As of February 12, ch-aviation research shows the following airlines have grounded A320/321neo aircraft:
> Air Astana (one A321neo),
> Air China (three A320neo),
> Hawaiian Airlines (one A321neo),
> HK Express (one A320neo),
> Indigo (three A320neo),
> LATAM Airlines (two A320neo),
> Lufthansa (one A320neo),
> Sichuan Airlines (three A320neo),
> Spirit Airlines (one A320neo),
> Tianjin Airlines (two A320neo),
> VietJetAir (one A321neo),
> Volaris (one A320neo),
> West Air (China) (one A320neo).
https://www.ch-aviation.com/portal/news/64272-select-a320neo-grounded-over-new-pw-1100g-issues