General Aviation - FAQ

The EASA aircraft lists are at
http://www.easa.europa.eu/ws_prod/c/c_da_main.php and there are separate links for EU and non-EU products.

The Annex II list is at
http://www.easa.europa.eu/ws_prod/c/doc/ptf/annex_II_01_Jan_2010.pdf

Annex II types are, by definition, not EASA aircraft and are therefore handled under national rules.

Application for STCs are made on the EASA Form 33

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.
   

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.

These questions are all answered by reference to the table attached here

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.

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”.

If the aircraft comes within the definition of Annex II to regulation 216/2008, 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.

A Light Sport Airplane (LSA) is a simple two-seater with a maximum take-off weight of 600kg. There are several cases where applicants want to apply for approval of Flight Conditions for aircraft originating from Annex II aircraft (“Microlight”) or developed according the US “Light Sport Aircraft” (LSA) rule. For these aircraft an EASA Permit to Fly (PtF) according to Regulation 1702/2003 (as amended by Regulation 375/2007) Part 21A.701 (15) could be an option. The principles for the issuance are based on the ongoing rulemaking task MDM.032. The intention of this task is to create a lighter regulatory regime based around a new process for the European Light Aircraft (ELA). ELA is not a new category of aircraft but is a substantially simpler new process for the regulation of aircraft and related products, parts and appliances. The intention is to issue type certificates for the type and certificates of airworthiness for the individual aircraft. With these processes and the introduced CS-LSA an EASA type certification for LSA is possible and therefore a PtF according to 21A.701(15) will then no longer be appropriate.

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 (EC) 216/2008.
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 216/2008 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:
(i) A Maximum Take-Off Mass of not more than 600 kg
(ii) 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.
(iii) A maximum seating capacity of no more than two persons, including the pilot.
(iv) A single, non-turbine engine fitted with a propeller.
(v) 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 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:

Su-29:  EASA.SAS.A.093

Su-31: EASA.SAS.A.094 

Yak-18T :  EASA.SAS.A.095

 

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.

Installations of ETSO’ed High Integrated Primary Electronic Flight Displays on Board CS-23 Aircraft

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