Comment A 2018 advisory was issued for those switches (Score 3, Informative) 43
See https://ad.easa.europa.eu/blob... That's an old advisory (December 2018) that applies across a variety of Boeing aircraft. It should have been the case that all operators did and documented the required inspections.
Model 717-200 airplanes; Model 737-700, -700C, -800, and -900ER
series airplanes; Model 737-8 and -9 airplanes; Model 747-400, -400D, -400F, -8, and -8F series
airplanes; Model 757-200, -200CB, -200PF, and -300 series airplanes; Model 767-200, -300, -
300F, -400ER, and -2C series airplanes; Model 787-8, -9, and -10 airplanes; Model MD-11 and
MD-11F airplanes; and Model MD-90-30 airplanes of the potential for disengagement of the fuel
control switch locking feature.
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.
It's my understanding that part of the cockpit was recovered pretty much intact, so I'm sure there'll be forensic investigation into those switches.