Holdover Tables

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Holdover Table

'Formula IV' Aircraft Ground Anti-Icing Fluid  

(Effective:  October 1, 2003)

FAA Guideline for Holdover Times Anticipated for SAE Type IV Fluid Mixtures as a Function of Weather Conditions and OAT.

 

                 CAUTION:  THIS TABLE IS FOR DEPARTURE PLANNING ONLY AND SHOULD BE USED IN CONJUNCTION WITH PRE-TAKEOFF CHECK PROCEDURES.

OAT

Manufacturer Specific Type IV Fluid Concentration

Neat-Fluid/Water

(Vol. %/Vol. %)

Approximate Holdover Times Under Various Weather Conditions (hours: minutes)

°C

°F

Frost*

Freezing Fog

Snowu

Freezing   Drizzle***

Light Freezing Rain

Rain on Cold Soaked  Wing

Other‡

 

above 0

 

above 32

100/0

18:00

1:05-2:15

0:35-1:05

0:40-1:10

0:25-0:40

0:10-0:50

 

CAUTION:

No holdover

time guidelines

exist

75/25

6:00

1:05-1:45

0:30-1:05

0:35-0:50

0:15-0:30

0:05-0:35

50/50

4:00

0:15-0:35

0:05-0:20

0:10-0:20

0:05-0:10

CAUTION:

Clear ice

may require

touch for

confirmation

 

0 to -3

 

32 to 27

100/0

12:00

1:05-2:15

0:30-0:55

0:40-1:10

0:25-0:40

75/25

5:00

1:05-1:45

0:25-0:50

0:35-0:50

0:15-0:30

50/50

3:00

0:15-0:35

0:05-0:15

0:10-0:20

0:05-0:10

below

-3 to -14

below

27 to 7

100/0

12:00

0:20-1:20

0:20-0:40

**0:20-0:45

**0:10-0:25

75/25

5:00

0:25-0:50

0:20-0:35

**0:15-0:30

**0:10-0:20

below

-14  to -25

below

7 to -13

100/0

12:00

0:15-0:40

0:15-0:30

 

below -25

below -13

100/0

SAE Type IV fluid may be used below –25 °C (-13 °F) provided the freezing point of the fluid is at least 7 °C(13 °F) below the OAT and the aerodynamic acceptance criteria are met.  Consider use of SAE Type I when SAE Type IV fluid cannot be used.

 

              °C = Degrees Celsius            OAT = Outside Air Temperature

              °F = Degrees Fahrenheit         VOL  = Volume

              

           THE RESPONSIBILITY FOR THE APPLICATION OF THESE DATA REMAINS WITH THE USER.

          *                During conditions that apply to aircraft protection for ACTIVE FROST

          **               No holdover time guidelines exist for this condition below  -10 °C (14 °F)

          ***  Use light freezing rain holdover times if positive identification of freezing drizzle is not possible

          ‡     Snow pellets, ice pellets, heavy snow, moderate and heavy freezing rain, and hail

                 u     Snow includes snow grains

     

CAUTIONS:

·          THE TIME OF PROTECTION WILL BE SHORTENED IN HEAVY WEATHER CONDITIONS.  HEAVY PRECIPITATION RATES OR HIGH MOISTURE CONTENT, HIGH WIND VELOCITY, OR JET BLAST MAY REDUCE HOLDOVER TIME BELOW THE LOWEST TIME STATED IN THE RANGE.  HOLDOVER TIME MAY BE REDUCED WHEN AIRCRAFT SKIN TEMPERATURE IS LOWER THAN OAT.

·          SAE TYPE IV FLUID USED DURING GROUND DEICING/ANTI-ICING IS NOT INTENDED FOR AND DOES NOT PROVIDE PROTECTION DURING FLIGHT.

This Holdover Table is a guideline for use in departure planning, and should be used in conjunction with your pre-takeoff check procedures.  It presents an estimated range of time that the applied deicing fluid can be expected to be effective, dependent principally upon the outside air temperature and type of precipitate.  Note, however, that these times are variable with weather conditions, and that high rates of precipitation, high atmospheric moisture content, high wind velocity, and jet blast can reduce the estimated time of effectiveness.

Caution!!  The Pilot-in-Command holds the ultimate responsibility to remove all frozen contaminants from critical aircraft surfaces and components, to conduct visual and tactile inspection of the aircraft after deicing/anti-icing operations and prior to takeoff, and to ensure that the aircraft is safe for departure.

Caution!!  The responsibility for the application of the data presented remains with the user.

Aircraft Deicing, Inc. Voice & Fax 866-268-3449 sales@aircraftdeicinginc.com      10/1/03 Data}
{Source: FAA FSAT 0205: See www.faa.gov/avr/avr/afs200//afs200/hot2004.doc}