Here is a list of hotels in the immediate vicinity of the Royal Aeronautical Society (there are many other choices to suit every budget, including self-catering apartments, via either booking.com, hotels.com, etc).
London Hilton Park Lane
London Hilton on Park Lane - Guest Reservations (Let them know you are with IPPAC group).
Sheraton Grand Park Lane
Sheraton Grand London Park Lane - Guest Reservations
Intercontinental Park Lane
InterContinental London Park Lane - Hotels in London City Centre
The Dorchester London - 5-star hotel | Dorchester Collection
Luxury Mayfair Hotel | 5 Star Boutique Hotel London | The Athenaeum (athenaeumhotel.com)
5-Star Mayfair Hotel - Park Lane | Grosvenor House, A JW Marriott Hotel
Chesterfield Mayfair, Luxury Hotel in Mayfair, London
Hotel near London | The Wellesley Knightsbridge, a Luxury Collection Hotel, London Amenities
See Archives page for past conferences presentation notes.