Launch Operations
Once you have safely arrived at the runway, you must do your normal glider checks (except for hooking up the towrope), PLUS the power checks (fuel, temperature, ignition, electrical). Finally ready to enter the runway? Better check it for traffic and announce your departure, both things the towpilot normally does.
Some things are easier: the steerable tail wheel makes a wing down launch, even in a cross-wind, easier than a calm wind takeoff with a towed glider; also, no towplane wake to mess things up. It's a help during the landing and rollout, too.
During the first 500' of the climb, you have a higher risk than a glider pilot being towed, though still not as much as a towpilot normally assumes (think about that...buy your towpilot a beer next chance you get!). The main reason for this increased risk is the much higher sink rate of the motor glider with its propeller extended. For a PIK-20E, the glide ratio becomes 15:1 (from 40:1), for my ASH26E, about 20:1 (from 50:1). If there is a power failure, this does make landing ahead a little easier, but means a turn back to the runway must be started at a higher altitude than a towed glider.
As the "towpilot" it is your job to steer the aircraft and avoid flying into other aircraft, sky diver drop zones, noise avoidance areas, and so on. You can't just follow the towplane as you used to!
Locating lift under power is more difficult than under tow. The propeller wake disturbs the vario on many motorgliders, the audio is difficult to hear with headset on and the engine noise, the vibration seems to hinder the feel of a thermal, and you don't have the lift and sink cues the motion of the towplane provides. Also, the nose up attitude in climb seems to reduce the horizon cues.
Converting to a glider: Once established in a thermal, it's time to re-configure as a glider. The engine must be cooled at reduced power, stopped, prop centered, and finally retracted. Then the headset can be removed and stowed, audio volume reduced, fuel shut off and engine master switch turned off, and (optional) a sigh of relief breathed. It's a very busy couple of minutes best spent well away from other gliders, so don't join a motorglider in its thermal until the "hummer" has disappeared into the fuselage!
Restarting the engine in flight has its special concerns, too. Safe flying means you cannot assume the engine will start and let you climb away. Besides a failure to start, it might not retract after use, leaving you with half your normal glider ratio. It is not just the mechanical problems that must be considered, but also the possibility of pilot error; furthermore, the sink, terrain, density altitude and other factors may be more than even a properly running engine can overcome. You must be prepared to landout, as tempting as it is to believe your engine will once more hoist you into the sky.
This means the usual drill: selecting a field, entering downwind, completing all checks and lowering the gear. Only then should you attempt to extract and start the motor. If is runs, fine, otherwise you must continue the landing to your selected field.
A glider pilot who is also a current power pilot won't be so intimidated by all this, but other glider pilots should reflect on it carefully before they decide a motorglider is an unmitigated delight.