Cruising is painful..

[Siegfried]

Why would they add it to other planes? It's either there or not. May as well in cockpit aileron and rudder trim to the 109. :P

 

I don't know about you speak. The 109 has preflight trim tabs and the 190 too. Where am I saying about give that feature to planes that don't have this feature? Where am I speak about give the 109 incockpit trims as P51???

 

I never asked unrealistic features to planes didn't have.

[Ala13_ManOWar]

So it's right if I say:

1.15 ATA is not cruise it's it's a step under cruise (Sparleistung or save gas mode).

Cruise itself starts above 1.15 ATA up to max 1.35 ATA. So at least is 1.35 ATA cruise power (Dauerleistung).

 

Is that right?

Nope, cruise setting usually means the best compromise between fuel consumption and speed (best range usually but not necessarily in a fighter), also preferable over the endurance (an even lower engine setting than best range). Manufacturer says 109 cruise setting is 1.15, not more, not less, so we should suppose that's the more optimal setting. You can fly whatever you want after that of course, in a simulator where you don't pay fuel bills may be doesn't matters a lot, but you know that's not the theoretically more optimal setting manufacturer recommends.

 

S!

[Crumpp]

Please Please Please ED, ensure no adjusted or default pre tab setting is maximal fighter performance setting in this and all future WWII war birds!

 

It is noted in the Flugzueg-handbuch what the standard trim speed is set too. Usually it is Sparleistung.

[IIIJG52_Otto_]

Max. continous cruise is 1.35 ata / 2400 rpm (Höchtszulaessige Dauerleistung)

economic cruise is 1.15 ata / 2000 rpm (Sparleistung)

 

on the K-4 with DB 605DB/DC we have in the sim. See:

 

 

 

 

 

Dear Kurfürst:

 

YoYo take as reference a russian VVS test of a captured BF-109G2 for modeling the elevator trim,

see spoiler

 

Ok guys, talk it over with Yo-Yo some this morning, raised concerns with trim that some had, and for the most part what I found was correct. He shared with me a chart showing what I think is exactly what we experience in the sim, if you take into account the shorter flight sticks we all use:

 

 

I did also raise concern about air starts, I still feel like it couldnt hurt to have the aircraft trimmed to 1.5 on an air start, but its not a blocking issue. I will request it, along with the ability to change manual trim tabs were available on the 109.

 

So with all that, I really am going have to say that I am confident the 109 is modelled pretty damn well in this case, and if other sims that we might have played in the past dont fly like this, they have tweaked for player comfort over accuracy.

 

 

Now Yo-Yo say that the stick position is not the same for full power, gliding (power-off), etc. Months ago we told that, and he ignored us.

 

You mix things again.

 

To maintain 1g flight with the increasing airspeed the stable plane requires stick forward movement.

 

At high power rate at low speeds 109 IS UNSTABLE like some other high-performance planes.

 

If you compare the stick position at 270-300 kph IAS for 1.4+ ata poer ratings and in gliding conditions (power-off) you can see that in the first case stick is noticable fore than in the second at the same speed.

And it's exactly as it must be.

 

...and this is aplicable to the russian test too performed at 1.3ATA/2600rpm..

For bf-109G2

Max. continous cruise is 1.15 ata / 2300 rpm (Höchtszulaessige Dauerleistung)

Economical cruise at altitude: 1.00 ATA/ 2100rpm( Höchste Dauersparsleinstung)

...Kurfürst, please check you own page,:book: ...

Edited October 6, 2015 by III/JG52_Otto_+

[NineLine]

Time to let it go and move on Otto...

[Crumpp]

Otto,

 

What exactly is your issue because I am confused by your posting and issue with cruise settings?

 

You do know that once you have a known point, the math can predict the stability at any other point in the envelope?

[IIIJG52_Otto_]

Time to let it go and move on Otto...

is there any intention to fix the exaggerated nose-up pitch moment at cruise power with elevator trim in ZERO?

[NineLine]

is there any intention to fix the exaggerated nose-up pitch moment at cruise power with elevator trim in ZERO?

 

No, as there is no "exaggerated nose-up pitch", there is nose up pitch, but its not exaggerated, and can be trimmed out easily.

 

I should add that I generally dont trim it out because I use the 109 for dogfighting, I am too busy fighting to worry about how level it flies...

