Skip to main content

Questions tagged [constant-speed-propeller]

A propeller that uses a governor to keep its rotation speed from varying excessively.

Filter by
Sorted by
Tagged with
2 votes
1 answer
85 views

Understanding the constant speed prop and 2-4 degrees optimum

I've read through some answers on here and just wanted to write my own description of how this works and let someone check for me. Currently I've just started to fly an King air 100 with PT6A We ...
Ollie Seaward's user avatar
5 votes
3 answers
144 views

How can I find the minimum and maximum airspeeds for efficiency with a specific prop/engine combination?

I'm operating a Cessna 180 with various wing and weight mods with a TCM IO550D engine and a McCauley Black Mac (D3A34C401/90DFA-2 3 blade (88 inch) seaplane prop. I operate Lean of Peak (LOP) for most ...
DustyFlier's user avatar
1 vote
1 answer
87 views

Constant Speed Propeller and Angle of Attack

Question regarding the AoA (Angle of Attack) on a Constant speed. The CSU (governor) sets the blade angle based on the desired RPM, and the flyweights keep it from speeding up or slowing down using ...
Ben-FI's user avatar
  • 21
2 votes
1 answer
205 views

Do full-feathering constant-speed propellers have a high-pitch stop for the prop governor?

On full-feathering (hydraulic) constant speed propellers in general, and specifically Hartzell and McCauley props, does the propeller governor have a high-pitch stop (like non-feathering propellers, ...
TheEagle's user avatar
  • 1,404
0 votes
0 answers
52 views

Constant Speed Prop Power Settings [duplicate]

I'm studying the performance data for a Piper Arrow with a constant speed propeller. The rule of thumb that I've heard is not to let manifold pressure go above RPM. This performance data seems to show ...
Tom's user avatar
  • 387
3 votes
0 answers
166 views

What are the range of feathering speeds for electric constant speed props?

I flew a motorglider with an MT-7-A electric CS prop which takes 90 seconds to fully feather. Contrast that to a hydraulic governed prop, which takes just a few seconds to go from one extreme to the ...
Kenn Sebesta's user avatar
  • 5,230
0 votes
0 answers
115 views

where is the centrifugal force the flyweights experience coming from?

The T6b uses a PT6-68 engine which has a variable pitch, constant speed, feather, and non-reversible prop system. There is only one lever in the cockpit which regulates Torque and the Power Management ...
YamchaAviator's user avatar
4 votes
3 answers
278 views

What is the cause of possible crash in an accidental low RPM takeoff?

I've read from quite a few sources that during the World War II, it was not that uncommon a mishap for a fighter pilot to take off with a "coarse pitch" / "low RPM" prop setting. ...
mkay's user avatar
  • 183
2 votes
1 answer
1k views

Do constant speed propellers actually increase fuel efficiency?

I have a few questions regarding constant speed props. As a pilot who just recently moved up to aircraft equipped with constant speed props (Cessna 182, Piper Dakota), I understand that a constant ...
geckofox's user avatar
12 votes
3 answers
8k views

Why do pilots move the propeller lever full forward before landing?

Is it because aircraft can get more "instant" power for go-around, with throttle full-forward? Or is it for protecting the aircraft's engine from high RPM, low PROP stress in case of go-...
Student412's user avatar
0 votes
2 answers
2k views

Why does the centrifugal twisting force move variable pitch propellers to fine?

In my research on the forces acting on and influencing a single engine, non feathering variable pitch propeller's ability to change blade angle, I've come across a bit of a roadblock. Aerodynamic ...
hiigaran's user avatar
  • 185
0 votes
1 answer
1k views

Why does RPM increase when you lean the mixture in constant speed propeller engine? [duplicate]

In constant speed propeller aircraft like Diamond star DA-40, during run-up checks the AFM mentioned to increase throttle to increase RPM to 2000 and then do magneto check then rpm check then mixture ...
Krishna Kanth's user avatar
8 votes
2 answers
1k views

During an engine failure in Diamond DA-40, should the prop lever be at fine pitch or coarse pitch?

