The pilot due to fly a 'Moyes Out' banner over Old Trafford on Saturday said he would also carry a banner in support of the manager if he was asked to.
Speaking to ITV News sports correspondent Ian Payne, Chris Mustow said his company Air Ads had declined some "colourful" requests for messages in the past.
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More than 20,000 allegations of abuse by care home workers have been made in the last three years, figures show.
Two private citizens have already paid a "significant deposit" to take the week-long trip.
Slippy start tomorrow with frost & ice