I learned how to slip during my powered training as a way to lose altitude when too high and, of course, a way to track the runway center-line during a crosswind landing.
Quite a bit more emphasis was put on slipping during my glider training. I guess the reason for this is pretty much common sense. There is no concept of a "go-around" when landing a glider...you only get one shot. That said, I don't practice slips often enough when soaring because purposefully losing altitude in a glider is counter-productive, except when too high in the pattern.
For this reason, I've now gotten into the habit of using a slip to descend when flying powered. This allows me to practice slipping with the knowledge that I am guaranteed by virtue of having an engine to have the option of regaining that altitude. Note: I usually only do this while flying solo since slipping can be a comfort issue for passengers.
This got me to wondering...
Putting aside the comfort of passengers, Is there any disadvantage to always using a slip to descend when flying powered?
If not, why does it seem that this method of losing altitude is not used/taught more frequently?
Update after reviewing answers
I wanted to give this some time to stew before I checked an answer. I came into this fairly (but not absolutely) certain that the short answer was no. I think the responses confirm this. I understand the need some have to "warn" against stalling, but I don't really see how this warning couldn't be applied to any maneuver and really has nothing to do with the fact that you are slipping, short of making a mistake...like skidding instead.
The conclusion I'm taking from the answers is:
- Slipping can be uncomfortable to passengers, pretty much for the same reason that healing in a sailboat can be perceived as uncomfortable.
- Slipping is aerodynamically inefficient. Since the objective is to lose altitude, this would appear to be a benefit, rather than a detractor.
- That some planes, in some configurations, have restrictions on when slipping is allowed/recommended/optimal.
- That slipping will get you down faster, thus making it preferred if getting down faster is the objective.