Appendix A A-13 Table A-2. Examples of Significant Changes for Small Airplanes (Part 23) (continued) Example Description of change Is there a change to the general configuration?
§ 21.101(b)(1)(i) Is there a change to the principles of construction?
§ 21.101(b)(1)(i) Have the assumptions used for certification been invalidated?
§ 21.101(b)(1)(ii) Notes
26. Conversion from normal category to commuter category airplane.
Yes No Yes Requires compliance with all commuter regulatory standards. In many cases, this change could be considered a substantial change to the type design. Therefore, a proposed change of this nature would be subject to FAA determination under § 21.19.
27. Installation of a full authority digital engine control (FADEC) on an airplane that did not previously have a FADEC installed.
No No Yes
Appendix A A-14 A.1.3 Table A-3 contains examples of changes that are “not significant” for small airplanes (part 23).
Table A-3. Examples of Not Significant Changes for Small Airplanes (Part 23) Example Description of change Is there a change to the general configuration?
§ 21.101(b)(1)(i) Is there a change to the principles of construction?
§ 21.101(b)(1)(i) Have the assumptions used for certification been invalidated?
§ 21.101(b)(1)(ii) Notes
1. Addition of wingtip modifications (not winglets).
No No No A major change to the airplane. Likely, the original general configuration, principles of construction, and certification assumptions remain valid.
2. Installation of skis or wheel skis.
No No No Although a major change to the airplane, likely the original general configuration, principles of construction, and certification assumptions remain valid.
3. Forward looking infrared (FLIR) or surveillance camera installation.
No No No Additional flight or structural evaluation may be necessary, but the change does not alter basic airplane certification.
4. Litter, berth, and cargo tie down device installation.
No No No Not an airplane-level change.
Appendix A A-15 Table A-3. Examples of Not Significant Changes for Small Airplanes (Part 23) (continued) Example Description of change Is there a change to the general configuration?
§ 21.101(b)(1)(i) Is there a change to the principles of construction?
§ 21.101(b)(1)(i) Have the assumptions used for certification been invalidated?
§ 21.101(b)(1)(ii) Notes
5. Increased tire size, including tundra tires.
No No No Not an airplane-level change.
6. Replacement of one propeller type with another (irrespective of increase in number of blades).
No No No Although a major change to the airplane, likely the original general configuration, principles of construction, and certification assumptions remain valid.
7. Addition of a turbo-charger that does not change the power envelope, operating range, or limitations (e.g., a turbo-normalized engine, where the additional power is used to enhance high altitude or hot day performance).
No No No Not an airplane-level change.
8. Substitution of one method of bonding for another (e.g., change in type of adhesive).
No No No Not an airplane-level change.
Appendix A A-16 Table A-3. Examples of Not Significant Changes for Small Airplanes (Part 23) (continued) Example Description of change Is there a change to the general configuration?
§ 21.101(b)(1)(i) Is there a change to the principles of construction?
§ 21.101(b)(1)(i) Have the assumptions used for certification been invalidated?
§ 21.101(b)(1)(ii) Notes
9. Substitution of one type of metal for another.
No No No Not an airplane-level change.
10. Any change in construction or fastening not involving primary structure.
No No No Not an airplane-level change.
11. A new fabric type for fabric-skinned aircraft.
No No No Not an airplane-level change.
12. Increase in flap speed or undercarriage limit speed.
No No No Although a major change to the airplane, likely the original general configuration, principles of construction, and certification assumptions remain valid.
13. Structural strength increases.
No No No Although a major change to the airplane, likely the original general configuration, principles of construction, and certification assumptions remain valid.
Appendix A A-17 Table A-3. Examples of Not Significant Changes for Small Airplanes (Part 23) (continued) Example Description of change Is there a change to the general configuration?
§ 21.101(b)(1)(i) Is there a change to the principles of construction?
§ 21.101(b)(1)(i) Have the assumptions used for certification been invalidated?
§ 21.101(b)(1)(ii) Notes
14. Instrument flight rules (IFR) upgrades involving installation of components (where the original certification does not indicate that the airplane is not suitable as an IFR platform, e.g., special handling concerns).
No No No Not an airplane-level change.
15. Fuel tanks where fuel is changed from gasoline to diesel fuel and tank support loads are small enough that an extrapolation from the previous analysis would be valid. Chemical compatibility would have to be substantiated.
No No No Not an airplane-level change.
Appendix A A-18 Table A-3. Examples of Not Significant Changes for Small Airplanes (Part 23) (continued) Example Description of change Is there a change to the general configuration?
§ 21.101(b)(1)(i) Is there a change to the principles of construction?
§ 21.101(b)(1)(i) Have the assumptions used for certification been invalidated?
§ 21.101(b)(1)(ii) Notes
16. Limited changes in a pressurization system,
e.g., number of outflow valves, type of controller, or size of pressurized compartment, but the system must be resubstantiated if the original test data are invalidated.
No No No Although a major change to the airplane, likely the original general configuration, principles of construction, and certification assumptions remain valid.
17. Install a different exhaust system.
No No No Not an airplane-level change.
18. Changes in engine cooling or cowling.
No No No Not an airplane-level change.
19. Changing fuels of substantially the same type, such as AvGas to AutoGas, AvGas (80/87) to AvGas (100LL), ethanol to isopropyl alcohol, Jet B to Jet A.
