P&W Engines Winter 2008

• JT15D-5A and -5D Engine Bleed Valves
• More on the PW305A & 305B Fan Blade
• PW305A Engine Positioning Plate Attach Bolts

JT15D-5A and -5D Engine Bleed Valves

— Ken Kuchenreuther

JT15D-5A and JT15D-5D are similar engines and both have bleed valve systems. If you are experiencing an ITT split with an associated N2 split, the hotter engine with the higher N2 may have a bleed valve problem. I have gathered the following information that you may find helpful during troubleshooting:

1. With a loss of power (or ground) to the bleed valve controller on top of the engine or the bleed valve actuator solenoid on the right side of the engine, the bleed valve should close or be closed.
   
2. Bleed valve actuator down means the bleed valve is probably closed.
   
3. Each engine bleed valve has its own circuit breaker in the pilot’s CB panel labeled “BOV” (“LH” or “RH”).
   
4. Pulling the breaker removes power, thus closing the bleed valve due to high pressure fuel pushing the bleed valve actuator piston down.
   
5. Bleed valve should be closed at pressure altitude less that 25,500 feet.
   
6. Bleed valve controller inputs are pressure altitude and N2 speed.
   

If you suspect you have a bleed valve issue, please contact me at 269.969.8486 and I will guide you through a check.

More on the PW305A & 305B Fan Blade

— Ken Kuchenreuther

On October 25th, 2007, Pratt & Whitney released Service Information Letter (SIL) PW300-094 to update operators on the results of fan blade inspections associated with SB PW300-72-A24588– Inspect 40 engine’s fan blades for under minimum condition on the airfoil root trailing edge. It has resulted in removal of some blades with the under minimum condition. Moving forward, Pratt & Whitney has taken steps to make SB 24582– Fluorescent Penetrant Inspection of fan blades–obsolete. Concurrently, SB 24595 was released calling for fan blades to be checked for an under minimum condition, affecting approximately 500 additional engines. Pratt & Whitney recommends that this inspection be accomplished at next access to the fan blade assembly, which in most cases will be the next IBR inspection event. SIL PW300-094 contains a list of facilities trained to perform the under minimum condition inspection (SI 37-2007). Pratt & Whitney also released Commercial Support Program #1003142 on October 30, 2007, offering assistance for labor required to perform the inspection called out in SB 24595.

PW305A Engine Positioning Plate Attach Bolts

— Ken Kuchenreuther

In October, 2007, Pratt & Whitney released SB 24592 calling for a one-time boroscope inspection of the positioning plate assemblies for missing bolts. The suspect missing bolts are adjacent to the actuator vane ring half and can be accessed through the 2.5 bleed air port. The SB only applies to seventeen select engines between (but not all) and including PCE-CA0457 and PCE-CA0524. Pratt & Whitney recommends that the SB be accomplished at next scheduled maintenance or within 300 hours, whichever comes first. If bolts are found installed, no further action is required. If bolts are found missing, the area can be accessed by carefully removing the outer and inner upper bypass ducts to permit bolt installation.

If you have questions about this, or any issue in this publication, please contact me:

( Return to top )