Edited October 6, 2015 by NineLine

[IIIJG52_Otto_]

Otto,

 

What exactly is your issue because I am confused by your posting and issue with cruise settings?

 

You do know that once you have a known point, the math can predict the stability at any other point in the envelope?

 

The worst problem in an aircraft for stability and maneuverability, "exaggerated nose-up pitch moment at cruise power with elevator trim in ZERO", this remains equal in ver 1.5.

 

Nose no piches down when cut trottle, with trim in ZERO. :(

Edited October 7, 2015 by III/JG52_Otto_+

[NineLine]

The worst problem in an aircraft for stability, and maneuverability "exaggerated nose-up pitch moment at cruise power with elevator trim in ZERO", this remains equal in ver 1.5.

 

Nose no piches down when cut trottle, with trim in ZERO. :(

 

And its been explained to you over and over that zero doesnt mean level. Zero means none.

[Crumpp]

Otto says:

The worst problem in an aircraft for stability, and maneuverability "exaggerated nose-up pitch moment at cruise power with elevator trim in ZERO", this remains equal in ver 1.5.

 

Nose no piches down when cut trottle, with trim in ZERO.

 

 

OK, thank you for clarifying it!

 

Zero does not mean "zero moments at cruise". It is just a reference for nose up or down trim angle. In otherwords, it is just a datum point.

 

It represents the trim speed of the aircraft's design coefficient of lift for whatever mission (speed) the aircraft was designed to fulfill. Many GA aircraft and Large Catagory Transport aircraft have a design point for cruise settings. The Bf-109 is a fighter, If Mtt design point (zero mark on the stabilizer trim) is at best turn speed or any speed below cruise speed, then it will pitch up nose up and seek that trim speed when set to zero.

 

 

Power changes effect stability. If you trim for a power on condition...chances are you will have to retrim if you remove the power.

 

So the fact our stability changes with power is realistic and expected.

[Ala13_ManOWar]

OK, thank you for clarifying it!

 

Zero does not mean "zero moments at cruise". It is just a reference for nose up or down trim angle. In otherwords, it is just a datum point.

 

It represents the trim speed of the aircraft's design coefficient of lift for whatever mission (speed) the aircraft was designed to fulfill. Many GA aircraft and Large Catagory Transport aircraft have a design point for cruise settings. The Bf-109 is a fighter, If Mtt design point (zero mark on the stabilizer trim) is at best turn speed or any speed below cruise speed, then it will pitch up nose up and seek that trim speed when set to zero.

 

 

Power changes effect stability. If you trim for a power on condition...chances are you will have to retrim if you remove the power.

 

So the fact our stability changes with power is realistic and expected.

Thank you mate, may be this time not being me he believes what you are saying :smilewink:.

 

S!

[Crumpp]

You are welcome.

[IIIJG52_Otto_]

Zero does not mean "zero moments at cruise". It is just a reference for nose up or down trim angle. In otherwords, it is just a datum point.

 

Exactly!! :thumbup:.. ZERO elevator trim is the DATUM (or reference point), used by the pilot for centering the elevator trim control. This is standard for all aircraft with this zero mark.

 

Power changes effect stability. If you trim for a power on condition...chances are you will have to retrim if you remove the power.

You are right!!, and due to this you say, the Bf-109 was pre-trimmed on ground according to a more precise manifold pressure reference, instead IAS airspeed.

With elevator trim in ZERO, this reference for manifold pressure was usually at"cruise power" (i.e. 1.0 ATA/2000 rpm for a RL Bf-109G2 "black 6") resulting in a specific engine torque and nose-up moment, which is the CENTER or DATUM for all flight envelope.

For our Bf-109K4 and acording to Kurfurst said, the "Datum" or reference power must be 1.35ATA/2400rpm.

IMO in our K4, we haven´t got the aircraft centered in flight, in this setting.

So the fact our stability changes with power is realistic and expected.

IMO pitch effect is wrong. It's exaggerated nose-up for cruise, and engine torque NO effect to pitch axis as reality, when you move the throttle control, now only affect to roll axis. Nose no pitches down when i cut the trottle. (in Zero or neutral trim).

And its been explained to you over and over that zero doesnt mean level. Zero means none.

