Cessna CitationJet’s Erroneous Altitude Data Led to Near-collision with Embraer 170

Citation’s Erroneous Altitude Data Led to Near-collision

French BEA says incorrect altitude information from a faulty air data computer in a Cessna CitationJet resulted in a near-collision with an Embraer 170.

F-HGPG landing in Valencia Spain. (Photo: AIN)

By Gordon Gilbert • Contributor - Accidents and Regulations

July 20, 2023

Incorrect altitude information from a faulty air data computer in a Cessna CitationJet resulted in a near-midair collision with an Embraer 170, according to the final incident report incident from France's BEA. Because of the Citation's errant data, the Embraer's traffic collision avoidance system (TCAS) failed to warn of the close call, while the air traffic controller believed that the altitude separation was adequate based on radar data.

On Jan. 12, 2022, the French-registered Citation was carrying two pilots and two passengers on a charter flight from Paris to Geneva. After observing that the left and right altimeters were giving different indications on climb-out, the crew didn’t inform ATC of the discrepancy until they were en route. Controllers informed the Citation crew of converging traffic—the Embraer 170—two miles distant and 1,000 feet higher than the business jet.

The rest of this article continues for AIN Members with the full report, analysis and background. The rest of this article continues for AIN Members with the full report, analysis and background. The rest of this article continues for AIN Members with the full report, analysis and background. The rest of this article continues for AIN Members with the full report, analysis and background. The rest of this article continues for AIN Members with the full report, analysis and background.