Originally Posted by
Pilot DAR
The pilot wrote that he "cut the throttle"? What did he mean? He cut the throttle effect, which effect would reduce power, so power was increased? Or, he cut back the throttle control, which has the effect of throttling the engine, and reducing power? The language is skewed in two places in the report, why focus on one language error, and not the other?
All I can say to this is you have got to be joking...
Originally Posted by
Pilot DAR
In reading the original report, if that were being reported to me by a competent pilot, who was probably still justifiably excited reporting such an encounter, I would interpret what the pilot meant to say to be that he moved the propeller pitch control to the "increase" position - which is a lesser blade angle. Interpreting that the pilot rapidly reduced power, and extended some flaps, there is no plausible reason to then coarsen propeller pitch. I bet that if you asked the pilot did he mean to say that he "increased the propeller RPM?, he's say: "yeah... that's what I meant". If power is being reduced in maneuvering, or anticipation of landing, you want the prop to be in fine pitch. If not, if/when the power is increased, perhaps quickly, and to a high power setting, a constant speed propeller would govern to a lower RPM, and cause damaging overboost of the engine.
For the P-51, the propeller control is labelled: "RPM" "Increase" (forward), "decrease" (rearward). This is because that control controls the propeller governor, so the pilot selects RPM, not pitch - the governor controls propeller pitch in the governing power range. At low power, the governor no longer governs, so then the propeller control can move the blade angle to fine pitch. The P-51 Pilot Operating Instructions do state that on approach (so power reducing, flaps being extended) the propeller is to be set to 2700 RPM, which is the maximum continuous RPM, so increase RPM, decrease pitch.
For the information which you are selectively interpreting from the report, while overlooking some simply realities of piloting constant speed propeller planes, I think you're leading yourself off the track somewhat.
The fact is, as I pointed out before, everywhere a pitch increase is mentionned by real pilots it means an increase in the blade pitch
angle. Your argument is dependent on
interpreting a forward movement of the control, as designed in the cockpit, as "increase", which is not how the term is used, and in fact makes no sense, since here an "increase" would be refering to
lesser speed use, which is exactly why it is never used that way...
I'm afraid your argument that increasing the throttle could mean less power is reavealing as to YOUR bias...
You also say, "
there is no plausible reason to then coarsen propeller pitch" but you don't mention that explaining this oddity is
precisely the entire point of my post. I ask you one more time: Forget your -biaised- interpretation of increased pitch, and find me a reason other than what I came up with to explain why he might have found it better to coarsen the pitch...
There was asymmetrically accelerated air inside that prop, that's why the coarser pitch... This is the simplest explanation that makes the most sense,
if we accept the basic terms used.
And yes, that and a 30 lbs/square foot aircraft being
vastly out-turned (in all instances that I know of), in low speed sustained turns, by a 45 lbs/square foot aircraft, does mean there is something fundamentally wrong with flight physics on these particular types. If you can't accept that, then accept you can't discuss this with an open mind, as the throttle issue seems to indicate...
Gaston