Narrative:

On apr/xa/01, at approximately XA00, I received a call from the captain of flight abc saying that mechanic was there and they were deferring the pitot static heater for the right side. He told me it would be a 30-5. I referred to the MEL, saw the words 'right lower probe' and that as long as the aircraft was not operating in known or forecasted icing conditions, the flight was permissible. The captain agreed. There was no icing along the route of flight. It was later called to my attention by the superintendent on duty that the aircraft had been dispatched illegally because it was a -700 aircraft, and that type of aircraft can only operate with this MEL in daylight conditions. The flight departed bna at XA15 and arrived in fll at approximately XB15. That would have placed the flight outside VMC conditions. I referred back to the MEL and scrolled further down the screen and then noticed the exception for the -700. Also, that what the captain was talking about was the 'upper probe' not the 'lower probe.' for some reason, the auxiliary probe limitations are listed first which are less restr. Then I read that the -700 was restr to VMC. There were also different restrs for the auxiliary (lower and upper) pitots. I feel a combination of trust in the judgement of the captain and maintenance to know all the restrs, plus my own inexperience in knowledge of the pitot system of a -700 as compared to a -200, -300, and -500, and rush to accommodate the captain and passenger, led me to fail to scroll completely through the MEL to see if any other restrs may apply. You can be sure I am doing that now.

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Original NASA ASRS Text

Title: A B737-700 IS DISPATCHED WITH AN INOP LOWER R PITOT HEATER IN ACCORD WITH THE MEL RESTRS LISTED FOR OTHER MODELS OF THE B737, NOT THE -700 TYPE.

Narrative: ON APR/XA/01, AT APPROX XA00, I RECEIVED A CALL FROM THE CAPT OF FLT ABC SAYING THAT MECH WAS THERE AND THEY WERE DEFERRING THE PITOT STATIC HEATER FOR THE R SIDE. HE TOLD ME IT WOULD BE A 30-5. I REFERRED TO THE MEL, SAW THE WORDS 'R LOWER PROBE' AND THAT AS LONG AS THE ACFT WAS NOT OPERATING IN KNOWN OR FORECASTED ICING CONDITIONS, THE FLT WAS PERMISSIBLE. THE CAPT AGREED. THERE WAS NO ICING ALONG THE RTE OF FLT. IT WAS LATER CALLED TO MY ATTN BY THE SUPERINTENDENT ON DUTY THAT THE ACFT HAD BEEN DISPATCHED ILLEGALLY BECAUSE IT WAS A -700 ACFT, AND THAT TYPE OF ACFT CAN ONLY OPERATE WITH THIS MEL IN DAYLIGHT CONDITIONS. THE FLT DEPARTED BNA AT XA15 AND ARRIVED IN FLL AT APPROX XB15. THAT WOULD HAVE PLACED THE FLT OUTSIDE VMC CONDITIONS. I REFERRED BACK TO THE MEL AND SCROLLED FURTHER DOWN THE SCREEN AND THEN NOTICED THE EXCEPTION FOR THE -700. ALSO, THAT WHAT THE CAPT WAS TALKING ABOUT WAS THE 'UPPER PROBE' NOT THE 'LOWER PROBE.' FOR SOME REASON, THE AUX PROBE LIMITATIONS ARE LISTED FIRST WHICH ARE LESS RESTR. THEN I READ THAT THE -700 WAS RESTR TO VMC. THERE WERE ALSO DIFFERENT RESTRS FOR THE AUX (LOWER AND UPPER) PITOTS. I FEEL A COMBINATION OF TRUST IN THE JUDGEMENT OF THE CAPT AND MAINT TO KNOW ALL THE RESTRS, PLUS MY OWN INEXPERIENCE IN KNOWLEDGE OF THE PITOT SYS OF A -700 AS COMPARED TO A -200, -300, AND -500, AND RUSH TO ACCOMMODATE THE CAPT AND PAX, LED ME TO FAIL TO SCROLL COMPLETELY THROUGH THE MEL TO SEE IF ANY OTHER RESTRS MAY APPLY. YOU CAN BE SURE I AM DOING THAT NOW.

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.