# Presentation: 660120

## Working Example;Alternator Change

- Mike Heusser, ACE-115N
-   Peter Pupator, ACE-115N
-    Mark Wilson,    AAL-235

## Alternator Change

- Replacement of an existing Alternator  with a higher output alternator
- Cessna 207A.  TCDS #A16CE, Cert Basis 14 CFR part 23 as amended 23-1 through 23-6 (14v electrical system serial number aircraft)
- Maximum aircraft weight 3800 lbs
- We are assuming the aircraft has a US registration
- We are assuming that the alternator has a good aviation service history

## Initial Considerations

- Establish the correct aircraft certification basis
- 	For example:
- 14 Code of Federal Regulations, Part 23
- Civil Air Regulations(CAR), Part 3
- Bureau of Air Commerce, Aeronautics Bulletin No. 7-A
- Air Commerce Regulations

## Initial Considerations

**Predecessor Regulations are still in effect for many certification projects**
- Civil Air Regulations(CAR), Part 3
- Bureau of Air Commerce, Aeronautics Bulletin No. 7-A
- Air Commerce Regulations

## Initial Considerations

- Pulley Diameters (sets the alternator speed)
- Voltage regulator
- Torque limiting features
- Mounting brackets
- Cooling air requirements

## Initial Considerations

- Over voltage protection
- Wire size and type
- Circuit protection (circuit breaker type)
- Electrical loads
- Electrical distribution system capacity

## Required information

- Output voltage
- Maximum Alternator speed
- Minimum Alternator speed for rated output
- Maximum Alternator temperatures
- Maximum output current

## Regulation and Possible method of compliance

**14 CFR 23.601**
- Section 3.291, when working with a CAR-3 aircraft
- Suitability of design details and parts
- Compliance can be shown by use and service history of parts on other aircraft.

## Regulation and Possible method of compliance

**14 CFR 23.603**
- Section 3.292, when working with a CAR-3 aircraft
- Materials and workmanship
- Compliance can be shown by using standard materials or aviation type components.
- Workmanship of standard aviation practices.

## Regulation and Possible method of compliance

**14 CFR 23.611**
- Section 3.296, when working with a CAR-3 aircraft
- Accessibility
- The unit must be installed such that access is available, in typical maintenance situations, for close examination (and adjustment) required for inspection, lubrication, or alignment.

## Regulation and Possible method of compliance

**14 CFR 23.1163**
- Section 3.635, when working with a CAR-3 aircraft
- Power Plant accessories
- Bracket strength considerations.
- Use existing mounting on engine.
- Mount so as to avoid contact with flammable fluids and vapors.  Do not mount in a possible low area where vapors can accumulate.  Ventilate alternator properly.

## Regulation and Possible method of compliance

**14 CFR 23.1163** (continued)
- Power Plant accessories
- Expect to measure alternator temperatures at the critical condition
- Bearing temperatures
- Case temperatures
- Stator temperature
- Propose testing method:
- Thermocouples, temp. sensitive labels
- On the ground or in the air?

## Regulation and Possible method of compliance

**14 CFR 23.1301**
- Section 3.651, when working with a CAR-3 aircraft
- Easy Stuff
- Does the new alternator perform its intended function as related to the whole aircraft system.
- Have the switches been labeled.
- Does all of the other installed equipment function properly.

## Regulation and Possible method of compliance

- 14 CFR 23.1322
- Does the system have a warning annunciator?
- If so, the annunciator must be ***amber*** colored

## Regulation and Possible method of compliance

**14 CFR 23.1351**
- Sections 3.690, 3.693 & 3.687, when working with a  CAR-3 aircraft
- Electrical loads must be established
- Loads can be found by analysis or measurement (Propose a test)
- MIL-E-7016F, Electrical loads analysis contains methods and procedure
- AC 43.13 latest revision

## Regulation and Possible method of compliance

**14 CFR 23.1357**
- Sections 3.690 & 3.691 when working with a  CAR-3 aircraft
- Circuit breakers must be “Trip Free”
- Circuit breakers must be of the correct size
- Must be readily reset in flight
- If the alteration uses fuses, there must be spares available to the pilot
- Must be identified (labeled)

## Regulation and Possible method of compliance

**14 CFR 23.1361**
- Section 3.688 & 3.689 when working with a  CAR-3 aircraft
- Must have a master switch to disconnect the alternator
- Master switch must be properly located
- Master switch must be easy to see
- Above items probably ok, if similar to the previously existing installation

## Regulation and Possible method of compliance

**14 CFR 23.1367**
- Section 3.694, when working with a  CAR-3 aircraft
- Switches must be labeled
- Switches must be of adequate capacity and voltage rating
- Distance or Insulation of connecting wire.
- Vibration in flight cannot cause shorting.

## Final Considerations

- Must have drawings or photos describing the installation.
- Must have Schematic and Distributions Diagrams (Part of ICA)
- Drawings/Photos need to indicate component part numbers and source of supply
- Reports: Electrical loads, Other as required.
- Originals go with aircraft records:  337, 8110-3, Reports, FMS...
- I/A has no requirement to hold copies.