|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||0601 To 1200|
|Locale Reference||atc facility : bal|
|Altitude||msl bound lower : 20000|
msl bound upper : 20800
|Controlling Facilities||artcc : zdc|
|Operator||general aviation : corporate|
|Make Model Name||Medium Transport, Low Wing, 2 Turbojet Eng|
|Flight Phase||climbout : intermediate altitude|
|Route In Use||enroute airway : zdc|
|Function||flight crew : captain|
oversight : pic
|Qualification||pilot : commercial|
pilot : instrument
|Experience||flight time last 90 days : 100|
flight time total : 10000
|Function||controller : radar|
|Qualification||controller : radar|
|Anomaly||altitude deviation : overshoot|
conflict : airborne less severe
|Independent Detector||atc equipment other atc equipment : unspecified|
|Resolutory Action||controller : issued new clearance|
none taken : insufficient time
|Miss Distance||vertical : 200|
|Primary Problem||ATC Human Performance|
|Air Traffic Incident||Pilot Deviation|
On climb out of iad, bwi approach handed us off to ZDC just northeast of the balance VOR and instructed us to climb to FL190. Communication was established with ZDC. On the handoff both pilots thought the center controller cleared us up to FL290. The altitude was set in the altitude alerter and read back 'roger climbing to 290,' and calling the aircraft's call sign. There was no response from the controller. At FL208, the controller instructed us to turn right to 180 degrees and descended immediately to 20000'. When questioned about the turn and descent, the controller said she had cleared us to 20000'. When we told her we had understood and read back the clearance as climbing to FL290, she said there must have been a misunderstanding. End of issue. In answer to your questions: a) the problem was discovered by altitude readout on the controller's scope. B) factors that contributed to the situation: 1) crew and controller were under a heavy workload. 3 handoffs in that short a distance causes confusion and increases workload in the cockpit. Area congested with air traffic increases the controller's work (and neither the crew nor controller listened closely enough). Also, there were a lot of blocked xmissions on the frequency. C) solution: more frequencys, a better ATC plan in the washington area, better equipment and more controllers.
Original NASA ASRS Text
Title: POTENTIAL CONFLICT AS CORPORATE JET CLIMBED ABOVE ALT EXPECTED BY CTLR. ALT ASSIGNMENT CONFUSION RESULTED FROM FLT CREW MISTAKING FL200 ALT ASSIGNMENT FOR FL290, WHICH THEY WERE EXPECTING. SITUATION EXACERBATED BY HIGH CTLR AND FLT CREW WORKLOAD, TRAFFIC VOLUME, FREQ CONGESTION BLOCKED AND SIMULTANEOUS TRANSMISSION.
Narrative: ON CLBOUT OF IAD, BWI APCH HANDED US OFF TO ZDC JUST NE OF THE BAL VOR AND INSTRUCTED US TO CLB TO FL190. COM WAS ESTABLISHED WITH ZDC. ON THE HDOF BOTH PLTS THOUGHT THE CENTER CTLR CLRED US UP TO FL290. THE ALT WAS SET IN THE ALT ALERTER AND READ BACK 'ROGER CLBING TO 290,' AND CALLING THE ACFT'S CALL SIGN. THERE WAS NO RESPONSE FROM THE CTLR. AT FL208, THE CTLR INSTRUCTED US TO TURN RIGHT TO 180 DEGS AND DESCENDED IMMEDIATELY TO 20000'. WHEN QUESTIONED ABOUT THE TURN AND DSCNT, THE CTLR SAID SHE HAD CLRED US TO 20000'. WHEN WE TOLD HER WE HAD UNDERSTOOD AND READ BACK THE CLRNC AS CLBING TO FL290, SHE SAID THERE MUST HAVE BEEN A MISUNDERSTANDING. END OF ISSUE. IN ANSWER TO YOUR QUESTIONS: A) THE PROB WAS DISCOVERED BY ALT READOUT ON THE CTLR'S SCOPE. B) FACTORS THAT CONTRIBUTED TO THE SITUATION: 1) CREW AND CTLR WERE UNDER A HEAVY WORKLOAD. 3 HDOFS IN THAT SHORT A DISTANCE CAUSES CONFUSION AND INCREASES WORKLOAD IN THE COCKPIT. AREA CONGESTED WITH AIR TFC INCREASES THE CTLR'S WORK (AND NEITHER THE CREW NOR CTLR LISTENED CLOSELY ENOUGH). ALSO, THERE WERE A LOT OF BLOCKED XMISSIONS ON THE FREQ. C) SOLUTION: MORE FREQS, A BETTER ATC PLAN IN THE WASHINGTON AREA, BETTER EQUIP AND MORE CTLRS.
Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.