Another possible malfunction is failure of the drogue chute  to inflate fully. If this happens, the canopy “streams” like  a twisting ribbon of nylon, providing only a fraction of the  drag that would occur if the canopy had fully inflated. Full  inflation is unlikely after streaming occurs, but if it does  occur, drag increases substantially. It is much better to fly  with a known drag configuration and adjust for it rather  than be faced with a substantially increased drag coefficient  at a place and time where a safe landing is no longer  possible. If in doubt regarding the degree of deployment  of the drogue chute, the safest option may be to jettison  the drogue. Regardless of the malfunction type, the pilot  should review approach and landing options for the drogue  chute conditions. signs of impending difficulty include excessively high  engine temperatures, abnormal engine oil temperatures, low  oil pressure, low rpm despite high throttle settings, low fuel  pressure, and erratic engine operation (surging, backfiring, and  missing). Abnormal engine performance may be a precursor to  complete engine failure. Even if total engine failure does not  occur, operation with an engine that cannot produce full power  translates into an inability to climb or perhaps an inability  to hold altitude despite application of full throttle. The best  course of action, if airborne, is to make a precautionary  landing first and then discover the source of the trouble. Regardless of the type of engine failure, the pilot’s first  responsibility is to maintain flying airspeed and adequate  control of the glider. If power failure occurs, lower the nose  as necessary to maintain adequate airspeed. Pilots flying  self-launching gliders with a pod-mounted external engine  above the fuselage need to lower the nose much more  aggressively in the event of total power loss than those with  an engine mounted in the nose. In the former, the thrust of  the engine during full power operations tends to provide a  nose-down pitching moment. If power fails, the nose-down  pitching moment disappears and is replaced by a nose-up  pitching moment due to the substantial parasite drag of the  engine pod high above the longitudinal axis of the fuselage.  Considerable forward motion on the control stick may be  required to maintain flying airspeed. If altitude is low, there  is not enough time to stow the engine and reduce the drag  that it creates. Land the glider with the engine extended.  Glide ratio in this configuration is poor due to the drag of the  extended engine and propeller. The authoritative source for  information regarding the correct sequence of pilot actions  in the event of power failure is contained in the GFM/POH.  The pilot must be thoroughly familiar with its contents to  operate a self-launching glider safely. In addition to the standard flight control systems found on  all gliders, self-launching gliders have multiple systems to  support flight under power. These systems may include but  are not limited to the following: The complexity of these systems demands thorough  familiarity with the GFM/POH for the self-launching glider  being flown. Any malfunction of these systems can make it  impossible to resume powered flight. If the power failure occurs during launch or climb, time to  maneuver may be limited. Concentrate on flying the glider  and selecting a suitable landing area. Remember that the  high drag configuration of the glider may limit the distance  of the glide without power. Keep turns to a minimum and  land the glider as safely as possible. Do not try to restart the  engine while at very low altitude because it distracts from the  primary task of maintaining flying airspeed and making a safe  precautionary landing. Even if power in the engine system  were restored, chances are that full power is not available. The  problem that caused the power interruption in the first place  is not likely to solve itself while trying to maneuver from  low altitude and climb out under full power. If the problem  recurs, as it is likely to do, the pilot may place the glider low  over unlandable terrain with limited gliding range and little  or no engine power to continue the flight. Even if the engine  continues to provide limited power, flight with partial power  Engine failures are the most obvious source of equipment  malfunction in self-launching gliders. Engine failures can be  subtle (a very slight power loss at full throttle) or catastrophic  and sudden (engine crankshaft failing during a full-power  takeoff). High on the list of possible causes of power  problems are fuel contamination and exhaustion. To provide adequate power, the engine system must have fuel  and ignition, as well as adequate cooling and lubrication. Full  power operation is compromised if any of these requirements  is not satisfied. Monitor the engine temperature, oil pressure,  fuel pressure, and revolutions per minute (rpm) carefully to  ensure engine performance is not compromised. Warning  8-26 Self-Launching/Sustainer Glider Engine Failure  During Takeoff or Climb Self-Launching Gliders •  Fuel tanks, lines, and pumps •  Engine and/or propeller extension and retraction  systems •  Electrical system including engine starter system •  Lubricating oil system •  Engine cooling system •  Engine throttle controls •  Propeller blade pitch controls •  Engine monitoring instruments and systems