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As a result of turbulence and icing conditions, an air carrier flight crew could not comply with crossing restr, citing minimum power setting requirement as cause.
| Attributes | |
| ACN | 302779 |
| Time | |
| Date | 199504 |
| Day | Wed |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | airport : atl |
| State Reference | GA |
| Altitude | msl bound lower : 13000 msl bound upper : 16000 |
| Environment | |
| Flight Conditions | IMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | tracon : atl |
| Operator | common carrier : air carrier |
| Make Model Name | B737-200 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | descent other |
| Route In Use | arrival other arrival star : star enroute airway : atl |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 200 flight time total : 11000 |
| ASRS Report | 302779 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Events | |
| Anomaly | altitude deviation : crossing restriction not met altitude deviation : undershoot non adherence : clearance |
| Independent Detector | other controllera other flight crewa |
| Resolutory Action | controller : issued new clearance other other |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
Flying macey 1 arrival north of atl. Just no F macey intersection at 16000 ft, 310 KTS, entered clouds with turbulence and icing. ATC instructed us to slow to 250 KTS then cross womac at 13000 ft. We were approximately 16 mi from womac and required to use engine anti-ice, therefore, the engine must maintain 55 percent N1. In a 737-200 under those conditions it is virtually impossible to slow down and descend at a high rate. Realized we would be unable to meet the crossing restr at womac but because of all the thunderstorm activity in the area we were unable to get on the frequency. ATC finally called us and asked if we would make the restr. We replied that we were unable at the slow airspeed. They said to pick up the rate and speed and issued a turn to the west. Once reaching 13000 ft, ATC asked us to flow to 190 KTS and resume the arrival. Situation was a combination of several factors all coming together at the same time. In bad WX (thunderstorms, ice, etc) and high traffic sits these things sometimes happen.
Original NASA ASRS Text
Title: AS A RESULT OF TURB AND ICING CONDITIONS, AN ACR FLC COULD NOT COMPLY WITH XING RESTR, CITING MINIMUM PWR SETTING REQUIREMENT AS CAUSE.
Narrative: FLYING MACEY 1 ARR N OF ATL. JUST NO F MACEY INTXN AT 16000 FT, 310 KTS, ENTERED CLOUDS WITH TURB AND ICING. ATC INSTRUCTED US TO SLOW TO 250 KTS THEN CROSS WOMAC AT 13000 FT. WE WERE APPROX 16 MI FROM WOMAC AND REQUIRED TO USE ENG ANTI-ICE, THEREFORE, THE ENG MUST MAINTAIN 55 PERCENT N1. IN A 737-200 UNDER THOSE CONDITIONS IT IS VIRTUALLY IMPOSSIBLE TO SLOW DOWN AND DSND AT A HIGH RATE. REALIZED WE WOULD BE UNABLE TO MEET THE XING RESTR AT WOMAC BUT BECAUSE OF ALL THE TSTM ACTIVITY IN THE AREA WE WERE UNABLE TO GET ON THE FREQ. ATC FINALLY CALLED US AND ASKED IF WE WOULD MAKE THE RESTR. WE REPLIED THAT WE WERE UNABLE AT THE SLOW AIRSPD. THEY SAID TO PICK UP THE RATE AND SPD AND ISSUED A TURN TO THE W. ONCE REACHING 13000 FT, ATC ASKED US TO FLOW TO 190 KTS AND RESUME THE ARR. SIT WAS A COMBINATION OF SEVERAL FACTORS ALL COMING TOGETHER AT THE SAME TIME. IN BAD WX (TSTMS, ICE, ETC) AND HIGH TFC SITS THESE THINGS SOMETIMES HAPPEN.
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.