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cvearl
February 7th, 2010, 18:17
For some aircraft I have, like the Piper Arrow IV from Carenado, I have found checklists online that include the "Configurations" or "Flight Profiles" that are sometimes refered to the "fly by numbers" charts.

These charts cover Climb, Cruise (high and low), approach decent, downwind, abeam to touchdown, finals and touchdown.

Example: Piper Arrow IV
Climb = 25"/2500rpm 95 KIAS
Cruise = 22"/2400rpm 123 KIAS
Downwind Pattern = 20"/2400 95 KIAS 10deg Flaps
Base = 16"/2400 90 KIAS 25deg Flaps

and so on.

I also have this information for the Mooney Bravo and the Cessna 206.

But I cannot find it for many.

I am looking for the profiles of the Cessna 182RG.

Why is this not in all checklists out there? If it's in the Power tables of the POH, I have a hard time understanding how to transition them to the table as I described above.

For now I have been using the profiles of the 206 for the 182RG but only as a guidline.

Any thoughts on that?

Charles.

Lionheart
February 7th, 2010, 19:03
Hey Charles,

Man, that is alot of data, and guess what. Its variable.. All variables.....

If you have one more passenger, and its 104F instead of just you with 96F temp, then the airspeeds change. In real life, this would include humidity/barametric pressure as well.

So, to find all the cumulative data for flying a plane in all aspects (landing, cruise, performance cruise, pattern, approach, etc), you need to find someone that knows the exact speeds....


Now.. to add some bad news. Getting planes to fly those numbers in FS is one heck of a hard thing to do. They might be off in oil press, RPM/thrust, lift at 100 knots compared with 140 knots, etc, etc, etc, etc, etc... Its a mountain of worms trying to match real world planes with sim planes. Plus, even real world planes will behave differently.


What should be done, for sim planes, is for the builder to log a list of perfomance specs so that you can fly by, but note that this would be fictional.


Remember, this is a sim... Nothing more...


Bill

cvearl
February 7th, 2010, 20:28
Good stuff. Ok thanks.

C.

azflyboy
February 7th, 2010, 20:49
In naturally aspirated aircraft, pilots normally adjust power to get to a desired airspeed rather than using fixed power settings for anything other than cruise.

Most small aircraft simply use full power for climb (with maybe an RPM reduction on a constant speed prop), with the pilot adjusting pitch to maintain Vy or cruise-climb speed, and the exact climb rate varies significantly with altitude, weight and temperature.

I'm a real-world flight instructor, and I'll give my students "ballpark" power settings for traffic pattern speeds, but the specific RPM can vary drastically depending on weather and weight.

As an example, when it's cold outside (-20F or so), I only need to use about 2,000RPM on a Piper Warrior to hit my 90kt downwind speed, but when it's 80F outside, that same airplane will require 10-20% more RPM to hit that same airspeed.

If you can find the "V speeds" for a given aircraft, you can figure out climb and approach speeds (normally Vy and about 1.2 Vso respectively), and some quick testing with a "standard day" weather in FSX and the default GPS can give you something pretty close to the correct cruise power settings.

cvearl
February 8th, 2010, 06:34
In naturally aspirated aircraft, pilots normally adjust power to get to a desired airspeed rather than using fixed power settings for anything other than cruise.

Most small aircraft simply use full power for climb (with maybe an RPM reduction on a constant speed prop), with the pilot adjusting pitch to maintain Vy or cruise-climb speed, and the exact climb rate varies significantly with altitude, weight and temperature.

I'm a real-world flight instructor, and I'll give my students "ballpark" power settings for traffic pattern speeds, but the specific RPM can vary drastically depending on weather and weight.

As an example, when it's cold outside (-20F or so), I only need to use about 2,000RPM on a Piper Warrior to hit my 90kt downwind speed, but when it's 80F outside, that same airplane will require 10-20% more RPM to hit that same airspeed.

If you can find the "V speeds" for a given aircraft, you can figure out climb and approach speeds (normally Vy and about 1.2 Vso respectively), and some quick testing with a "standard day" weather in FSX and the default GPS can give you something pretty close to the correct cruise power settings.

Excelent! Thanks for this.

Often the Landing checklist mentions FULL MIXTURE, FULL RPM when you do your GUMPS. Also the book I have MSFS for Pilots talks about going to full mix and full prop near the end of the pattern so that if you have to execute a go around, you are already set for full power.This would be on final then?

I ask because you are the second pilot (CFI in your case) talking about a downwind configuration where the RPM is alot lower than say 2400 rpm in a Piper or Cessna. Obviously knowing your aircraft and adjusting to different speeds for different stages of flight rather than a set rigid configuration combos to aim for. I am starting to realise it's like trying to use 1" of peddal in a car for a desired speed but not taking into consideration if you are going up hill or down hill. The 1" of peddal has infinate results depending on the situation of the car relative to external factors.

