1 hour ago, Kristofski said:

Spent the day yesterday going through ILS landings for practice with and without AP, and I found that there were times I was trimmed nose down on the glideslope and had to flare more/pull harder at the end to slow enough for a softer landing - I was coming in above 200 fpm a lot. I felt it was too fast, like the flare wasn't smooth unless you reset the trim. When I wasn't worrying about the localizer before I felt I'd come in slower, more of a glide, and by the time I cross the threshold I was already more level and needed less flare to slow. I found I was resetting trim to 0% after putting the landing flaps down, at around 1000ft give or take.

So on a clear day with no wind, would properly trimmed for landing be the same as the trim setting for take off, which is at or around 0%? My assumption is yes, since that's the default for the airplane to have good control and lift at lower speeds? 100-50ft above the runway, wouldn't you have more control over the plane with trim set for T/O, than still set for descending the glideslope? That would better support the go-around?

It's very difficult to give an accurate answer.  Two major factors will affect the trim settings:  different weights, different power, and different flap settings. Those will slightly change the CG location, even for one touch-and-go. If the airplane is in calm conditions and trimmed correctly, taking your hand off the yoke or stick should give you stable/balanced flight. While in a flare, when you slowly pull power to idle and arrest ROD, your control forces should not change so much to require additional trim. Each airplane is different, and each flight has a different weight distribution. Some may be in FWD or AFT CG, requiring different trim settings. In cruise and landing, the trim setting will always differ, so we are trying to find an impossible answer. T.O. is a different story; we have exactly correct data for a known condition.

 

48 minutes ago, ATRguy said:

No.  You trim it so the controls feel neutral, you aren’t looking for a specific position on landing.
 

Despite the other comment, trimming in the flare on the Caravan is extremely common, almost every pilot I know that flies it, does it.  In over 1000 hours of flying Caravans, I’m pretty well versed in its quirks, and that’s one of them.  

I'm having trouble with "extremely common." From what I understand, the Caravan can require noticeable backpressure in the flare and is known for heavy pitch forces. Regardless, on any airplane, it is not a good/best practice to trim during flare. If so critical, perhaps a very slow power reduction on even landing with residual power (not completely idle on touch down) might help that tendency, the feeling of heavy pitch. I don't know, just a thought that might help. Some airplanes, if you chop the power in a flare, will fall like a brick; that's why we do that kind of power reduction. But what do I know, not familiar at all with the Caravan, just what I heard.

14 minutes ago, ATRguy said:

No.  You trim it so the controls feel neutral, you aren’t looking for a specific position on landing.
 

Despite the other comment, trimming in the flare on the Caravan is extremely common, almost every pilot I know that flies it, does it.  In over 1000 hours of flying Caravans, I’m pretty well versed in its quirks, and that’s one of them.  

A friend of mine is a C208 pilot for Fly Flapper in the Spanish Canarian Islands.  I asked him about this and he said he, and the other C208 pilots, do this exact technique.  He said that it works because the electric trim rate is just perfect to get that gentle round out from the trim, on flare and touchdown.

In both the RW and in the sim I use the trim wheel for quick response or initial position, then, only if needed, tweak the feedback with the servo - basically for some fine-tuning.

As some have stated, I set the approach pressure to neutral when at the attitude and speed I desire.  I do not make any changes from then on, including the flare.

There are certainly special practices for some aircraft, but I would always shoot for neutral pressures when working with a new airframe until you get used to it or if the POH recommends specific procedures outside of the norm.

Talking about 172 landing , experienced instructors always recommended three additional trim wheels spins on round up  to ease up controls on round up. No reason to wrestle with yoke when your initially trim  for 65 for approach and need to bleed to 45 for touch down 

I find it so difficult to understand the scenario described. At the airlines and even in GA flying, during training, we teach the candidate not to use the trim to arrive at the point of an out-of-trim situation. This is a perfect example of why trimming during flare, all the way down to touchdown, is not recommended and qualifies as an out-of-trim situation. During a go-around, when power is applied, the airplane will pitch up to a drastic pitch condition different than a normal take off, in a condition leading to an almost stall condition, forget about a wind gust that might aggravate this situation. A condition similar to a runaway trim scenario, difficult to counteract at high altitudes, forget being so close to the ground or on the ground. I wonder if any of these guys tried to take off with so much wrong trim setting to see the real reaction. 

This sounds to me like a "hangar talk" versus a normal event. Sorry to say this, but in 45 years of flying, I have never heard of a normal operation in which a pilot would flare and land using elevator trim. 

2 hours ago, LRBS said:

I find it so difficult to understand the scenario described. At the airlines and even in GA flying, during training, we teach the candidate not to use the trim to arrive at the point of an out-of-trim situation. This is a perfect example of why trimming during flare, all the way down to touchdown, is not recommended and qualifies as an out-of-trim situation. During a go-around, when power is applied, the airplane will pitch up to a drastic pitch condition different than a normal take off, in a condition leading to an almost stall condition, forget about a wind gust that might aggravate this situation. A condition similar to a runaway trim scenario, difficult to counteract at high altitudes, forget being so close to the ground or on the ground. I wonder if any of these guys tried to take off with so much wrong trim setting to see the real reaction. 

