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Strong Pitch up on Go-around

design4p

Active Member
Hi,

Well into to test flying my RV14A and my test pilot has noticed there is a strong pitch up on Go-around which needs a lot of trim whilst dealing with the stick force.

Has anyone experienced the same.

Regards John
 
Hi,

Well into to test flying my RV14A and my test pilot has noticed there is a strong pitch up on Go-around which needs a lot of trim whilst dealing with the stick force.

Has anyone experienced the same.

Regards John

Yup! Need to be “on the trim” as soon as a go-around decision is made.
 
I do not have a 14, but the 10 seems very similar in it's wing and Horiz stab design.

In the 10, this is an area where a good amount of practice is required; probably more so in the 10 with it wider W&B envelope and dual trim tabs. When solo, the plane requires a lot of up trim on final with full flaps. When you pour on the coals during the go around, that trim tab becomes powerfull and creates a significant pitch up force. As long as you know it's coming, you can exert enough force to control it, but it is a lot of force. However, if you don't know its coming or forget and panic, it probably wouldn't take a lot of time to get into a stall if you were well into the flare and slow when you applied the power for the go around.

For this reason, I do not trim to hands off on final and instead keep a bit of back pressure to minimize this effect.

Practice and awareness are the key,

Larry
 
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Well into to test flying my RV14A and my test pilot has noticed there is a strong pitch up on Go-around which needs a lot of trim whilst dealing with the stick force. Has anyone experienced the same.

Sure, normal. It's not just an RV thing either. Just for fun, trim a C-182 for 80 knots, then add full throttle and see if you can hold the yoke forward with one hand.

Recent thread focusing on runaway trim. Although not necessarily a comfortable experience, all RV's are assumed to be flyable given trim limits at any normal speed.

https://vansairforce.net/community/showthread.php?t=190071&highlight=trim
 
This effect is quite noticeable in my Harmon Rocket, it was quite a challenge to bring flaps up, adjust trim, talk to the tower and push forward on the stick while climbing like a Rocket.

My first attempt at fixing this was to put secondary trim switches on the throttle, which helped reduce the number of hands required from three to two, and helped during formation flight when I was holding the stick near the base with my thumb and finger.

In the end, I reprogrammed my trim controller to automatically run the flaps up and set the pitch trim to takeoff position with one touch of the throttle up button. Just because I could, I programmed the down button to configure the flaps and trim to landing configuration, which is not as usable because you have more time and hands available on approach.

It was all originally coded in assembly language, but eventually I migrated it to Arduino-C. I think there is a thread on this site somewhere with the hardware description. If I had known it was a problem for the other RVs, I would have pushed out the source code as well, but I think the EFIS vendors could easily implement this in their systems now.

VV.
 
Normal on the -6 as well. I find it helps to go to 10 degrees flap first, and do a coarse trim adjustment to reduce the stick forces. Then zero the flap and do a final trim adjust. I'm working with manual flaps and trim, mind you... Electric flaps and trim would definitely benefit from a TOGA button/circuit/program.
 
This effect is quite noticeable in my Harmon Rocket, it was quite a challenge to bring flaps up, adjust trim, talk to the tower and push forward on the stick while climbing like a Rocket.

I skip the underlined part, at least until the plane is more stabilized in the climb, or even level at pattern altitude. The folks in the tower can see the go-around most days. If the weather is bad, the RADAR will show them you went around. Most ATC folks are quite understanding that sometimes we're busy and not able to talk.

Remember; aviate, navigate, communicate.
 
Normal on the -6 as well. I find it helps to go to 10 degrees flap first, and do a coarse trim adjustment to reduce the stick forces. Then zero the flap and do a final trim adjust. I'm working with manual flaps and trim, mind you... Electric flaps and trim would definitely benefit from a TOGA button/circuit/program.

Agreed, but the 10 and assuming the 14 to a lesser degree, requires WAY more stick force to control in this case than the 6. Own both of them. That said, I have a 160HP and FP prop, so expect other configurations have a bigger issue. I assumed this was problematic due to a wide CG envelope flown near the FWD CG. On the 10, I use almost no up trim on final at gross, whereas solo I am using 80% of it. No surprise that when the flaps come up and throw 260HP of thrust it becomes an arm wrestling match with the stick.

Larry
 
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There's a lot of information missing from the OP's description of events.

However, as others have said, accurately, [applying full power by smoothly pushing the throttle forward] *without* a corresponding adjustment of pitch trim & flaps will require a large amount of force to keep the nose where you want it.
 
