Merlin negative G cutout too quick?

[Viper2000]

Originally Posted by Crumpp

Yes the onset rate is extremely important. Very rarely do you experience gradual onset rates in an airplane depending on the definition. That is why I asked IvanK about the onset rate information in the report.

Onset rate doesn't make much if any practical difference to the carburettor's behaviour because the determining factors are the geometry of the float chamber, the position of the float and the fuel flow rates into and out of the chamber, none of which are going to be a strong function of dg/dt.

As soon as the g level falls below about +0.1 indicated, the float stops floating properly, and the carburettor therefore stops metering. Exactly what reduced positive g will cause misbehaviour will depend upon the friction in the system and any slosh in the float chamber, leading to slight variation on a case by case basis; but this sort of detail is way beyond the scope of a simulation of this nature.

Much earlier in this thread I calculated the approximate subsequent chain of events for both the reduced positive and negative g cases.

In both cases, I would expect a lag between departure from 1 g flight and cut behaviour due to the volume of the float chamber, engine demand, and fuel pump delivery rate.

(For this reason, normal turbulence would seem quite unlikely to produce cut behaviour.)