This sounds to me like a "hangar talk" versus a normal event. Sorry to say this, but in 45 years of flying, I have never heard of a normal operation in which a pilot would flare and land using elevator trim. 

 

You don't JUST use it, you just hold down nose up trim, as you enter the flare to ease the control forces on the yoke.  It's the only airplane I've ever done this in, and it's not uncommon at all for Caravan pilots to do this.  I've gone around plenty in both the 675-hp and 867-hp versions and it's fine, the trim on landing is usually a little more nose up than takeoff.  So there you go, 45 years of flying, and you learned something new today 😉

We don't trim the ATR much past 500 feet or so, since it's configured, stable, and all that airline stuff.  It also flies like a dump truck, so it's fine not to trim much.

 

Edited April 12Apr 12 by ATRguy

3 hours ago, LRBS said:

I find it so difficult to understand the scenario described. At the airlines and even in GA flying, during training, we teach the candidate not to use the trim to arrive at the point of an out-of-trim situation. This is a perfect example of why trimming during flare, all the way down to touchdown, is not recommended and qualifies as an out-of-trim situation. During a go-around, when power is applied, the airplane will pitch up to a drastic pitch condition different than a normal take off, in a condition leading to an almost stall condition, forget about a wind gust that might aggravate this situation. A condition similar to a runaway trim scenario, difficult to counteract at high altitudes, forget being so close to the ground or on the ground. I wonder if any of these guys tried to take off with so much wrong trim setting to see the real reaction. 

This sounds to me like a "hangar talk" versus a normal event. Sorry to say this, but in 45 years of flying, I have never heard of a normal operation in which a pilot would flare and land using elevator trim. 

Ok flying is not instructing. As one FAA inspector said to me once: there a license to teach, and there is license to fly. A good pilot a not necessarily good instructor. 🙂 So from my experience what out saying absolutely doesn't correspond to my reality. There is no out of trim situation because when you trim you  are not trimming  for a good sport, you actually know exactly what you are doing and how much trim you applying. Like you mentioned it airframe specific. 

I'm curios to see you were asked to go around in Cessna 172N with 40 degrees of flaps during flare.  Spoiler alert - you will run out trim regardless. It just part of the business and that is a reason you won't find 4 degrees flaps in later model of Cessna. 

5 hours ago, ATRguy said:

 

You don't JUST use it, you just hold down nose up trim, as you enter the flare to ease the control forces on the yoke.  It's the only airplane I've ever done this in, and it's not uncommon at all for Caravan pilots to do this.  I've gone around plenty in both the 675-hp and 867-hp versions and it's fine, the trim on landing is usually a little more nose up than takeoff.  So there you go, 45 years of flying, and you learned something new today 😉

We don't trim the ATR much past 500 feet or so, since it's configured, stable, and all that airline stuff.  It also flies like a dump truck, so it's fine not to trim much.

 

 

Agreed, I learn something new every day. My question—just a curiosity, not a challenge—is whether your FCOM or the aircraft manufacturer's manual mentions using trim during flare and touchdown as a standard procedure, or is it simply a pilot technique? I'm not looking to spark any unproductive debate. 

4 hours ago, sd_flyer said:

Ok flying is not instructing. As one FAA inspector said to me once: there a license to teach, and there is license to fly. A good pilot a not necessarily good instructor. 🙂 So from my experience what out saying absolutely doesn't correspond to my reality. There is no out of trim situation because when you trim you  are not trimming  for a good sport, you actually know exactly what you are doing and how much trim you applying. Like you mentioned it airframe specific. 

I'm curios to see you were asked to go around in Cessna 172N with 40 degrees of flaps during flare.  Spoiler alert - you will run out trim regardless. It just part of the business and that is a reason you won't find 4 degrees flaps in later model of Cessna. 

 

I don't think we are on the same page about the interpretation of the out-of-trim issue. When we are fighting the flight controls, applying pressure on the yoke due to an incorrect trim setting, it's a clear case of out-of-trim. In a go-around situation, trimming before and after flare all the way down to the touchdown, even if you knew what you were trimming for before, that value (trim index) will not be the same, leading to improper pitch control, and can get aggravated under different conditions. I'm not sure what's specific to the C 172, but aerodynamically/mechanically, an out-of-trim situation is just that. 

I agree with you, but this doesn't apply to our situation: a skilled pilot might not be as effective as an instructor who hasn't received proper training.

