Comment by interestica

https://ad.easa.europa.eu/blob/NM-18-33.pdf/SIB_NM-18-33_1

> Recommendations The FAA recommends that all owners and operators of the affected airplanes incorporate the following actions at the earliest opportunity: 1) Inspect the locking feature of the fuel control switch to ensure its engagement. While the airplane is on the ground, check whether the fuel control switch can be moved between the two positions without lifting up the switch. If the switch can be moved without lifting it up, the locking feature has been disengaged and the switch should be replaced at the earliest opportunity. 2) For Boeing Model 737-700, -700C, -800, and -900ER series airplanes and Boeing Model 737- 8 and -9 airplanes delivered with a fuel control switch having P/N 766AT613-3D: Replace the fuel control switch with a switch having P/N 766AT614-3D, which includes an improved locking feature.