessna aircraft under licence. These included the F150, F152, F172, F177, F182, F337, F406 and their variants. These aircraft were identical to the US-built aircraft but the French aircraft were given DGAC Type Certificates. For this reason, FAA STCs approved for US-built Cessna models do not formally apply to Reims-Cessna models; this also applies to validated STCs. However, because the Reims-Cessna aircraft are identical to the US-built aircraft, and because there is no technical investigation necessary to extend the applicability of STCs to the French-built aircraft, EASA can extend the grandfathered approval to Reims-built aircraft but the approval has to be legally recorded. The mechanism that is used is the minor change, even if the modification would normally be classified as STC (ie, a major change). The applicant should apply on an EASA Form 32 referring to the FAA STC and its EASA grandfathered approval in the application.
Note that all Reims-Cessna models are now covered under FAA Type Certificates, with the exception of the FTB337G and GA which are covered by EASA SAS and the F406, which is still the responsibility of Reims Aviation Industries (RAI).
How does EASA deal with Applicable Model Lists?
In general, an STC can apply to only one Type Certificate. Certain exceptions can be made where the installation of a piece of simple equipment is clearly identical from one aircraft type to another, but EASA procedures state that an STC should apply to one TC only. Each new TC should be the subject of a new application.
This principle also applies to the validation of FAA STCs.
My aircraft has been modified in the USA by Form 337 action. Can EASA accept this?
There is no automatic acceptance of Form 337 approvals by EASA, except under certain limited conditions. They need to be assessed individually and may need to be separately approved, normally by application for a minor change or by an approved organization under their DOA.
How do I apply for an STC approval?
Application for STCs are made using the specific form available in the Application forms page.
Applications can be ot two types:
- An application from an EU organization for the EASA approval of a new STC. This requires theat the applicant has Design Organisation Approval (DOA) or, at least, Alternative Procedures (AP to DOA).
- An application from a non-EU organization for the EASA validation of a non-EU STC. The application must be made in accordance with any Working Arrangement or Bilateral agreement. In the case of STCs issued by the FAA, for example, the STC holder must make the applicaion via the FAA Aircraft Certification Office (ACO) that did the original approval.
How do I apply for an STC approval?
The STC holder must make the application via the FAA Aircraft Certification Office (ACO) that did the original approval. The ACO must provide a covering letter endorsing and classifying the application (Basic or non-Basic) and forward it to EASA. Applications where EASA agrees the classification as 'Basic' are normally dealt with quickly. Please note that FAA STCs that apply to a number of different aircraft types as referred to in the 'Applicable Model List' (AML) will generally not be accepted by EASA.
unless split into different applications, one per Type Certificate. This split may be done at EASA if not done by the applicant but will effectively be treated as multiple applications. If in doubt, please contact EASA.
How do I know whether an STC has been grandfathered?
Any STC approved or validated by any member state before the establishment of EASA is deemed to be 'Grandfathered' under Regulation 1702/2003 Article 2 (3)(a). Unfortunately, there are tens of thousands of these approvals and it has not been possible to put together a database. We normally recommend an enquirer to contact the STC holder (the FAA website has these details) and check with them directly whether they have any EU customers. The STC holder should know who his customers have been because he has obligations to maintain continued airworthiness for his modifications.
How do I know whether my aircraft is an EASA type?
The EASA aircraft lists can be found in the Product Certification page and there are separate links for EU and non-EU products. Annex II types are, by definition, not EASA aircraft and are therefore handled under national rules.
How does EASA deal with Light Sport Airplanes?
A Light Sport Airplane (LSA) is a simple two-seater with a maximum take-off weight of 600kg. Commission Regulation (EC) No 748/2012 (Part 21) issued on August 2012, introduced a new process for the European Light Aircraft (ELA) that, together with the certification specifications CS-LSA published in 2011, create a lighter regulatory regime for the EASA certification of LSA aircraft.
Before the ELA process was in place an EASA Permit to Fly (PtF) according to Regulation (EC) No 1702/2003 (as amended by Regulation 375/2007) Part 21A.701 (15) was an option. The principles for the issuance were based on the rulemaking task MDM.032. With the new ELA process a PtF according to 21A.701(15) is no longer appropriate and the approval of flight conditions will be gradually stopped during the next 2 years and 6 month period. During this transition period all the LSA aircraft flying under PtF will need to obtain a normal or restricted Certificate of Airworthiness, after inspection and, if necessary, modification. The conditions and time schedule for the transition period are explained in the following document:
Permit to Fly principles:
- The ASTM Standard for light sport aircraft is accepted as a "certification" basis for issuing a permit to fly following Part21A.701 (15) until such regulations are in place in Europe.
