Piper PA28 Trim Wheel

[vannav]

Piper PA28 Trim Wheel total number of turns?
Neutral to full forward?
Neutral to full aft?
Trim wheel is between seats.

 

[Aviator305]

I have a PA-28-236. I have about 6 1/4 turns forward and backwards from neutral.

 

[RyanB]

Never counted

 

[Aviator305]

Never counted

My trim tab was showing neutral when in fact it was aft. This caused me to have to work harder during takeoffs as I struggled to pitch down. I caught on to what was happening when I counted the full travel. Now, my takeoffs are as smooth as they have ever been. I originally attributed my difficulties to lack of familiarity with a recently purchased aircraft. The mechanic has to fix. At any rate, my point is that it was worthwhile for me to count the full travel as it helped me determine that the indicator was wrong.

 

[frfly172]

Was thinking seven full turns.

 

[vannav]

From the picture I see a max of 6 turns. The indicator shows more aft than forward. So the question is how many turns from neutral to forward and neutral to aft? Thanks to all in advance for their replies.

 

[WannFly]

No idea, I trim by feel not by count

 

[vannav]

Thank you for the response. I am an old pilot that does not fly anymore due to medical. I am converting a 1971 Piper Cherokee fuselage into a flight simulator. I am converting the trim crank on the ceiling to the trim wheel between the seats. I never counted the number of trim wheel turns during my flying history. From the indicator markings on the cover I know it does not turn 3 turns back and 3 turns forward. Just looking for anyone who could count the turns for me. Piper PA28 only please.
Thanks in advance.
Vangyver

 

[vannav]

I was taught this 40 years ago. As part of the FAA certification testing for each aircraft has to demonstrate a minimum (sometimes called maximum) trim glide. Every light aircraft I know will fly with power off and trim at maximum aft position. The airplane will not stall.

I plan to adhere to this when designing my trim control.

More info here:https://www.aopa.org/news-and-media...ight-training-magazine/the-minimum-trim-glide

 

[smv]

Thank you for the response. I am an old pilot that does not fly anymore due to medical. I am converting a 1971 Piper Cherokee fuselage into a flight simulator. I am converting the trim crank on the ceiling to the trim wheel between the seats. I never counted the number of trim wheel turns during my flying history. From the indicator markings on the cover I know it does not turn 3 turns back and 3 turns forward. Just looking for anyone who could count the turns for me. Piper PA28 only please.
Thanks in advance.
Vangyver

I will be spending several hours in a PA-28-161 on Sunday. I will try my best to remember to count for you if you do not have a definate answer by then.

 

[brcase]

I was taught this 40 years ago. As part of the FAA certification testing for each aircraft has to demonstrate a minimum (sometimes called maximum) trim glide. Every light aircraft I know will fly with power off and trim at maximum aft position. The airplane will not stall.

I plan to adhere to this when designing my trim control.

More info here:https://www.aopa.org/news-and-media...ight-training-magazine/the-minimum-trim-glide

I have seen this taught. I have also seen it over simplified to the point it is dangerous.
A key point is you should arrive at your landing area at about 1000 feet AGL and will “May need to reconfigure for landing.” Best glide speed might be to slow to have the energy to safely round out and flare for a power off landing. Other factors start to coming into play such as illusions of speed and a natural tendency to apply back pressure as many pilots get closer to the ground, especially in stressed situations.
The article also states that the full trim back setting will likely put you a few knots below the best glide speed. Looking at performance polars, when available, you will find the altitude loss per mile penalty for being a few knots slow is almost twice the penalty for being the same number of knots fast. Plus being slow just puts you that much closer to a stall.
If you need every little bit of glide distance then go for using this technique, but once below pattern altitude configure and fly as normal of a power off approach speed as you can at normal power off approach speeds. Note in many aircraft the power off approach speed should be higher than a power on approach speed.

In most power failure situations it is probably much more important to just keep the airplane flying (don’t stall) and make as normal approach as possible than to worry much about best glide speed.

Brian
CFIIG/ASEL

 

[vannav]

I will be spending several hours in a PA-28-161 on Sunday. I will try my best to remember to count for you if you do not have a definate answer by then.

I will be forever in your debt. I have been searching many months for this information. Thank you So Much. Awaiting your response.

 

[vannav]

I have seen this taught. I have also seen it over simplified to the point it is dangerous.
A key point is you should arrive at your landing area at about 1000 feet AGL and will “May need to reconfigure for landing.” Best glide speed might be to slow to have the energy to safely round out and flare for a power off landing. Other factors start to coming into play such as illusions of speed and a natural tendency to apply back pressure as many pilots get closer to the ground, especially in stressed situations.
The article also states that the full trim back setting will likely put you a few knots below the best glide speed. Looking at performance polars, when available, you will find the altitude loss per mile penalty for being a few knots slow is almost twice the penalty for being the same number of knots fast. Plus being slow just puts you that much closer to a stall.
If you need every little bit of glide distance then go for using this technique, but once below pattern altitude configure and fly as normal of a power off approach speed as you can at normal power off approach speeds. Note in many aircraft the power off approach speed should be higher than a power on approach speed.

In most power failure situations it is probably much more important to just keep the airplane flying (don’t stall) and make as normal approach as possible than to worry much about best glide speed.

Brian
CFIIG/ASEL

Thank you for your input. Although I do not fly anymore I still continue to learn from experience pilots like yourself.

 

[kshaw]

Before you spend a lot of money on re-rigging, a common cause of this is someone buys new placards and sticks them on without aligning the neutral mark on the placard with the neutral trim. My checklist prescribes setting trim aft of neutral but if I set it to neutral, it works perfectly. So either make your own adjustment like I did or realign the placard.

 

[vannav]

Before you spend a lot of money on re-rigging, a common cause of this is someone buys new placards and sticks them on without aligning the neutral mark on the placard with the neutral trim. My checklist prescribes setting trim aft of neutral but if I set it to neutral, it works perfectly. So either make your own adjustment like I did or realign the placard.

Thank you for the input. The information i seek is just for a simulator project. Converting a 1971 Piper Cherokee Flite Liner fuselage.

 

[smv]

Piper PA28 Trim Wheel total number of turns?
Neutral to full forward?
Neutral to full aft?
Trim wheel is between seats.

Using the shroud around the wheel as a reference, from full Nose Down to full Nose Up, it took nine full pulls of the wheel as far as it could be moved at one time due to the limitations imposed by the shroud. The shroud covers a little more than 180° of the wheel. Given that, I would say four full 360° revolutions from one end to the other.

Hope this helps.

Edit: This was on a PA-28-161.

 

[vannav]

Using the shroud around the wheel as a reference, from full Nose Down to full Nose Up, it took nine full pulls of the wheel as far as it could be moved at one time due to the limitations imposed by the shroud. The shroud covers a little more than 180° of the wheel. Given that, I would say four full 360° revolutions from one end to the other.

Hope this helps.

Edit: This was on a PA-28-161.

Terrific ! I know Piper design the wheel with a indicator groove for a maximum of 6 turns (360 degrees ea turn). So it makes sense that they would use 4 turns giving them a tolerance of one turn in each directions. Forever in your debt. Thank You So Very Much !