The HS-125 corporate jet operated on a round trip from Denver, Colorado, USA to France. The return flight landed at Malaga, Spain, at Luton, Great Britain and Edinburgh, Scotland before continuing to Reykjavik, Iceland. The next leg was from Reykjavik to Narsarsuaq, Greenland. From Iceland to Greenland the crew initially employed VHF navigation followed by “dead reckoning”. The crew estimated a fix prior to Greenland 62N 40W and was at that time receiving OZN (Prins Christians Sund). From the calculations on the flightlog and the ground features depicted on the radar scope the crew believed that they were at the planned position. When tuning in the last NDB enroute crew encountered problems in getting station identification. After what the crew thought was a station passage, descend to lower altitude was initiated. The crew now encountered navigational problems, as the NDB still could not be identified, nor could the crew get a signal making the radio compass track on the ADF. The crew initiated a climb and tried to tune in other ADF’s and locators with negative result. Finally a broadcasting station was tuned in with positive result but before landing was assured the aircraft ran out of fuel and a wheels up forced landing was made on the icecap. CONCLUSIONS: 1. The crew and the aircraft was properly certified 2. The Loop amplifier in the navigational system was malfunctioning i.e. a signal ten times stronger than normal was required. 3. The ADF sense antenna installation was not in agreement with specifications. 4. Relying on the ADF system and not employing other navigational means sufficiently the crew became lost.