1.   The gas leak was caused by a faulty heating system.

2.   An American Eagle commuter plane that made an emergency landing Tuesday nigh in a mix of rain and snow had a faulty de-icing system, a Federal official said.

3.   A faulty heating system was blamed for the death of Vitas Gerulaitis, the tennis star, in a cottage in Southampton, N.Y., in September.

4.   A Fire Department spokesman, Paul Iannizzotto, said that a faulty heating system had caused carbon monoxide levels to soar in the basement.

5.   After a couple of years of having nature laugh at us we switched to in vitro methods to augment faulty systems.

6.   He has managed to change a faulty system.

7.   He said the plan had several weaknesses, including a lack of any attention to the problem of pollution from dispersed sources like agricultural runoff and faulty septic systems.

8.   If you let them start fiddling with bits and pieces of a faulty system, you are asking for trouble.

9.   NTSB officials already have ruled out bombs, adverse weather, faulty braking systems and structural failure.

10.   Some faulty systems freeze while others continue operating but produce erroneous data or gibberish.