Subject: 14 CFR Part 23 Type Certification of an 

Airplane Originally Certificated to Joint Aviation 

Regulations - Very Light Airplane (JAR-VLA) 

Standards

Date: 7/14/03 

Initiated By: ACE-100 

AC No: 23-11A 

Change: 

What is the purpose of this Advisory Circular (AC)? 

This AC presents one way, but not the only way, to show compliance to Title 14 Code of

Federal Regulations (14 CFR) part 23 for the type certification of certain small airplanes. 

• This AC does not present mandatory material. 

• This AC is not a rule or regulation. 

• The material presented in this AC has no legal status. 

Who does this AC apply to? 

This AC applies to you if you seek any of the following for a Joint Aviation Regulations - 

Very Light Airplane (JAR-VLA): 

• A part 23 normal or utility category type certificate; 

• A type certificate as a “Special Class” airplane, following § 21.17(b).
7/14/03 AC 23-11A 

Does this AC cancel any previously published ACs?

Yes, the following AC is canceled: 

AC 23-11, Type Certification of Very Light Airplanes with Powerplants and Propellers 

Certificated to Parts 33 and 35 of the Federal Aviation Regulations, dated December 2, 

1992. 

s/ 

Michael Gallagher 

Manager, Small Airplane Directorate 

Aircraft Certification Service

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7/14/03 AC 23-11A 

CONTENTS 

SECTION 

PAGE 

CHAPTER 1 - INTRODUCTION 

1-1. Why is this AC being rewritten?...........................................................................1 

1-2. What is the background behind the certification of very light airplanes? ............ 1 

1-3. What is a “JAR-VLA Airplane?” ......................................................................... 1 

1-4. Who is “you” and who is “we?” ........................................................................... 2 

1-5. What documents are related to this AC? .............................................................. 2 

1-6. Definitions ............................................................................................................ 4 

CHAPTER 2 - DAYTIME VISUAL FLIGHT RULE (DAY-VFR) OPERATIONS 

2-1. I am an applicant and my airplane is certificated to JAR-VLA regulations. 

Am I automatically eligible for a Special Class Type Certificate?....................... 6 

2-2. My airplane is certificated to JAR-VLA regulations. My engine and propeller 

are certificated to 14 CFR parts 33 and 35, respectively. I desire daytime Visual 

Flight Rule operations only. How does this affect me?........................................6 

2-3. My airplane is certificated to JAR-VLA regulations. My engine and propeller 

are certificated to JAA JAR-22 subparts H and J. I desire daytime Visual Flight 

Rule operations only. How does this affect me? ..................................................6 

2-4. For Day-VFR operations, does it make a difference if the engine and propeller are 

certificated to either JAR-22 subparts H and J or 14 CFR parts 33 and 35 or JARE and JAR-P?........................................................................................................ 7 

2-5. Are there any differences in operational limitations between JAR-VLA airplanes 

certificated with a JAR-22 engine and propeller, a 14 CFR parts 33 and 35 engine 

and propeller, or a JAR-E and JAR-P engine and propeller? .............................. 7 

2-6. My airplane is certificated to JAR-VLA regulations. My engine and propeller 

are certificated to JAR-22 subparts H and J. Is this airplane eligible for a 

part 23 type certificate (TC)?................................................................................7 

2-7. I understand the JAR-VLA requirements are based on the 14 CFR part 23 

regulations. Is that true?........................................................................................7

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AC 23-11A 7/14/03 

CONTENTS – (continued) 

SECTION 

PAGE 

CHAPTER 3 - NIGHTTIME VISUAL FLIGHT RULE (NIGHT-VFR) AND 

INSTRUMENT FLIGHT RULE (IFR) OPERATIONS 

3-1. I would like to fly my U.S. Type Certificated JAR-VLA airplane in Night-VFR 

conditions. Does my Standard Airworthiness Certificate, Special Class allow 

me to do that?........................................................................................................ 8 

3-2. I would like to fly my U.S. Type Certificated JAR-VLA airplane in IFR 

conditions. Does my Standard Airworthiness Certificate, Special Class allow 

me to do that?........................................................................................................ 8 

3-3. What do I need to do to update my JAR-VLA airplane to fly in Night-VFR or 

IFR conditions?..................................................................................................... 8 

3-4. If I go through the part 23 certification process to permit Night-VFR or IFR 

operations, will the Type Certification Data Sheet (TCDS) reflect part 23 or 

§ 21.17? ................................................................................................................ 8 

3-5. To be clear, is it correct to state “To fly my U.S. Type Certificated JAR-VLA 

airplane in Night-VFR or IFR conditions, the airplane must be certificated 

under part 23?”...................................................................................................... 8 

3-6. I am seeking approval for flight in icing conditions. I know I will need to earn 

a part 23 TC, showing compliance to the part 23 rules applicable for IFR 

operations. Are there additional rules I will need to address for flight in icing 

conditions? ............................................................................................................ 9 

3-7. Where can I find additional information on the various Airworthiness 

Certificates available for these types of airplanes?...............................................9 

CHAPTER 4 - 14 CFR PART 23 TYPE CERTIFICATION 

4-1. How is the part 23 certification basis for my JAR-VLA airplane established?.... 10 

STEP 1 Differences in Part 23 Due to Amendment Levels.........................................10 

STEP 2 JAR-VLA and Part 23 Regulations - Content Difference .............................. 10 

STEP 3 Part 23 Regulations Not Provided in JAR-VLA............................................. 11 

STEP 4 Rules Specific to Nighttime or Instrument Operations...................................11 

iv 
7/14/03 AC 23-11A 

CONTENTS – (continued) 

SECTION 

PAGE 

4-2. I am an Aircraft Certification Office (ACO) Program Manager. Does an Issue 

Paper template exist that can be used for each JAR-VLA airplane that seeks 

part 23 type certification? ..................................................................................11 

4-3. Is there a process that I should follow to receive FAA certification of my 

product? ............................................................................................................. 12 

4-4. Can I apply for a type certificate (TC) in the utility or acrobatic category? .....12 

CHAPTER 5 – RULES OF INTEREST 

5-1. Is there any additional information you can provide for 14 CFR, § 23.562, 

Emergency Landing Dynamic Conditions? ....................................................... 14 

5-2. Is there any additional information you can provide for 14 CFR, § 23.572, 

Metallic Wing, Empennage, and Associated Structure?....................................15 

5-3. Is there any additional information you can provide for 14 CFR, § 23.573, 

Damage Tolerance and Fatigue Evaluation of Structure? .................................16 

5-4. Do I need to perform a flight flutter test?..........................................................17 

5-5. Is there any information you can provide for 14 CFR, § 23.1309, 

Equipment, Systems, and Installation? ..............................................................17 

CHAPTER 6 - BACKGROUND OF 14 CFR PART 23 AND JOINT AVIATION 

REQUIREMENTS – VERY LIGHT AIRPLANES 

APPENDIX 1................................................................................................................A1 

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AC 23-11A 7/14/03 

THIS PAGE IS INTENTIONALLY LEFT BLANK 

vi 
7/14/03 AC 23-11A 

CHAPTER 1 - INTRODUCTION 

1-1. Why is this AC being rewritten? 

