Trimming Rudder in Slip for x-wind land?

[InHot]

I've always believed you should learn something new on every flight, but this one really surprised me - never seen this in 27 years of flying.

The fellow who flew as my co-pilot the other day was taught to trim the rudder in the slip on a crosswind landing - as opposed to holding the pressure. He sets up the slip about 1/2 mile out, trims the rudder and and flys it down.

Technique I normally use is to crab the aircraft until short final and feed in the rudder in for the slip at about 50' AGL. I've used this technique for everything from 152's to DC9's (never flown castering gear trucks).

Trying to be open minded about this - however one concern about trimming in the rudder is the balked landing /engine failure scenario wher you now have to apply additional rudder to overcome the out-of-balance trim.

Any comments?

 

[bobbysamd]

Rudder trim

I flew for eleven years before my current nine year hiatus. Nothing big - primarily singles and light twins. I used and taught crabbing part of the way down and wing low when getting closer in my spam cans. I believe the old Flight Training Handbook called this the "combination method." Never heard of, or taught, trimming the rudder. I used and told my students to hold pressures on aileron and rudder all the way down after switching to wing-low and on the after-landing roll.

For what it's worth.

 

[boxcar]

Guess there's always something else to learn! I've never heard of this technique, but don't see it as being very useful. Personally, I think holding a prolonged slip in a crosswind is a p-poor technique. It takes extra power to hold the glideslope and and is uncomfortable for the passengers. Every professional pilot I've flown with crabs to the threshold and kicks it straight in the flare.

 

[corp_da20_guy]

I think the idea of trimming the rudder is a bad idea. While in most situations may not be an issue...but the potential to snowball with other situations (ie engine failure, etc). Not to mention if trimmed at say 500' AGL...I can't imagine the same amount of rudder trim is needed at touchdown. (Due to different wind velocities, direction, crosswind component, or what have you)

I have never heard or this technique...like Boxcar said...prolonged slips are usually not recommended for jet aircraft. It sets up the potential like many other situations to snowball to something beyond a pilots abilities. (Go around because an aircraft enters the runway, engine quits or sucks up some birds, get a little too slow, etc) Pilots should realize that not only are we pilots, but also "risk managers." The risk of a given situation should be minimized. This is our job as professionals...to always conduct ourselves in this manner.

We as pilots can never realistically know everything, so we should be learning something new with each flight. But when someone we fly with especially if a person is less experienced...we owe it to ourselves and them to mentor. Try to point out the fact that that technique may not be the safest and explain why.

Happy flying!

 

[sabreliner]

I would think that in many large transport category airplanes, the slip method is something to be avoided rather than trimmed in a half mile out.

For one thing, in strong x-winds, it is just asking to scrape a wing tip or nacelle.

Also, I KNOW that the freight in the back doesn't like that falling sideways feeling while that are pinned against the sidewall or the person next to them. I always cringe a little when I see people slip it in from a ways out.

Like others have mentioned, it also could produce a problem on a missed approach, single engine or otherwise. You want the airplane coordinated with a minimal amount of thought and input from you during that pretty hectic time.

Finally, and this is sort of selfish, when in the a/c I fly, the rudder trim also trims the NWS. So, if you have trim in to make it fly crooked, it is going to taxi crooked when I take it form the FO on the roll out, making my job more difficult and probably giving the folks in the back a little swerve while I try to figure out what it is that you did to the airplane.

So in other words, I give trimming the rudder to maintain a slip a BIG THUMBS DOWN!

 

[DLF8108]

Rudder Trim in X-Wind?

Once again...RTAFM (refer to Aircraft Flight Manual) & if it ain't in the AFM...

MY $00.02...consider this:
Most multi-eng AFMs call for CENTERING the rudder trim for landing under all engine-out situations...(so you'll know what to do with the controls when power comes to idle)...

SIMILARLY...when the wind shifts direction in a cross-wind... you'll want the controls to feel "normal" when you make needed corrections to keep the aircraft pointed straight down the rwy...

Rudder trim during crosswind landings??....poor technique... & possibly DANGEROUS under the wrong conditions <methinks>

 

[LimoDriver]

I must second the motion - bad technique!

I think you are just setting yourself up for more problems if you have a balked landing or engine failure, as others have pointed out.

In my 25+ years in this game, I've never heard of this technique!

 

[RJones]

This is a first for me as well. Sounds like a lazy copilot to me. Just hold the pressure till your in the flare then take it out and put a little wing down and land. If it's trimmed you can't really do that or you have to push on the opposite rudder more than you'd have to which would...hummm.

Hard to imagine

 

[mar]

All the trimmings

-<<Also, I KNOW that the freight in the back doesn't like that falling sideways feeling while that are pinned against the sidewall or the person next to them>>-

-<<Try to point out the fact that that technique may not be the safest and explain why.>>-

-<<Personally, I think holding a prolonged slip in a crosswind is a p-poor technique. It takes extra power to hold the glideslope and and is uncomfortable for the passengers. Every professional pilot I've flown with crabs to the threshold and kicks it straight in the flare.>>-

Enough said, but I always seem to have $0.02:

Trim however you want, you're the one flying the airplane but for Pete's sake at least keep it coordinated until the touchdown--if for no other reason it's more comfortable and passengers (and pilots) judge our skill by smooth handling--and that's all.

 

[lookup]

Trim however you want, you're the one flying the airplane but for Pete's sake at least keep it coordinated until the touchdown--if for no other reason it's more comfortable and passengers (and pilots) judge our skill by smooth handling--and that's all.

Agreed keep it coordinated, but it is more than that. Spend the whole arrival phase cobbing the throttles and yanking and banking and we notice too...

Of course a crappy landing after 3 peaceful smooth hours is a bummer.

The smoothest arrival ride recently (complete with a total greaser at the end) was a MD-88 captain (plenty of silver hair) from AUS-SJC. Silky smooth.... told him so too! Something to strive for in my flying.