Interagency Single Engine Air Tanker Operations Guide - National ...

INTERAGENCY SINGLE ENGINE AIR TANKER OPERATIONS GUIDE
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
automatically be selected. Separate selector switches shall be
provided for the pilot to permit selecting receiver audio from any one
or a combination of all receivers.
IV. Tank and Gate Requirements and Standards.
Tank capacities and drop gate configurations vary with make and model
and between individual contractor's equipment. The volumes range from
500 to 800 gallons. Some operate differently than others, but their basic
functions and capabilities are similar. The following requirements are
common to all SEATs, regardless of make, model, or release mechanism:
Tank/Hopper
1. Tank/Gate systems should not leak when loaded at the
interagency carded permissible loads (gallons in the hopper).
2. Tank (hopper) quantity indicators shall be visible to the loading
crew and pilot.
Gate/ Drop Door
1. Gate must be re-closable in flight (as opposed to manually
resetting the door on the ground after a single-shot salvo drop).
2. Gates must be capable of salvo drops as well as split drops. (For
instance, one full hopper may be expended in a single drop, or
split between two or more drops in substantially equal
quantities). Constant flow and/or variable opening doors, split
doors, and trail doors are acceptable. Controls may be
mechanical, hydraulic, pneumatic, or a combination of all. The
retardant release switch location must be standardized across the
operator’s entire fleet of available aircraft.
*In the past, when SEATs were acquired through the rental process,
standard Transland type dry product gates were acceptable for use in
lighter fuel conditions. Now that SEATs are contracted for and may
be dispatched to any fuel/terrain type, unmodified agricultural gates
are no longer acceptable.
3. All systems must have an emergency dump feature that enables
the pilot to drop the load in less that 6 seconds by using the
normal dump handle in a single, one-step operation.
Hopper/Tank Venting
1. The tank must be properly vented to insure against negative
pressures developing within the tank, resulting in cavitation and
non-uniform flows. Vents may be top mounted, spring loaded
doors, which are vacuum operated, venturi or positive pressure
scoop type vents, or mechanically operated vents which deploy
-40-