National Interagency Fire Cache

Last updated July 06, 2004 www.freqofnature.com


 

 

National Incident Radio Support Cache (NIRSC)
Channel		Description				RX	 TX	  PL
--------------  --------------------------------------  -------- -------- -----
TAC-1 USFS	Forest Service Tactical 1		168.0500
TAC-2 USFS	Forest Service Tactical 2		168.2000
TAC-3 USFS	Forest Service Tactical 3		168.6000
TAC-1 BLM	Interior Tactical 1			166.7250
TAC-2 BLM	Interior Tactical 2			166.7750
TAC-3 BLM	Interior Tactical 3			168.2500
CMD-1		Command 1				168.7000 170.9750 *
CMD-2		Command 2				168.1000 170.4500 *
CMD-3		Command 3				168.0750 170.4250 *
CMD-4		Command 4				166.6125 168.4000 *
CMD-5		Command 5				167.1000 169.7500 *
CMD-6		Command 6				168.4750 173.8125 *

*Command channels use 110.9, 123.0, 136.5 and 141.3 PLs.
FED CMN		Federal Common (Ground Tac/Tanker Ramp	163.1000
FED CMN  	Federal Common (Ground Tac/Hot Shots)	168.3500
FED CMN		Federal Common 				418.0500
FED CMN		Federal Common				418.5750
FED CMN		Federal Common				418.0750
FED CMN		Federal Common				408.4000
LE CMN		USFS Law Enforcement Common		168.0250
ICS CALLUP	Incident Command System Callup		168.5500
AIR GUARD   	Air Guard				168.6250          110.9
AIR SAFETY  	Air Safety				172.6000
FLGHT FLW	Flight Following			168.6500
AIR TAC-1	Air Tactics 1 (Air to Air)		166.6750
AIR TAC-2	Air Tactics 2 (Air to Air)		169.1500
AIR TAC-3	Air Tactics 3 (Air to Air)		169.2000
AIR TAC-4	Air Tactics 4 (USFS Air to Ground)	170.0000
AIR TAC-5	Air Tactics 5 (BLM Air to Ground)	167.9500
LOG-1	Logistics 1					414.6500 410.7750
LOG-2	Logistics 2					415.4000 411.4000
LOG-3	Logistics 3					415.5000 411.5000
LOG-4	Logistics 4					417.3000 411.7500
LOG-5	Logistics 5					417.3500 411.9250
LOG-6	Logistics 6					417.5000 412.1500
LOG-7	Logistics 7					417.8000 412.2000
V1		Rotor, Fixed, Air-Air, Air-Ground	122.925
V2		Rotor, Air-Air, Air-Ground		123.025
V3		Rotor, Air-Air				122.975
V4		Rotor, Air-Air, Air-Ground		122.850
V5		Rotor, Air-Air, Air-Ground		123.075 (HELIPORT)
V6		Rotor, Air-Ground			123.050 (HELIPORT)
V7		Fixed, Air Tanker-Air Tanker Base	135.975
V8							119.950
V9							119.975
		FAA					169.3500
See the California (Forest Service Region 5) Section below for Region 5
 only, additional frequencies.

