Merlin negative G cutout too quick?

[WTE_Galway]

Originally Posted by IvanK

A second related document is in the UK National Archives "AVIA 18/1281 Tests of RAE devices for the reduction of "Negative G" engine cutting on merlin engined fighter aircraft". This document details flight test data on 3 devices (Including the Schilling orifice ... though its called the RAE Restrictor .... PC in action back in the 40's).

It compares each of the devices to an unmodified aircraft. In the tables presented the G used to induce cutout are in the order of -0.5G up to -1.5G. Though emphasis of the document is on the time taken to recover from cutout rather than preventing it, despite the document title.

Its worth pointing out that the Shilling modifications (which involved more than just fitting the famous flow constrictor) main effect was to substantially delay the onset of the second stage flooding cut-off. The shilling orifice was a stopgap.

The "Shilling Orifice" did not actually fix the problem, just delayed its onset a few seconds. Sustained inverted flight was still impossible in a Shilling equipped Spitfire, that required a pressure carburetor.