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B737-300 crew was denied a turn to avoid WX in the ZDV class east airspace. The crew and controller then had a miscom about cleared altitude.
| Attributes | |
| ACN | 515759 |
| Time | |
| Date | 200106 |
| Day | Wed |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | airport : den.airport |
| State Reference | CO |
| Altitude | msl bound lower : 15000 msl bound upper : 15500 |
| Environment | |
| Flight Conditions | IMC |
| Weather Elements | Thunderstorm |
| Aircraft 1 | |
| Controlling Facilities | artcc : zdv.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | B737-300 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | climbout : vacating altitude |
| Flight Plan | IFR |
| Aircraft 2 | |
| Controlling Facilities | artcc : zdv.artcc |
| Operator | Other |
| Make Model Name | Any Unknown or Unlisted Aircraft Manufacturer |
| Operating Under FAR Part | other : unk |
| Flight Phase | other |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| ASRS Report | 515759 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude conflict : airborne less severe inflight encounter : weather inflight encounter other non adherence : far non adherence : published procedure other anomaly other |
| Independent Detector | atc equipment other atc equipment : radar aircraft equipment other aircraft equipment : wx radar other controllera other flight crewa other flight crewb |
| Resolutory Action | controller : issued new clearance flight crew : returned to assigned altitude other |
| Consequence | other |
| Supplementary | |
| Problem Areas | Weather Flight Crew Human Performance FAA ATC Human Performance |
| Primary Problem | ATC Human Performance |
| Situations | |
| ATC Facility | procedure or policy : zdv.artcc |
Narrative:
At XA15, 30 mi southwest of den, climbing to FL230, on an assigned heading of 190 degrees. This heading pointed us at WX with a steep gradient of green to red. We requested to come right to avoid and was then told unable by ATC with no other information. Approximately 1 min later we requested to come right again. We were told unable by ATC. We then informed ATC that we were leveling at 15000 ft to avoid WX, as we could see the ground even though virga and heavy rain were coming out of the large buildups with bases at 16000 ft. ATC said this would run us into the mountains. He then gave us a turn to 310 degrees (towards the terrain). We started a climbing turn to FL230 and heading 310 degrees. ATC then said don't climb, our clearance was 15000 ft. We immediately started (at 15500 ft) to return to 15000 ft. We then received an RA for traffic above us, immediately followed by clear of conflict. Soon thereafter we changed frequency with all else uneventful. Concerns: no feedback from ATC on not allowing right deviation. Conflicting information from ATC regarding the risk of terrain avoidance versus traffic avoidance. The captain had to use his authority/authorized (and I agreed) in order to avoid severe WX as well as terrain.
Original NASA ASRS Text
Title: B737-300 CREW WAS DENIED A TURN TO AVOID WX IN THE ZDV CLASS E AIRSPACE. THE CREW AND CTLR THEN HAD A MISCOM ABOUT CLRED ALT.
Narrative: AT XA15, 30 MI SW OF DEN, CLBING TO FL230, ON AN ASSIGNED HDG OF 190 DEGS. THIS HDG POINTED US AT WX WITH A STEEP GRADIENT OF GREEN TO RED. WE REQUESTED TO COME RIGHT TO AVOID AND WAS THEN TOLD UNABLE BY ATC WITH NO OTHER INFO. APPROX 1 MIN LATER WE REQUESTED TO COME R AGAIN. WE WERE TOLD UNABLE BY ATC. WE THEN INFORMED ATC THAT WE WERE LEVELING AT 15000 FT TO AVOID WX, AS WE COULD SEE THE GND EVEN THOUGH VIRGA AND HVY RAIN WERE COMING OUT OF THE LARGE BUILDUPS WITH BASES AT 16000 FT. ATC SAID THIS WOULD RUN US INTO THE MOUNTAINS. HE THEN GAVE US A TURN TO 310 DEGS (TOWARDS THE TERRAIN). WE STARTED A CLBING TURN TO FL230 AND HDG 310 DEGS. ATC THEN SAID DON'T CLB, OUR CLRNC WAS 15000 FT. WE IMMEDIATELY STARTED (AT 15500 FT) TO RETURN TO 15000 FT. WE THEN RECEIVED AN RA FOR TFC ABOVE US, IMMEDIATELY FOLLOWED BY CLR OF CONFLICT. SOON THEREAFTER WE CHANGED FREQ WITH ALL ELSE UNEVENTFUL. CONCERNS: NO FEEDBACK FROM ATC ON NOT ALLOWING R DEV. CONFLICTING INFO FROM ATC REGARDING THE RISK OF TERRAIN AVOIDANCE VERSUS TFC AVOIDANCE. THE CAPT HAD TO USE HIS AUTH (AND I AGREED) IN ORDER TO AVOID SEVERE WX AS WELL AS TERRAIN.
Data retrieved from NASA's ASRS site as of July 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.