- The permit to fly will have a limited validity (2 years) and will not be extended when ELA-rules are in place in Europe.
- A permit to fly based on Part 21A.701 (15) is only valid for non commercial activities according to the Basic Regulation .
- There is no automatic transfer of these PtF into another kind of EASA approval. As an EASA certification following ELA processes will be appropriate in future the PtF has to be replaced.
- Showing of compliance (load analysis, static test, flight test etc.) has to be done and the EASA needs to be satisfied that the aircraft is able to perform safe flights when operated according to the approved flight conditions. The approval can only be granted for the MTOM for that the showing of compliance with the requirements is valid.
- The involvement of the "holder of the type design" is required for establishing the flight conditions as the future regulation will define some kind of TC and TC-Holder obligations according to Part 21 and the showing of compliance with ASTM Standard requires detailed knowledge of the design. In absence of a TC-Holder private owners need to organize themselves and find an acceptable organisation performing the required "certification" activities.
- For the first application a more detailed review of the documentation for ASTM "Certification" will be done and flight conditions will be developed. For the following applications the process can be simplified and the agreed flight conditions can be approved when manufacturing documentation and inspection reports are submitted.
- With approved flight conditions registration of the aircraft is possible in all EU member states.
- Pilot licence needed is at least the national licence for an aeroplane in that weight category.
- A maintenance regime has to be defined following basic principles of "new" Part-M.
- Limitations will prohibit at least IFR, Night VFR, Aerobatics, Solo-Training.
- Modifications of the aircraft require a new approval of flight conditions.
Alternative (Restricted) Type Certification
As there are still some open issues left e.g. for issue of CofA for such PtF aircraft an alternative way should be mentioned. Without ELA processes there is already the possibility to get a certification for products not fully conforming to CS-VLA and Part 21.
- As the ASTM Standard needs to fulfil the essential airworthiness requirements of Basic Regulation it can be applied using a special condition with public consultation.
- When engine and propeller have no type certification EASA has already the option to accept a restricted type certification for such an aircraft.
- Holder of such an (restricted) TC needs to demonstrate their capability through design organisation approval (DOA) or alternative procedures to DOA.
- Manufacturing requires production organisation approval
- Maintenance needs to be done according to Part-M.
EASA Definition Light Sport Aeroplane
Light Sport Aeroplane complies with the following criteria:
- A Maximum Take-Off Mass of not more than 600 kg
- A maximum stalling speed in the landing configuration (VS0) of not more than 45 knots CAS at the aircraft's maximum certificated Take-Off Mass and most critical centre of gravity.
- A maximum seating capacity of no more than two persons, including the pilot.
- A single, non-turbine engine fitted with a propeller.
- A non-pressurised cabin
These specifications apply to aeroplanes intended for "non-aerobatic" and for "VFR day" operation only.
The airworthiness code is ASTM International standard F2245.
The Multi-Disciplinary Measure (MDM) group MDM.032 is working on proposals to reduce the regulatory burden on these recreational aircraft. These changes to the regulations, when in place, will replace the interim measures set out above.
How does EASA deal with Russian general aviation (GA) aircraft types Su-26, Yak-54, Yak-55, Su-29, Su-31, and Yak-18T?
When it comes to the above mentioned Russian GA aircraft types, the situation can be described as follows:
1) Aircraft covered by transitional arrangements:
A limited number of the above mentioned Russian GA aircraft types have been covered by transitional arrangements (identified by serial number) .
According to article 5 of Regulation 748/2012, for a certain number of Russian GA aircraft that were on a Member State´s register before the applicability of the Basic Regulation, the Agency has developed Specific Airworthiness Specifications (SAS) on the basis of which the aircraft are eligible for the application for a Restricted Certificate of Airworthiness (RCofA) at the Member State´s NAA in accordance with art. 21.A.173(b). However, this only applies to the aircraft specifically listed (by serial number) in the SAS (SAS.A.093 for Su-29; SAS.A.094 for Su-31 and SAS.A.095 for Yak-18T).
Additionally, for aircraft that, although in the register of one of the Member States at the date of applicability of the Basic Regulation, could not fulfil all the criteria of article 5 for the issue of an SAS, the Agency has issued flight conditions which have allowed these aircraft to continue to fly based on a national Permit to Fly. This was done based on the same grandfathering principles (to cover aircraft already registered in the Member States), based on information received from the Member States of registry, and limited to a restricted number of individual aircraft (identified by serial number).
