Takeoff Trim

[Stewartb]

Lay the whip to a Cessna in landing configuration and 40° flaps? You’d better be man enough to push the yoke forward. It’s perfectly safe if you know it’s coming, but few ever train for it.

 

[Lindberg]

Reading the beechtalk thread on the KSLE Bonanza fatal a few days ago... several posters mention that a large trim change is required during transition from landing to go-around. They were saying that going full power without re-trimming will produce a large pitch up and stall.

This seems foreign to me; all my time is in Cherokees, which will pretty much fly a set speed for a set trim position regardless of power. Cram the power in at Vref and it turns into a Vx climb.

Is this particular to v-tails? Other makes & models?

I find this thread interesting because usually when the topic of trim comes up the majority of posts have some variation of eat you're saying here. Trim for a speed and the plane will hold it regardless of power setting. But here, you started the thread with that and the majority of replies are to the contrary.

Would you be able and willing to make a short video demonstrating the Cherokee maintaining a trimmed speed from idle to full throttle?

 

[schmookeeg]

It's a thing on my A36 ( a straight tail Bonanza) too. It isn't something that can't be handled though. Like mentioned above - you just push and adjust the trim after adding throttle. It's definitely not a reason to avoid flying a Bonanza.

It is if you can't find the time in your go-around procedure to flick that trim wheel down two notches.

 

[Jim K]

Would you be able and willing to make a short video demonstrating the Cherokee maintaining a trimmed speed from idle to full throttle?

Possibly. I do have a camera, but I haven't rigged up a cockpit mount for it. I'll see if I can figure a way to hang it. Also depends on whether airport ops. bothered to clear the t-hangars yet.

@NealRomeoGolf has a nice in-cockpit setup....

 

[JEB]

It is if you can't find the time in your go-around procedure to flick that trim wheel down two notches.

Pest -
When are you headed back down to the warm part of the state?

 

[luvflyin]

Lay the whip to a Cessna in landing configuration and 40° flaps? You’d better be man enough to push the yoke forward. It’s perfectly safe if you know it’s coming, but few ever train for it.

Yeah. More than once on a BFR or a rental checkout or something when I've done go around and push and trim, a CFI comments on it like he's surprised I did it as if most folk don't.

 

[Jim K]

I find this thread interesting because usually when the topic of trim comes up the majority of posts have some variation of eat you're saying here. Trim for a speed and the plane will hold it regardless of power setting. But here, you started the thread with that and the majority of replies are to the contrary.

Would you be able and willing to make a short video demonstrating the Cherokee maintaining a trimmed speed from idle to full throttle?

Ask and ye shall receive:

Please forgive my crap camera and lack of editing skills, mercifully it's only 3 minutes long. I couldn't get audio figured out at the time (but I think I know how to do it now), so it's just engine noise. And yes, I did bump my head on the camera once.

I learned a couple things today. My plane does indeed have about a 20mph range from idle to full power without touching the trim. Also, with no trim and no configuration change, she will go through pretty large pitch changes, although it was slow, and she never stalled.

In a real go-around, immediately reducing one notch of flaps seems to tame that tendency. I did give a little forward pressure (and I mean a little, like one finger's worth) , as I didn't want to get slow low to the ground, and I was surprised to see how quickly the speed built up. Also, MORE RIGHT RUDDER!

I wish I had done the power range thing clean and with 10 degrees flaps. Maybe next time. I presume the air from the prop is pushing against the stabilator, which changes the downforce back there, and consequently the pitch. This is a good demonstration of that effect. I presume a t-tail doesn't do this? How about twins?

 

[sourdough44]

Just skimmed though, may or may not be covered.

If lightly loaded, can we add most power, but save full power until trimmed down some? I guess we would call this a more gently powered go around, initially.

The other thing is piloting, remember the RIO saying, ‘Mav do some of that Pilot chit’? While trim is very nice, one should be able to move manually where you want to be. I don’t own a mighty Bo, maybe it’s trim is a little more extreme.

I don’t know what happened with that referenced accident, kinda crazy if it is just a mistrim on go around. As is often the case, people that knew him gave him high marks with flying.

 

[Lindberg]

Ask and ye shall receive:

Please forgive my crap camera and lack of editing skills, mercifully it's only 3 minutes long. I couldn't get audio figured out at the time (but I think I know how to do it now), so it's just engine noise. And yes, I did bump my head on the camera once.