No No No Although a major change to the airplane, likely the original general configuration, principles of construction, and certification assumptions remain valid.
Appendix A A-19 Table A-3. Examples of Not Significant Changes for Small Airplanes (Part 23) (continued) Example Description of change Is there a change to the general configuration?
§ 21.101(b)(1)(i) Is there a change to the principles of construction?
§ 21.101(b)(1)(i) Have the assumptions used for certification been invalidated?
§ 21.101(b)(1)(ii) Notes
20. Fuels that specify different levels of “conventional” fuel additives that do not change the primary fuel type. Different additive levels (controlled) of MTBE, ETBE, ethanol, amines, etc., in AvGas would not be considered a significant change.
No No No Although a major change to the airplane, likely the original general configuration, principles of construction, and certification assumptions remain valid.
21. A change to the maximum takeoff weight of less than 5 percent, unless assumptions made in justification of the design are thereby invalidated.
No No No Although a major change to the airplane, likely the original general configuration, principles of construction, and certification assumptions remain valid.
22. An additional aileron tab
(e.g., on the other wing).
No No No Although a major change to the airplane, likely the original general configuration, principles of construction, and certification assumptions remain valid.
Appendix A A-20 Table A-3. Examples of Not Significant Changes for Small Airplanes (Part 23) (continued) Example Description of change Is there a change to the general configuration?
§ 21.101(b)(1)(i) Is there a change to the principles of construction?
§ 21.101(b)(1)(i) Have the assumptions used for certification been invalidated?
§ 21.101(b)(1)(ii) Notes
23. Larger diameter flight control cables with no change in routing, or other system design.
No No No Not an airplane-level change.
24. Autopilot installation (for IFR use, unless the original certification indicates that the airplane is not suitable as an IFR platform).
No No No Although a major change to the airplane, likely the original general configuration, principles of construction, and certification assumptions remain valid.
25. Increased battery capacity or relocate battery.
No No No Not an airplane-level change.
26. Replace generator with alternator.
No No No Not an airplane-level change.
27. Additional lighting (e.g., navigation lights, strobes).
No No No Not an airplane-level change.
28. Higher capacity brake assemblies.
No No No Not an airplane-level change.
Appendix A A-21 Table A-3. Examples of Not Significant Changes for Small Airplanes (Part 23) (continued) Example Description of change Is there a change to the general configuration?
§ 21.101(b)(1)(i) Is there a change to the principles of construction?
§ 21.101(b)(1)(i) Have the assumptions used for certification been invalidated?
§ 21.101(b)(1)(ii) Notes
29. Increase in fuel tank capacity.
No No No Not an airplane-level change.
30. Addition of an oxygen system.
No No No Not an airplane-level change.
31. Relocation of a galley. No No No Not an airplane-level change.
32. Passenger to freight (only) conversion with no change to basic fuselage structure.
No No No Although a major change to the airplane, likely the original general configuration, principles of construction, and certification assumptions remain valid.
Requires certification substantiation applicable to freighter requirements.
33. New cabin interior with no fuselage length change.
No No No
34. Installation of new seat belt or shoulder harness.
No No No Not an airplane-level change.
Appendix A A-22 Table A-3. Examples of Not Significant Changes for Small Airplanes (Part 23) (continued) Example Description of change Is there a change to the general configuration?
§ 21.101(b)(1)(i) Is there a change to the principles of construction?
§ 21.101(b)(1)(i) Have the assumptions used for certification been invalidated?
§ 21.101(b)(1)(ii) Notes
35. A small increase in center of gravity (CG) range.
No No No At airplane level, no change in general configuration, principles of construction, and certification assumptions.
36. Auxiliary power unit (APU) installation that is not flight essential.
No No No Although a major change to the airplane level, likely the original general configuration, principles of construction, and certification assumptions remain valid.
Requires certification substantiation applicable to APU installation requirements.
37. An alternative autopilot. No No No Not an airplane-level change.
38. Addition of Class B terrain awareness and warning systems (TAWS).
No No No Not an airplane-level change.
Appendix A A-23 Table A-3. Examples of Not Significant Changes for Small Airplanes (Part 23) (continued) Example Description of change Is there a change to the general configuration?
§ 21.101(b)(1)(i) Is there a change to the principles of construction?
§ 21.101(b)(1)(i) Have the assumptions used for certification been invalidated?
§ 21.101(b)(1)(ii) Notes
39. Extending an established life limit.
No No No This extension may be accomplished by various methods, such as ongoing fatigue testing, service life evaluation, component level replacement, and inspections based on damage tolerance principles.
40. Flightdeck replacement of highly integrated and combined electronic display systems with other highly integrated and combined electronic display systems.
No No No Not significant if the architecture concepts, design philosophies, human-machine interface, or flight crew workload assumptions are not impacted.
41. Interior cabin reconfigurations are generally considered not significant. This includes installation of in-flight entertainment (IFE), new seats, and rearrangement of furniture.
No No No
Appendix A A-24 Table A-3. Examples of Not Significant Changes for Small Airplanes (Part 23) (continued) Example Description of change Is there a change to the general configuration?
§ 21.101(b)(1)(i) Is there a change to the principles of construction?
§ 21.101(b)(1)(i) Have the assumptions used for certification been invalidated?
§ 21.101(b)(1)(ii) Notes
42. Modification to ice protection systems.
No No No Re-certification required, but certification basis should be evaluated for adequacy.