This list includes the entire STANDARD National Incident Radio Support
Cache frequencies. In most incidents (wildland fire or otherwise), many
of the local Land Management agency's frequencies will play a role in
the communications plan.
During extremely large incidents, additional frequencies may be
specifically assigned to that incident for that time, but will vanish
afterwards. Many times these will result in names such as command 8, etc.
The cache primarily contains frequency agile radios, which allow the
Communications Unit to add or change frequencies as needed.
In many instances there will be frequencies used that are not approved 
by the Communications Unit, or even known to the Incident Command.
These are mostly used as "squad" or "crew" frequencies.   
These are usually frequencies used by the unit at home. i.e.: A Hotshot 
crew from the Coconino National Forest, may be using the Coconino 
National Forest simplex frequency amongst themselves, even though they 
are on a fire in Utah. This can get interesting, as many frequencies 
are re-used by completely different agencies in other areas. e.g.: BLM 
units from Idaho use frequencies that are used by the FBI most everywhere 
else in the nation!
Basic VHF Channel Chart (Scheme) - King Radios CH Group 1 Group 2 Group 3 
 USFS NATIONAL INTERIOR 
 1 TAC 1 Air to Air TAC 1 
 2 TAC 2 Air to Air TAC 2 
 3 TAC 3 Air to Air TAC 3 
 4 C-1 Monitor Air to Ground C-4 Monitor 
 5 C-1 Repeater Air to Air C-4 Repeater 
 6 C-2 Monitor Blank C-5 Monitor 
 7 C-2 Repeater Blank C-5 Repeater 
 8 C-3 Monitor Blank C-6 Monitor 
 9 C-3 Repeater Blank C-6 Repeater 
10 FS Law Enforcement Blank FAA 
11 Govt Wide ICS Call-Up Govt Wide 
12 Govt Wide Blank Govt Wide 
13 Blank Blank Blank 
14 Air Guard Air Guard Air Guard 
King portable radios are the primary radios used in the cache. Some older GE, 
& Motorola radios are still used and are configured similarly, or are set up 
with only one group.
At first blush the order of the frequencies may not make sense. But there is 
a reason behind the setup. (King radios do not scan between banks).
The groupings are set up so that most incidents, or divisions of incidents, 
use the same group. i.e.: When a Command Channel 1 repeater is sent to the 
incident, all of the tactical channels will be from Group 1, and likewise 
if a Command 5 repeater is sent, all the channels will be out of group 3.
On very large, or complex incidents, they may use both groups, and divide 
the incident in half, with one side or function operating on Group 1, and 
the other half or another function on Group 3. In these incidents you may 
see two Command Repeaters linked together (one out of each group).
The other MAJOR reason why one group or another may be used, is location. 
The Interior frequencies are not cleared nationwide like the USFS frequencies 
are, and even though they are mostly clear in the Western U.S., they are 
still used in several metro areas by other agencies. See the comment below 
about the Interior Command Channels and IRS.
Tactical Frequencies
168.050, 168.200, 168.600 are the three Forest Service tactical frequencies. 
These have been cleared nationwide for incident use.   You will see only these 
used east of the Mississippi River.
166.725, 166.775, 168.250 are the Interior Tactical frequencies. These are not 
cleared nationwide, and the duty communications officer at the National 
Interagency Fire Center must approve use of these for any given incident.
Command Frequencies
The Command Frequencies are the least likely to change once they are used on 
an incident. The Command Repeaters are fixed frequency (crystalled & duplexer 
tuning is not done in the field). So unless they replace the entire repeater, 
it will be set for the duration of the incident. 
Once again the Forest Service Command Frequencies are cleared nationwide, 
where as the Interior is not. As a matter of fact, you may notice that Command 5 
& 6 use frequencies also used by the Internal Revenue Service.
The other confusing item is the terminology used of C-1 "Monitor", this is really 
operating simplex on the repeater output frequency, more commonly called 
"talk around".
Most of the command repeaters are now equipped to allow CTCSS tone (PL) operation, 
to allow closer spacing of the same command channels on different incidents. 
They use the first four standard USFS tones. [110.9 Hz, 123.0 Hz, 136.5 Hz, 141.3 Hz]
Forest Service Law Enforcement Frequency
168.025 was previously the input to what is now the Air Guard Frequency. 
During the 80's all of the 168.625 repeaters were phased out, and all are 
now remote base stations operated on either wireline, or microwave control. 
When this occurred, the 168.025 was dedicated as the common frequency for 
Forest Service Law Enforcement Personnel. It is also available in the NIRSC radios, 
and is available as a ground tactical frequency, if needed. Many of the Forests 
that have large law enforcement programs, (West Coast), also have dedicated 
Law Enforcement nets with repeaters operating on other frequencies.

