crosswind approaches
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During my initial training slipping was the preferred method on the tailwheel trainers, but we were taught the crab method too, mostly to use it in the initial phase of getting lined up. Moving on to bigger and heavier singles I still prefer to slip, whether it's in a low wing or high wing airplane. I was stunned to discover that the man who did my chechout on the C177RG Cardinal didn't know the technique: WHAT THE HELL ARE YOU DOING?!! he screamed at me when I "established" wing-down on final in a brisk crosswind.
Slipping is still my preferred crosswind technique. I never thought of it as something that is more difficult to do than crabbing; in fact I find it easier and I think its advantages outweigh its disadvantages.
YMMV. What is important that you can land safely, regardless of technique.
Disadvantages:
- greater side loads on the aircraft and control surfaces that may have load limits, such as flaps, particularly in turbulent/gusty conditions.
- loss of lift due to yaw component, requiring a higher approach speed.
- increased stall speed, requiring a higher power setting.
Advantages:
- early alignment with the runway
- control all the way down without big changes at the last minute
- good "feel" of the wind all the way down
- reduced risk of traversing on touchdown and putting side loads on the gear.
A greater rate of descent can be a disadvantage as well as a great help. The limiting factor is the ability of the aircraft to bear side loads with effective control surfaces to keep the desired flight path. I was once told by an airline pilot that the best way to get down fast on loss of cabin pressure is a controlled sideslip. It works for small aircraft and at lesser altitudes too, but you have to keep inertia in mind -- it takes time for an airfraft to come out of its slip so the load must be eased off in time or else it can be a very hard landing!
Slipping is still my preferred crosswind technique. I never thought of it as something that is more difficult to do than crabbing; in fact I find it easier and I think its advantages outweigh its disadvantages.
YMMV. What is important that you can land safely, regardless of technique.
Disadvantages:
- greater side loads on the aircraft and control surfaces that may have load limits, such as flaps, particularly in turbulent/gusty conditions.
- loss of lift due to yaw component, requiring a higher approach speed.
- increased stall speed, requiring a higher power setting.
Advantages:
- early alignment with the runway
- control all the way down without big changes at the last minute
- good "feel" of the wind all the way down
- reduced risk of traversing on touchdown and putting side loads on the gear.
A greater rate of descent can be a disadvantage as well as a great help. The limiting factor is the ability of the aircraft to bear side loads with effective control surfaces to keep the desired flight path. I was once told by an airline pilot that the best way to get down fast on loss of cabin pressure is a controlled sideslip. It works for small aircraft and at lesser altitudes too, but you have to keep inertia in mind -- it takes time for an airfraft to come out of its slip so the load must be eased off in time or else it can be a very hard landing!
In gliders it's a crab until a couple feet off the ground, then you push rudder to line up.
Rudder is not kicked.
Gliders have the sneaky advantage that there's much less wind in the 3 feet just above the ground.
No such luck in taildraggers which are mostly high wing. It really helps to land the upwind main first with the a/c pointed straight down the runway, i.e in a sideslip.
One reason for using less flap in Cessna singles in a crosswind is to avoid landing nosewheel first which can do bad things to the firewall.
Rudder is not kicked.
Gliders have the sneaky advantage that there's much less wind in the 3 feet just above the ground.
No such luck in taildraggers which are mostly high wing. It really helps to land the upwind main first with the a/c pointed straight down the runway, i.e in a sideslip.
One reason for using less flap in Cessna singles in a crosswind is to avoid landing nosewheel first which can do bad things to the firewall.
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When I find a pilot who has problems keeping the airplane straight down the runway on landings I have them fly down the runway at around ten feet for the complete length of the runway using both methods of keeping the airplane going down the center line.
When they can comfortably maintain the center line using both methods they generally have far less problems during the actual landings.
When they can comfortably maintain the center line using both methods they generally have far less problems during the actual landings.
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One reason for using less flap in Cessna singles in a crosswind is to avoid landing nosewheel first which can do bad things to the firewall.
Avoid slips with flaps extended
The POH goes into more detail:
When landing in a strong crosswind, use the minimum flap setting required for the field length, If flap settings greater than 20° are used in sideslips with full rudder deflection, some elevator oscillation may be felt, at normal approach speeds. However, this does not affect control of the airplane. ...
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In the C172 I fly there is a placard saying:
Avoid slips with flaps extended
Avoid slips with flaps extended
ie if the x-wind is bad enough that you have full opposite lock on rudder / ailerons, you wouldn't be using full flap for the landing.
FWIW when I asked about this I was told a) the reason for the placard is that under full flaps a slip can in certain circumstances reverse control input and b) the placard relates to full rather than partial flap. And by full flap I mean the 40-deg "barn doors" that many of the old C172's I fly have. I've never tried it
so can't tell you if it's true or not!
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There was a whole thread about that some months back, I recall the conclusion was that the placarding and wording wasn't consistent between models. There are plenty of tall stories, but again, I believe the conclusion is in the use of the word 'avoid', rather than prohibited - if control reversals occured, I think the wording might be rather stronger! As for nosewheels, if you're half competant to pilot the thing, landing on the mains isn't hard, even with 40degree barndoors.
In a glider you're also pushed towards a crab by long wings and low ground clearance - landing on a wingtip is not advised. Powered I usually fly a crab right into the flare, push straight with the rudder, and drop the windward wing as required to maintain the centreline. Not really rocket science. In either case you fly the aeroplane all the way, and you can judge the crosswind by how far off the runway heading you're pointing (reference to trex540) Stabilised approaches are for big jets
In the main, I'm inclined to think whole thing is rather more down to personal preference, perhaps coloured by your handling comfort, and in some cases dictated by the aeroplane (e.g. wheelers, gliders etc)
In a glider you're also pushed towards a crab by long wings and low ground clearance - landing on a wingtip is not advised. Powered I usually fly a crab right into the flare, push straight with the rudder, and drop the windward wing as required to maintain the centreline. Not really rocket science. In either case you fly the aeroplane all the way, and you can judge the crosswind by how far off the runway heading you're pointing (reference to trex540) Stabilised approaches are for big jets
In the main, I'm inclined to think whole thing is rather more down to personal preference, perhaps coloured by your handling comfort, and in some cases dictated by the aeroplane (e.g. wheelers, gliders etc)
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One reason for using less flap in Cessna singles in a crosswind is to avoid landing nosewheel first which can do bad things to the firewall.
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it didn't feel too bad. I'm looking forward to trying it for real, obviously under supervision!
The angle of bank requred into a x/wind at or below the demonstrated limit of most aircraft is not excessive. Certainly not enough to slide you out of your seat. I personally crab in then change to wing down for the landing. If I crabbed all the way to the flare and got some float and hence drift, this is what I'd be doing anyway.
As for the avoidance of flap in the slip in a 172. My considered opinion based on considerable experience is.... B...ocks!
As for the avoidance of flap in the slip in a 172. My considered opinion based on considerable experience is.... B...ocks!