FAA Order 1320.46C “Advisory Circular System,” chapter 3, paragraph 9, states that an 

AC cannot add, reduce, or change the burden imposed by a regulation. However, some

individuals misinterpreted the original release of AC 23-11. They believed the AC stated 

that certain small airplanes were exempt from or entitled to a positive finding of

Equivalent Level of Safety (ELOS) to certain requirements. In addition, they believed 

this ELOS could be based solely on the physical characteristics of the airplane. To 

suggest that the AC could grant an ELOS or exemption would contradict FAA Order 

1320.46C. This contradiction was not the intent of those individuals who wrote the 

original AC 23-11. 

By revising this AC, we intend to clarify the issues that surround type certification of a 

JAR-VLA airplane. 

1-2. What is the background behind the certification of very light airplanes? 

For a description of the history and background on this subject, see Chapter 6 

“Background - 14 CFR part 23 and Joint Aviation Requirements – Very Light 

Airplanes.” 

1-3. What is a “JAR-VLA Airplane?” 

Airplanes that meet the regulations specified in the European Joint Aviation 

Regulations – Very Light Airplanes (JAR-VLA) are known as JAR-VLA airplanes. 

These airplanes must meet the following limitations: 

• Single engine with spark or compression ignition 

• Maximum occupancy of two (2) 

• Maximum certificated takeoff weight of 1,654 pounds (750 Kg) 

• Maximum power-off stall speed of 45 knots Calibrated Air Speed (CAS) in the 

landing configuration at maximum weight 

• Normal category maneuvers only. Per JAR-VLA 3 and § 23.3(a), these 

maneuvers include: 

 Maneuvers incident to normal flying; 

 Stalls (except whip stalls); and, 

1 
AC 23-11A 7/14/03 

 Lazy eights, chandelles, and steep turns in which the angle of bank is 

not more than 60 degrees. 

• Daytime Visual Flight Rule (Day-VFR) Operations only 

1-4. Who is “you” and who is “we?” 

In general, when the word “you” or “me” is used, it refers to the applicant. When the 

word “we” or “us” is used, it is referring collectively to the Federal Aviation 

Administration (FAA). When the terms “you” or “we” would be vague or non-specific, 

groups or individuals will be referenced by their unique title. For example, the formal 

title of Airplane Certification Office (ACO) will be used when referring to an action done 

specifically by the ACO. 

1-5. What documents are related to this AC?

a. Orders, Federal Regulations, and ACs.

FAA Order 8110.4B, Type Certification 

FAA Order 8100.5, Airplane Certification Directorate Procedures 

FAA Order 1320.46C, Advisory Circular System

Title 14 Code of Federal Regulations (CFR) part 21 – Certification Procedures 

for Products and Parts 

Title 14 Code of Federal Regulations, part 23 – Airworthiness Standards: 

Normal, Utility, Acrobatic, and Commuter Category Airplanes, Subpart C – 

Structure 

Title 14 Code of Federal Regulations, part 33 - Airworthiness Standards: 

Aircraft Engines 

Title 14 Code of Federal Regulations, part 35 – Airworthiness Standards: 

Propellers 

Title 14 Code of Federal Regulations, part 36 – Noise Standards: Aircraft Type 

and Airworthiness Certification 

Title 14 Code of Federal Regulations, part 43 – Maintenance, Preventive 

Maintenance, Rebuilding, and Alteration 

Title 14 Code of Federal Regulations, part 45 – Identification and Registration 

Marking 

2 
7/14/03 AC 23-11A 

Title 14 Code of Federal Regulations, part 91 – General Operating and Flight 

Rules 

FAA Report No. AFS-120-73-2, “Fatigue Evaluation of Wing and Associated 

Structure on Small Airplanes,” Federal Aviation Administration, Washington, 

D.C., 1973. (Available from the Small Airplane Directorate, 901 Locust, Suite 

301, Kansas City, MO 64106.) 

FAA Report, “Fatigue Evaluation of Empennage, Forward Wing and 

Winglet/Tip Fins on Part 23 Airplanes,” Federal Aviation Administration, 

Kansas City, Missouri. (Available from the Small Airplane Directorate, 901 

Locust, Suite 301, Kansas City, MO 64106.) 

Copies of the current publication of the ACs listed below can be obtained from

the U.S. Department of Transportation, Subsequent Distribution Office, DOT 

Warehouse, SVC 121.23, Ardmore East Business Center, 3341Q 75th Avenue, 

Landover, MD 20785: 

AC 20-73, Aircraft Ice Protection, dated April 21, 1971 

AC 20-107A, Composite Aircraft Structure, dated April 25, 1984 

AC 21.17-3, Type Certification of Very Light Airplanes Under FAR 

§ 21.17(b), dated December 21, 1992 

AC 23-8A, Flight Test Guide for Certification of Part 23 Airplanes, dated 

February 9, 1989 

AC 23-15, Small Airplane Certification Compliance Program, dated 

January 2, 1997 

AC 23.143-1, Ice Contaminated Tailplane Stall (ICTS), dated 

December 20, 2001 

AC 23.1309-1C, Equipment, Systems, and Installations In Part 23 

Airplanes, dated March 12, 1999 

AC 23.1419-2B, Certification of Part 23 Airplanes for Flight in Icing 

Conditions, dated September 26, 2002 

b. Other References. 

