brien23
Cleared for Takeoff
1964 Cessna 150 horizontal stabilizer how much should it flex, the later 150 model stabilizer have a stronger center the older ones straight tail are a little different and I am not sure how much they should flex.
1964 Cessna 150 tail
- Thread starter brien23
- Start date
- Joined
- Sep 19, 2005
- Messages
- 9,486
- Display Name
Display name:
Pilawt
1964 (150D) was the first year that had the counterbalances at the outboard ends of the elevators. Were later ones structurally changed?
The Parts Manual would detail this.
“Usable On Code “ in particular.
Never encountered a spec for flex
Stab/Fuselage Attach was beefed up over the years.
Saw some real nasty cracks on 68/69s.
Lots of creaking .
“Usable On Code “ in particular.
Never encountered a spec for flex
Stab/Fuselage Attach was beefed up over the years.
Saw some real nasty cracks on 68/69s.
Lots of creaking .
Inboard leading edge ribs like to crack. The tail cone skin and forward bulkhead like to wear and crack. There is a service kit to upgrade the bulkhead and repair the skin. These repairs require the tail to be dismantled to gain access. Don't be surprised to find other cracks and loose rivets once the tail starts coming apart.
Dan Thomas
Touchdown! Greaser!
- Joined
- Jun 16, 2008
- Messages
- 11,365
- Display Name
Display name:
Dan Thomas
The 172 has long had a problem of cracking its forward stabilizer spar due to people pushing down on the stab to lift the nose to turn the airplane. The 150's forward stab spar is even lighter--it's just the skin folded into the stab shape with a leading edge attached--and abusing it like that could crack or deform the spar. I wouldn't fly that thing until the stab and its attachments were inspected in their entirety for looseness or deformation. This stuff should be relatively stiff.
The stabilizer/elevator form a single, adjustable-camber airfoil, and as such the center of pressure is near the aft stab spar, not the front, so that aft spar is far stronger than the front. Add to that the fact that the main wheels are well aft of the center of lift, and so pushing the stab down to lift the nose off the ground involves higher stab forces than is required in flight, and those forces are concentrated on the very light forward spar, not anywhere near the aft spar that is near the real work. Cessna forbids it.
The stabilizer/elevator form a single, adjustable-camber airfoil, and as such the center of pressure is near the aft stab spar, not the front, so that aft spar is far stronger than the front. Add to that the fact that the main wheels are well aft of the center of lift, and so pushing the stab down to lift the nose off the ground involves higher stab forces than is required in flight, and those forces are concentrated on the very light forward spar, not anywhere near the aft spar that is near the real work. Cessna forbids it.