I learned a couple things today. My plane does indeed have about a 20mph range from idle to full power without touching the trim. Also, with no trim and no configuration change, she will go through pretty large pitch changes, although it was slow, and she never stalled.

In a real go-around, immediately reducing one notch of flaps seems to tame that tendency. I did give a little forward pressure (and I mean a little, like one finger's worth) , as I didn't want to get slow low to the ground, and I was surprised to see how quickly the speed built up. Also, MORE RIGHT RUDDER!

I wish I had done the power range thing clean and with 10 degrees flaps. Maybe next time. I presume the air from the prop is pushing against the stabilator, which changes the downforce back there, and consequently the pitch. This is a good demonstration of that effect. I presume a t-tail doesn't do this? How about twins?

Thank you for making that, I found it informative. As one of my instructors is fond of saying, "Learning has occurred!"

 

[luvflyin]

Ask and ye shall receive:

Please forgive my crap camera and lack of editing skills, mercifully it's only 3 minutes long. I couldn't get audio figured out at the time (but I think I know how to do it now), so it's just engine noise. And yes, I did bump my head on the camera once.

I learned a couple things today. My plane does indeed have about a 20mph range from idle to full power without touching the trim. Also, with no trim and no configuration change, she will go through pretty large pitch changes, although it was slow, and she never stalled.

In a real go-around, immediately reducing one notch of flaps seems to tame that tendency. I did give a little forward pressure (and I mean a little, like one finger's worth) , as I didn't want to get slow low to the ground, and I was surprised to see how quickly the speed built up. Also, MORE RIGHT RUDDER!

I wish I had done the power range thing clean and with 10 degrees flaps. Maybe next time. I presume the air from the prop is pushing against the stabilator, which changes the downforce back there, and consequently the pitch. This is a good demonstration of that effect. I presume a t-tail doesn't do this? How about twins?

You are now an official POA Test Pilot

 

[Jim K]

You are now an official POA Test Pilot

All my dreams are coming true!

 

[Bill]

it's a big thing on mooneyspace as well. while it's true that it takes a good push on the yoke for a go-around, I don't understand why it's so difficult to do. you, uh, push a little, BFD. yeah, retrim as part of the go-around, not sure why all of a sudden trimming or using 1/100th of your muscle power to push the yoke a bit forward is such a difficult thing. .

View attachment 104341

Thinking about this some, it's not the push I'm worried about, I can do that no problem. What I do worry about is the 40yr old seat, seat frame, and seat track. Anything in there lets go while you're doing the Popeye push and you're done.

 

[Dan Thomas]

Thinking about this some, it's not the push I'm worried about, I can do that no problem. What I do worry about is the 40yr old seat, seat frame, and seat track. Anything in there lets go while you're doing the Popeye push and you're done.

Yup. Even in a normal takeoff, if the acceleration results in a seat failure, the natural reaction is to to pull yourself back up, and what is it you pull on? The control wheel. Oops.

I believe that's the scenario in the 1990s 185 floatplane crash that resulted in a $450 million lawsuit. The investigators found that the seat/rails weren't properly maintained as per the original AD on them.

 

[Jim K]

Thinking about this some, it's not the push I'm worried about, I can do that no problem. What I do worry about is the 40yr old seat, seat frame, and seat track. Anything in there lets go while you're doing the Popeye push and you're done.

Nice thing about being tall .. I'm always at the back of the rail.

Unfortunately for you guys Al Mooney was 6'5".

 

[Dan Thomas]

Nice thing about being tall .. I'm always at the back of the rail.

Unfortunately for you guys Al Mooney was 6'5".

That might not save you. The newer AD calls for inspection of the roller housings, since they're subject to wear against the underside of the rail, and if they get thin enough they let go. And the seat back structure is still a problem.

 

[Jim K]

That might not save you. The newer AD calls for inspection of the roller housings, since they're subject to wear against the underside of the rail, and if they get thin enough they let go. And the seat back structure is still a problem.

Of course you're correct, and I doubt Piper engineers had 270 lb dudes in mind in the first place.

Along those lines, when I first got my plane, the right seat was pretty loose. I eventually figured out that someone had put the wrong rollers in (or swapped the seat for a different year). I also discovered that if you rocked the seat it could unlatch. Put in the correct rollers for my model year and it's solid. Makes you wonder.