Only individual aircraft that were registered in one of the Member states before the date of applicability of the Basic regulation to that State were covered by the transitional arrangements described above.
The dates of applicability of the Basic Regulation for the various EASA Member States are:
- 27. September 2003: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxemburg, Portugal, Spain, Sweden, The Netherlands, United Kingdom.
- 1. May 2004: Czech Republic, Cyprus, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovak Republic, Slovenia.
- 1. June 2005: Iceland, Norway, Liechtenstein.
- 1. December 2006: Switzerland.
- 1. January 2007: Bulgaria, Romania.
- 1. July 2013: Croatia.
2) Aircraft not covered by transitional arrangements:
For all other Russian GA aircraft of the types listed above, the general procedure according to Part-21 applies. This means that applicants for the approval of flight conditions by the Agency need to demonstrate “that the aircraft is capable of safe flight under the specific conditions and restrictions” (art. 21.A.710c), hence need to provide the Agency with a comprehensive certification plan for each application/aircraft. The certification plan should consider the relevant Certification Specification (CS) for the aircraft (e.g. CS-23) as well as for engine (e.g. CS-E) and propeller (e.g. CS-P). Also, the continued airworthiness of the aircraft needs to be ensured.
An aircraft registered by a Member State before 28 September 2003 was fully in compliance with the respective TCDS at that time. However EASA issued a TCDS in the meantime, which differs from the grandfathered national TCDS. Is the owner required to retroactively modify the aircraft?
With regard to products which had a type-certificate issued or validated by a Member State before 28 September 2003, the product in Principle is deemed to have a type-certificate issued in accordance with Commission Regulation (EC) No 1702/2003. In such cases where more than one TCDS for the same product existed within the Member States (e.g. TCDS of the State of Design and TCDS of another Member State having validated that TC), the Agency used the TCDS of the Member State of Design as basis for its TCDS in most cases. If the EASA-TCDS differs from one of the grandfathered TCDS, the owner is not required to modify the product retroactively, provided that the circumstances of Article 2a of Commission Regulation (EC) No 1702/2003 are fully met with. Any future Regulation on air operation may however require the installation of other or additional equipment.
What are grandfathered approvals?
Any STC approved or validated by any member state before the establishment of EASA is deemed to be approved under Regulation (EC) No 1702/2003 Article 2a. This covers all previous approvals from minor changes to major changes, STCs and complete aircraft, both certifications and validations with the exception of products of the former Soviet Union. It also covers the flight conditions approved for aircraft operating under national Permits to Fly issued before 28 March 2007.
How to move an orphan aircraft from Restricted Certificate of Airworthiness (RCoA) to an EASA Permit to Fly (PtF)?
For a number of reasons, an aircraft owner may wish to move an orphan aircraft from a Restricted Certificate of Airworthiness (RCoA) which has been issued based on an existing Specific Airworthiness Specification (SAS) to a Permit to Fly (PtF).
Several (at present mostly) French built orphan aircraft types of the same basic Type Design are operated under RCoA (based on SAS) and also under PtF. The service experience, based on occurrence data available at DGAC, suggests that currently a safety risk does not exist when aircraft are moved from an SAS (RCoA) to a PtF. On the basis of this evidence EASA policy is to allow any aircraft with an SAS (RCoA ) to transfer to a PtF if the owner requests.
The transfer process is initiated by sending both EASA Forms 37 to EASA online, together with drafted Flight Conditions (FC). The fees for the approval of the FC are invoiced iaw. actual Commission Regulation on Fees and Charges.
Once the Flight Conditions (FC) have been approved by EASA, an EASA PtF is issued by the Competent Authority of the State of Registry (SoR) based on the approved FC. This involves the applicant making a separate application to the Competent Authority of the SoR.
If the technical aspects of an FC are deemed to be generic for a specific type or model, they will be published together with the appropriate SAS. Where there is a need, Generic Flight Conditions (GFC), if not yet existing, will be developed by EASA in cooperation with the National Aviation Authority (NAA) of the State of Design and added to the SAS.
