Another less commonly used method of increasing trim  speed is to increase tension on the crossbar by pulling it back  further, slightly increasing the nose angle and reducing twist.  This increases the angle of attack (AOA) of the tips producing  more lift, and it lowers the nose to a higher trim speed. This  is a typical in-flight trim adjustment for high performance  hang gliders. The roll control is diminished with this faster  and stiffer wing.  Ground adjustable trim systems are described in the Pilot's  Operating Handbook (POH) for each aircraft. Different loads  may require different pitch settings.  Being able to adjust the trim systems in flight has a number of  advantages as discussed later in the flight sections. A number  of inflight adjustable systems are available with different  manufacturers. A common in-flight adjustable trim system  is raising and lowering the trailing edge. Raising the trailing  edge increases airfoil reflex and slows the wing. Lowering  the trailing edge decreases airfoil reflex and speeds up the  wing. Typically, a crank on a downtube controls a wire that  runs up the downtube to the top of the wing. As a result of  moving the crank, the trailing edge wires are raised and  lowered and the trim speed changed.  [Figure 3-22]  Hydraulic  or electrical systems can move the hang point on the wing  for other inflight trim systems.  [Figure 3-23] Another pilot-actuated trim system in flight is an elastic  system in which the pilot increases tension on the elastic  system which raises the nose for climb and slower fl ight.  [Figure 3-24] The carriage is a completely separate structure from the  wing. Without the wing, the carriage can be driven around  if needed. Most of the weight and cost of the WSC aircraft  is in the carriage. There is a wide range of carriage designs  from the most simple and basic open trikes to the more  sophisticated and complex trikes that integrate cowlings and  offer a number of adjustments for the pilot and passenger,  resulting in comfort and less fatigue during fl ying. Generally,   Inflight Adjustable Trim Systems   Carriage  F r o n t K e e l Front Kee Elastic pulling down on keel raising nose. K e e l P o c k e t Keel Pocket R e a l K e e l Real Keel Nose Figure 3-23.  Hydraulic inflight trim systems that move the hang  point in flight controlled by the pilot.  Figure 3-22.  A crank on the downtube of the control bar that adjusts  the trailing edge reflex during flight.  Figure 3-24.  More tension on elastic pulling down on the rear of  the wing keel reduces the trim speed and is controlled by the pilot  in flight. 3-10