Piccadilly Line: No service between Hounslow central and Heathrow Terminals and SEVERE DELAYS between Acton Town and Hounslow Central while we fix a signal failure at Hatton Cross. Tickets are being accepted on London Buses, Elizabeth line and South Western Railway services. MINOR DELAYS between Acton Town and Cockfosters Eastbound only due to an earlier faulty train at Hyde Park Corner. GOOD SERVICE on the rest of the line.