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An MD11 first officer report on the problem encountered with the ATIS WX report reporting the temperature in degrees fahrenheit instead of degrees celsius at blv, il.
| Attributes | |
| ACN | 482324 |
| Time | |
| Date | 200008 |
| Day | Thu |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | airport : blv.airport |
| State Reference | IL |
| Altitude | agl single value : 0 |
| Environment | |
| Flight Conditions | IMC |
| Weather Elements | Fog |
| Light | Daylight |
| Aircraft 1 | |
| Operator | common carrier : charter |
| Make Model Name | MD-11 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | ground : preflight |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : multi engine pilot : cfi pilot : atp |
| Experience | flight time last 90 days : 179 flight time total : 11000 flight time type : 1346 |
| ASRS Report | 482324 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Events | |
| Anomaly | non adherence : published procedure non adherence : far other anomaly other |
| Independent Detector | other flight crewa |
| Resolutory Action | none taken : anomaly accepted |
| Consequence | Other |
| Supplementary | |
| Problem Areas | ATC Facility ATC Human Performance Flight Crew Human Performance Environmental Factor Airport |
| Primary Problem | ATC Facility |
| Situations | |
| ATC Facility | procedure or policy : blv.tower |
Narrative:
Temperature on ATIS is reported in degrees fahrenheit. This is something I have not heard since the FAA adopted the standardized ICAO format in 1996. This creates the potential for 2 very real problems when calculating aircraft performance: 1) my aircraft performance is calculated using degrees celsius, as I presume are most other transport category aircraft. When airport meteorological information includes temperature in degrees fahrenheit, the flight crew must perform an additional unnecessary calculation when working up takeoff or landing performance figures. This process allows for the introduction of an error. 2) during periods of colder WX, it may not be immediately obvious that the temperature is not given in degrees celsius, as the word 'fahrenheit' was not used in the ATIS broadcast. This misunderstanding would ensure an inaccurate calculation of aircraft performance.
Original NASA ASRS Text
Title: AN MD11 FO RPT ON THE PROB ENCOUNTERED WITH THE ATIS WX RPT RPTING THE TEMP IN DEGS FAHRENHEIT INSTEAD OF DEGS CELSIUS AT BLV, IL.
Narrative: TEMP ON ATIS IS RPTED IN DEGS FAHRENHEIT. THIS IS SOMETHING I HAVE NOT HEARD SINCE THE FAA ADOPTED THE STANDARDIZED ICAO FORMAT IN 1996. THIS CREATES THE POTENTIAL FOR 2 VERY REAL PROBS WHEN CALCULATING ACFT PERFORMANCE: 1) MY ACFT PERFORMANCE IS CALCULATED USING DEGS CELSIUS, AS I PRESUME ARE MOST OTHER TRANSPORT CATEGORY ACFT. WHEN ARPT METEOROLOGICAL INFO INCLUDES TEMP IN DEGS FAHRENHEIT, THE FLC MUST PERFORM AN ADDITIONAL UNNECESSARY CALCULATION WHEN WORKING UP TKOF OR LNDG PERFORMANCE FIGURES. THIS PROCESS ALLOWS FOR THE INTRODUCTION OF AN ERROR. 2) DURING PERIODS OF COLDER WX, IT MAY NOT BE IMMEDIATELY OBVIOUS THAT THE TEMP IS NOT GIVEN IN DEGS CELSIUS, AS THE WORD 'FAHRENHEIT' WAS NOT USED IN THE ATIS BROADCAST. THIS MISUNDERSTANDING WOULD ENSURE AN INACCURATE CALCULATION OF ACFT PERFORMANCE.
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.