My question is about Exxon/BP/Eastman 2380.   Seems that aircraft that utilize 2380 go thought a lot of it compared to aircraft that use 254 or Mobil Jet II  is there a reason for this? Any input would be great.


Sir James...

They have a sweet spot they like to run at. I don't know your background with turbines so if I'm being basic, my apologies and disregard my post. If the tank is serviced full you will be blowing overboard about a qt or 2 out the case breather in 1 flight. Bad accessories shafts seals can be leaking. Sometimes airframe manufacturer route the shafts seal drains into the case vent tube to overboard sometimes not. Do you have oil trails from the drain tubes? Engine / airframe type?
I have been around pratt pt6, jt15 and allied signal 731, 331. Never found any to use more oil than any other in a noticeable amount.

It varies on the engines condition on the planes I work on the line. Plus, have many legs the planes fly during the day.

Guess I should have thrown a few more details out there.  Work at a fairly busy FBO so the line gets tasked with oil servicing. Seems that the jets that use 2380 Citiation's(espesially) Globals EMB 135's use a lot of it compared to jets that use other grades of oil. Just curious if it does not have as good as lubricating qualities or I guess maybe the engine mfgr is the issue Pratt?  Dunno just something I have been pondering.


Sir James...

The Citation and Emb have the same turbines (essentially), and most of that oil goes out the accessory box. I've never seen one without all the little tell tale windows full of oil. Most common one is the seal for the air starter, but the hyd pump and 2 generators eat em up as well.  

The rest gets burned up in the number 0 bearing, especially at take off when the drain sump gets overwhelmed, which then leads to smoke in the cabin, RTF, and you know the rest  Not as bad as it used to be anymore though.  

Who is telling you to service the engine? Most run a quart or two low. If a pilot is telling you, he probably doesn't know what propped servicing is.

It varies with the Airlines and their engine preference.  For example, I have seen Rolls engines that don't need to add oil (mainly on 777). Then I seen Rolls (757 and classic 747) takes more oil than normal.

I believe that it depends how hard the flight routing for the planes and when the last time the engine went to over hall.  The engines that can stay on wing the longest makes the plane in service at a higher rate proving nothing goes wrong.