34 minutes ago, LRBS said:

 

Agreed, I learn something new every day. My question—just a curiosity, not a challenge—is whether your FCOM or the aircraft manufacturer's manual mentions using trim during flare and touchdown as a standard procedure, or is it simply a pilot technique? I'm not looking to spark any unproductive debate. 

Hi,

Well, some aircraft have the ability to auto trim the aircraft (737NG for example) and the auto trim features are disabled during these phases of flight. It's only armed at high power settings (N1 greater than 60% for the -800). Trimming in the flare also increases the possibility of a tail strike.

Edited April 13Apr 13 by Mike_CFII_MEL

54 minutes ago, Mike_CFII_MEL said:

Hi,

Well, some aircraft have the ability to auto trim the aircraft (737NG for example) and the auto trim features are disabled during these phases of flight. It's only armed at high power settings (N1 greater than 60% for the -800). Trimming in the flare also increases the possibility of a tail strike.

Exactly, I'm aware of the 737, 748, 777, 787, and 388. Also, during autoland, many airplanes stop trimming between 1500 ft and 500 ft and use only the flight controls for necessary aileron or elevator corrections. For those without that feature, we train before FAF to zero out the trim tabs and use minimal stabilizer trim adjustments. Some airplanes activate tail strike protection before flare, preventing out-of-trim conditions. Of course, a GA or small airplane will not have such systems, but I have never heard of any aircraft manufacturer mentioning trimming during flare all the way down through touchdown. Additionally, the FAA Airplane Flying Handbook (FAA-H-8083-3C) instructs pilots to have the airplane trimmed for a safe approach speed, allowing smooth backpressure application for flare and landing, rather than using the trim. Many training manuals also advise against using elevator trim during flare and touchdown.

I'm having trouble digesting this and would like to see where it is stipulated in any manuals, just for my educational/training purposes. 

1 hour ago, LRBS said:

 

I don't think we are on the same page about the interpretation of the out-of-trim issue. When we are fighting the flight controls, applying pressure on the yoke due to an incorrect trim setting, it's a clear case of out-of-trim. In a go-around situation, trimming before and after flare all the way down to the touchdown, even if you knew what you were trimming for before, that value (trim index) will not be the same, leading to improper pitch control, and can get aggravated under different conditions. I'm not sure what's specific to the C 172, but aerodynamically/mechanically, an out-of-trim situation is just that. 

I agree with you, but this doesn't apply to our situation: a skilled pilot might not be as effective as an instructor who hasn't received proper training.

The first I was introduced trimming during flare was by 50+ years flying experience  retired airline pilot (707, 727, 737 and multiple turboprops) who still actively instructing in his 70th. At the time I didn't get either, it took me many years of instructing finesse when I understood it. I can tell that 70 % CFIs time builder would beat sh of airplane without feeling conscious about their fast past effective golden seal pipeline. And I assume it works OK  pipe line squeeze next gen airline pilots adopt navy style recovery landings. Things look a bit different when instruct in what you own, and when mechanic bills bites your pocket, which force you to contemplate  there is way to prolong a life of oleo strut seals.

We can ask folks here how many times their butt took a beating flying as passengers by "properly" trained airline pilots. My personal experience 80% of the time. Probably the worst ever landing  I have experienced was curtesy Austrian Dash 8. I have huge respect to that airframe, and was shocked that struts didn't shoot through the wing after that terrible slam landing! My spine almost gave birth to my colon, I don't know what kind of training those airline pilots received, but sure enough they kept their door locked through deboarding. LOL

I also want to remind a great stories of WW2 when bomber and fighter planes were landing with shut off elevator/aileron cable and were able to land by using only trim, rudder and power.   

It's so much simpler in gliders 🙂

I simply trim nose heavy, since ever and since getting a big / nasty surprise early in my instruction days in a Blanik L-13 where I was so distracted with the "scenery" and the trees getting too high and the runway too far away that the turn into base almost got me into a spiral 😕  From there on, nose heavy allways !!! I like to feel the force on the stick as I pull it to flare. But heck, it's gliders, not complex turboprop or airliners that I fly.

But I guess set trim and don't touch it again is also what FBW does in Airbuses. Bellow 50 feet or a bit lower I don't recall, stab trim stays put and in those airplanes no SOPs would induce trimming lduring flare 🙂

Boings I don't know, at  least the modern ones ... 

In reference to the 208 using Electric Trim down to landing - here's a video from the series I was watched where I first noticed it. Apologies if videos are not allowed (I do not own this video). Pick up around 5:45 and you'll see (and hear it) used all the way to the flare and during.

Trying it yesterday in the sim had mixed results - definitely a practice thing. It does feel 'wrong' as using your thumb vs whole arms to feel the plane move seems like you have less control, not more, however the results were fairly practical, after several attempts.

13 hours ago, ATRguy said:

It also flies like a dump truck

I guess my last question is, do you feel this is represented well in the Sim? Much of the discussion is around the real 208 technique, but does that translate to the Sim? And is it worth practicing?