Turbine
First. Why on Earth would you sideslip the aircraft on the approach and then ‘into’ the flare rather than instead crabbing the aircraft and applying the proper crosswind condition?
We were not taking about the approach, but seeing as you asked.....
I would crab down final and start slipping on short final. Better for the passengers and better technique. I believe in teaching students to slip all the way, so they get to see the effects of aileron and rudder.
What happens if you get an engine failure and find yourself with the controls all crossed up?
Best glide, landing spot, memorised checklist. Controls would be 'uncrossed' rather early in that process, probably automatically.
What happens, given the turbulent and gusty conditions, if you require additional power but you are already using extra thrust to compensate for the additional drag of a slip?
I have plenty of extra power available in the pattern. I don't get that far from the runway, usually I am power idle from abeam the numbers. You may do differently of course, and standard teaching is to power the plane in. Even if you go power to 1800 abeam the numbers and keep that all the way - not that I would - you still have plenty of power. Besides, it takes zero time to go from uncoordinated flight to coordinated flight, it's not an issue.
Even so, it doesn't matter, you are on the same glideslope whether crabbing or slipping, and in both cases if your engine quits you will either land on the runway or not.
Applying crossed controls to the aircraft in turbulent conditions can also apply a significant stress on the aircraft since it essentially twists the aircraft like a tin can. Light aircraft should be flown (and landed) in a way that minimises the stress on the aircraft.
Airframes are incredibly overengineered and certified to handle stresses far higher than you will encounter in a side slip.
I agree with landing stresses being minimised, the gear should be looked after especially well, that's the weakest point.
Some aircraft, like most of the Cessna series, don’t like prolonged slips as well. If you set yourself up in a slip on a 172 on very early final you could well starve the engine of fuel in a slipped condition!.
If you arrive at your destination with that little fuel you are negligent. Probably an old wives tail anyway, and I said you should crab on early final. Slipping is for landing.
Many believe that if they slip down the approach then you won’t have to apply a crosswind technique. This is incorrect.
The slip
is the crosswind technique.
As you flare and the speed of the aircraft decreases, the aircraft will drift (and yaw) with wind as the amount of control you applied becomes less than what is required to keep straight.
Indeed, you dynamically change your control input according to the conditions, its called flying. In practice, by rollout, you will have full aileron control input towards the wind - well you know what I mean
The only advantage of slipping is you don’t have to think about what aileron and what rudder is required.
Do you mean "The only disadvantage of slipping is you have to think about what aileron and what rudder is required." ????
This concern can be entirely eliminated with proper and competent instruction.
Yep.
Aileron arrests unwanted drift and rudder keeps the aircraft straight. Simple.
Indeed it is. That's why it's the proper configuration to be in during the flare. You gotta think about your landing gear, they tend to collapse if you apply nasty side forces to them, or more likely your tyres might just part company. You don't need either. If the tyres stay attached, they are going to be pushing you off the runway towards the upwind side, which is also the direction you are pointing, and you are at risk of ending up in the dirt. It's a very very bad idea to crab when landing, crosswind or not.
Gusts just need a bit more aquired skill. More fun too!!!
Anyway, to the thread, nothing wrong with using less flap when its gusty. The reasons you gave seem sound, and it seems to work better in practice too I'd say.