A Data Sheet (DS) should be understood as an aircraft design definition document and is an essential part of the FC. Such DS will not extend the scope of the SAS (initial TCDS), but specify the design of the particular aircraft at the time of initial PtF issuance. Any later design changes, other than Minor Changes as defined in the FC, have to be approved by EASA by reissuing (approving) of the FC for the affected s/n. Supplemental Type Certificates (STCs) approved/grandfathered before the SAS was issued initially may be used without separate FC approval (this should be clearly indicated in the FC). The same approach is valid for Standard Changes (changes approved per CS-STAN).
In legal terms, Airworthiness Directives (AD’s) do not automatically apply to EASA permitted aircraft. The only way to solve any airworthiness issues is to revoke the EASA approved FC and issue a new FC which specifies the Airworthiness Directive as mandatory. If necessary, the NAAs will be notified by EASA accordingly.
The FC also include a reference to the arrangements for the continued airworthiness regime for the aircraft, which may differ from one SoR to another, depending on local arrangements.
Theoretically, it is possible to move back from a PtF to an SAS (RCoA). During this process the State of Registry should be satisfied that the aircraft in questions meets the SAS type design and has been maintained iaw. Part M in the meantime. However in practice this will be extremely difficult, if not impossible.
How do I find out if my aircraft has an SAS or TC?
The EASA aircraft lists can be found in the Product List page.
These lists specify whether the aircraft has a TC or SAS. This only applies for aircraft (including rotorcraft and lighter-than-air) but not to propulsion. If an engine or propeller becomes an orphan, there is no SAS.
What is a Specific Airworthiness Specification (SAS)?
Commission Regulation (EC) No 1702/2003 requires products, parts and appliances to be issued with certificates as specified in Part 21. Aircraft without a valid type certificate holder cannot comply with Subpart B of Part 21 and cannot therefore hold type certificates. The Specific Airworthiness Specification (SAS) is the replacement document. Specific Airworthiness
Specifications are issued to aircraft without a valid Type Certificate Holder ('Orphan' aircraft) or for certain aircraft General Aviation types from CIS that have been certificated in CIS but not validated by EASA.
The eligibility of the proposed product should first be reviewed. Annex II aircraft, for example, cannot qualify for SAS as they are outside of the remit of the Agency. If a Type Certificate Holder (TCH) still exists, the preferred path to certification of the product is through a Type Certification or Type Validation. If the current Certification Specifications cannot be met, the option of a Restricted Type Certificate can be offered.
If the aircraft Type Certificate Holder is no longer in business ("orphan TC") or does not wish to apply for Type/ Restricted-Type Certification, the application for SAS can be initiated by an operator/owner. It should be emphasised that the SAS should not be seen as a mechanism for avoiding type certification in accordance with Part 21. For General Aviation types the SAS has been used to 'legalise' aircraft that had not been certificated in accordance with Part 21 but which were already on the registers of EU member states on accession to the EU. Whilst it legalises these aircraft, it is not intended to be used to allow the import of additional aircraft of the same type which should be certificated in the normal way.
The loss of an engine or propeller TC holder does not automatically invalidate the aircraft TC, so an orphan engine does not have to result in an orphan aircraft if the aircraft TC holder is prepared to accept the continued airworthiness responsibility of the engine. SASs do not apply to engines or propellers.
Before the creation of EASA, some orphan aircraft have been allowed to operate on non-ICAO level certificates of airworthiness (Permit to Fly, CDNR, etc) and cannot usually be returned to Restricted Certificate of Airworthiness standard. These examples are listed by serial number on the SAS and continue to qualify for EASA Permit to Fly under 21A.701(15). There is no intention to permit aircraft to otherwise voluntarily default to Permit to Fly if they otherwise conform to the SAS.
Aircraft conforming to the appropriate SAS are eligible for the issue of a Restricted Certificate of Airworthiness.
The SAS consists of:
- The original State of design TCDS in EASA format
- Airworthiness Directives
- Instructions for reporting continued airworthiness occurrences
- Any additional limitations including a prohibition from commercial activities#
Link to Specific Airworthiness Specifications page
See Article 5 (4) of the Basic Regulation and Regulation (EC) 1702/2003 Part 21, 21A.184
What might lead to an "acoustical change"?
A light propeller driven aircraft's certificated noise level is dependant on two factors, the aircraft's noise at source and the aircraft's take-off performance as defined the AFM. An adverse change to either could lead to a finding of an "acoustical change".
Factors that might adversely affect an aircraft's noise at source
The two principle sources of noise are the propeller and the engine.
Propeller noise is highly dependent on the propeller helical tip Mach number. Other factors that influence propeller noise include the number of blades, blade tip shape, blade thickness and the inflow angle of air flowing into the propeller. Any change that could affect any of these factors is potentially an acoustical change.