The other pilot I refer to flys a Cessna Centurion C210 and said something to me like "In the circuit you will see me change the configuration of the plane to get 110 to 105 downwind (22 inches 1700 rpm, gear and flaps 10 degrees, 80 on final (20 - 30 degrees) and 60 to 70 on the flare (full flaps 40).
Regardless, is there a time in the pattern (base and or final) where you DO go to 100% mix and 100% prop as a standard and simply work with throttle for the last bit?

Charles.

cvearl
February 8th, 2010, 06:50
Hey Charles,

Man, that is alot of data, and guess what. Its variable.. All variables.....

If you have one more passenger, and its 104F instead of just you with 96F temp, then the airspeeds change. In real life, this would include humidity/barametric pressure as well.

So, to find all the cumulative data for flying a plane in all aspects (landing, cruise, performance cruise, pattern, approach, etc), you need to find someone that knows the exact speeds....


Now.. to add some bad news. Getting planes to fly those numbers in FS is one heck of a hard thing to do. They might be off in oil press, RPM/thrust, lift at 100 knots compared with 140 knots, etc, etc, etc, etc, etc... Its a mountain of worms trying to match real world planes with sim planes. Plus, even real world planes will behave differently.


What should be done, for sim planes, is for the builder to log a list of perfomance specs so that you can fly by, but note that this would be fictional.


Remember, this is a sim... Nothing more...


Bill

Further to this though... The really well made planes are fun in the sim because they do get close to the operating characteristics I read about. These configurations in the pattern get close to the speeds and decents and I really enjoy that "operations" part the most. When the sim behaves parallel to a document from the real world and I perform the excersize correctly, I get that YES! feeling. I really like that moment when the plane does what I meant it to do. :)

This 182RG was the first plane I picked up where I could not get those reference numbers. No big deal though now that I am understanding it better. I still need to wrap my head around why someone would use higher RPM and less throttle/MP versus the other way around when both can consiveable provide the same level of thrust. I getting closer to the answer through.

C.

jmig
February 8th, 2010, 09:49
Cveral, It has been a good while since I have flown complex aircraft and I may be confusing myself here. Hopefully, Ken Stallings, azflyboy, or some other real world pilot who is current will correct me, if I said something wrong.

You can think of the prop as a transmission in a car. Low gears will give you higher RPM and more pulling power but less speed and it uses more fuel. The higher gears give you less pull but lower RPM and save on fuel. Prop settings are similar.

With the Prop lever full forward, the propeller pitch is set where the prop bite more. This is analogous to the low gear on your car. During take off you want as much bite or pull as possible so you can climb. that is why you will set the prop to full pitch on landing, in case you need to go around.

At altitude you are more interested in saving fuel and speed. A prop with a lot of pitch will also give you more drag. By flattening out the pitch you will lower the prop RPM, lessen drag and get more speed for less fuel.

Manifold settings (MP) are how hard you are working the engine. How much of a load is on the engine. Airplane engines are different from auto engine in the aspect of loading. A car will use full load only while accellerating or pulling a load uphill. Once you reach highway speeds the engine load drops to 30% or less. Not so with an airplane engine. It is loaded constantly which, but the way, is why it doesn't last as long as a car engine. Even at cruise you are loading it 70-80%.

Every airplane and engine combination will have the sweet settings for cruise at different altitudes and gross weights. These will be a combination of MP settings and prop pitch (rpm) setting.

azflyboy
February 8th, 2010, 18:13
where you DO go to 100% mix and 100% prop as a standard and simply work with throttle for the last bit?

Charles.

On the aircraft I fly, the mixture is usually enriched as part of the descent checklist, and it's verified again on the before landing checklist. MSFS does a terrible job of simulating mixture controls, so you might want to wait until you're close to the pattern altitude before enriching the mixture to avoid the massive (and unrealistic) power loss FSX gives from a rich mixture at anything but sea level.

As for the prop, it depends. In many aircraft, the props are set to a climb RPM until either abeam the touchdown point or on final, and the prop controls are set full-forward (high RPM) at that point.

The reasoning behind this is that if a go-around or missed approach is conducted, the climb RPM offers the best performance for that situation, whereas the high RPM setting is best suited for the relatively slower speeds of a "last minute" go around.

In the complex aircraft I've flown (Piper Arrows and Seminoles), the props are normally set to around 2500RPM in the pattern, with the prop controls going to high RPM when the aircraft is either on short final (for a straight-in approach) or abeam the touchdown point on downwind.

cvearl
February 8th, 2010, 21:20
As stupid as this might sound, yall have no idea how much I appreciate this data. I like to fly "as close to realistic as FSX allows" when I do get into FSX and the limited time I have for FSX is enriched by attention to detail. Makes it feel far more worthwhile. :)

Thanks! :salute:

Charles.