what if you fly a wilga? WONT SOMBODY PLEASE THINK ABOUT THE WILGA PILOTS!

You know I just took for granted that everybody knew that left-turning tendency is caused by suspenders.



What is the last thing you do when you take off? You lean forward to push the throttle in. Of course your left suspender gets caught on the stick/wheel. When you lean back, due to airplane acceleration, the suspender stretches and pulls. Thus left-turning tendency! This isn't rocket science folks!

MTV,
1969? HA! I got ya beat by a couple years, so............LETS HAVE A LITTLE MORE RESPECT AROUND HERE!
Sure, you got more hours and more ratings and whatnot, but I'm the senior pilot! (well, with you).

Sorta like, I got more years of education than most you guys, too. Yes, I do count all the repeats.

Thought it was my fat A$$ weighing down the left seat!.........haha

I find my left turning tendency is from exposure to right wing wackos on internet chat sites.

Durango, you disgrace the 'Rebel' name and cause (states rights)........

Look who's a conformist in their definition of the word rebel. Now, as for me the Rebel moniker is an accident of my plane, a Murphy Rebel, I am upgrading to a skywagon so that may change. I do think of myself as rebellious in my own way leaning toward individual rights, which for me means a bit left, which I think means the P factor in my plane is even more pronounced.

I've got to second DonC .... I was taught ( recently at that ) that it is strictly p-factor. The Wiki link has a pretty good definition for those who don't want to follow don's link- "P-factor, also known as asymmetric blade effect and asymmetric disc effect, is an aerodynamic phenomenon experienced by a moving propeller with a high angle of attack that produces an asymmetrical center of thrust[1]" There's also a good discussion of this in the Aerodynamics for naval aviators book ( required reading from my flight instructor).
NCB

1SeventyZ wrote:"Please answer this simple question to help keep spambots out:
Name one of the 4 contributing factors to left-turning tendency in an aircraft."

Maybe I need a new question.

Z........It gives you a better look at the WEEDS from the front windscreen of a C170..especially on takeoff with a left crosswind. There is only one factor involved here..it is the tendancy of the pilot to holler...OH S*%T!!
HC

NCBearhawk,

DonC's link described ALL the forces we lump into "left turning tendency", not just P-factor. That phenomenon is a lot more complex than just P-factor.

MTV

mtv wrote:NCBearhawk,

DonC's link described ALL the forces we lump into "left turning tendency", not just P-factor. That phenomenon is a lot more complex than just P-factor.

MTV

So...

...what happens to that left turning tendency when one is flying an aircraft with an engine and prop that rotates "backwards"?

Just asking...

Bob

Bob,

Precisely the same thing, only in the opposite direction. Then, it's called....(drum roll....) RIght turning tendency .

The Wilga and any of the other airplanes running CCW rotating engines such as the M-14P will exhibit this characteristic. Everything works precisely the same, just to the right instead of to the left.

An interesting historical note that is pertinent:

Most of the Messerschmit ME (BF if you prefer) 109 aircraft operated during the war were destroyed at the end of hostilities. The Spanish, however, got some not yet completed airframes, and many of the fixtures to build the airplane. The Spanish government (at least I think it was the Spaniards) assembled a number of these airplanes AFTER the war, to use in their own air force. Unfortunately, the Spaniards didn't have access to any of the Daimler or ?? engines that the Germans had used in the ME 109, so they substituted an engine built in Spain by Hispano Suiza. Problem was that the original ME 109 engine and the Hispano engine turned opposite directions.

By all accounts, the Messerschmit was a handful on the runway in any case. I can't even imagine what those Spanish airplanes must have been like, with the prop turning the wrong way, and the tail aligned for the original engine.