Trim zero mark is the center,or neutral point, and it is standard for all aircraft, trust me, i work repairing aircraft. Aircraft with NO center in trim, have not the ZERO mark.;)

Edited October 7, 2015 by III/JG52_Otto_+

[Crumpp]

Otto says:

ZERO elevator trim is the DATUM (or reference point), used by the pilot for centering the elevator trim control.

 

Yes...but you ignored the most relevant part:

 

 

Crumpp says:

It represents the trim speed of the aircraft's design coefficient of lift for whatever mission (speed) the aircraft was designed to fulfill. Many GA aircraft and Large Catagory Transport aircraft have a design point for cruise settings. The Bf-109 is a fighter, If Mtt design point (zero mark on the stabilizer trim) is at best turn speed or any speed below cruise speed, then it will pitch up nose up and seek that trim speed when set to zero.

 

You seem to think that design coefficient of lift has to be cruise speed. It does not. It is whatever the designer chooses and it is not unusual for a fighter to have a design coefficient of lift in the vicinity of maneuvering speed (Va).

[Ala13_ManOWar]

You are welcome.

Despite your effort it didn't work... again... :doh:

 

Exactly!! .. ZERO elevator trim is the DATUM (or reference point), used by the pilot for centering the elevator trim control. This is standard for all aircraft with this zero mark.

Nope mate, the datum is an airframe reference point, usually at the firestop bulkhead, not what you think it is here... It isn't standard to all aircraft as you say, every aircraft have it's own, and no, it has nothing to do with zero trim mark. Zero trim mark only means (again) neutral, no trim, that's all.

 

 

You are right!!, and due to this you say, the Bf-109 was pre-trimmed on ground according to a more precise manifold pressure reference, instead IAS airspeed.

:doh::doh::doh: You have no idea, definitely. Can you explain the kind of magic needed to trim on ground using a manifold pressure reference? Manifold pressure changes with altitude, it's quite a bad if not impossible reference, that's why we use a constant reference for the whole flight envelope, indicated airspeed, as we talked before on this very same post (and like 20 threads before this one).

 

 

With elevator trim in ZERO, this reference for manifold pressure was usually at"cruise power" (i.e. 1.0 ATA/2000 rpm for a RL Bf-109G2 "black 6") resulting in a specific engine torque and nose-up moment, which is the CENTER or DATUM for all flight envelope.

For our Bf-109K4 and acording to Kurfurst said, the "Datum" or reference power must be 1.35ATA/2400rpm.

IMO in our K4, we haven´t got the aircraft centered in flight, in this setting.

You don't know what is datum, definitely, and it has nothing to do with any trim center. Anyway, and even you don't knowing what you're talking about, 1.35 ATA not being cruising as you claim for the module can't be a good reference for anything. If some engine cruise setting should be taken as reference for cruising it should be 1.15 ATA and in any case it isn't related with any trim reference.

 

 

IMO pitch effect is wrong. It's exaggerated nose-up for cruise, and engine torque NO effect to pitch axis as reality, when you move the throttle control, now only affect to roll axis. Nose no pitches down when i cut the trottle. (in Zero or neutral trim).

 

Trim zero mark is the center,or neutral point, and it is standard for all aircraft, trust me, i work repairing aircraft. Aircraft with NO center in trim, have not the ZERO mark.

"In your wide NASA pilot experience opinion it's wrong", sure. After what you said anybody can trust you anything. You repair aircraft (say which, I don't want to fly in anything repaired by you after what you said...). I'm pilot, trust me :smilewink:, neutral or 0 trim doesn't mean at all what you what it to mean, and it doesn't mean at all any cruise setting as neutral is usually used to take off, you can't cruise at neutral trim even in a slow Cessna, you aren't strong enough to do so holding the controls.

 

S!

[IIIJG52_Otto_]

Yes...but you ignored the most relevant part:

...

You seem to think that design coefficient of lift has to be cruise speed. It does not. It is whatever the designer chooses and it is not unusual for a fighter to have a design coefficient of lift in the vicinity of maneuvering speed (Va).

 

I'm not ignoring that, you are right in your point, it is true for the entire angles trim, .. and that is the reason that the Bf-109K4 have -6 degrees of trim in nose-up direcctión, and +1 degree 10 min. for nose-down trim only. This trimmable elevator configuration is able to moving the aerodynamic center near or forward of CoG for optimal corner speed, and for landing approach in three point actitude with the stick relatively centered..

