Air safety advocates say a GOP proposal won't mandate the collision warning system airline jets need

The NTSB says an anti-collision system called ADS-B In could have prevented the DC air crash.

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• A bill that would have implemented NTSB safety recommendations failed in the House.
• Opponents cited cost and security concerns with broadcasting aircraft positions to avoid collision.
• The bill's advocates say a Republican counter-proposal lacks the monitoring system pilots need.

Lawmakers appear to be at an impasse after the failure of a...