Aggressive stall characteristics, C150

Vector4Food

Vector4Food

This job would be easier without all the airplanes
So, been a while since I've flown...

I joined a little flight club up here, they rent a C150 for half the cost of any other outfit up here...

Anyway I went up with a friend who has Texan time (Harvard actually) and aerobatics, also an instructor.

Anyway we go to practice some stalls, power off...

Every time it snaps 60-70 degrees to the right, perfectly coordinated and it did this 5 times in a row...

We assumed the airplane is bent somehow. It was recently painted if that matters much...

Something I should be concerned about? It flies hands off no issue otherwise, performs normally (for a 150)

I'm likely being paranoid, but I've done spins as part of my Canadian commercial training, and stalls in 6 different types, as I only have 350 hours...

Any thoughts appreciated!
 
Is one of you heavier than the other? Is there a fixed metal rudder trim piece bent more than it should be? Is one wing slightly higher than the other (this is somewhat normal)? Can you counteract it with correct rudder and yoke inputs?

Just spitballing ideas, but no, not something I would worry much about. Most aircraft aren't rigged in a perfectly balanced way.
 
My thoughts exactly, I would pay particular attention to the trim tab and, the weight of you RT seat occupant. There's no shame in this. If they are a heavier fella, you've likely found your answer. It's not rocket science.
 
Park the airplane on a known flat surface and make sure the ball is in the center.

Does the airplane bank one way or the other when you let go of the controls?

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SKYROCK said:
My thoughts exactly, I would pay particular attention to the trim tab and, the weight of you RT seat occupant. There's no shame in this. If they are a heavier fella, you've likely found your answer. It's not rocket science.
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Interestingly, I am about 40 pounds heavier than my right seat guy in this situation

I'll check the trim tab next time!
 
trafficinsight said:
Park the airplane on a known flat surface and make sure the ball is in the center.

Does the airplane bank one way or the other when you let go of the controls?

Sent from my XT1254 using Tapatalk
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If it did at all it wasn't pronounced, nor was it really noticeable to have to counteract.

Don't get me wrong, it's an old 150, so I wasn't exactly expecting to manhandle this thing.

When the stall occurred, full opposite rudder wasn't enough, the stall would break well before wings level. I guess what I was most concerned with was, if it spun, would it be more difficult to recover.


Thanks for the input guys!
 
The 150 I used to fly had these stall characteristics too, even when the student and I weighed the same. Whenever we would do stalls in the 152 though, it was much less aggressive. I was told that that was one of the main differences between the 150 and 152. The 152 has wing twisting so that there's always a slightly different angle of attack as you move down the wing. The 150 just has a straight wing and therefore dips more when stalled. Not sure if that's correct but it definitely looked and felt to be true.
 
All kinds of things that could be causing it on an old 150. Cessnas have adjustable wing incidence, flaps could be out of rig, someone could have rebuilt or reskinned a a control surface or two without a jig....
 
Pachong said:
The 150 I used to fly had these stall characteristics too, even when the student and I weighed the same. Whenever we would do stalls in the 152 though, it was much less aggressive. I was told that that was one of the main differences between the 150 and 152. The 152 has wing twisting so that there's always a slightly different angle of attack as you move down the wing. The 150 just has a straight wing and therefore dips more when stalled. Not sure if that's correct but it definitely looked and felt to be true.
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Ya, the 150 actually spins really great to. You don't have to hold it in or anything. Very different stall characteristics than a 172.
 
Roger Roger said:
All kinds of things that could be causing it on an old 150. Cessnas have adjustable wing incidence, flaps could be out of rig, someone could have rebuilt or reskinned a a control surface or two without a jig....
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Adjustable incidence. Where did you get that from? There are 4 to 5 bolt attach points on Cessna braced wings. The incidence is fixed for the most part.

The only plausible explanation is re-skinning the leading edge. She sharpness of the leading edge could affect the airflow causing more aggressive stall. A tighter radii on the leading edge towards the wing tip is very possible froma re-skinned wing. A re-skinned aileron or flap has very little effect.
 
Vector said:
Adjustable incidence. Where did you get that from? There are 4 to 5 bolt attach points on Cessna braced wings. The incidence is fixed for the most part.

The only plausible explanation is re-skinning the leading edge. She sharpness of the leading edge could affect the airflow causing more aggressive stall. A tighter radii on the leading edge towards the wing tip is very possible froma re-skinned wing. A re-skinned aileron or flap has very little effect.
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The forward wing attach bolt sits in a cam bushing. Wing incidence is adjustable.

The wing incidence may be off and sometime in the past the flap rigging was adjusted to fix the rolling tendency. That would mask the issue.


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trafficinsight said:
The forward wing attach bolt sits in a cam bushing. Wing incidence is adjustable.

The wing incidence may be off and sometime in the past the flap rigging was adjusted to fix the rolling tendency. That would mask the issue.


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In fact, both attachment points on the fuselage set in a cam bushing and it is simply to prevent wear to the aluminum piece they slide into. The angle of incidence is the angle formed between the longitudinal axis and the chord line. I can't think of any aircraft in which you can change the incidence merely by adjusting a bushing at the wing root. The wing attach points are solid aluminum channels.

The flap tracks on Cessna 100 series are fixed. How would you adjust it? Unless he did a spin with the flaps deployed, it makes no difference.
 
Vector said:
In fact, both attachment points on the fuselage set in a cam bushing and it is simply to prevent wear to the aluminum piece they slide into. The angle of incidence is the angle formed between the longitudinal axis and the chord line. I can't think of any aircraft in which you can change the incidence merely by adjusting a bushing at the wing root. The wing attach points are solid aluminum channels.

The flap tracks on Cessna 100 series are fixed. How would you adjust it? Unless he did a spin with the flaps deployed, it makes no difference.
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My memory is fuzzy about the number and location, truly it isn't something that's often messed with.

either way you don't seem to understand what you're talking about.


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trafficinsight said:
The forward wing attach bolt sits in a cam bushing. Wing incidence is adjustable.

The wing incidence may be off and sometime in the past the flap rigging was adjusted to fix the rolling tendency. That would mask the issue.


Sent from my XT1254 using Tapatalk
Click to expand...
On the 200s (all the way up through the 208!) the rear spar attach point has an eccentric bushing that with much swearing and a mousetrap collection of sockets, u joints, and extensions, can be adjusted to in theory straighten a crooked airplane. I assume the 100s are the same way.
 
Vector said:
In fact, both attachment points on the fuselage set in a cam bushing and it is simply to prevent wear to the aluminum piece they slide into. The angle of incidence is the angle formed between the longitudinal axis and the chord line. I can't think of any aircraft in which you can change the incidence merely by adjusting a bushing at the wing root. The wing attach points are solid aluminum channels.

The flap tracks on Cessna 100 series are fixed. How would you adjust it? Unless he did a spin with the flaps deployed, it makes no difference.
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Dude you reeeeally are out of your depth here.
 
Roger Roger said:
On the 200s (all the way up through the 208!) the rear spar attach point has an eccentric bushing that with much swearing and a mousetrap collection of sockets, u joints, and extensions, can be adjusted to in theory straighten a crooked airplane. I assume the 100s are the same way.
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Rear then! I remember it being a royal pain, the rest I've apparently blocked out. ;)

Kinda like fuel bladders.

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