Chapter 3 of AFM doesn't mention anything about prop lever setting during engine restarting for both windmilling as well as stationary propeller
Krishna Kanth's user avatar
21 votes
8 answers
5k views

Variable pitch propellers: Why are they constant speed too?

I am studying for my PPL, and after going through aerofoils, lift, drag, optimal L/D ratio, propeller blades and the like, the need for a variable pitch propeller is absolutely clear to me. It is also ...
user815129's user avatar
3 votes
2 answers
3k views

Why, with a constant speed propeller, does moving the propeller control forward increase drag?

Could someone explain why, let's say in a constant speed propeller, with moving propeller control forward the drag increases? It is noticeable when we push the blue knobs forward in flight that the ...
Konrad's user avatar
  • 2,035
3 votes
2 answers
7k views

Why does a low pitch propeller have better acceleration/take-off and climb characteristics than a high pitch propeller?

Why does a propeller with a low pitch have better acceleration/take-off and climb characteristics vs. a high pitch propeller? And conversely, why is a propeller with a high pitch not as good during a ...
Konrad's user avatar
  • 2,035
0 votes
2 answers
794 views

In constant speed propeller, if i increase RPM lever from 2300 to 2500, will the Blade AOA decrease?

Assume I am flying straight and level with power setting 21 inches of MAP and 2300 RPM with TAS=100 kts, now I change my Prop lever only (MAP = no change & TAS = no change) from 2300 to 2500, ...
Krishna Kanth's user avatar
8 votes
1 answer
1k views

What is prop RPM control logic on PC-12?

Pilatus PC-12 has a constant speed propeller, but it does not have a prop control lever in cockpit, just a power lever and small fuel on/off lever. So how does it determine the prop RPM? Does it ...
Jan Hudec's user avatar
  • 56.4k
2 votes
2 answers
630 views

Does a constant speed prop maintain the optimal angle of attack at all time?

From an answer on this site: The governor just knows: Speed too fast, flyweights move out, routes pressure to move the blades more coarse; speed too slow, flyweights move in, routes pressure to move ...
user avatar
0 votes
1 answer
190 views

Does a constant speed prop deliver max speed at max manifold pressure and max RPM?

I was reading a discussion in flight simulator forum and I found this statement: Ignoring the issue of engine overheating, max MAP and max RPM is the best thing for max speed Do you agree with that? ...
user avatar
1 vote
2 answers
338 views

Will the blade angle of a constant speed propeller be at its least angle (fine pitch) during full throttle and prop full?

During low power settings, low throttle setting and prop full during taxi, the blade angle will be at its finest pitch. As we increase the throttle for take-off, will the blade angle remain in its ...
Krishna Kanth's user avatar
5 votes
6 answers
2k views

What other advantage(s) does an adjustable prop give you?

From what I understand, the purpose of a variable-pitch propeller (be it manually adjustable, or constant speed) is that it allows the engine to always operate at its most efficient speed, much like ...
HiddenWindshield's user avatar
2 votes
2 answers
602 views

Does a constant power prop exist? What are the tradeoffs compared to a constant speed prop?

Variable-pitch props allow pilots to adjust the angle of attack of the propeller to change the load on the engine. The most common implementation of this is a constant speed prop where the prop ...
digitalPhonix's user avatar
3 votes
2 answers
2k views

Does it ever happen that increasing the prop RPM without moving the throttle actually decreases the thrust and power delivered to the airframe?

A) In an airplane with a piston engine and a constant-speed prop, flying at some given airspeed with the manifold pressure and RPMs in a typical cruise configuration, would it ever happen that ...
quiet flyer's user avatar
  • 22.9k
3 votes
2 answers
431 views

What are the design considerations for variable-pitch folding-propellers?