JAA Joint Aviation Requirements for Very Light Aeroplanes (JAR-VLA) 

JAA Joint Aviation Requirements for Engines, JAR-E 

3 
AC 23-11A 7/14/03 

JAA Joint Aviation Requirements for Propellers, JAR-P 

Society of Automotive Engineers Aerospace Standard AS8049A, Performance 

Standards for Seats in Civil Rotorcraft, Transport Aircraft, and General 

Aviation Aircraft, dated September 1997 

Aircraft Crash Survival Design Guide, Volume 1 – Design Criteria and 

Checklist, Report Number USAAVSCOM TR 89-D-22A, US Army Aviation 

Systems Command, dated December 1989 

1-6. Definitions 

JAR-VLA: Joint Aviation Requirements – Very Light Airplanes (or Aeroplanes), 

prescribe the airworthiness criteria leading to issuance of a type certificate as 

instituted by the Joint Airworthiness Authorities (JAA) for certain very light 

airplanes. The requirements are based on Title 14 CFR part 23. 

Special Class Airplane: A special class airplane is an airplane, which may include 

the installed engines and propellers, for which airworthiness standards have not been 

issued under 14 CFR part 21 Subpart B – Type Certificates. Following 14 CFR part 

21, § 21.17(b), applicable airworthiness requirements are those portions of parts 23, 

25, 27, 29, 31, 33, and 35 found appropriate by the Administrator for the airplane. 

The Administrator may also use airworthiness criteria that provide an equivalent level 

of safety to those parts. 

Normal and Utility Category: Categories of airplanes whose airworthiness 

standards are defined in 14 CFR part 23. Any JAR-VLA airplane that seeks night 

VFR or IFR capability must satisfy the requirements listed under part 23 for one of 

these categories. One of the requirements of part 23 is that the airplane must be 

equipped with a powerplant and propeller type certificated to 14 CFR parts 33 and 

35, respectively. 

Equivalent Level of Safety (ELOS) Finding: The FAA will grant a positive finding 

of ELOS when it determines that an applicant’s design does not demonstrate literal 

compliance to an FAA requirement, but does satisfy the intent of the requirement. A 

positive finding of ELOS shows no reduction in safety. Title 14 CFR § 21.21(b) 

permits ELOS findings, and the Small Airplane Directorate has authority over all 

ELOS findings to any part 23 rule. An ELOS finding is NOT a public process. 

In addition, per AC 21.17-3, the Small Airplane Directorate has been assigned 

national technical policy standardization functions (which includes ELOS findings) 

concerning the use of JAR-VLA in the U.S., including the type certification of VLA 

as special class aircraft under 14 CFR § 21.17(b). 

Exemption: Exemptions are a public process where the applicant seeks relief from a 

specific FAA requirement, as guided by 14 CFR § 11.81. The applicant must show 

that the exemption is in the public interest and that safety is not adversely affected. 

4 
7/14/03 AC 23-11A 

The process for seeking an exemption, as described in 14 CFR § 11.81, is more 

formal than a finding for ELOS. 

5 
AC 23-11A 7/14/03 

CHAPTER 2 - DAYTIME VISUAL FLIGHT RULE (DAY-VFR) OPERATIONS 

We do not prescribe airworthiness standards specific to very light airplanes (as defined in 

this AC). However, 14 CFR § 21.17(b) does allow the FAA to use airworthiness criteria 

that provide an equivalent level of safety appropriate for the airplane. Therefore, you may 

seek certification of a JAR-VLA airplane as a Special Class airplane under 14 CFR 

§ 21.17(b). In this case, the JAR-VLA regulations serve as the airworthiness criteria. 

Airplanes certificated to JAR-VLA standards under 14 CFR § 21.17(b) are limited to the 

conditions stated in JAR-VLA, which includes the limitation of Day-VFR operations 

only. 

2-1. I am an applicant and my airplane is certificated to JAR-VLA regulations. 

Am I automatically eligible for a Special Class Type Certificate? 

No. If you are a foreign (non-United States) applicant, you must earn a Special Class 

Type Certificate, as required by 14 CFR § 21.29. This is referred to as the validation 

process. 

If you are a United States (U.S.) applicant, and you design your aircraft to the JAR-VLA 

regulations, you must still earn a Special Class Type Certificate per 14 CFR § 21.17 and 

§ 21.21. 

The AC will assume, from this point forward, that an applicant (either foreign or U.S.) 

has received a Special Class Type Certificate.

2-2. My airplane is certificated to JAR-VLA regulations. My engine and 

propeller are certificated to 14 CFR parts 33 and 35 (or JAR-E and JAR-P), 

respectively. I desire daytime Visual Flight Rule operations only. How does 

this affect me? 

This airplane is eligible for a Standard Airworthiness Certificate, Special Class, under 14 

CFR § 21.175(a). It is important to note that JAR-VLA is limited to Daytime Visual 

Flight Rules (Day-VFR) operations only. Therefore, an airplane certificated under these 

standards is limited to Day-VFR operations. 

2-3. My airplane is certificated to JAR-VLA regulations. My engine and 

propeller are certificated to JAA JAR-22 subparts H and J. I desire daytime 

Visual Flight Rule operations only. How does this affect me? 

JAR-VLA permits the use of engines and propellers that meet the powerplant 

airworthiness requirements of JAA JAR-22 Sailplanes and Powered Sailplanes, subparts 

H and J. This is known as approving the engine and propeller as an integral part of the 

airplane. 

This airplane is eligible for a Standard Airworthiness Certificate, Special Class, under 14 

CFR § 21.175(a). In addition, this airplane is limited to Daytime Visual Flight Rules 

(Day-VFR) operations only. 

6 
7/14/03 AC 23-11A 

2-4. For Day-VFR operations, does it make a difference if the engine and 

propeller are certificated to either JAR-22 subparts H and J, 14 CFR parts 

33 and 35, or JAR-E and JAR-P? 

No, it does not. For Day-VFR operations only, it doesn’t matter if the engine and 

propeller are certificated to 14 CFR parts 33 and 35, JAR-22 subparts H and J, or JAR-E 

and JAR-P. 

2-5. Are there any differences in operational limitations between JAR-VLA 

airplanes certificated with a JAR-22 engine and propeller, a 14 CFR parts 33 

and 35 engine and propeller, or a JAR-E and JAR-P engine and propeller? 