Such changes would include:
- An increase in take-off rpm ("red line"), or highest rpm in the normal operating range ("top of green arc");
- A change leading to an increase in the best rate of climb speed (Vy);
- An increase in propeller diameter;
- A change to the propeller tip shape;
- An increase in the propeller blade thickness;
- A change in the number of propeller blades;
- The installation of a variable pitch propeller in place of a fixed pitch propeller;
- Any change in the propeller inflow angle.
Engine noise is directly related to engine power. Many engines are fitted with noise suppression devices. Any change that increases engine power or modifies in any way the engine exhaust or the performance of the mufflers, if fitted, is potentially an acoustical change and should be referred to C.1.6.
Factors that might adversely affect an aircraft's take-off performance
The noise certification reference take-off procedures are defined in terms of the approved take-off distance (D15), rate of climb (ROC) and best rate of climb speed (Vy). Any change that causes an increase in D15, a decrease in ROC or a change in Vy will potentially mean the aircraft is lower when it overflies the microphone and therefore noisier.
Such changes would include:
- An increase in take-off weight;
- A decrease in engine power;
- In the case of an aircraft where take-off power/rpm is time limited a change in the period over which take-off power/rpm may be applied;
- A change that increases the aircraft's drag (e.g. the installation of external cargo pods, external fuel tanks, larger tyres to a fixed undercarriage, floats etc.).
Other factors to be taken into account
Aerodynamic noise, although potentially a significant source of noise for large aircraft, is not generally a significant source for light propeller driven aircraft. Modifications such as the fitting of vortex generators, drooped leading edges or gloves, and extensions or re-profiling of the wing tips would not themselves be considered to be acoustical changes.
However such modifications are often associated with an increase in take-off weight and may therefore be considered as "acoustical changes". A modification to an aircraft that involves the removal of such devices might also be considered to be an "acoustical change" since their removal may lead to a deterioration in the aircraft's performance.
In addition such changes may affect the aircraft incidence during climb-out and potentially change the propeller inflow angle which might itself constitute an "acoustical change".
How does EASA treat my uncertificated ultralight/microlight aircraft?
If the aircraft comes within the definition of Annex II to the Basic Regulation, it is not an EASA type and is handled under national rules. If it does not fit into this definition it is an EASA type and is covered under the procedures below.
When do the noise aspects of a propeller and/or engine lead to a classification as major or STC?
Any change that has an "appreciable effect" on the noise characteristics of an aircraft is referred to as an "acoustical change", and by definition is considered to be a major change. An "acoustical change" is defined as a change that increases the noise certification level by more than 0.1 dBA.
What should the Applicant do?
In the first instance the Operator should establish whether the defective condition is covered by any of the existing approved data, eg. MMEL, CDL etc..
If none of these options are applicable the next step is to contact their Competent Authority to start the process for the issue of a Permit to Fly. At this stage the operator needs to agree with his Competent Authority whether the Flight Conditions are related to safety of the design. If they are not, then the complete process can be dealt with by the CA.
If the CA determines that safety of the design is affected, then the flight Conditions will need to be approved either by EASA, or by a suitably approved DOA. In many cases the TC holder will have privileges to do this, based on previously approved Flight Conditions agreed with EASA.
If the Flight Conditions cannot be approved either by the CA or by a DOA, then an application to EASA using Form 37 will be necessary. EASA will require technical data to support the application which identifies the defective condition (eg pictures of any visible damage), actions taken to minimise the effects (eg statement from the manufacturer supporting the flight), and proposals for the Flight Conditions (using Form 18b) that further mitigate the situation in order that it can be clearly determined that a safe flight can be performed.
Where it is known that Flight Conditions will need to be approved by EASA, application for these could be made in parallel with the application to the CA for a Permit to Fly.
Why do I need Flight Conditions Approval?
Because the Permit to Fly will be issued on the basis of the approved flight conditions, and these will identify the limitations applicable.
Who can Approve Flight Conditions?
In accordance with Part 21A.710 EASA is normally responsible for the approval of Flight Conditions where they relate to safety of the design. However, certain DOA holders may have the privileges to approve flight conditions related to safety of the design. Where the Flight Conditions are not related to safety of the design, they may be approved by the competent authority.
What is the EASA responsible for?
As described above, EASA is normally responsible for the approval of the flight conditions on the basis of which a permit to fly can be issued by the Competent Authority.