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I'm wondering about the comment about trim forces on a go around as most powerful aircraft behave similarly in go arounds.Try a go around with flaps on a 185 cessna....if your a woman or an older guy its unlikely that youd have enough upper body strength to get the nose down properly.
When I do checkouts on a 185 I ask the student not to apply full power on a go around...apply maybe 70% power or so and that will get you in the air or keep you in the air and allow you to roll in lots of nose down trim without overtaxing your strength...only a few seconds and you're ready for full power but it sure removes all the drama.
Yes the 6 does the same thing but the pressures are very low compared to many certified aircraft and the trim is very sensitive so in a few seconds you can trim off the stick pressure. :)
 
Why shove it to the wall?

I'm wondering why people go "balls to the wall" on go around. Smooth application of power as needed unless you are crashing into the ground. To blindly shove full power up on a go around is in 99.9% of ALL go arounds just not necessary.

Just "IMHO"
 
I concur with the smooth application of power on a go around. Go arounds on even much larger aircraft can be challenging for pitch up with the 757 bring a good example. Boeing even added software to reduce power and limit ROC to 2000 feet a minute.
G
 
I'm wondering why people go "balls to the wall" on go around. Smooth application of power as needed unless you are crashing into the ground. To blindly shove full power up on a go around is in 99.9% of ALL go arounds just not necessary.

Just "IMHO"

I think this is an example of the ‘first learned, best remembered’ law of primacy in learning. Put two people in a 152, full flaps, a bit under 60 kias, and it pretty much takes full throttle to go around. And that’s what is remembered.
 
I think this is an example of the ‘first learned, best remembered’ law of primacy in learning. Put two people in a 152, full flaps, a bit under 60 kias, and it pretty much takes full throttle to go around. And that’s what is remembered.

Then I submit people need more, better, training. Cramming the power in just because is just not necessary. Maybe on a bolter off a carrier, not in 99.9% of go arounds.
Of course, opinions are worth what you pay for them. I will say that in 53 years and 27 plus thousands hours of flying most types from cubs to 1011’s I’ve never had to cram the throttles full forward except in a simulator for severe wind shear. In my 8, nah!
 
Being smooth on the controls usually goes a long way towards preventing unnecessary excitement. One of my first instructors demanded smoothness. A rap on the back of my head from the back seat of the Champ was a sufficient reminder.

Executing a smooth, safe go-around to the point it’s second nature is a skill well worth practicing in any plane.
 
Thanks

Thanks to this thread, I am going to try a few go arounds with a slower application of power. Last go around got exciting because the power came on too fast and caused a pitch up due to P-factor.
 
In my 14 I do not go to full power in a go around for this reason.

I increase power smoothly as I start bringing the flaps up and retriming. It doesn't take a lot of throttle in the 14 to arrest the descent and start climbing in the landing configuration.

There is plenty of power there if you need to go to full throttle immediately but you will need to push hard to keep pitch under control.
 
Nope

Thanks to this thread, I am going to try a few go arounds with a slower application of power. Last go around got exciting because the power came on too fast and caused a pitch up due to P-factor.

‘P-factor’ is not responsible for pitch up. P factor causes left yaw in our airplanes because the down-swinging propeller blades have a higher angle of attack than the up-swinging blade.

Pitch up has more to do with the existing up trim that was made during the approach, with throttle reduction. Thrust now causes the elevators to make the airplane pitch up unless you stop it by pushing down elevator.

Regards,
 
I used to do a of annual insurance checkouts and transition training, BFRs etc. and one thing I've noticed over the years is that a lot of people have never been taught the relationship between trim and airspeed. I should preface this by saying that I've never flown an RV14, but what you're describing is common to pretty much any airplane thats dynamically stable. Somebody mentioned a C-182 and it's a prefect example.

Sure, you trim to neutralize pitch forces, but if you come in with a bunch of power, most airplanes are going to pitch up until they find a climb angle that will have neutral pitch force on the stick at that same airspeed. If you reduce power, they will lower the nose to start a glide at the same previously trimmed airspeed.

Close to the ground isn't the place to be monkeying around with this, but the point is that if you're on approach at 65 kts and trimmed for neutral elevator at that speeding add a a ton of power, then yeah, the airplane is going to pitch up. Its trying to maintain 65 kts due to where the trim is, and the only way it can do that with all that power you just abruptly dumped on it is to pitch up like crazy
 
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I'm wondering why people go "balls to the wall" on go around. Smooth application of power as needed unless you are crashing into the ground. To blindly shove full power up on a go around is in 99.9% of ALL go arounds just not necessary.