Folding props are increasingly used on self-launch gliders in order to reduce drag. Here is an example of 1m dia. props from LZ Design's FES system: For self-launch gliders, due to minimally-sized ...
Kenn Sebesta's user avatar
  • 5,230
3 votes
3 answers
5k views

What is the relation between manifold pressure, RPM, and power, in a constant speed prop?

I know that there are similar topics here, one is mine even, but still I have few questions about constant speed propeller. My questions: Why if we decrease RPM and maintain throttle lever setting ...
Konrad's user avatar
  • 2,035
2 votes
1 answer
8k views

Manifold pressure vs power vs rpm

From what I know MAP is a way of measuring engine power with variable pitch propeller. Greater throttle setting - greater power - greater MAP on the gauge. It happens because MAP is in fact vacum ...
Konrad's user avatar
  • 2,035
10 votes
2 answers
818 views

Do constant maximum lift to drag ratio variable pitch propeller exist?

Are there variable pitch propellers, where pitch is set so that the blades constantly are at their maximum lift to drag ratio AoA, whatever the incoming relative wind speed & direction? Such a ...
user avatar
3 votes
2 answers
539 views

Would shutting down the engine have prevented the Atlantic Southeast Airlines Flight 2311 crash?

In the crash of Atlantic Southeast Airlines Flight 2311, a worn propeller quill caused the propeller blades to go flat, which created enough drag on that side of the airplane to make the aircraft ...
Matthew James Briggs's user avatar
3 votes
1 answer
3k views

At what point does the throttle control RPM on a constant speed prop?

On an airplane with a constant speed prop, the prop lever typically controls the RPM (pitch) of prop, and the throttle controls the power, measured as Manifold Pressure ("MP"). However, at low power ...
Devil07's user avatar
  • 8,584
5 votes
4 answers
4k views

On a constant speed propeller, how is blade pitch related to airspeed and efficiency?

I'm trying to wrap my head around what the PHAK (Pilot's Handbook of Aeronautical Knowledge from the FAA) states for constant speed propellers. First, why is it that if airspeed increases, for a ...
Flak's user avatar
  • 123
1 vote
4 answers
1k views

Constant speed propeller blade pitch compared to fixed-pitch

I just transitioned to a complex airplane (Piper Arrow II). While I get how to use the Manifold Pressure / Propeller levers, I still find myself trying to piece together how all the components would ...
Ryan Griffith's user avatar
3 votes
1 answer
10k views

Difference between constant speed and variable pitch propellers?

Here is how I currently understand constant speed and variable pitch propellers. In constant speed propellers, the pilot controls the governor via the prop control knob and the speeder spring, ...
Liandro Miguel de Paula's user avatar
1 vote
2 answers
425 views

Did the Doolittle raid run their engines over square?

My flight instructor made a comment when talking about complex airplanes that "never over-square an engine" is a good rule of thumb but secondary to POH instructions. The POH, (I presume) is the best-...
nodapic's user avatar
  • 1,827
2 votes
3 answers
2k views

Is the purpose of variable pitch propellers to maintain an optimal angle of attack?

I recently had a discussion with an aviation expert, who works as a Flight Instructor, about constant speed propellers - variable pitch propellers - on light piston aircraft. I have always known that ...
Paolo's user avatar
  • 31
1 vote
1 answer
2k views

How to lean with constant speed prop on multi-engine aircraft without EGT

This question is more about the indication of engine roughness. The procedure for leaning without an EGT is clear in the POH and Lycoming documentation which basically states as follows: Best power: ...
Devil07's user avatar
  • 8,584
9 votes
2 answers
964 views

Why did the propellers not fail to the feathered position in the Atlantic Southeast Airlines Flight 2311 Crash?

In the ASA Flight 2311 crash the failure of a quill resulted in the loss of propeller pitch control. The propellers ended up with a pitch angle of 3 degrees which caused reduced thrust and increased ...
DLH's user avatar
  • 5,819
5 votes
4 answers
5k views

Did WW2-era aircraft have constant-speed or variable-pitch props?

This is slightly related to my other question on variable-pitch controls. I want to know if WW2-era aircraft typically had variable-pitch or constant-speed propellers. Variable-pitch lets the pilot ...
DrZ214's user avatar
  • 17.8k
18 votes
4 answers
5k views

Why are there extra restrictions on constant-speed propellers?

Constant-speed propellers are far more efficient than non-constant-speed propellers, allow the engine to be made considerably simpler (due to removing the need to continuously adjust the ignition ...
Vikki's user avatar
  • 28.4k
0 votes
1 answer
5k views

How to calculate Blade angle?

If we know the helix angle is 3angle, forward speed is 150mph, and rotational speed of propeller is 1500rpm How can i calculate the blade angle of propeller ?
Krissakorn Kantaworaphan's user avatar
2 votes
1 answer
1k views

Why do MP and RPM adjustments have to be made in a specific order in constant-speed props?

Can anybody explain why do I have to pull back RPM lever first and then pull back MP after climbout when setting up my cruising speed MP/RPM combination. When I make an approach to land I do vice ...
super jet 100's user avatar
2 votes
0 answers
374 views

What calculations are needed for counter-weight balancing on a propeller?

I am designing a small-scale propeller and i have managed to design on optimized geometry for the blade. However the blade pitch angle adjusts according to different flow speeds so i need to mount ...
george's user avatar
  • 77
2 votes
0 answers
351 views

What Inertial effects should be considered to achieve blade stability on a Variable Pitch Propeller tailoredby aerodynamic loads?

I am developing a self adjusting variable pitch propeller tailored by its pitching moments due to aerodynamic loads setting the blade rotation axis in an offset from the aerodynamic center as shown ...
george's user avatar
  • 77
7 votes
3 answers
4k views

In a constant speed propeller, why does the RPM drop with a prop pitch increase?

When a constant speed propeller changes its pitch from low to high, RPM would decrease. Why is that the case? Wouldn't the RPM increase when we increase the blade angle since there's less drag and ...
nyorkr23's user avatar
  • 1,198
0 votes
0 answers
513 views

How to define pitch angle for a passive variable pitch propeller?

This question is a continuation of the question How to calculate variable pitch propeller parameters? mentioned before. Actually, the theory described as an answer on the question above is the exact ...
george's user avatar
  • 77
6 votes
2 answers
4k views

How do different RPM–MAP settings affect range?

For a cruise in constant-speed prop aircraft, you can choose different combinations of the manifold pressure and prop rpm to generate the same amount of power. For example, in order to generate 117 ...
lemonincider's user avatar
  • 7,565
5 votes
4 answers
34k views

What's the rule of thumb for power and rpm in a constant speed prop?

I think I understand the relationship between the power lever and the RPM lever in an aircraft with a constant speed prop thanks to this question. However, what'd be a general rule of thumb for flying ...
Pepedou's user avatar
  • 161
8 votes
1 answer
3k views

How to read the propeller range chart for DHC-6 Twin Otter?

I understand constant speed propellers and beta range. However, I'm not completely sure I'm extracting everything from this chart that appears in a manual for a flight sim model of the Twin Otter. ...
Steve's user avatar
  • 2,218
9 votes
1 answer
1k views

Why shouldn't variable pitch propellers be operated at low speed?

Aircraft with variable pitch propellers usually have a red arc on the propeller speed gauge somewhere between about 500 and 1000 rpm, often accompanied by placard like "stabilized propeller operation ...
Jan Hudec's user avatar
  • 56.4k
7 votes
2 answers
3k views

What dictates the prop RPM used during cruise?

I've seen on numerous different constant-speed propeller aircraft and different pilots using different RPMs during the cruise phase on a propeller aircraft. What dictates the RPM used during normal ...
Qantas 94 Heavy's user avatar