The Agency approves the Flight Conditions in cases related to the safety of the design, defined as follows:
- the aircraft does not conform to an approved design; or
- an Airworthiness Limitation, a Certification Maintenance Requirement or an Airworthiness Directive has not been complied with; or
- the intended flight(s) are outside the approved envelope.
How can I submit an application?
Applications for the approval of flight conditions can be sent at any time by fax, e-mail or regular mail to:
European Aviation Safety Agency
Applications and Procurement Services Department
Manager of the Product Applications Management Section
Postfach 10 12 53, D-50452 Köln, Germany
Fax: + 49 (0)221-89990 4455
E-Mail: flightconditions [at] easa [dot] europa [dot] eu
The process for applying for the PtF from your Competent Authority is detailed on their website or in their publications.
In the event of an emergency situation occurring outside office-hours, during week-ends or public holidays, your Competent Authority can contact EASA directly.
What is the EASA administrative validation of the FAA Basic STCs for second hand aircraft, serial number specific?
This is a simplification of the EASA validation process for the cases where the US STC Holder of a FAA STC classified as Basic is unwilling or unable to apply for EASA validation.
The scope is limited to Fixed Wing aircraft and installed engines, if applicable, in the following categories:
- > 2 000 kg ≤ 5 700 kg MTOW
- ≤ 2 000 kg MTOW
- Very Light Aeroplane
- Light Sport Aeroplane
- Powered Sailplanes
Please note that STCs that involve changes which impact the aircraft’s noise characteristics are excluded from this simplified process.
Please note that this process is valid only for Fixed Wing aircraft STCs.
What does the EU applicant need to do?
The EU applicant needs to:
- check against the latest EASA-FAA Technical Implementation Procedures (TIP) provisions that the FAA STC is Basic, and in this case:
- complete the application form, FO.CERT.00134, “EASA validation of FAA Supplemental Type Certificate classified as Basic and limited to one serial number”,
- submit the application form together with a copy of the FAA STC, applicable documentation, correspondence with the STC Holder (STCH) as well as STCH statement of “no objection for EASA validation”, if available, at STC [at] easa [dot] europa [dot] eu,
- acknowledge his/her obligations as Holder of the STC in accordance with Part 21, point 21.A.118A and
- sign the declaration of fulfilling those obligations.
What is a FAA Basic STC?
In accordance with the Technical Implementation Procedure (TIP) for Airworthiness and Environmental Certification between FAA and EASA rev 5, Section 1.6 Definitions:
(f) “Basic Supplemental Type Certificate (Basic STC)” means a Supplemental Type Certificate whose validation does not require Validating Authority (VA) technical involvement.
What is the classification criteria for Basic STCs?
The classification criteria for Basic STCs are stipulated in Appendix C, Section II, Paragraph 6, of the , listed below:
6.2 Non-Basic STCs will generally be more complex and may require some VA involvement. Criteria for a Non-Basic STC are:
6.2.1. Changes classified as significant, in accordance with 14 CFR 21.101(b) and EASA’s Part 21A.101(b).
6.2.2. Changes requiring, or, for concurrent programs, anticipated to require, a special condition, exemption/deviation, equivalent level of safety finding, or acceptable means of compliance identified in a CA issue paper/CRI.
6.2.3. Changes introducing design features or operational capabilities identified on the VA generic VI list if the authority has published the list (see paragraph 4.5 of this Appendix).
6.2.4. Changes where the STC compliance checklist includes standards included in the VA SSD list if the authority has published the list (see paragraph 3.2 of this Appendix).
6.2.5. Any other design changes categorized as a Non-Basic STC by the CA.
6.3 All other STCs are considered Basic STCs.
Where can I find the application form for this process?
The application form can be found in the document library under applications forms.
With whom in EASA can I speak about this process?
Please use the mailbox below for any queries regarding this process.
GADadmin [at] easa [dot] europa [dot] eu
What is the fee charged?View
What document do I receive?
The application form FO.CERT.00134, “EASA validation of FAA Supplemental Type Certificate classified as Basic and limited to one serial number” contains on page 3 the EASA statement and approval number which will be signed, dated and stamped.
The statement below is proof of EASA validation. Please place this page in the aircraft log.
6. EASA Statement - To be filled in only by the European Aviation Safety Agency
The FAA Supplemental Type Certificate specified in section 3 is classified as Basic and hereby validated for the aircraft identified in section 4. This validation is limited to the serial number under 4.1.
EASA Approval Number