MTV

Hi,
I'm new to the post board here. I am not an A&P but I would like to help answer your turn question as my plane did this also. When you say the plane has a tendency to turn left, I assume this is the tendency of the plane, with hands off, to leave straight and level flight and turn left. The first thing to consider is the weight differences on a side by side aircraft. If the plane is very light, the weight difference of flying alone or with passenger can be noticeable. Also consider the following:
On a new construction experimental or on any plane that has had control cables or struts removed or disconnected for annual or repair, the rigging could be off. What kind of turn is it? The left turn could be either a flat turn with wings level or it could be a roll turn. If it was flat, it is most likely an unequal drag issue with more drag on the left side causing the nose to go left inducing the flat left turn. It might need to have the flaps adjusted to make them drag equally in the zero flap position while aligning with the trailing edge of the wing. The next step could be to install a rudder trim to hold the nose straight with the tail. It is not uncommon to find this on many certified aircraft also and they can be bent from hangar rash.
If it is a roll turn away from straight and level with hands off look for unequal washout between the two wings. It will not be an aileron issue since the opposing actions of the ailerons become self balancing.
Normal wing washout has the outer end of the wing flatter so that during climb it reaches the same angle of attack later than the inboard section which buffets first as a warning early in the stall while the outer end's lower angle maintains flight and aileron control. Washout is a saftey factor that gives the pilot a built in early warning of stall while there is still control on the ailerons. With a left roll tendency induced by unequal washout, the left outer wing is flatter (more washout) than the right outer wing. In level flight the higher angle of attack of the outer right wing produces more lift than the left causing a rising right wing and the roll to the left. On my Tundra, a high wing plane with two struts per side, the length of the rear strut controls the amount of washout. Decreasing the length steepens the angle and increases lift. On the Tundra I could easily count the threads exposed at the lower adjustable clevis of each rear strut. Setting that equal is the starting point. After setting both rear strut clevises to eight threads as recommended I reflew it and still had to reduce the left one another half turn to increase the angle and lift to equal the right wing and make the plane fly hands off level.
Each plane will have its own flight characteristics since differences from one wing to another can vary as well as the weight of instrumentation from one side of the aircraft to the other. A certified aircraft can have these same differences and must be adjusted during the initial test period.
Leaving a lot of unequal washout in the wing equates to unequal lift on the right wing vs. left which can also cause one wing to drop before the other in a stall or at the critical time of landing. I do not mean to say to you your plane is unsafe or that you should attempt to correct it yourself but I say this as incentive to tell your A&P of the degree and type of turn your plane makes and don't wait till annual time.
Fly safe.
dirtstrip

For those who like to answer the subject line without reading the original post:

1SeventyZ wrote:Are the 4 main factors (torque, pitch factor (p-factor), gyroscopic force, slipstream) that contribute to left turning tendency in an aircraft something that has only recently been taught in the FAA Private curriculum?

The reason I bring this up is because I ask this question in the registration form to prove the registrant is not a spam bot, and about 25% don't answer 1 of the above factors.

Dirtstrip, that was a great lesson on the hazards of improper rigging, but why did you answer "rudder" in your registration question?

I guess the wires are too easily crossed on this question. I guess I'll change it to something easier like "what's the thing on the front of the plane that goes round and round, and is sometimes found affixed to the top of novelty hats?" It started as just a question to prove registrants are not automated, but I became curious when I started reading the various answers.

Board index ‹ Pilots ‹ Theory, Practice, and Procedures

The question was asked within the overall Board index of Pilots, Theory, Practice, and Procedures. I actually thought all the answers given fit under one or more of those headings with "Theory" even covering the suspender answer. I think partial credit should be given because "Teach" asked too broad a question. The four factors answer does not address the pilot, practice or procedures and relates only to theory and that it is no help to those who have a real world problem with an airplane turning away from straight and level. But this is only theory.

I am new here but so far I like the board and comments since I consider myself a highly educated person especially if you count the grades I repeated.

Sorry for any misunderstanding on my part.
dirtstrip

I think I like this board. Its challenging.
I consider myself a very highly educated person especially if you count the grades I repeated.


dirtstrip

A good question to ask to keep spammer's out is "What makes the airplane fly?" All good pilots know the correct answer is money.

Skystrider wrote:

1SeventyZ wrote:"Please answer this simple question to help keep spambots out:
Name one of the 4 contributing factors to left-turning tendency in an aircraft."

Maybe I need a new question.

How about "Name them there flat thingys sticking out the sides of the aeroplaney"?

WANGS!

Fisherman wrote:

Skystrider wrote:

1SeventyZ wrote:"Please answer this simple question to help keep spambots out:
Name one of the 4 contributing factors to left-turning tendency in an aircraft."

Maybe I need a new question.

How about "Name them there flat thingys sticking out the sides of the aeroplaney"?

WANGS!

We have a winner!

mtv wrote:Bob,

Precisely the same thing, only in the opposite direction. Then, it's called....(drum roll....) RIght turning tendency .

The Wilga and any of the other airplanes running CCW rotating engines such as the M-14P will exhibit this characteristic. Everything works precisely the same, just to the right instead of to the left.

An interesting historical note that is pertinent:

Most of the Messerschmit ME (BF if you prefer) 109 aircraft operated during the war were destroyed at the end of hostilities. The Spanish, however, got some not yet completed airframes, and many of the fixtures to build the airplane. The Spanish government (at least I think it was the Spaniards) assembled a number of these airplanes AFTER the war, to use in their own air force. Unfortunately, the Spaniards didn't have access to any of the Daimler or ?? engines that the Germans had used in the ME 109, so they substituted an engine built in Spain by Hispano Suiza. Problem was that the original ME 109 engine and the Hispano engine turned opposite directions.

By all accounts, the Messerschmit was a handful on the runway in any case. I can't even imagine what those Spanish airplanes must have been like, with the prop turning the wrong way, and the tail aligned for the original engine.

MTV

Right MTV,

Then it is really all about "P-factor" huh? Just playing devil's advocate here. Zane was just trying to keep the spammers out.

Bob