This statement is also factually incorrect.
In the PT-6 Series of engines (I have no experience with Garrett or Allison and therefore will not comment on them), beta range is defined as any time when the propeller is not being controlled by the constant speed section of the propeller governor.
No, the statement is factually correct, and was written specific to the discussion under way regarding the TPE-331. You need to read the thread and understand what is written before comment.
Seeing as you chose to comment, however, what you just said is exactly what I said; everything aft of the low pitch stops. That's beta. From the cockpit perspective, everything aft of the idle stop is beta. Some pilots try to differentiate between beta and reverse, but it's all beta, including reverse. There are two modes of propeller operation; alpha, and beta. Alpha is anything forward of the low pitch stops, and beta is everything aft.
Some pratt manuals refer to the alpha range as the "power range," and the entire beta range as the beta range. This is the nomenclature used by P&W.
The low pitch stops on some aircraft are variable; this isn't a P&W function, but a customer (aircraft) function using squat switches or other trigger devices that help the engine differentiate between high and low idle, or flight and ground idle. Never the less, once aft of the alpha, power or forward range (aft of the idle pitch stops), one is in beta range, and this is "factually correct" (as you like to put it) regardless of whether one is talking about a PT6A, TPE-331, or T-56.
Your understanding of beta range and beta operations are incorrect.
In summary: During on-speed conditions, the constant speed section of the propeller governor controls oil supply towards the objective of maintaining selected propeller RPM.
Only when operating in the governing range. Until that time, the propeller blades rest on the low pitch stops. You may be thinking of the beta functions of the fuel control, but you don't seem to understand the function of the beta relationship in the propeller and the engine. When the propeller is operating forward of the idle stops in ground operations, the blade angle can't be reduced further to correct an "underspeed" condition. The blades are already on the low pitch stops, and these won't be moved until the propeller is commanded into the beta range (roughly equivalent to neutral and reverse thrust, but always aft of the low pitch stops). The propeller governor doesn't actually govern, insofar as constant speed operations, until the propeller is spinning fast enough to be governed, and in this respect any propeller installation on the PT6A is no different than a constant speed propeller on a piston installation. Until the engine is operating in the governing range, RPM is a function of engine power; you'll have lower propeller RPM at idle than on takeoff, because the propeller isn't operating fast enough to be governed, yet.
Beta functions take place when the propeller is commanded into a lower pitch than the low pitch stops. This takes place when the power lever is moved aft of the idle gate or idle stops. Various airframes use various methods of providing these stops and limits, or in a few cases, multiple limits. Some pilots incorrectly correlate the turboprop sound with a beta, but anything aft of the low pitch stops is beta; specifically, any blade angle aft of the low pitch stops is beta.
You may have read cautions regarding moving the power lever into the reverse range, from the cockpit, when the engine isn't operating. The reason for this is the potential for damaging your beta control, and beta blocks.
Think of it this way: at idle with the propeller feathered, the propeller isn't being operated in beta, though it's certainly in an "underspeed" condition. "underspeed" isn't beta in the alpha, forward, or power range (alpha, forward, and power range being the same thing).
Same for me - I would have though for sure that the loss of oil to the prop hub/governor would have the prop going full-coarse, but as it turns out I was wrong.
You're right, but only for some propeller installations. Not all. Some will feather, will go coarse, some will go fine. On light single engine horizontally opposed piston installations and on many radial engines, the propeller goes to the low pitch stops, or full fine, and the propeller essentially acts as a fixed pitch prop. On some installations, the opposite is true, and on some one can cause the propeller to default to full coarse or high pitch by retarding the propeller lever all the way. Some turboprops will automatically feather, some won't, and some that should, don't. One should never count on the propeller feathering, especially if one has any amount of airspeed and engine rotation present. Some propellers must be manually feathered, and will come right back out of feather and start producing drag again if not feathered correctly or if the pump motor isn't stopped in time. Some have additional safeguards to automatically feather a motor that's not producing torque, even if the installation should feather on it's own, even if the pilot has the capability.
