What are the differences between Airworthiness Directives and Service Bulletins

Airworthiness Directives(AD) are issued when the FAA finds that an unsafe condition exists in a product (aircraft, aircraft engine, propeller, or appliance.) 

These AD's notify aircraft owners and operators of potential unsafe conditions and require special inspections, repairs, or alterations to correct the unsafe condition.

Service Bulletins (SB) are notices to aircraft operators from a manufacturer notifying them of a product improvement. 

Alert service bulletins are issued by the manufacturer when a condition exists that the manufacturer feels is a safety related item as opposed to just a product improvement. These SB's usually result in the FAA issuing an AD. The AD will reference the alert service bulletin as a method of compliance with the airworthiness directive. 

If a service bulletin is not an alert service bulletin or a bulletin referenced in an AD, it becomes optional and may or may not be incorporated by the operator.

Checking Brake Wear on Citation 525 Series Aircraft

This video demonstrates how to check the brake wear on Cessna Citation models 525, 525A, 525B, and 525C aircraft.

SEL-78-01R1 - Exhaust Inspection for Cracks (CESSNA MODEL T206H)

CESSNA SEL-78-01

TITLE:     EXHAUST - EXHAUST INSPECTION FOR CRACKS

EFFECTIVITY:  

MODEL SERIAL NUMBERS                         T206H T20609063 thru T20609125, T20609132 thru

                                                                                                     T20609143, T20609145

COMPLIANCE : MANDATORY. 

Until the Lycoming 40B22621 or 40B23388 Cylinder Number 3 Exhaust Pipe has no less than 400 flight hours, an Exhaust System Inspection must be accomplished as follows: (Refer to the Model 206H/T206H Maintenance Manual, Chapter 78, Exhaust System (Turbocharged) - Maintenance Practices)

1. Before further flight if one or more of the conditions that follow exist:

• Cowl Discoloration in the area of the Number 3 Exhaust Pipe

• CO alert

• Uncommanded or unexplained reduction of Manifold Absolute Pressure (MAP).

2. Within the next 25 hours or at the next scheduled oil change, whichever occurs first, and then again at each subsequent oil change not to exceed 50 hours since last inspection.

NOTE: The holder of a pilot certificate issued under 14 CFR Part 61 may perform the special inspections required by this service letter and the associated required logbook entries on any aircraft owned or operated by that pilot which is not used under part 14 CFR Part 121, 14 CFR Part 129, or 14 CFR Part 135.

If a crack is found, Lycoming Mandatory Service Bulletin No. 614A must be accomplished before

further flight.

NOTE: Lycoming Mandatory Service Bulletin No. 614A may be accomplished in lieu of the special

inspections required by this service letter.

NOTE: When the Lycoming 40B22621 or 40B23388 Cylinder Number 3 Exhaust Pipe has more than 400 flight hours or when Lycoming Mandatory Service Bulletin No. 614A has been accomplished, the special inspections required by this service letter are no longer necessary

WINGS - ACCESS PANEL INSTALLATION (Cessna Model T240)

CESSNA SEL-57-02

EFFECTIVITY

MODEL SERIAL NUMBERS                                              T240 2001 thru 2058

COMPLIANCE:     MANDATORY.

1. Special visual inspection as follows:

• During each preflight, the attachment screws for all under wing panels specified in the Accomplishment Instructions must be visually checked to make sure that they are not loose.

• If a loose screw is found, it must be tightened.

NOTE: The holder of a pilot certificate issued under 14 CFR Part 61 may perform the special inspections required by this service letter on any aircraft owned or operated by that pilot which is not used under part 14 CFR Part 121, 14 CFR Part 129, or 14 CFR Part 135.

2. The maintenance procedure specified in the Accomplishment Instructions Section of this service

letter must be accomplished within the next 100 hours of operation.

3. After the maintenance procedure specified in the Accomplishment Instructions Section of this service letter has been accomplished, the special visual inspections during preflight are no longer necessary.

WIRE INSPECTION AT THE AIR-CONDITIONING COMPRESSOR MOUNTING BRACKET (CESSNA T240)

CESSNA : SEL-24-06

TITLE: ELECTRICAL POWER - WIRE INSPECTION AT THE AIR-CONDITIONING COMPRESSOR MOUNTING BRACKET

EFFECTIVITY:   CESSNA MODEL T240 SERIAL NUMBERS T240 T24002001 thru T24002038

REASON

Cessna has determined that wires at the rear of the engine may chafe on the air-conditioning compressor mounting bracket.

DESCRIPTION

This service letter provides parts and instructions to do an inspection of wires adjacent to the air-conditioning compressor mounting bracket for damage. If damage is found, the damaged wire is replaced. Then spiral wrap and sleeving is installed over the wires in the area of the mounting bracket, and the wires are attached securely with tie straps to adjacent wiring.

COMPLIANCE

MANDATORY. This service letter must be accomplished at the next 100-hour or 12-month (annual-type) inspection.

REFERENCES

Model LC41-550FG/T240 Maintenance Manual

Shimmy Damper Servicing Check on 500-Series Citations

Video: Shimmy Damper Servicing Check on 500-Series Citations  - Models: 500, M2, 525, 525A, 525B, 550, S550, 560, 560XL

Locations of Emergency Lighting Battery Packs Model 560XL

Video: Locations of Emergency Lighting Battery Packs Model 560XL - Models: 560XL, XLS, XLS+ 

Questions, please contact:

Cessna Customer Service
+1 316-517-5800

Using a Towbarless Tug On the Citation CJ4

Video: Using a Towbarless Tug On the Citation CJ4 - Models: 525C

Preferred GPU Connection Procedures

How to Access Garmin G3000 LRU Status Information

Single Engine Climb Performance CPCalc