General aviation - FAQ

Grandfathered approvals

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.

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.

Permits to Fly

When do I need a Permit to Fly?

Any aircraft that does not hold a valid CoA or R-CoA, but are capable of safe flight under defined conditions and for the following purposes may be eligible for an EASA Permit to Fly:

  1. development;
  2. showing compliance with regulations or certification specifications;
  3. design organisations or production organisations crew training;
  4. production flight testing of new production aircraft;
  5. flying aircraft under production between production facilities;
  6. flying the aircraft for customer acceptance;
  7. delivering or exporting the aircraft;
  8. flying the aircraft for Authority acceptance;
  9. market survey, including customer's crew training;
  10. exhibition and air show;
  11. flying the aircraft to a location where maintenance or airworthiness review are to be performed, or to a place of storage;
  12. flying an aircraft at a weight in excess of its maximum certificated takeoff weight for flight beyond the normal range over water, or over land areas where adequate landing facilities or appropriate fuel is not available;
  13. record breaking, air racing or similar competition;
  14. flying aircraft meeting the applicable airworthiness requirements before conformity to the environmental requirements has been found;
  15. for non-commercial flying activity on individual non-complex aircraft or types for which a certificate of airworthiness or restricted certificate of airworthiness is not appropriate.

Only those purposes where design elements are involved require EASA to approve the Flight Conditions, except where DOA privileges exist.

Note that aircraft qualifying for Permits to Fly do not necessarily comply with the Essential Requirements set out in he Basic Regulation, Article 5, and referred to in Annex 1 to that Regulation.

The Permit to Fly can be used for LSA-type aircraft prior to the introduction of legislation under MDM.032 if they comply with the conditions of 21A.701(15). When the revisions to the legislation are in place, the use of 21A.701(15) will no longer be appropriate (hyperlink to LSA).

How do I apply for a Permit to Fly?

Application for an EASA Permit to Fly is made in two parts:

  • To EASA for approval of Flight Conditions (EASA Form 37, incorporating Form 18b)
  • To NAA of state of registry for issue of Permit

Approval of Flight Conditions

Flight Conditions consist of:

  1. the configuration(s) for which the permit to fly is requested;
  2. any condition or restriction necessary for safe operation of the aircraft, including:
    1. the conditions or restrictions put on itineraries or airspace, or both, required for the flight(s);
    2. the conditions and restrictions put on the flight crew to fly the aircraft;
    3. the restrictions regarding carriage of persons other than flight crew;
    4. the operating limitations, specific procedures or technical conditions to be met;
    5. the specific flight test programme (if applicable);
    6. the specific continuing airworthiness arrangements including maintenance instructions and regime under which they will be performed;
  3. the substantiation that the aircraft is capable of safe flight under the conditions or restrictions of subparagraph (b);
  4. the method used for the control of the aircraft configuration, in order to remain within the established  conditions.

These can be as simple as applying additional limitations for a specific purpose for a limited duration or be as comprehensive as a full description of the individual aircraft, including its modification state, limitations, flight manuals and maintenance instructions.

The former would apply to a fully certificated aircraft whose certificate of airworthiness is invalidated because it is fitted with a modification that has not yet been approved. Limitations may include:

  • Day VFR for an aircraft normally approved for Night IFR
  • No flight over built-up areas
  • Crew limitations
  • Operating altitude or airspeed limitations
  • Prohibition from using cabin pressurization
  • ...

The latter would apply to an aircraft that has not been otherwise certificated, an example being the Sukhoi Su-26. These may be different for each serial number.

The validity of the approved Flight Conditions will normally be limited. The maximum validity is 12 months.

Orphan aircraft

How does EASA deal with aircraft without a Type Certificate holder?

An aircraft becomes orphan when:

  1. 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
  2. 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)
  3. 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.

Specific Airworthiness Specifications

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#

 

See Article 5 (4) of the Basic Regulation and Regulation (EC) 1702/2003 Part 21, 21A.184

How do I find out if my aircraft has an SAS or TC?

The EASA aircraft lists can be found in the Product Certification 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.

EASA types and Annex II types

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.

STCs

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:

  1. 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).
  2. 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.
(see below)

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.

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 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 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.

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).

Classification of Avionics Changes

How do I know whether my proposed change is Minor or STC?

How does EASA classify single and dual GNS4xx/5xx installations?

How does EASA classify Transponder Mode S Diversity and dual Transponder installations?

How does EASA classify antenna installations?

These questions are all answered by reference to the table FAQ table of design change classification

Fuel

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.

Classification of changes (non-avionics)

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 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:

  1. An increase in take-off rpm ("red line"), or highest rpm in the normal operating range ("top of green arc");
  2. A change leading to an increase in the best rate of climb speed (Vy);
  3. An increase in propeller diameter;
  4. A change to the propeller tip shape;
  5. An increase in the propeller blade thickness;
  6. A change in the number of propeller blades;
  7. The installation of a variable pitch propeller in place of a fixed pitch propeller;
  8. 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:

  1. An increase in take-off weight;
  2. A decrease in engine power;
  3. 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;
  4. 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.

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:

  1. 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.
  2. The permit to fly will have a limited validity (2 years) and will not be extended when ELA-rules are in place in Europe.
  3. A permit to fly based on Part 21A.701 (15) is only valid for non commercial activities according to the Basic Regulation .
  4. 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.
  5. 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.
  6. 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.
  7. 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.
  8. With approved flight conditions registration of the aircraft is possible in all EU member states.
  9. Pilot licence needed is at least the national licence for an aeroplane in that weight category.
  10. A maintenance regime has to be defined following basic principles of "new" Part-M.
  11. Limitations will prohibit at least IFR, Night VFR, Aerobatics, Solo-Training.
  12. 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.

  1. 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.
  2. When engine and propeller have no type certification EASA has already the option to accept a restricted type certification for such an aircraft.
  3. Holder of such an (restricted) TC needs to demonstrate their capability through design organisation approval (DOA) or alternative procedures to DOA.
  4. Manufacturing requires production organisation approval
  5. Maintenance needs to be done according to Part-M.

EASA Definition Light Sport Aeroplane

Light Sport Aeroplane complies with the following criteria:

  1. A Maximum Take-Off Mass of not more than 600 kg
  2. 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.
  3. A maximum seating capacity of no more than two persons, including the pilot.
  4. A single, non-turbine engine fitted with a propeller.
  5. 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.

Russian Aircraft

How does EASA deal with my Russian light aircraft?

Russian general aviation types are:

  • Sukhoi Su-26
  • Sukhoi Su-29
  • Sukhoi Su-31
  • Yakovlev Yak-18T
  • Yakovlev Yak-54
  • Yakovlev Yak-55

Of these the Su-26, Yak-54 and 55 are not certificated and can qualify for EASA Permits to Fly under 21A.701(15). The Flight Conditions can be similar to the Airworthiness Approval Notes issued by CAA-UK. Examples can be provided from EASA.

The other types have been certificated by CIS and qualify for SAS and Restricted Certificates of Airworthiness.

The SASs can be found at:

Installations of highly-integrated electronic primary flight displays on CS-23 aircraft

This guidance applies to ETSO'd Garmin, Aspen, Avidyne, Honeywell, IS&S and other similar primary flight instruments that are replacing conventional electro-mechanical instrumentation. This guidance clarifies general aspects and applicability of software-related Certification Memos as part of an STC or major change application where  highly-integrated electronic primary flight displays are installed on CS-23 aircraft.

Operational GA issues

For further details of EASA initiatives to ensure better regulation of recreational activities, please see http://easa.europa.eu/flightstandards/ga-ba.html

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.