As pilots began undergoing tests for cancer on Sunday, a team of technical personnel from the Israel Air Force flew to Fort Worth, Texas, for consultations with their American counterparts and Lockheed Martin concerning the recent discovery of carcinogenic material in an Israeli F-16I. The discovery of the material prompted OC IAF Maj.-Gen. Elazar Shkedy to ground all F-16I training flights until the investigation is concluded. Shkedy decided to suspend training flights - the plane will continue to be used in necessary operations - after a number of pilots complained of a bad smell coming from the cockpit of one of the planes. The IDF Medical Branch conducted tests and discovered that the smell was caused by a type of formaldehyde known to be carcinogenic in high concentration. As a result, the IAF on Sunday began taking blood samples from F-16I pilots to test them for cancer. Although traces of the material were found in only one plane, Shkedy's decision to stop training flights was indicative of the severity of the problem, defense officials said. In addition, since deciding to suspend F-16I training flights, the IAF has been in touch with other militaries to discuss the discovery. "If it was just one plane and was a maintenance issue, then there wouldn't have been a need to suspend all training flights," one official said. "The fear is that the problem is much more extensive." Lockheed Martin said it was cooperating with the investigation completely and raised the possibility that it was an isolated incident - the carcinogenic material has thus far been found in one plane - and was connected to the maintenance of the aircraft. The Israeli F-16I is part of a batch of planes manufactured at Fort Worth and supplied not just to the IAF but also to Poland, Greece and the US Air Force. None of these countries have reported discovering formaldehyde in their aircraft.