All of these airplanes are eligible for a Standard Airworthiness Certificate, Special Class, 

under 14 CFR § 21.175(a). Each of these airplanes share the same operational limitation, 

they are all limited to Day-VFR operations. (See Section 3 for information regarding 

Night-VFR or IFR operations).

2-6. My airplane is certificated to JAR-VLA regulations. My engine and 

propeller are certificated to JAR-22 subparts H and J. Is this airplane 

eligible for a part 23 type certificate (TC)? 

No, your airplane is not eligible for a part 23 TC. Only those JAR-VLA airplanes 

equipped with an engine and propeller certificated to 14 CFR parts 33 and 35, 

respectively, would receive further consideration. 

Another way to say this would be: 

A necessary, but not the only condition for a part 23 TC, is that the airplane have an 

engine and propeller certificated to 14 CFR parts 33 and 35, respectively. 

2-7. I understand the JAR-VLA requirements are based on the 14 CFR part 23 

regulations. Is that true? 

Yes, that is true. The JAA issued “Joint Aviation Requirements for Very Light 

Aeroplanes,” also known as JAR-VLA, in April 1990. The substance of these regulations 

has much in common with 14 CFR part 23. However, 14 CFR part 23 contains 

requirements for several airplane categories. Therefore, changes and deletions to these 

rules were made when the JAA identified requirements as either impractical or 

unnecessary for safety, given the design features of JAR-VLA airplanes.

7 
AC 23-11A 7/14/03 

CHAPTER 3 - NIGHTTIME VISUAL FLIGHT RULE (NIGHT-VFR) AND 

INSTRUMENT FLIGHT RULE (IFR) OPERATIONS 

3-1. I would like to fly my U.S. Type Certificated JAR-VLA airplane in NightVFR conditions. Does my Standard Airworthiness Certificate, Special Class 

allow me to do that? 

No, JAR-VLA airplanes are restricted to Day-VFR operations only. 

3-2. I would like to fly my U.S. Type Certificated JAR-VLA airplane in IFR 

conditions. Does my Standard Airworthiness Certificate, Special Class allow

me to do that? 

No, JAR-VLA airplanes are restricted to Day-VFR operations only. 

3-3. What do I need to do to update my JAR-VLA airplane to fly in Night-VFR 

or IFR conditions? 

• Equip the airplane with an engine certificated to 14 CFR part 33; 

• Equip the airplane with a propeller certificated to 14 CFR part 35; 

• Obtain a part 23 TC. 

3-4. If I go through the part 23 certification process to permit Night-VFR or IFR 

operations, will the Type Certification Data Sheet (TCDS) reflect part 23 or 

§ 21.17? 

The TCDS will reflect a part 23 certification basis. The airplane is certificated under part 

23, not the special class category under 14 CFR § 21.17. 

3-5. To be clear, is it correct to state “To fly my U.S. Type Certificated JAR-VLA 

airplane in Night-VFR or IFR conditions, the airplane must be certificated 

under part 23?” 

Yes, that is correct. A manufacturer of a JAR-VLA airplane that desires operations in 

Night-VFR or IFR conditions must apply for a 14 CFR part 23 normal or utility category 

TC. The amendment level for the part 23 TC is the amendment level that is current on the 

date of application, as required by 14 CFR § 21.17. The operation of these airplanes is 

limited to normal or utility category maneuvers. Applicants seeking utility category 

certification must address aircraft spin and more stringent structural design criteria. 

Reference 14 CFR part 23 for further information. 

Appendix 1 provides an example of the regulations that govern Night-VFR operations, 

valid at Amendment level 23-46. However, this list will likely change depending upon 

the actual certification basis of your airplane. Chapter 4 of this AC explains how we 

develop the part 23 certification basis for JAR-VLA airplanes. 

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7/14/03 AC 23-11A 

Appendix 1 serves only as an example of how to document the certification basis. There 

may be additional part 23 rules, not identified in Appendix 1, required for IFR 

operations. 

3-6. I am seeking approval for flight in icing conditions. I know I will need to 

earn a part 23 TC, showing compliance to the part 23 rules applicable for 

IFR operations. Are there additional rules I will need to address for flight in 

icing conditions? 

Yes. As of amendment level 23-50, an applicant that seeks approval for flight in icing 

conditions will need to show compliance, as a minimum, to the following rules: 

14 CFR Part 23 Rule Title 

 23.775(f) Windshields and windows 

 23.929 Engine installation ice protection 

 23.1095* Carburetor deicing fluid flow rate 

 23.1097* Carburetor deicing fluid system capacity 

 23.1099* Carburetor deicing fluid system detail design 

 23.1323(d) Airspeed indicating system

 23.1325(g) Static pressure system

 23.1326 Pitot heat indication systems 

 23.1416* Pneumatic de-icer boot system

 23.1419 Ice protection 

* If applicable 

The following ACs provide additional information: 

• AC 20-73 Aircraft Ice Protection 

• AC 23.143-1 Ice Contaminated Tailplane Stall 

• AC 23.1419-2B Certification of Part 23 Airplanes for Flight in Icing Conditions

3-7. Where can I find additional information on the various Airworthiness 

Certificates available for these types of airplanes? 

AC 21.17-3, Type Certification of Very Light Airplanes Under FAR 21.17(b), should be 

consulted for further information. It provides guidance on the Airworthiness Certificates 

available for JAR-VLA airplanes, depending upon the purpose of the airplane and its 

airworthiness standard. 

9 
AC 23-11A 7/14/03 

CHAPTER 4 - 14 CFR PART 23 TYPE CERTIFICATION 

4-1. How is the part 23 certification basis for my JAR-VLA airplane established? 

There are four (4) steps that you (the applicant) and we (the FAA) must execute to 

establish a part 23 TC certification basis for airplanes originally certificated under 

§ 21.17(b), Special Class. These four steps are discussed below. 

STEP 1 Differences in Part 23 Due to Amendment Levels 

The certification basis for any JAR-VLA airplane seeking a part 23 TC is the part 23 

amendment level in effect at the time of application for certification. We will make a 

comparison between the part 23 requirements at this amendment level and the JAR-VLA 

regulations (dated April 26, 1990). 

We will identify those part 23 rules that are part of the current amendment level, are 

applicable to JAR-VLA airplanes, and were not in effect in April 1990. You will need to 

demonstrate compliance to these additional part 23 rules. 

You can show compliance to a part 23 rule by one of the following actions: 

• Literal compliance; 

• ELOS; or 

• Exemption. 

