(Update: To be clear, this was not a normal pre-boarding delay, but a delay that was due to a malfunctioning gear on the plane that forced us to land, but it was a short stop and they were able to get us back in the air within 60 mins)
Dear Mr Lai,
On behalf of United Airlines, please accept my apologies for the delay and inconvenience you experienced on Flight 854.
I was made aware of the circumstances regarding our precautionary diversion of your flight to Chicago for mechanical reasons, and requiring a change of aircraft. I want to assure you regardless of the reason, I understand how frustrating or unsettling it can be to have your travel plans suddenly altered. I know that in choosing air travel you do so with time constraints in mind, and I am truly sorry if we did not provide the level of service that you expect or deserve from United. Thank you for your patience and cooperation as we made preparations to get you safely on your way.
Let me assure you that we are thoroughly evaluating our recovery efforts in order to improve coordination of services for our customers on future flights. Meanwhile, your satisfaction and business mean a great deal to United, and I am pleased to offer you this choice of a goodwill gesture. I hope you will use it with the full confidence that United is committed to meeting your expectations and we hope for an early opportunity to serve your travel needs.
Sherri Hermance United Airlines Customer Relations