One must know the systems in use.
If, as you claim, you operated the C130 as both a pilot and F/E, and acted as a mechanic and inspector at line and depot levels, you obviously did not understand the Allison T56/Reduction gearbox system as you should have.
I understand it quite well, thanks.
So am I to understand that the airlines are hiring people that have no idea about the consequences of a low oil pressure indication...so ergo.... despite being taught to check the oil level prior to a flight they have no clue as to why that brown sticky stuff dripping on them is in there to begin with...??
Why would you "understand" this when no one in this thread has said any such thing, in any way, shape, or form?
What has being "taught to check the oil level prior to flight" to do with losing oil in flight?
Losing oil quantity may not be nearly so important as other effects that take place when oil is lost.
In some airplanes, oil is used to heat fuel (and conversely, to cool the oil), and other such functions. In the event of an oil loss, heating the fuel is really immaterial, as one has much bigger issues, such as loss of thrust, loss of torque, and so forth.
If one does have the capability of monitoring the oil supply, then one doesn't necessary simply shut the engine down. The airplane I fly directs us to shut it down when the oil quantity reaches .5 gallons. It also directs us to start it back up for landing, as necessary and prudent, depending on the nature of the loss, speed of the loss, etc. Until then, so long as it's producing usable thrust and we aren't seeing other problems, we keep the engine, and don't shut it down.
Some engine installations have instructions for aircrew directing them to continue running the engine with a loss of oil pressure, so long as other indications don't exist. The same may be true for oil supply. If one sees an oil loss in a turbopropeller engine, such as previously discussed, but sees torque and the effects of oil pressure in use, one may or may not shut the engine down, depending on what one sees (and the number of engines one has available, as well as the conditions under which the problem occurs.
The point is, simply learning to check the oil, and simply understanding what "the brown sticky stuff" is, doesn't imbue the user with an innate knowledge for the proper procedures in a particular airplane, or a particular powerplant. In fact, having operating experience with the powerplant in one airframe doesn't necessarily mean that one is thoroughly versed in another installation. Furthermore, simply because one understands the procedures in one airplane doesn't mean one understands the procedures in other airplanes. It's not that simple. The original poster asked a question which sparked discussion; this isn't a statement that airlines are hiring idiots; hiring was never discussed, airlines were never discussed, and nobody claimed to have no idea what oil does.
Discussions have been had about types of oil and fluids, about the application of oil in the engine, about various procedures and examples, but one is always beholden to the procedures given by both the engine manufacturer and the airframe manufacturer, as well as propeller or accessory or appliance manufacturer, as well. Sometimes all of them. One should not only expect to have procedures available, but should be well versed in their use, specific to the aircraft one is operating at any given time.
Yes, one should refer to the checklist. It's there for a reason. One should know which procedure to use, the immediate action (or memory) items, and should understand how to fly the aircraft until the problem is stabilized and handled, whatever the case may be.
Most certainly problems may arise which are not addressed in a quick reference handbook or in the flight manual. Generally the symptoms of these problems may be individually addressed, or broken down by priority and addressed. One may have a flap problem but may not have a specific procedure for addressing the flap problem. One may be best to leave the flaps alone and land without them; one should then have available data for landing without flaps (speeds, certain cautions, etc). As complexity (and size) of aircraft increases, the number of procedures generally increase, and these procedures by necessity must be followed. One may *think* one is doing the right thing, but there may be additional considerations which are addressed by the use of the procedural checklist, and these must not be ignored. One may simply wish to shut down the engine that has no oil pressure, but may neglect to take into account that engine as the only source of hydraulic power, for example; deferring the shutdown, or configuring the airplane first, may be a big consideration. Advising the pilot body to use common sense, particularly when addressing complex systems, may be bad advice; common sense alone doesn't cut it when complexity dictates that details count.