Welcome Guest. Sign in or Signup

1 Answers

Amount of FSII in fuel

Asked by: 2889 views Aircraft Systems

Fuel system icing inhibitor (FSII) is added to aviation jet fuel to prevent the formation of ice.  I've read that the amount of FSII has been revised from 0.10 % - 0.15 %, down to 0.07 % - 0.10 % by volume.  Regardless, what are the implications if the amount of FSII exceeds the stipulated amount (0.10 % or 0.15 %)?

Ace Any FAA Written Test!
Actual FAA Questions / Free Lifetime Updates
The best explanations in the business
Fast, efficient study.
Pass Your Checkride With Confidence!
FAA Practical Test prep that reflects actual checkrides.
Any checkride: Airplane, Helicopter, Glider, etc.
Written and maintained by actual pilot examiners and master CFIs.
The World's Most Trusted eLogbook
Be Organized, Current, Professional, and Safe.
Highly customizable - for student pilots through pros.
Free Transition Service for users of other eLogs.
Our sincere thanks to pilots such as yourself who support AskACFI while helping themselves by using the awesome PC, Mac, iPhone/iPad, and Android aviation apps of our sponsors.

1 Answers

  1. Jeffrey A. Baylor on Jan 19, 2014

    What is the proper mixing ratio of PRIST® Hi-Flash™ to AvGas and Jet turbine fuels and why is this important?
    PRIST® Hi-Flash™ Fuel Additive should be mixed properly at the correct ratio of 0.10-0.15% by volume or 1000-1500 PPM. Proper mixing of PRIST® Hi-Flash™ Fuel Additive in to AvGas and turbine Jet fuels is critical to its effectiveness at preventing freezing of suspended water in jet fuel.
    PRIST® Hi-Flash™ Fuel Additive cannot simply be poured or dumped into fuel, as it will coagulate and sink to the bottom. This means the fuel being “splash blended” will have a low concentration and the water in the bottom of the tank will have a high concentration of DiEthylene glycol Monomethyl ether (DiEGME). This may even cause microbial growth to accelerate.

    Improper mixing can also lead to early separation of PRIST® Hi-Flash™ Fuel Additive from suspension in aviation fuels. This can be worsened when an aircraft is stored outside in direct sunlight. The condensation as the tank heats in daylight and cools at night leads to water formation via condensation. The PRIST® Hi-Flash™ Fuel Additive will separate out and settle in the bottom of the tank leaving a very high concentration of PRIST® Hi-Flash™ Fuel Additive in the low points over a period of time.

    The main ingredient in PRIST® Hi-Flash™ Fuel Additive, DiEthylene glycol Monomethyl ether (DiEGME), a strong solvent that can damage fuel bladders and filters in high concentrations. For this reason, we do not recommend

    It may also damage integral tanks and sealants.

    0 Votes Thumb up 0 Votes Thumb down 0 Votes

The following terms have been auto-detected the question above and any answers or discussion provided. Click on a term to see its definition from the Dauntless Aviation JargonBuster Glossary.

Answer Question

Our sincere thanks to all who contribute constructively to this forum in answering flight training questions. If you are a flight instructor or represent a flight school / FBO offering flight instruction, you are welcome to include links to your site and related contact information as it pertains to offering local flight instruction in a specific geographic area. Additionally, direct links to FAA and related official government sources of information are welcome. However we thank you for your understanding that links to other sites or text that may be construed as explicit or implicit advertising of other business, sites, or goods/services are not permitted even if such links nominally are relevant to the question asked.