Jump to content
Aero Precision provides OEM part support for military aircraft operators across more than 20 aircraft

3505786-1 air turbine starter


Recommended Posts

Yes,

The main problem is the very small amount of lubrication inside the starter. after a few minutes the starter will fail and will most likely come apart and damage the engine, cut hoses and electrical wires. Of the two that I know of each time resulted in a FIRE light.

Link to post
Share on other sites

Yes,

The main problem is the very small amount of lubrication inside the starter. after a few minutes the starter will fail and will most likely come apart and damage the engine, cut hoses and electrical wires. Of the two that I know of each time resulted in a FIRE light.

3505786-1 is the part no. for a newer model air turbine starter, older model starter only engages onto the engine when start valve is open and there's bleed air going into the starter, hence damage will occur when start valve is opened in flight and the starter is engaged onto the engine at rpm that is above the limit. is there any new fail safe built into the newer model to prevent this scenario that is not available on the older model?

Link to post
Share on other sites

3505786-1 is the part no. for a newer model air turbine starter, older model starter only engages onto the engine when start valve is open and there's bleed air going into the starter, hence damage will occur when start valve is opened in flight and the starter is engaged onto the engine at rpm that is above the limit. is there any new fail safe built into the newer model to prevent this scenario that is not available on the older model?

No there is no safe guard in place.

If the start valve is “open†and air is going to the starter the starter will try and engage no matter which part you have installed.

The air turbine drive will try to engage and mesh with the rotating gear attached to the gearbox. If it does not mesh the starter will accelerate to maximum rpm then disintegrate after a minute of two; maybe more maybe less.

Link to post
Share on other sites
  • 7 years later...

Hi dears,let me clear your concept,although its too late,

Old or new model

Both have a clutch mechanism, I.e jaw pawls and hub with its drive shaft assy,drive shaft will disengage form starter when starter drive shaft rpm reaches to 8000 to 10000,

During flight engine rpm alway above 13000 , due to high rpm,starter drive shaft will remain disengaged,due drive shaft pawls flung out,weather air pressure going to starter turbine or not.

I hope you understand my broken English.

Link to post
Share on other sites
1 hour ago, Abid kamal said:

Hi dears,let me clear your concept,although its too late,

Old or new model

Both have a clutch mechanism, I.e jaw pawls and hub with its drive shaft assy,drive shaft will disengage form starter when starter drive shaft rpm reaches to 8000 to 10000,

During flight engine rpm alway above 13000 , due to high rpm,starter drive shaft will remain disengaged,due drive shaft pawls flung out,weather air pressure going to starter turbine or not.

I hope you understand my broken English.

I agree it should not actually be able to engage but the fact it will be "disengaged" does not mean it will not try to engage as it spins up nor that it will spin up to max rotation speed "unladen" and disintegrate causing damage to the engine. 

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...