Just "IMHO"

JMHO, but a "go around" is by definition an abnormal condition - trained as a borderline emergency procedure. Yes, most are routine, but if one is to "train like you fly and fly like you train", then its quite appropriate to extract all the performance of the airplane on every go around, because that's exactly what your want your lizard brain muscle memory to revert to on those rare occasions that it IS a real emergency.

If a pilot is able to differentiate between a "real" go around and a "routine" go around when the airport truck enters the runway or wind shear strikes AND that pilot is adept at the difference between trim forces of a "balls to the wall" emergency and a "gentle" go around then that pilot is better than me.
 
Bait

‘P-factor’ is not responsible for pitch up. P factor causes left yaw in our airplanes because the down-swinging propeller blades have a higher angle of attack than the up-swinging blade.

Pitch up has more to do with the existing up trim that was made during the approach, with throttle reduction. Thrust now causes the elevators to make the airplane pitch up unless you stop it by pushing down elevator.

Regards,

Sorry but I baited you, most of the pitch up is caused by the downward prop blade causing a large pitch up moment and also a smaller yaw. The force from the downward blade acts about 70degrees in lag. I can show you the math. The p-factor as defined by the faa learning material is not completely correct. Again, I can show the math. It has to do with the rigid mounting on the propeller shaft. This was derived during the Lockheed Cheyanne program (First true rigid rotor helicopter . Anyone who sets up RC helicopters for competition understands this due to their rigid rotor design)
 
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JMHO, but a "go around" is by definition an abnormal condition - trained as a borderline emergency procedure. Yes, most are routine, but if one is to "train like you fly and fly like you train", then its quite appropriate to extract all the performance of the airplane on every go around, because that's exactly what your want your lizard brain muscle memory to revert to on those rare occasions that it IS a real emergency.

If a pilot is able to differentiate between a "real" go around and a "routine" go around when the airport truck enters the runway or wind shear strikes AND that pilot is adept at the difference between trim forces of a "balls to the wall" emergency and a "gentle" go around then that pilot is better than me.

+1 for a good counter opinion.

I once landed on a nasty, windy day and as I started to level off I got a strong 10' rapid sink/down draft and almost pancacked, even with full throttle application. We have a lot obstructions that create weird stop/start wind patterns. I was really happy that my instinct was for full throttle. I can't say for sure if I would have done that if I had practiced 100 partial power go arounds. muscle memory is likely to be used in high stress situations.

I have gotten pretty good at varying the power to deal with these "sinks," as it is my home airport, but what about the guy who finds himself in this situation that hasn't done 1000's of landings at an airport like that. It would seem that full power go around training would be advantageous.

Larry
 
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The effects of a full power go around vary from aircraft to aircraft....flying an Aeronca 7AC and applying full power on a go around is rather a yawn moment, yup you have to apply some forward stick as you reach up to slide the trim lever forward....both of these take about 2 seconds.....all the while fighting with 65 hp.:)

The RV6 is not far off a Champ, stick pressures a bit higher but trim is almost as quick...sorta a nothing sandwich.

A Cessna 185 with a single pilot is another cup of tea as the forward pressures required in the same situation are many times higher and the trim is many times slower....it too is a nothing sandwich as long as its flown properly.

There is no one size fits all situation but all aircraft tend to handle in a similar fashion on full throttle go arounds....some a bit more of a chore to deal with but if handled properly.......nothing sandwiches.
 
I can't say for sure if I would have done that if I had practiced 100 partial power go arounds.
...
It would seem that full power go around training would be advantageous
I don't think anyone is suggesting that one should use less than full power in any emergency... Applying full power by shoving the throttle forward quickly, however, can cause some engines to stumble or quit. A smooth application of the throttle over a short time (I seem to recall being taught that it should take 3-5 seconds to go from idle to firewalled) will ensure the engine can keep up.
 
I don't think anyone is suggesting that one should use less than full power in any emergency... Applying full power by shoving the throttle forward quickly, however, can cause some engines to stumble or quit. A smooth application of the throttle over a short time (I seem to recall being taught that it should take 3-5 seconds to go from idle to firewalled) will ensure the engine can keep up.

I understand that no one was suggesting anything but full power in an emergency. I was just adding that there are many factors in play and in some circumstances it may be possible that a pilot will fall back upon their habits and may be unable to apply well thought out judgement in a high stress situation. It would seem from the literature that in very high stress situations, we humans can have an inability to apply judgement and instead fall back on deeply entrenched habitual behavior.

Really more adding additional items to the discussion than questioning the others guidance.

In my example above, I was very glad that my engine was tuned to be able to accept an immediate full throttle application. I definitely would have created some damage if it had stumbled. This may be a good point to indicate that even carbs can be tuned to support this. It requires properly tuning the idle mixture, main jet and accelerator pump linkage.

