Aircraft departed London Heathrow enroute to Rome Ciampino. Flight proceeded normally until the later stages of the approach into Rome, when difficulties were experienced in obtaining reliable ADF indications from the terminal holding facility. Bearings from another MF non-directional beacon were therefore used to assist in positioning the aircraft. The initial part of the final approach was in cloud, and touchdown on the runway was made with the landing gear retracted. Damage was mainly to the center section and stub wings, and to a lesser extent to the fuselage. Undercarriage doors and engine cowlings had to be renewed, one pod tank and inboard flaps were replaced, all engines were changed as the originals were removed for inspection for possible shock-loading damage. Aircraft was repaired and returned to service 45 days after the incident.