A formal process exists that governs a showing of compliance to a part 23 regulation by 

use of an ELOS or an exemption. Both require coordination with the Small Airplane 

Directorate (the Directorate). Further information on the ELOS process can be located in 

FAA Order 8110.4B, paragraph 2-10. 14 CFR part 11, § 11.81 gives additional 

information on the exemption process. 

STEP 2 JAR-VLA and Part 23 Regulations – Content Difference 

There are rules present in JAR-VLA and in 14 CFR part 23 that have the same rule 

number and section title, but they are substantively different in content. That is, these two 

regulatory documents prescribe a different level of safety for the same rule. 

An established method exists that identifies and resolves significant regulatory and 

administrative differences: the Issue Paper (Reference FAA Order 8100.5, Appendix 3). 

Once documented in the Issue Paper, the FAA-ACO, the Directorate, and the Applicant 

can work to reach a satisfactory resolution to those JAR-VLA and part 23 rules that 

provide different levels of safety. 

10 
7/14/03 AC 23-11A 

AC 23-15 Small Airplane Certification Compliance Program, provides historically 

acceptable means of compliance to selected 14 CFR part 23 rules. STEP 4 provides 

additional information on this subject. 

STEP 3 Part 23 Regulations Not Provided in JAR-VLA 

This step covers the instance when no JAR-VLA rule comparable to a part 23 section 

exists. There are numerous rules in part 23 that were not included in JAR-VLA because it 

was obvious the rules were not applicable. For example, any rules governing twin engine 

operations or performance, or turbine engine requirements, are clearly not applicable. 

Those rules are not the topic of this section. 

Rules addressed by part 23 and not listed in JAR-VLA, but deemed as necessary for part 

23 type certification, must be identified in an Issue Paper. The methods of compliance to 

these specific rules will be documented in the Issue Paper. 

STEP 4 Rules Specific to Nighttime or Instrument Operations 

The 14 CFR part 23 regulations specific for the desired Night VFR and/or IFR operations 

must be addressed. The applicant will be required to show compliance to these 

regulations. You may find a listing of those rules specific to Night-VFR operations, 

applicable at Amendment level 23-46, in Table 3 of Appendix 1. 

4-2. I am an Aircraft Certification Office (ACO) Program Manager. Does an 

Issue Paper template exist that can be used for each JAR-VLA airplane that 

seeks part 23 type certification? 

Yes, Appendix 1 of this AC contains a sample Issue Paper. This Issue Paper was 

generated during a recent JAR-VLA/part 23 certification program. It should serve as an 

excellent starting point for the ACO Program Manager, and improve coordination 

between the Applicant, ACO Program Manager, and Directorate Project Officer. 

A Word About Compliance and our Understanding of the Simplicity of a JAR-VLA 

Airplane 

If you seek a part 23 TC, you should be prepared to demonstrate literal compliance to 

each rule. However, we understand the inherent level of safety that is fundamental to this 

airplane, and we believe that the use of an ELOS (or an exemption) may also show 

compliance to a rule. 

A JAR-VLA airplane is not automatically entitled to either of these two methods of 

compliance. In the case of an ELOS, you will need to demonstrate a safety equivalence, 

with the understanding that very prescriptive rules are not well suited for findings of 

ELOS. 

11 
AC 23-11A 7/14/03 

In the case of an exemption, you will likely need to incorporate mitigating factors into the 

airplane design to ensure safety is not adversely affected. You will also need to show 

how an exemption would be in the public’s interest. 

In summary, we feel that a simplified method of compliance to certain 14 CFR part 23 

rules may be in order (see AC 23-15). However, it is not an option to relax the applicable 

requirements of 14 CFR part 23. This has been the single largest source of confusion 

governing the certification of these airplanes. 

AC 23-15 provides rationale that supports simplified methods of compliance to part 23 

regulations. This AC does not attempt to identify every 14 CFR part 23 rule not covered 

by JAR-VLA standards. Rather, it provides a rationale that should be considered when 

evaluating small airplanes (like JAR-VLA airplanes), with a focus on the inherent level 

of safety expected of these airplanes. 

We understand that many certification requirements in 14 CFR part 23 are not necessary 

for JAR-VLA airplanes. A careful and deliberate attempt to establish a valid certification 

basis will ensure that rules deemed unnecessary for a light, single-reciprocatingengine/propeller airplane are not included in the certification basis. 

4-3. Is there a process that I should follow to receive FAA certification of my 

product? 

You should follow the certification procedures identified in FAA Order 8110.4B. 

4-4. Can I apply for a type certificate (TC) in the utility or acrobatic category? 

Airplanes that were previously certificated to JAR-VLA regulations, and that are 

presented for part 23 type certification, are eligible for type certificates in the normal and 

utility categories. If you apply for a normal category TC only, then your airplane is 

limited to the normal category maneuvers described in Section 1.3. 

If you apply for a utility category TC only, then your airplane must meet the part 23 

utility category requirements and be limited to utility category maneuvers. Per 14 CFR 

§ 23.3(b), utility category maneuvers include: 

• Maneuvers permitted under the normal category; 

• Spins (if approved for the particular type of airplane); 

• Lazy eights, chandelles, and steep turns, or a similar maneuver, with bank angles 

greater than 60 degrees but less than 90 degrees. 

You cannot convert a JAR-VLA approval to a part 23 acrobatic category airplane. If your 

airplane shows full compliance to all part 23 acrobatic category requirements, then your 

airplane may be eligible for a type certificate in this category. However, this is well 

12 
7/14/03 AC 23-11A 

beyond the scope of this AC. We are not aware of any airplane that earned a JAR-VLA 

approval and then sought a part 23 acrobatic category type certificate. 

13 
AC 23-11A 7/14/03 

CHAPTER 5 – RULES OF INTEREST 

5-1. Is there any additional information you can provide for 14 CFR, § 23.562,

Emergency Landing Dynamic Conditions? 

Yes. This rule has garnered the interest of applicants with JAR-VLA airplanes seeking 

part 23 certification. Previous guidance on this subject has been misinterpreted, leaving 

applicants to believe that the physical characteristics of the airframe will provide ELOS 

to this particular rule. This is not true. 

For a very prescriptive rule like § 23.562, you should either demonstrate literal 

compliance to the rule or pursue an exemption. An exemption to § 23.562 is possible 

provided: 

• You can show it is in the public’s interest, and 

• You can show safety is not adversely affected. 