Itinerant Frequencies
163.100 and 168.350 are both federal nationwide common frequencies that any 
federal agency can use. They have also been used in repeater configurations. 
The land management agencies have started using them more heavily in the past 5 years, 
and they have replaced local tactical (work) channels in many cases 
(Several forests previously used the NIRSC tactical channels locally). 
These two frequencies are available as ground tactical frequencies, and in many cases 
you will also hear communications between crews as they travel on this frequency. 
Keep in mind that any other federal agency may also pop up on these. Many agencies with 
little communications equipment, rely on these for their operations. 
(USGS gage tech., etc.). 

ICS Call Up
168.550 Mhz is the ICS Calling Frequency. SmokeJumpers are also using it as the 
primary frequency for air-to-ground operations between the spotter and the jumpers 
on the ground.   If there is "silk in the air" the jump operation will be operating 
on this frequency.   Note that other special air operations (aerial ignition, explosives) 
may also utilize this frequency. 
Air Guard
Taken from the GB Mob Guide:     Air Guard is defined as emergency communications for 
aviation. The national, interagency Air Guard frequency is 168.625. The Air Guard 
channel provides a continuous communications link to any aircraft and dispatch unit 
with Air Guard capabilities. 
1. Requirements.
All units dispatching aircraft, including dispatch centers and air tanker bases, 
shall have the capability of transmitting and receiving the interagency Air Guard 
frequency 168.625. Ground or ground-mobile transmitters on this frequency should be 
equipped with a CTCSS Encoder on 110.9 Hz. (Southern California suffers from interference 
from Mexico on this frequency and the CTCSS is used to reduce the impact of that interference.) 
All aircraft assigned to an incident must have a radio configuration that includes 
the interagency Air Guard frequency of 168.625.   Also all NIFC NIRSC Cache radios 
will always have the Air Guard Frequency as the last channel in every mode. 
(Usually ch. 14, but may be in ch. 12 in older 12 channel per mode radios [GE's & Motorola's]). 
Continuous monitoring of the Air Guard frequency is required by both aircraft and dispatch.     
To meet this requirement, all Federal "carded" aircraft used in incidents have dual 
receiver FM Radios, so that one receiver is always tuned to the "Guard" frequency. 
2. Limitations. Use of this frequency is limited to: 
Emergency air-ground communications 
Emergency air-air communications 
Initial call, recall, and re-direction of aircraft when no other contact 
frequency is available
Air Guard is not to be used for tactical communications, local dispatching, 
administrative, flight-following or logistical use, unless it is the only way 
to communicate in order to identify another frequency for communications. 
Aircraft operations are considered high risk, and have a very high priority 
when communications assets are assigned.
Flight Following
VHF-FM 168.650 has been assigned as the National Interagency Flight Following 
frequency. This frequency should be used for flight following and air-to-ground 
administrative radio traffic.
Air-Dispatch Communications. Communications between dispatch and aircraft will 
be on the local unit frequency assigned at the time of dispatch or as changed 
and relayed at the time of arrival. The national flight following frequency 
may be used when local unit VHF-FM channel is congested. 





Air Tactical Frequencies
There are five (5) national VHF-FM air-to-air and air-to-ground frequencies 
which are designated as Air Tactical frequencies for large incidents.
The five (5) frequencies are:
* 166.675 * 167.950 (added in 1996) * 169.150 * 169.200 * 170.000 
1. Restrictions. These frequencies are restricted to use West of the 
Mississippi River (95W). 170.000 cannot be used in the Columbia River 
Basin in WA. In CA, 166.675, 169.150 and 169.200 will be used as air-to-air only, 
and 170.000 is used as Air-to-Ground. 
AM - Aircraft Frequencies 
CHART 1 - NATIONAL VHF-AM FREQUENCIES  

Frequency    	Air-to-Air	Air-to-Ground	Fixed Wing	Rotor Wing  
122.925		YES  		YES  		YES  		YES  
122.975  	YES  		NO  		NO  		YES  
122.850  	YES  		YES  		NO  		YES  
123.025  	YES  		YES  		NO  		YES  
123.050  	NO  		YES  		NO  		YES  
123.075  	YES  		YES  		NO  		YES  

