percent of liftoff airspeed by the midpoint, the condition of the remainder of the runway may not allow further
acceleration. The entire length of the runway should be inspected prior to takeoff to ensure a usable surface.
c. This "rule of thumb" applies only to runway required for actual liftoff. In the event that obstacles affect the
takeoff climb path, appropriate distance must be available after liftoff to accelerate to best angle of climb speed
and to clear the obstacles. This will, in effect, require the airplane to accelerate to a higher speed by midpoint,
particularly if the obstacles are close to the end of the runway. In addition, this technique does not take into account
the effects of upslope or tailwinds on takeoff performance. These factors will also require greater acceleration than
normal and, under some circumstances, prevent takeoff entirely.
d. Use of this "rule of thumb" does not alleviate the pilot"s responsibility to comply with applicable Federal
Aviation Regulations, the limitations and performance data provided in the FAA approved Airplane Flight Manual
(AFM), or, in the absence of an FAA approved AFM, other data provided by the aircraft manufacturer.
In addition to their use during takeoff, runway half-way signs offer the pilot increased awareness of his or her
position along the runway during landing operations.
NOTE-
No FAA standard exists for the appearance of the runway half-way sign. FIG 7-6-1 shows a graphical depiction of a typical
runway half-way sign.
FIG 7-6-1

Typical Runway Half-way Sign

7-6-9. Seaplane Safety
a. Acquiring a seaplane class rating affords access to many areas not available to landplane pilots. Adding a
seaplane class rating to your pilot certificate can be relatively uncomplicated and inexpensive. However, more
effort is required to become a safe, efficient, competent "bush" pilot. The natural hazards of the backwoods have
given way to modern man-made hazards. Except for the far north, the available bodies of water are no longer
the exclusive domain of the airman. Seaplane pilots must be vigilant for hazards such as electric power lines,
power, sail and rowboats, rafts, mooring lines, water skiers, swimmers, etc.
b. Seaplane pilots must have a thorough understanding of the right-of-way rules as they apply to aircraft
versus other vessels. Seaplane pilots are expected to know and adhere to both the U.S. Coast Guard"s (USCG)
Navigation Rules, International-Inland, and 14 CFR Section 91.115, Right-of-Way Rules; Water Operations.
The navigation rules of the road are a set of collision avoidance rules as they apply to aircraft on the water. A
seaplane is considered a vessel when on the water for the purposes of these collision avoidance rules. In general,
a seaplane on the water must keep well clear of all vessels and avoid impeding their navigation. The CFR requires,
in part, that aircraft operating on the water ". shall, insofar as possible, keep clear of all vessels and avoid

Potential Flight Hazards

7-6-7