To show that safety is not adversely affected, you must provide the following mitigating 

factors in the airframe: 

SEAT/RESTRAINT DESIGN 

• Each seat is to be equipped with a 4-point harness (a 5-point harness is also 

acceptable). 

• Each seat/harness system must be statically tested to an ultimate load of 3,060 

pounds (Note that 18G multiplied by 170 pounds = 3,060 pounds). The lapbelt 

should react 60 percent of this load, and the upper torso restraint should react 40 

percent of this load. You may reference the Society of Automotive Engineers 

Aerospace Standard AS8049A, pages 16 through 19, for additional information. 

HEAD STRIKE (INSTALLATION CONSIDERATIONS) 

• The head strike path will be conservatively determined from actual test data, 

specifically, “Airplane Crash Survival Design Guide, Volume 1 – Design 

Criteria and Checklists,” report number USAAVSCOM TR 89-D-22A. This 

report is available, for a fee, from the National Technical Information Service. 

You may reach them at 1-888-584-8322 or (703)-605-6050. 

• The applicant should overlay the flail envelope from Figure 43 of this document 

with the cockpit of the airplane. 

• The overlay of the head strike path with the cockpit must show that a head 

strike will not occur. 

14 
7/14/03 AC 23-11A 

A request for exemption is a public process, and the public may comment on the 

exemption request. While we intend to issue an exemption if you satisfy the criteria in 

this Section, we must either be able to resolve the comments in a successful manner or 

deny the grant of exemption. You should refer to § 11.81 for further details on the 

exemption process. 

5-2. Is there any additional information you can provide for 14 CFR, § 23.572, 

Metallic Wing, Empennage, and Associated Structure? 

Yes. For part 23 certification, you must show compliance to 14 CFR § 23.572 for 

metallic wing, empennage, and associated structures. 

One acceptable method of compliance to § 23.572 is to establish a fatigue safe-life. For 

wing structure, we advise establishing a safe-life using the methods contained in FAA 

report AFS-120-73-2, Fatigue Evaluation of Wing and Associated Structure on Small 

Airplanes. For empennage structure, we advise using FAA report ACE-100-1, Fatigue 

Evaluation of Empennage, Forward Wing, and Winglets/Tip Fins on Part 23 Airplanes. 

Other acceptable methods of showing compliance to § 23.572 include demonstrating that 

a structural element will have an “infinite” fatigue life. You can do this by showing that 

the stresses produced by an appropriate usage loading spectra will not cause fatigue 

damage to accumulate. You could use a graphical representation of appropriate material 

S-N data to demonstrate that fatigue damage will not accumulate. 

The S-N data you use in this analysis should provide the same probability of a fatigue 

crack-free life as provided by the AFS-120 report, 99.98 percent probability (equivalent 

to a 99.82 percent probability with 95 percent confidence). You may need to adjust your 

S-N data to achieve the AFS-120 probability level using your S-N curve’s statistical 

properties. Your S-N data should also accurately reflect the stress concentrations, Kt’s, 

found in your structure. 

You should base an appropriate usage spectra on the anticipated usage and an adequate 

database that defines the loadings expected for that usage. Published sources, including 

FAA publications, are acceptable databases. Flight test data may be acceptable if 

statistically significant data is available. However, in some instances, such as water loads 

on an amphibian airplane, flight data may be necessary to define the usage spectrum.

For aluminum structures, you may use the S-N curve from the AFS-120-73-2 report. At 

your discretion, a different S-N curve may be used if the S-N curve is for the same

material and for the same stress concentration factor, Kt, found in the structure. 

15 
AC 23-11A 7/14/03 

5-3. Is there any additional information you can provide for 14 CFR, § 23.573, 

Damage Tolerance and Fatigue Evaluation of Structure? 

14 CFR part 23, § 23.573, addresses both the Damage Tolerance/Fatigue evaluation of 

the composite airframe structure and the development of the maintenance program for 

part 23 aircraft. 

You will need to use static and fatigue tests to substantiate repairs. You will need to 

perform these tests on coupons, subcomponents, and full-scale articles. The following is a 

synopsis of how 14 CFR part 23 addresses repairs for composite aircraft. 

14 CFR part 23, § 23.573 requires composite structures and bonded joints to be damage 

tolerant. The basic building block for damage tolerant design is selecting the largest 

defect and unrepaired damage allowed in components and assemblies during 

manufacturing and service. You must be able to inspect for these damage levels. You 

must also include this damage in the static strength and damage tolerant test articles. 

You may use an impact survey to select the appropriate damage criteria to determine the 

“Threshold of detectability." The testing accomplished will help develop criteria for 

imparting and inspecting impact damage. 

Test specimens from the impact survey form the basis for development of inspection 

criteria for the quality assurance program. Typical repairs for the damaged specimens are 

developed and substantiated in the damage tolerant test articles. 

Per 14 CFR, part 23, § 23.573 (a)(1): The damaged test article is statically tested up to 

ultimate load to show sufficient capability with impact damage up to the threshold of

detectability. 

Per 14 CFR, part 23, § 23.573(a)(2): The test article has damage and is tested under 

repeated loading to establish the growth rate or no-growth rate of damage that may occur 

from fatigue, manufacturing flaws or impact damage. You may establish the criteria for 

"no growth" by visual and ultrasonic inspection. No change in the structural stiffness or 

strain response may also indicate "no growth." During this part of the test, you may repair 

some of the defects in order to validate repairs that will become part of the OEM 

Structural Repair Manual (SRM). 

Per 14 CFR, part 23, § 23.573 (a)(3): You will conduct limit load testing at the 

conclusion of the repeated loading. This will substantiate the residual strength of the 

aircraft. You must also address loads such as the critical limit flight loads with the 

combined effects of normal operating pressure and the expected external aerodynamic 

pressures that the structure must sustain when the airplane is pressurized. 

Per 14 CFR, part 23, § 23.573 (a)(4): Based on the data collected during cycle testing, 

you must establish a rational probability based inspection interval. This interval is 

16 
7/14/03 AC 23-11A 

specified in the aircraft's Continued Airworthiness Instructions contained in the FAA 

approved sections of the Aircraft Maintenance Manual. 