Note that 122.925 is the only authorized national air-air frequency for 
fixed-wing use. It is a government "all call" frequency, meaning that 
any governmental agency may use it. Its use as a standard air-air frequency 
is therefore not recommended. It is best used as a backup for immediate 
temporary use until another discrete frequency can be obtained. 
Many areas have pre-assigned AM frequencies for initial attack operations.         
Additional "Discrete" frequencies can be requested and assigned just for an 
incident. After the incident is complete that frequency may or may not be 
used again. (NIFC coordinates it with FAA, and they change regularly, not 
for any security reason, but rather as the FAA changes, and adds frequencies 
around the nation).

Airtanker Bases - National VHF-AM Frequency. 
The national air-ground frequency for all Airtanker Bases is 135.975. 
Note that 135.975 may be a change from the historic use of 122.925 at 
airtanker bases.     Also note that although not official, 163.100 
is commonly used as the ramp frequency for most air tanker bases. 
Logistics (UHF) Frequencies 
Lots of confusion occurs when you see logistics frequencies lists. 
The list above is accurate. However, it is important to note the 
"RX Simplex" frequencies (Repeater Inputs). 
The reason for the confusion, is that many times the UHF frequencies 
are used to link remote equipment. Much of the time this is done 
simplex, and by having the repeater input available on the portables, 
this doubles the number of simplex frequencies available for that.
Most of the "kits" for both the aircraft bases, and VHF repeaters 
are set up to allow a UHF radio to be plugged in, and allow it to 
be linked to another site. 
This may be used in a large (geographical) size incident to link 
two VHF Command repeaters to cover the large area. This will mean 
that traffic on one VHF input (i.e.: Command 6), will show up on 
another VHF Output (i.e.: Command 2), and may lead to confusion 
about repeater pairing. When in reality the two repeaters are 
linked together via a UHF frequency. The Logistics (UHF) Repeater 
may also be used to extend the distance between the command repeaters. 
There have been incidents where three command repeaters were used to 
cover a very large area. 
The other very common use of linking is to remote an AM aircraft 
frequency. The AM Radio will be linked to a UHF radio, and then fed 
back down the UHF frequency to the Helibase, or to Air Operations. 
The UHF Logistics repeater may be used to remote it quite a distance 
from the control point.
Of course the UHF equipment is also used for it's stated purpose - Logistics. 
Usually the UHF portables will be used as a "camp net" for coordination of 
the personnel involved in the Camp operations, and logistics needs. 
If there is a large area involved in the incident, and the UHF repeater is 
not needed for other functions you may see it set up for coordination of 
transportation units, or other logistics needs.
In the past, the lack of cell phones, Satellite phones, and just plain 
wired telephones near the command post, required the use of extensive 
logistics systems to create a path to the outside world. There is a telephone 
kit available for the logistics kits, that remotes 1 telephone line via the 
logistics repeaters to the camp. This is being used less and less, as other 
communications are becoming more plentiful. The improved coverage of most 
local forest, blm, nps, bia, and other systems also allows use of those 
systems for ordering resources.


FAA Frequency 
169.350 Mhz is an FAA frequency. It does appear in the NIRSC frequency 
scheme, but can only be used after approval of the NIRSC Communications 
duty officer. 

