When the press report a power pilot making a successful forced landing, they will often state, " The pilot had flown gliders so was trained for this" or words to that effect. Whilst it is true, that in most cases, in a glider you only get one attempt at a landing*, you have airbrakes which are used to fine tune your approach and touch down point.
If you were to use a glider, e.g. ASK13, with the airbrakes held open by the instructor to a position which gives an approximate glide angle and descent rate of the power aircraft, it would be a more realistic scenario for practicing FWLOP. Side slipping, circuit planning and speed would be the primary methods of adjusting the descent rate and touch down point.
There are (at least) a few issues though:
- Turns with airbrakes out are generally discouraged
- The pilot is closer to the ground at touch down so the view is different
- A glider may get away with landing on surfaces which would put a tricycle undercarriage aeroplane on its back
*The exception being at a hill site at which it may be possible to overshoot back into lift and have another go.