Per 14 CFR, part 23, § 23.573 (a)(5): You must substantiate the maximum disbonds of 

each bonded joint for limit load residual strength as indicated by § 23.573 (a)(3). You 

may determine this by test, analysis or both. A maximum disbond means an entire 

bondline is missing between any two primary structural components such as the 

spar/skin, skin/skin, rib/skin or rib/spar. 

Per 14 CFR, part 23, § 23.573 (a)(6): Damage tolerant criteria may be impractical for a 

particular structural component. If so, you must perform a sufficient number of 

component, subcomponent, element, or coupon tests to establish the fatigue scatter factor 

and the environmental effects for this component. You must show by tests, or analysis 

supported by tests, that the component will withstand the repeated loads of variable 

magnitude expected in service. 

In addition, you must perform component, subcomponent, element or coupon tests to 

establish the fatigue scatter factor and the environmental effects for these structural 

components. 

You may consult AC 20-170A for additional information. 

5-4. Do I need to perform a flight flutter test? 

Yes. A flight flutter test is required for all part 23 airplane categories. JAR-VLA 

airplanes that seek part 23 certification will not be exempt from this requirement. 

Reference 14 CFR § 23.629 for additional information and requirements. 

5-5. Is there any information you can provide for 14 CFR, § 23.1309, Equipment, 

Systems, and Installation? 

Yes. System reliability may be a significant issue when expanding a Day VFR airplane to 

a Night VFR airplane. The applicant will need to show compliance to § 23.1309 for some

of these systems. A thorough discussion on this topic is available in AC 23.1309-1C. We

encourage you to review this document, focusing on those areas that discuss Class I 

applications. 

17 
AC 23-11A 7/14/03 

CHAPTER 6 - BACKGROUND OF 14 CFR PART 23 AND JOINT AVIATION 

REQUIREMENTS – VERY LIGHT AIRPLANES 

In the early 1990’s, we attempted to address the burden that the general aviation industry 

felt was being placed on very light single engine airplanes with low stall speeds. Their 

concern was that the certification requirements of 14 CFR part 23 were unnecessarily 

burdensome to these simple, low speed airplanes. 

Our action followed a rule making activity undertaken by the JAA, known as “Joint 

Aviation Requirements for Very Light Aeroplanes,” or JAR-VLA, dated April 26, 1990. 

In developing the JAR-VLA standards, the JAA used 14 CFR part 23 to form the basis of 

the regulation. In an attempt to address the design features of these airplanes, changes 

and deletions were made to those requirements deemed as either impractical or 

unnecessary. 

Subsequently, we, in conjunction with industry, developed a simplified method to 

certificate very light airplanes. These airplanes would be treated as a “special class” of 

airplane under 14 CFR § 21.17(b). The requirements of JAR-VLA would stand as 

suitable airworthiness criteria for certification of these airplanes, with the following 

restrictions: 

• The airplanes are limited to normal category maneuvers, and 

• The airplanes are limited to Day-VFR operations only under 14 CFR part 91. 

In addition, JAR-VLA permits the use of engines and propellers certificated to JAR-22, 

Powered Sailplanes, Subparts H and J. The FAA agrees that these engine and propeller 

requirements are suitable for JAR-VLA airplanes operating under Day-VFR conditions. 

Therefore, a JAR-VLA airplane, equipped with an engine and propeller certificated to 

JAR-22, Subparts H and J, may earn FAA certification as a special class of airplane 

under 14 CFR § 21.17(b). 

14 CFR part 23 type certification, required for Night-VFR or IFR operations, is a more 

robust process. The material provided in previous sections of this AC provides guidance 

to applicants who seek this level of certification. 

18 
7/14/03 AC 23-11A 

Appendix 1 

ISSUE PAPER 

PROJECT: Acme Aircraft Company – Model 123 Night 

VFR Approval 

ITEM: G-1

Project No. BR-AWN22 STAGE: 2 

 

REG.REF.: 14 CFR parts 21 & 23 DATE: May 23, 2001 

(14 CFR part 21, § 21.17(b), JAR-VLA, VLA-Special 

Class Category, & 14 CFR part 23) 

NATIONAL 

POLICY REF.: Order 8110.4A, Advisory Circulars 

21.17-3 and 23.11-2 

ISSUE STATUS: Open 

SUBJECT: Night-VFR Certification Basis BRANCH ACTION: As required

COMPLIANCE 

TARGET: Pre-ATC 

Night-VFR Certification Basis 

STATEMENT OF ISSUE: 

Acme Aircraft Company (AAC) has applied for Night-VFR certification for the Model 

123 airplane. The country of origin has certificated the Model 123 airplane to the JARVLA regulations. The applicable airworthiness regulations, including special conditions 

as necessary (i.e., the type certification basis), must be designated in accordance with 14 

Code of Federal Regulations (CFR) part 21, § 21.101. 

BACKGROUND: 

The Model 123 is designed and manufactured by AAC. It is a fixed gear, two seat, sideby-side composite aircraft. A conventional elevator on the horizontal stabilizer provides 

pitch control. It uses a conventional yoke. The propulsion system consists of a TCM IO240-B engine and a McCauley fixed pitch propeller - both FAA certified. Its maximum

weight is 1,500 pounds (680 kg). 

If AAC requested Day-VFR operations only, the aircraft could be certificated as a 

§ 21.17(b) aircraft in the VLA-Special Class category. This method of certification is 

described in Advisory Circular (AC) 21.17-3, Type Certification of Very Light Airplanes 

Under Federal Aviation Regulations § 21.17(b), which are eligible for Day-VFR 

operation only. 

A1 

However, AAC has made application to include Night-VFR certification in the U.S. type 

certificate of the Model 123 aircraft. 
AC 23-11A 7/14/03 

Appendix 1 

FAA POSITION: 

The applicable airworthiness regulations must be designated in accordance with § 21.101 

of the Federal Aviation Regulations. 

The four (4) FAA steps for updating the § 21.17(b) VLA-Special Class airplane to 

include night certification, as described in AC 23-11-A, are: 

 Step 1 

Review the original application of the Model 123 to determine what the Federal Aviation 

Regulations part 23 certification basis would have been – which amendment level. Compare 

this amendment level with Federal Aviation Regulations part 23 amendment 42 (the 

amendment level of Federal Aviation Regulations part 23 when the JAR-VLA rules were 

adopted by the FAA) and review the effect on the basic JAR-VLA rules. Update the basic 

JAR-VLA rules as necessary to reflect the (application date) Federal Aviation Regulations 23 

certification basis amendment level. 