Forest Service Region 5 (California) 
Forest Service Region 5 (R5), has dedicated several frequencies for fire/ incident 
purposes. These are only used in California, and do not normally appear in the 
NIFC NIRSC frequency list. However, R5 maintains a large radio cache of their own, 
where these are used. There have been several articles published that listed the 
R5 frequencies as National Cache frequencies, which they are not. 
(see the note below about additional channel assignments).
The R5 caches have all the standard NIRSC frequencies (listed at the top), 
and also include the following:
VHF Radios have these additional frequencies:
173.9125         Tactical 4 
173.9625         Tactical 5 
173.9875         Tactical 6 
Logistics (UHF) Radios have these additional frequencies:
418.050         A-13 Common User Simplex 1
418.575         A-14 Common User Simplex 1
418.075         B-13 Common User Simplex 1
408.400         B-14 Common User Simplex 1
Incident Specific Frequencies 
During extreme fire seasons, or for other special longer term incidents, 
the NIFC NIRSC has been known to acquire additional frequencies for that 
specific incident. This occurs regularly for AM Aircraft frequencies, but 
it also can be done to acquire additional Command and Tactical frequencies 
if needed. This may also be done if on area of the country has a large 
number of incidents, and the standard frequencies become congested, and 
cannot support all of the needs. In the few cases where this happens, 
you might sometimes see a frequency list that had a command 7, etc, on it, 
and these will probably not be re-used elsewhere. In order to setup 
incident specific frequencies, the NIRSC Communications Staff, will 
actually go through the coordination process to get the frequencies 
assigned for that area.
There may also be cases where you will see a local special channel added 
to the NIRSC frequency list. This will happen in locations where they 
already have the frequencies authorized, and usually already have repeaters 
in place (Yellowstone is one example), and will use those during an 
incident in their area.
One other place that frequencies will appear from, is the region cache. 
Each forest service region usually has a pair of frequencies assigned, 
and you may see these in use at an incident. Some regions use them as 
portable or tactical frequencies, others have region wide radio nets 
on them for logistics ordering, or other support functions. It varies 

widely across the nation.
Kits 
The National Incident Radio Support Cache (NIRSC) packages everything 
as a "kit". I.e.: a command repeater kit, includes the repeater, antenna, 
batteries, mast, everything that will be needed to install and operate 
the repeater.
Unless an incident starts as a large one (and some do), the first radio 
order will usually be for a Starter System. 
This kit will include: 3 Command/Tactical Radio Kits, 1 Command Repeater, 
1 Ground Aircraft Radio/Link Kit, 3 Remote Kits, 1 Logistics Repeater, 
and 1 Logistics Radio Kit.
Command/Tactical Radio Kits. Contains: 16 VHF Portable Radios (48 for 3 kits), 
Extra Antennas, Mobile Antennas, 6 speaker microphones, and other supplies.
Command Repeater. Contains all the equipment to set up and operate one 
command channel.
Ground Aircraft Radio/Link Kit. Contains: Mast, and Base Antenna for 
VHF-AM (108-138 Mhz), Batteries, UHF antenna and cable for using a 
logistics radio for linking, and 5 ICOM aircraft portable Radios. 
One is used in the base equipment, and the other 4 are used by air 
personnel at the helibase, etc., and as a backup.
Remote Kits. Are used to remotely control a radio over wire. These 
include the adapters to plug in any VHF or UHF portable radio from the 
cache, and locate it up to a mile a way. Each kit contains a 1/2-mile 
spool of wire (2 conductor, stainless steel), to connect the radio to 
the remote control. This allow the separation of the radios to help 
prevent interference, and allows it to be placed at a better location 
than the camp or base may be located. The kit also contains the antenna 
mast, and antennas needed.
Logistics Repeater. Is a UHF repeater with all the associated parts, 
to install, and operate it.
Logistics Radio Kit. Contains 16 UHF portable radios, and assorted 
accessories.
Other Radio Resources 
The NIRSC contains lots of other equipment. They have L Band Satellite 
phones (IMARSAT), Key Telephone Systems, Microwave systems, Military 
Low Band Radios (for when military aircraft are involved), Public 
Address systems, and several other specialized kits.
There is also one other kit of interest, this is a low-band (Narrow) 
portable radio that can be used for linking of AM Aircraft frequencies 
for flight following of non incident aircraft (press, VIP's, etc). 
It is used very little, but may show up at a large incident 
(or one that draws a lot of attention). There are 8 low band frequencies 
available. 36.65, 36.75, 36.95, 38.35, 38.55, 38.75, 38.85, and 41.35.