TPE331 ADVISOR 4TH QUARTER DECEMBER, 2016

Service Bulletin of the Quarter SB 72-2208 AD 2016-18-17

AD 2016-18-17 applies to the second stage impeller part number 893482-1 through –5 inclusive or 3107056-1 or –2 installed. The AD was prompted by the discovery of cracks in a 2nd stage impeller during a routine shop visit. The AD was issued to prevent failure of the compressor impeller, uncontained parts release, damage to the engine and damage to the aircraft. Compliance with the AD is required at first removal of the second impeller or within 11,500 cycles of the effective date of this AD which is November 4, 2016.

Honeywell SB 72-2208 describes procedures for replacing the above listed 2nd stage impellers. Second stage impellers 893482-1 through –5 and 3107056-1 and –2 may be replaced with New 3108387-1 impel-lers which are life limited to 30,000 cycles.

Second stage impellers 893482-1 through –5 and 3107056-1 and –2 may be inspected and upon passing inspection be reworked to part numbers 3107167-1 though –5 with a life limit of 10,500 cycles. The rework option may represent a significant cost savings to operators however, if the impellers fail inspection they will still require replacement at additional cost to the operator. This inspection and rework must be accomplished by Honeywell. Please consult your Honeywell Service Center for Compliance.

Note: 3108387-1 and 3107167-1 though –5 2nd stage impellers are life limited and require a Life Limit Part Log Card to be maintained. Refer to TPE/TSE331-72-0019, TPE331-72-0117

72-2109 Low Carbon Combustor

 

 ENGINE – COMBUSTION SECTION – REPLACE COMBUSTION CHAMBER ASSEMBLY, PART NO. 3103215-3, 3103892- 4, 3107053-1, 3107173-1, 3107174-1, 3107188-1, 3108322-3, OR 3108322-5, WITH COMBUSTION CHAMBER ASSEMBLY, PART NO. 3107173-1, 3107174-1, 3107188-1, OR 3108322-5 Applicable to the TPE331-10 -11 and -12 engines.

 The engine manufacturer has developed a new combustion chamber assembly with improved carbon reduction design features. We have seen significantly reduced maintenance cost on engines with the low carbon combustor installed at HSI, CAM and OH. Cost savings on a TPE331-10 at Hot Section Inspection have been as much as 50%.

  • The new design greatly reduces heat stress and carbon erosion on the 1st and 2nd stage turbine wheels and stators. Be sure to ask your service center whether 72-2109 has been accomplished on your engine at your next shop visit.

Meet: Tim Forker

Tim began his aviation career in Branson, Missouri with Ozark Mountain Helicopters 35 years ago as an aircraft mechanic. Tim received his IA in 1991 while working for Worldwide Aircraft as an A&P mechanic. Tim Joined CD Aviation Services in 2008 as an engine mechanic and Line Inspector. In addition to Tim’s shop duties he is the crew chief for a Jetstream 31 in corporate configuration a Jetstream 32 in PAX configuration and a Lear 45XR. Tim has experience on a dozen different airframes and as many different engine models including piston, radial, turbo prop, turbo shaft, ram jet and turbo fan. Tim is an avid NAS-CAR fan and outdoorsman. He enjoys his spare time hunting with bow and rifle as well as spending time with his family and neighborhood friends at his home in Carl Junction, Missouri.

Here’s a tip!

TPE331 Operation.

One of the leading causes to damage to a TPE331 is improper operation!

During preflight inspection verify the following:

  • Check inlet and exhaust for FOD and obstructions and integrity.
  • Verify oil level and oil filter bypass is not extended.
  • Inspect propeller and spinner for security and damage.
  • Verify propeller is on the locks and engine turns freely.
  • Check power lever and speed (condition) lever for free and smooth travel.
  • Check power lever and speed lever for freedom of travel and position them for starting

​Starting your engine: 

Verify adequate power is available. It is recommended that a GPU be used whenever possible.

Verify residual turbine temperatures are below 200˚C on EGT systems or 300˚C on ITT systems.

Actuate start and verify rotation visually and by cockpit indication.

If performing a manual start turn on igniters and fuel at 10% rpm.

If light off has not occurred within ten seconds, as noted by an increase in turbine temperature, abort start.

Acceleration after light off:

After light off, closely monitor turbine temperatures to prevent exceeding limits and RPM acceleration for a 1% per the second rise. It is especially important to monitor this through the critical range of 18%-28% RPM.

If doing a manual start with SRL inoperative, SPR is required to maintain a one percent per the second rise in rpm while monitoring temperature.

On SRL equipped systems, the SRL will SPR as required to maintain a temperature of approximately 695˚C. Operator must still monitor temps and rpm for a one percent per second rise.

During this time the operator will also see oil pressure begin to rise, fuel flow will increase, and HP/Torque will begin to indicate.

Critical Range 18%-28%:

Critical range is a speed at which an engines harmonic vibration reaches its peak amplitude.

The critical range of the TPE331 is between 18%-28%

If an engine is allowed to dwell in this range the harmonic vibration can create damage internally to the engine.

Extra attention should be given to ensure that the acceleration through this rpm range is 1% per second.

If the engine starts to hang in this range the start should be aborted.

50%-60%

Critical range is a speed at which an engines harmonic vibration reaches its peak amplitude.

The critical range of the TPE331 is between 18%-28%

If an engine is allowed to dwell in this range the harmonic vibration can create damage internally to the engine.

Extra attention should be given to ensure that the acceleration through this rpm range is 1% per second.

If the engine starts to hang in this range the start should be aborted.

Engine Cooling & Normal Shutdown:

A minimum 3 minute cool down period is strongly recommended to prolong engine component life. This time can begin during taxi, provided engine condition lever is in the low RPM position and power at minimum power.

After cooling period, actuate the stop switch. This action closes the fuel shutoff valve, reducing fuel flow to zero, and opens the fuel manifold purge valve. Holding the stop switch for a minimum of 5 seconds ensures proper fuel system purging. Always verify on each shutdown that purge is working correctly. This is indicated by a momentary rise in temperature and rpm.

Around 50% RPM, move power lever to full reverse position and allow it to remain there until engine has decelerated to below 10% RPM. This allows the start locks to re-engage for next engine start. Power lever can then be returned to flight idle position.

Always refer to the aircraft POH for specific starting, operating, and shutdown procedures

Services Offered for your TPE331

  • Scheduled and Unscheduled Maintenance Engine Removal and Reinstallation
  • LRU Trouble Shooting and Replacement Field Service
  • Engine Evaluation Log Book Reviews
  • Engine Overhaul CAM Inspections Hot Section Inspections
  • Gearbox and Compressor Inspection Repair Vibration Analysis Prop Balance
  • Borescope Inspections 24-Hour AOG and Technical Support

Questions, comments, or need assistance? Call us anytime at 417-206-2327.

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