Ch 08.qxd 8/25/04 11:27 AM Page 8-5 Direction of Swell Direction of Swell Direction of Swell Position of Swell at Touchdown Position of Swell at End of Runout Positionof Sw ell Halfwa Through Runout Figure 8-6. Landing against the s well shortens the apparent distance between crests, and could lead to trouble. ing swell system. Alone, light and moderate chop are not considered dangerous for landings. Night landings in seaplanes on open water are extremely dangerous with a high possibility of damage or loss of the seaplane. A night landing should only be performed in an extreme emergency when no other options are available. A night landing on a lighted run- way exposes the seaplane to much less risk. Due to the rough sea state, landings should not be attempted in winds greater than 25 knots except in extreme emergencies. Crosswind limitations for each type of seaplane must be the governing factor in cross- wind landings. Chop consists of small waves caused by local winds in excess of 14 knots. These small waves ride on top of the swell system and, if severe, may hide the underly- NIGHT OPERATIONS EFFECT OF CHOP  Landing Heading Landin g Heading Primary Swell Direction Primary Swell Direction Secondary Swell Direction Figure 8-7. Landing heading in single and multiple swell systems. 8-5