The application date was 11/11/94. This would have resulted in a certification basis of 

Federal Aviation Regulations part 23, amendment 46. There are no changes to the basic 

JAR-VLA as a result of Federal Aviation Regulations part 23, amendments 23-43 

through 46. 

 Step 2 

Where JAR-VLA and Federal Aviation Regulations part 23 contain the same rule number but 

they are substantively different, demonstrate compliance with the Federal Aviation 

Regulations part 23 rule, request an Equivalent Level of Safety finding, or an exemption, if 

applicable. AC 23-15 describes simplified methods of compliance for certain Federal 

Aviation Regulations part 23 requirements. 

Listed in Table 1 below are the Federal Aviation Regulations part 23 rules that must be 

addressed and that are substantively different from the corresponding JAR-VLA rules. 

A2 
7/14/03 AC 23-11A 

Appendix 1 

 TABLE 1 

No. Federal Aviation Regulations part 23, amendment 23-46 

1 23.45 Performance

2 23.77 Balked Landing 

3 23.145 Longitudinal Control 

4 23.561 Emerg. Landing Condition, General 

5 23.572 Wing, Empennage, & Associated Structure 

6 23.629 Flutter

7 23.677 Trim System

8 23.733 Tires

9 23.783 Doors

10 23.807 Emergency Exits 

11 23.965 Fuel Tank Tests 

12 23.971 Fuel Tank Sump

13 23.1309 Equipment, Systems, and Installations 

14 23.1529 Instructions for Continued Airworthiness 

 Step 3 

The JAR-VLA rules address most of the Federal Aviation Regulations part 23 rules that 

would be applicable for an airplane of this size. Review and address the differences between 

the JAR-VLA and Federal Aviation Regulations part 23 requirements (at the appropriate 

Federal Aviation Regulations part 23 amendment level – see Step 1). 

Listed in Table 2 below are the Federal Aviation Regulations part 23, amendment 46 

rules that must be addressed but are not contained in the JAR-VLA rules: 

A3 
AC 23-11A 7/14/03 

Appendix 1 

 TABLE 2 

No. Federal Aviation Regulations part 23, amendment 23-46 

1 23.3 Special Retroactive Requirements 

2 23.31 Removable Ballast 

3 23.53 Takeoff Speeds 

4 23.253 High Speed Characteristics 

5 23.302 Canard or Tandem Wing Configurations 

6 23.507 Jacking loads 

7 23.509 Towing Loads 

8 23.511 Ground Load; Unsymmetrical Loads on Multiple-Wheel Units 

9 23.562 Emergency Landing Dynamic Conditions 

10 23.573 Damage Tolerance and Fatigue Evaluation of Structure 

11 23.851 Fire Extinguishers 

12 23.867 Lightning Protection of Structure 

13 23.954 Fuel System Lightning Protection 

14 23.997 Fuel Strainer or Filter 

15 23.1043 Cooling Tests 

16 23.1107 Induction System Filters 

17 23.1157 Carburetor Air Temperature Controls 

18 23.1181 Designated Fire Zones; Regions Included 

19 23.1311 Electronic Display Instrument Systems 

20 23.1329 Automatic Pilot System

21 23.1335 Flight Director System

22 23.1391 Minimum Intensities in the Horizontal Plane of Position Lights 

23 23.1393 Minimum Intensities in any Vertical Plane of Position Lights 

24 23.1397 Color Specifications 

25 23.1413 Safety Belts and Harnesses 

26 23.1441 Oxygen Equipment and Supply 

27 23.1443 Minimum Mass Flow of Supplemental Oxygen 

28 23.1445 Oxygen Distribution System

29 23.1447 Equipment Standards for Oxygen Dispensing Units 

30 23.1449 Means for Determining Use of Oxygen 

31 23.1523 Minimum Flight Crew 

32 23.1524 Maximum Passenger Seating Configuration 

33 23.1527 Maximum Operating Altitude 

34 23.1553 Fuel Quantity Indicator 

35 23.1563 Airspeed Placards 

36 23.1567 Flight Maneuver Placard 

A4 
7/14/03 AC 23-11A 

Appendix 1 

 

 

 Step 4 

The night specific Federal Aviation Regulations part 23 rules must be addressed. 

The night specific Federal Aviation Regulations part 23, amendment 23-46 rules that 

must be addressed are listed in Table 3: 

TABLE 3 

No. Federal Aviation Regulations part 23, amendment 23-46 rule 

1 23.1309 Equipment, Systems and Installations (listed in Table 2 also) 

2 23.1321 Arrangement and Visibility 

3 23.1351 Electrical Systems & Equipment, General 

4 23.1357 Circuit Protection Devices 

5 23.1381 Instrument Lights 

6 23.1383 Landing Lights 

7 23.1385 Position Light System Installation 

8 23.1387 Position Light System Dihedral Angles 

9 23.1389 Position Light Distribution and Intensities 

10 23.1395 Maximum Intensities in Overlapping Beams of Position Lights 

11 23.1401 Anticollision Light System

12 23.1431 Electronic Equipment 

13 23.1525 Kinds of Operation 

14 23.1555 Control Markings 

15 23.1559 Operating Limitations Placards 

If changes have been made which affect the noise level of the aircraft, compliance with 

part 36 will be required. 

By performing Steps 1, 2, and 3 above, the airplane will have addressed the applicable 

FAR part 23 rules for Day-VFR operations. With the addition of Step 4, the aircraft will 

be eligible for Night-VFR operations. 

A5 
AC 23-11A 7/14/03 

Appendix 1 

A6 

APPLICANT’S POSITION: 

Compliance with the night specific rules (Step 4) will be demonstrated to the FAA at 

FAR 23, amendment 46. Steps 1, 2, and 3 in the FAA Position will be addressed with the 

FAA for resolution. 

CONCLUSION: 

AAC agrees with the FAA’s position as defined above. 

________________________________________ _____________________________

Small Airplane Directorate 

Aircraft Certification Service 

Date 

CONTACTS: 

TITLE NAME PHONE 

Originator A. Smith (816) 555-1212 

Project Manager M. Jones (816) 555-1313 

Project Officer F. Johnson (816) 555-1414