Guimbal CABRI G2 Flight Manual page 150

Hélicoptères Guimbal SERVICE LETTER
CABRI G2 SL 13-001 A
This Service Letter details Flight Manual requirements and give simple ways to
comply.
The limitations given by the Flight Manual belong to two categories :
Limitations concerning supply :
1. Standards : Specified standards correspond to those that apply to
automotive gasoline in Europe (EN228) and the US (ASTM D4814).
2. Minimum octane number : Specified octane number of 98 corresponds to
the figure displayed on fuel pumps in Europe : research octane number.
Corresponding gasoline is generally called "UL98" or "Premium UL".
The Flight Manual also specifies the motor octane number of 87. Use of UL98
ensures compliance.
In some countries, such as the US, displayed number is the AKI, which is the
mean between above octane numbers. Its minimum value should be 93. This
fuel is also generally called "Premium".
3. Alcohol content
Among fuel compounds, alcohols can damage the engine and its fuel circuit in
the medium term. Therefore, their absence in the fuel used has to be ensured.
There is a simple way to do that, based on the alcohol property to be absorbed
by water: just add a volume of water to a gasoline sample, shake, and check
that water volume has not increased.
This check has to be done for each batch of gasoline.
Dedicated detection kits, simple to use, are available on the market.
Below is a selection of websites offering various testers :
http://w3.vliegwerkholland.nl/use-of-autofuel
http://www.autofuelstc.com/order_online.phtml
http://www.eaa.org/autofuel/autogas/test_kit.asp
http://www.maul-tank.de/
http://www.paclp.com/Lab_Instruments/QuickSpec
http://www.fuel-testers.com/order.html
Note : Ethanol is one of the most common alcohols in gasoline. Its presence is
usually advertised through letter "E" combined with its proportion (E5 of 5%
ethanol, E15, E85, etc.). Those fuels cannot be used.
Note : Some major petrol companies market a so-called premium grade that
generally meets those three criteria. For examples : "Shell V Power 98", "Total
Excellium 98" and "BP Ultimate unleaded 98".
It is still the responsibility of the operator to make sure of adequate
characteristics of the gasoline used.
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