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Mr Trim
8th Jun 2010, 13:37
Hi guys! I am currently building experience flying jet transport aircraft. Currently on the NG. I would appreciate if you could share the technique you apply during rollout on cross wind conditions. On some of my landings I have noticed that during rollout the aircraft tends to steer to the sides. Not sure if it's caused by applying too much aileron into the wind or too little. Would one be normally applying cross-controls? Thanks in advance.

BOAC
8th Jun 2010, 14:07
'Into-wind' aileron and 'downwind' rudder, all 'as required' (eventually nose-wheel steering takes over from the rudder). So, yes, 'crossed'.

IE Enough aileron to keep the wings level, enough rudder to keep straight. Don't let anyone persuade you to apply some sort of 'fixed' settings:mad:

safetypee
8th Jun 2010, 18:01
Don’t forget about the effects from thrust reverse.
See:-

Crosswind. (http://flightsafety.org/files/alar_bn8-7-crosswind.pdf)

Aircraft performance on slippery runways in crosswinds (http://ntrs.nasa.gov/search.jsp?R=1034480&id=1&as=true&or=false&qs=Ntt%3Dircraft%2Bperformance%2Bon%2Bslippery%2Brunways%2Bi n%2Bcrosswinds%26Ntk%3Dall%26Ntx%3Dmode%2Bmatchall%26Ns%3DHa rvestDate%257c1%26N%3D0) - view PDF file online; page 6 and the last diagram could be of interest.

Mr Trim
8th Jun 2010, 19:06
Guys, thanks a lot for your help! :ok: Greatly appreciated!

TopBunk
8th Jun 2010, 19:24
From experience, you can't apply too much into wind aileron after landing on a highly swept wing. The B747 upwind wing will lift until below 60kts on the landing roll. i agree with BOAC on the landing case, there is no fixed setting to apply - err on the side of caution and apply as much as you need - or more, it is unlikely that the (extra) aileron input will cause directional control problems.

Intruder
8th Jun 2010, 20:21
FLY THE AIRPLANE!!! Use the controls necessary to keep it rolling straight & level. Use whatever reverser technique your AFM/FHB/FCOM calls for.

If you transition to a slip to maintain track just prior to the landing flare, your controls will be "primed" in the correct direction for the rollout. Adjust as needed on the rollout.

FullWings
8th Jun 2010, 21:30
Hire a Cub or something like it and go and do some crosswind circuits and landings... When you can taxi it back to the hangar on one wheel, get back in the jet. ;)

galaxy flyer
9th Jun 2010, 02:30
Mr Trim

Assuming you learned on light planes--it is no different. Just look at the "taxi" chart for a C-150. OTOH, a swept wing, in a crosswind, presents the upwind wing at lower sweep angle than the downwind wing, so it has a more powerful lifting effect. Think of a 45-degree sweep in a right crosswind 45 degrees off the nose. The upwind wing has a wind component 90 degrees to the wind while the downwind wing has, essentially no wind normal to the chord. Strong lift on the right, little on the left.

Individual aircraft landing gear geometry, fin/rudder and aileron effectiveness, sweep angle and weathervane tendency will effect its roll/yaw component on the runway.

GF

Todders
9th Jun 2010, 14:40
As said above fly the a/c as you flair kick off the drift just before main gear contact/just after if you miss it as the the 737 is built to land with a crab if needed, think auto land in cross wind. As you straighten out the drift you will have to apply aileron in the opposite, upwind direction to keep the wings level. This position is exactly what you want on the roll out as well. As much of each as ness. no restrictions like on take off spoilers should be extended any way.

Congrats on realising the flight isn't over as the main wheels touch as this is a symptom that can occur and some people believe it or not think there days work is over let the nose wheel crash down and relax waiting for the capt. to say i have control. (providing your ops say they are pf on the ground ie. the one with the tiler):ugh:

Mr Trim
9th Jun 2010, 16:02
Thanks to all of you for your valuable input :ok:. Incidentally, for my private pilot course I exclusively flew in a Piper Cub – 65 hp (lots of fun - lots of foot work - great trainer) out from a lovely 1500 ft. grass strip. Once again, thanks for the posts.

