Citation Fall 1997

• Don’t Get Caught Short...
• JT15-D Ignitors, Check the Ignitor Boss
• Modify Your TFE-731 Engine Breather Valves
• Engine Shop Begins First Carbon Seal Inspection
• Winter Preflight Advice

Don’t Get Caught Short...

Are all recurrent inspections and component time change items current on your aircraft? If the answer is yes, are you absolutely sure?

Operators are often unaware when there are inspections and time change items that are not current. It’s particularly true when their aircraft has been modified by an STC.

For example, if you operate an Eagle modified aircraft, there is a 2500 hour inspection to be complied with and revisions to the accomplishment procedure for phase 49.

Any STC that has been incorporated, no matter how seemingly minor, could have additional specific inspection/time change requirements. The STC holder provides this information to the owner of record when the modification is accomplished. Revisions are mailed to the owner, and that information is often lost when an aircraft is sold. Therefore, the current operator may not be aware that these requirements exist.

This oversight can lead to dangerous conditions that may cause serious damage or injury. So, if your aircraft has been modified from the OEM original certification basis, make sure any subsequent inspection/time change intervals are thoroughly researched.

For more information, call Ed Johnson at 1.800.228.4277.

JT15-D Ignitors, Check the Ignitor Boss

When removing ignitors, be sure to look into the ignitor boss to make sure the floating spacers, seals or the entire grommet housing have not fallen out. This occurs when the seals or housing assembly fret against the housing or the combustor. When the ignitors are removed, the parts fall out and lay in the gas generator case. This results in a FOD issue as well as starting and performance problems. An unscheduled engine entry will then be required for combustor repair or replacement. P&WC SB 72-7199 was introduced to improve the durability of these components.

Modify Your TFE-731 Engine Breather Valves

Duncan Aviation has received documentation and authorization from AlliedSignal l to modify and update TFE 731 engine oil breather valves.

AlliedSignal , through specific SBs, is updating the TFE 731 oil breather valves from PN 3071564- 7, -8, -9 and 3075323-l and -2 to PN 3075323-3. Until this modification, customers were required to purchase updated valves.

For more information about this money-saving modification, contact Chris Gress at 1.800.228.4277.

Engine Shop Begins First Carbon Seal Inspection

The first industry inspection of the new style #l and #3 carbon seals and runners has recently been performed at Duncan. These seals were installed 1400 hours ago and made it through the entire MPI interval without any problems. The carbon seals appeared to be in excellent condition, showing little wear or carbon buildup. The seal runners were in the same excellent condition. They showed even wear patterns and no signs of seal skipping. The #l carbon seal and rotor were reinstalled. Although the #3 carbon seal was also in excellent condition, it was removed and sent to Phoenix for further testing. The seal runner was reinstalled with a new #3 carbon seal.

For more information about SB 72-3613, please contact Jon Dodson or Cecil Sloan at 1.800.228.4277.

Winter Preflight Advice

During a light inspection on a Citation 650, the right-hand main landing gear door lower attach bolt (pin 6227001-89 ipc 32-11-00 fig. 1 item 10) was found broken. The bolt, fittings and all washers and spacers appeared intact. The discrepancy was found by pulling outboard on the lower part of the door. Failure of this bolt may be more likely when the aircraft is operated on slushy runways and taxiways.

( Return to top )