Larry
 
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Agree

Yes, some are advocating less than full power...

Use what you need. If that means full power, use it. I will say that, at least in my -10, full power is not required for a typical go around...it is, however, always available...
 
JMHO, but a "go around" is by definition an abnormal condition - trained as a borderline emergency procedure. Yes, most are routine, but if one is to "train like you fly and fly like you train", then its quite appropriate to extract all the performance of the airplane on every go around, because that's exactly what your want your lizard brain muscle memory to revert to on those rare occasions that it IS a real emergency.

If a pilot is able to differentiate between a "real" go around and a "routine" go around when the airport truck enters the runway or wind shear strikes AND that pilot is adept at the difference between trim forces of a "balls to the wall" emergency and a "gentle" go around then that pilot is better than me.

I agree. So it’s an abnormal condition. That’s exactly the time to NOT do anything very fast. Barring a windshield full of airplane or dirt it’s a time of slowly and methodically doing what won’t get you into more trouble. Yanking or jamming any control usually won’t help most situations. We should all strive to be that pilot.

But then again, we should all expect a go around on every approach and then it wouldn’t be abnormal.
 
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We are talking about use of maximum power on a go around to get away from the earth as quickly as possible. How did that get linked to "yanking or jamming" a control?
 
We are talking about use of maximum power on a go around to get away from the earth as quickly as possible. How did that get linked to "yanking or jamming" a control?
The discussion was about shoving the throttle in quickly on a go-around vs. pushing it in slower and/or not pushing it in all the way.
 
Go Around-Birds

Two summers ago landing here at PAEN some whooping cranes were next to the edge of the runway. They were about 5-feet to the side of a runway light on the left side of the runway.

I did not see them until about 10-feet AGL with a touch down point that would put me on the ground right where they were located to the side of the runway.

That's when they started flapping their wings for take-off. They were all pointed into the wind (crosswind landing with winds from the right). In other words they were getting ready to fly right into me at my touchdown point.

I applied full power and initiated a right turn, approx. 20feet off the ground. I did not have any trouble keeping the nose down to accelerate for the turn (Excitement with adrenaline as a booster).

I missed everyone of them.

When I fly my patterns, found it easier to do 3-pointers with full nose down trim. With full down trim like that it is easy to do a good three point landing.

If I use any up trim, seems like the RV wants to climb causing me to drop like a rock the last foot or so.

I have a bad issue of over correcting when needing to slow down more, trying to maintain level attitude as the RV starts to settle with too much airspeed.

Once I started to use full down trim, my three pointers have really improved.

Like someone said, the tower could see me. When I made my call, the controller mentioned they saw the whole thing.

To this day, I've often thought about why I didn't see them sooner. Realized it had to be complacency, and fixation with my landing point. These are really big birds.

A Cessna 172 would not have been able to do that go-around. Gotta' love the acceleration of our RV's.

Best regards,
Mike Bauer
 
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Taking it one step further

The 7 is exactly the same. The control forces are manageable but a good 4 seconds of trim is needed. I upgraded the panel to full IFR recently and went out to practice approaches. The Dynon system flies fully coupled RNAV LPV approaches beautifully and auto trims as it goes. However, I wanted to see how it handled an auto go around at DH so I pushed the go-around button. The system announced “Go around”, it pitched up and “add power” annunciated on the PFD, which I did slowly and the aircraft promptly pitched up to 30 degrees nose up and was well on its way to more.. The auto trim function couldn’t cope and the pitch servo slipped. I was VMC and light , it was a non event but I’m sure glad I went out to explore the performance on a nice day first.

The use of partial flap on approach and slow application of power may help and make the auto go around a useable function.

Be warned, it’s a huge “gotcha!”
 
I'm surprised the autopilot will fly the go-around. Of the certified autopilots I've flown, the go-around button disconnects the autopilot as well.
 
I'm surprised the autopilot will fly the go-around. Of the certified autopilots I've flown, the go-around button disconnects the autopilot as well.

Not on the newest generation of G1000. It stays coupled. That change happened with new Piston singles coming out of Wichita about a year ago. Not sure about other brands
 
I'm surprised the autopilot will fly the go-around. Of the certified autopilots I've flown, the go-around button disconnects the autopilot as well.

I have a Trio Pro coupled to a GRT Hx, garmin 420W. If I push the ‘missed’ button and add power, the black boxes will execute the miss, including the hold, then wait for further instructions... (and the auto-trim does the trimming, I just adjust power as needed)
 
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