Takeoff53
9th Jun 2010, 20:21
I would like to follow up with an additional question in relation to the topic:

What's your SOP's regarding hand-over from FO to Capt during rollout on the RWY? I'm used to handover latest when the speedtape disappears (40kts) and/or if tiller needed (called by Capt "my controls")

gatbusdriver
10th Jun 2010, 05:20
If we are using an RET then I tell the F/O to take it off on the rudder pedals (757), if not, I take it between 40 and 60 knots.

fire wall
10th Jun 2010, 06:05
Topbunk, your "cannot apply too much into wind aileron" technique is a recipe for disaster. Having flown the whale for the last 9 years I can assure you that excessive aileron deflection at speeds > 80 knots will bury the # 1 or 4 pod (100 kts for the classic).
FW

Mr Trim
10th Jun 2010, 15:01
Takeoff53:

No set airspeed to hand over the controls to the captain during rollout. "At captains discretion", per SOPs. Just positive transfer of controls.

beamer
10th Jun 2010, 15:48
Call me old-fashioned but I do grimace when I read or hear people talking about 'kicking-off' the drift with regard to large commercial aircraft. The aircraft we fly today with powered controls feeding large control surfaces do not need aggressive inputs in normal operating conditions and crosswinds up to limitations should fall into that category. I seem to remember Leo Sullivan, the highly esteemed Lockheed test-pilot, warning against sudden control reversals whilst the Airbus accident in New York just after 9/11 involved very exaggerated rudder inputs.

Perhaps we could smoothly squeeze in rudder inputs balanced against opposite aileron rather than 'kick-in' a bootfull of size tens ?

Todders
10th Jun 2010, 17:19
I am sorry Beamer your absolutely correct.

Retract segments of previous post regarding said "Kicking off of drift" and please read smoothly apply appropriate pressure to the rudder pedals actuating the hydraulically controlled rudder at the rear of the vertical stabiliser. (Caution excessive deflection or rate there of may cause control issues).


:ugh:


PS no specific speed for transfer of control. Though i would say it is nice sometimes to let the handling pilot control the aircraft and it's rate of deceleration until you come off the rapid exit. This usually results in the smoothest and efficient runway occupation. Far to often in my humble opinion capts. jump on the controls through their own fear or what ever then proceed to stamp on the brakes, because they have no idea what kind of pressure the f/o is applying turning a nice smooth retardation into a smack in the face from the chair in front for the pax.

badrace
12th Jun 2010, 02:04
Very practical! On the other hand, Airbus aircraft ,due to sde stick control philosophy and no feed-back from control surfaces ,seems to me more difficult to transit from flare to roll out. especially A320 pilots can be really busy for crosswind landings ;since Airbus don't recommend x-control(side slip) techniques,there's more to consider after touchdown ,when rwy surface is wet ,then even more coordination required for directional control; not to mention different control laws during partially hydrallic system malfuction.
Flying airbus in strong gusty wind sometimes can be "shaky",so any good advice for a stablized landing?Also techniques for instucting a FO for xwind landings( prefered without dual-input). Thanks1

galaxy flyer
12th Jun 2010, 02:42
beamer

Yes, I quite agree. I was taught the "kick it out" phrase by old Boeing pilots; they, of course, really meant, "squeeze it out". One windy day landing with near limiting crosswind at Yakima, WA in the C-5. I was letting the reasonably experienced LT do the landing. He took "kick it out" too literally. I was completely surprised when he put in a yard of downwind rudder, the nose yawed downwind, followed rapidly by 600,000 pounds of Lockheed. I took the plane, he didn't fight it for an instant, and started a go-around at full take-off power. On downwind, I got my BP below 200/100 and landed it. NEVER used "kick it out" again.

GF