Aeronautical Information Manual (AIM), page 535

Index   534 -- Page 535 -- 536

TBL 7-5-1
Jurisdictions Controlling Navigable Bodies of Water
Authority to Consult For Use of a Body of Water

Location Authority Contact

Wilderness Area U.S. Department Local forest ranger
of Agriculture,
Forest Service
National Forest USDA Forest Local forest ranger
National Park U.S. Department Local park ranger
of the Interior,
National Park
Indian Reservation USDI, Bureau of Local Bureau
Indian Affairs office
State Park State government Local state
or state forestry or aviation office for
park service further

Canadian National Supervised and Park
and Provincial restricted on an Superintendent in
Parks individual basis an emergency
from province to
province and by
departments of the

consult Canadian
Flight Information
Manual and/or
Water Aerodrome

e. The FAA recommends that each seaplane owner
or operator provide flotation gear for occupants any
time a seaplane operates on or near water. 14 CFR

Section 91.205(b)(12) requires approved flotation

gear for aircraft operated for hire over water and

beyond power-off gliding distance from shore.

FAA-approved gear differs from that required for

navigable waterways under USCG rules. FAA-ap-

proved life vests are inflatable designs as compared

to the USCG's noninflatable PFD's that may consist

of solid, bulky material. Such USCG PFDs are

impractical for seaplanes and other aircraft because

they may block passage through the relatively narrow

exits available to pilots and passengers. Life vests

approved under Technical Standard Order (TSO)

TSO-C13E contain fully inflatable compartments.

The wearer inflates the compartments (AFTER

exiting the aircraft) primarily by independent CO2
cartridges, with an oral inflation tube as a backup. The
flotation gear also contains a water-activated,
self-illuminating signal light. The fact that pilots and

passengers can easily don and wear inflatable life
vests (when not inflated) provides maximum

effectiveness and allows for unrestricted movement.
It is imperative that passengers are briefed on the

location and proper use of available PFDs prior to
leaving the dock.

f. The FAA recommends that seaplane owners and
operators obtain Advisory Circular (AC) 91-69,
Seaplane Safety for 14 CFR Part 91 Operations, free
from the U.S. Department of Transportation,

Subsequent Distribution Office, SVC-121.23, Ard-
more East Business Center, 3341 Q 75th Avenue,
Landover, MD 20785; fax: (301) 386-5394. The
USCG Navigation Rules International-Inland
(COMDTINSTM 16672.2B) is available for a fee
from the Government Printing Office by facsimile
request to (202) 512-2250, and can be ordered using

Mastercard or Visa.

7-5-9. Flight Operations in Volcanic Ash

a. Severe volcanic eruptions which send ash and
sulphur dioxide (SO2) gas into the upper atmosphere

occur somewhere around the world several times
each year. Flying into a volcanic ash cloud can be
exceedingly dangerous. A B747-200 lost all four
engines after such an encounter and a B747-400 had

the same nearly catastrophic experience. Piston-
powered aircraft are less likely to lose power but
severe damage is almost certain to ensue after an
encounter with a volcanic ash cloud which is only a
few hours old.

b. Most important is to avoid any encounter with

volcanic ash. The ash plume may not be visible,

especially in instrument conditions or at night; and

even if visible, it is difficult to distinguish visually

between an ash cloud and an ordinary weather cloud.

Volcanic ash clouds are not displayed on airborne or

ATC radar. The pilot must rely on reports from air

traffic controllers and other pilots to determine the

location of the ash cloud and use that information to

remain well clear of the area. Additionally, the

presence of a sulphur-like odor throughout the cabin

may indicate the presence of SO2 emitted by volcanic

activity, but may or may not indicate the presence of

volcanic ash. Every attempt should be made to remain

on the upwind side of the volcano.

c. It is recommended that pilots encountering an
ash cloud should immediately reduce thrust to idle
(altitude permitting), and reverse course in order to

Potential Flight Hazards 7-5-7

Page 535 of the Aeronautical Information Manual (AIM.pdf)
AIM: Official Guide to Basic Flight Information and ATC Procedures

Index   534 -- Page 535 -- 536