Edited October 7, 2015 by III/JG52_Otto_+

[NineLine]

I feel like you are so close to a break-thru Otto... so close ;)

[Crumpp]

I'm not ignoring that, you are right in your point, it is true for the entire angles trim, .. and that is the reason that the Bf-109K4 have -6 degrees of trim in nose-up direcctión, and +1 degree 10 min. for nose-down trim only. This trimmable elevator configuration is able to moving the aerodynamic center near or forward of CoG for optimal corner speed, and for landing approach in three point actitude.

 

Irrelevant Otto..certainly confusing but irrelevant. Check out the zero trim measurements of the Bf-109...

 

http://forums.eagle.ru/showpost.php?p=2507787&postcount=67

 

If the design coefficient of lift occurs at a speed below cruise, the aircraft will pitch up if you set the trim to zero at cruise speed and release the stick.

[IIIJG52_Otto_]

I feel like you are so close to a break-thru Otto... so close ;)

 

Don´t angry with me, please , ..i'm very worried with the trim problem. :dunno:

Edited October 7, 2015 by III/JG52_Otto_+

[IIIJG52_Otto_]

Irrelevant Otto..certainly confusing but irrelevant. Check out the zero trim measurements of the Bf-109...

 

http://forums.eagle.ru/showpost.php?p=2507787&postcount=67

 

If the design coefficient of lift occurs at a speed below cruise, the aircraft will pitch up if you set the trim to zero at cruise speed and release the stick.

 

Irrelevant Crumpp,.. I´m saying nothing about "the design coefficient of lift at a speed below cruise". :music_whistling:

[IIIJG52_Otto_]

Despite your effort it didn't work... again... :doh:

 

Nope mate, the datum is an airframe reference point, usually at the firestop bulkhead, not what you think it is here... It isn't standard to all aircraft as you say, every aircraft have it's own, and no, it has nothing to do with zero trim mark. Zero trim mark only means (again) neutral, no trim, that's all.

 

:doh::doh::doh: You have no idea, definitely. Can you explain the kind of magic needed to trim on ground using a manifold pressure reference? Manifold pressure changes with altitude, it's quite a bad if not impossible reference, that's why we use a constant reference for the whole flight envelope, indicated airspeed, as we talked before on this very same post (and like 20 threads before this one).

 

 

You don't know what is datum, definitely, and it has nothing to do with any trim center. Anyway, and even you don't knowing what you're talking about, 1.35 ATA not being cruising as you claim for the module can't be a good reference for anything. If some engine cruise setting should be taken as reference for cruising it should be 1.15 ATA and in any case it isn't related with any trim reference.

 

"In your wide NASA pilot experience opinion it's wrong", sure. After what you said anybody can trust you anything. You repair aircraft (say which, I don't want to fly in anything repaired by you after what you said...). I'm pilot, trust me :smilewink:, neutral or 0 trim doesn't mean at all what you what it to mean, and it doesn't mean at all any cruise setting as neutral is usually used to take off, you can't cruise at neutral trim even in a slow Cessna, you aren't strong enough to do so holding the controls.

 

S!

Sir yes Sir :music_whistling:

Please, Read the definition of "datum" before write your tipical Cantinflas Speech ;)

http://www.oxforddictionaries.com/definition/english/datum

There are a lot of datums not only in aviation, and not only in airframes. :D

 

So... where is the "ZERO mark" in your Cessna trim handwheel? ..I only read "take off" mark ...anddd ..Are you a Professional pilot? ..If I am not misinformed you fly a Cessna some sundays, but You are a Piano teacher,. Am I right?:music_whistling:

 

Edited October 7, 2015 by III/JG52_Otto_+

[NineLine]

Don´t angry with me, please , ..i'm very worried with the trim problem. :dunno:

 

I'm not angry with you, I am cheering for Crump or anyone to find the right words to bring you peace of my mind ;)

[NineLine]

 

 

Where is the magical 'level flight at cruise' setting in that picture?

[Crumpp]

Otto says:

 

I´m saying nothing about "the design coefficient of lift at a speed below cruise".

 

I am really trying to help you understand what is going on. You are a knowledgeable guy and you have many concepts correct but the inability to see the fact :

 

If you are talking the zero mark on an aircraft trim...then you certainly are talking about the design coefficient of lift.

 

Blinds you to putting it all together to achieve understanding...

 

:cry: