Narrative:

Unscheduled aircraft swap. First officer proceeded to originating aircraft while I shut down our aircraft due to scheduled arrival of next crew. Arrived at gate; looked at release and noticed 'MEL 22-15 mode cont pnl' left navigation 0-1 RNAV operations are not conducted. I looked back through the logbook and saw the #1 navigation radio had been removed for troubleshooting; reinstalled; and the aircraft returned to CAT IIIA status the previous evening. Noticed 3 days prior that aircraft was written up for captain's HSI not displaying LNAV data. [I] noticed white MEL sticker next to captain's VOR/ILS; navigation switch. Selected switch to navigation and HSI responded correctly. Cycled again; ops normal. Went out into the jetway and called station maintenance. I told them the aircraft appeared to have been worked on the previous evening; but the MEL was not cleared. They said they would send someone out. [I] went back to the cockpit to continue setup. Discussing the write up with my first officer; I selected my VOR/ILS; navigation switch again; and the HSI showed a red flag; no CDI movement; and no auto-tuning on #1 navigation radio. Called maintenance on the radio and told them; 'never mind; it's still broken.' we pushed from the gate and blasted off to our destination. Enroute; I began to review in detail; MEL 22-15. Of all the panel switches/paddles it refers to; it does not mention the VOR/ILS; navigation selector switch. It does mention LNAV. Aircraft had GPS; waas (wide area augmentation system). It does not require auto-tuning. Legs page shows rnp (required navigation performance) of .03. LNAV is indeed selectable on mode control panel; just can't see it on my HSI. On the ground; I contacted dispatcher and conveyed my thoughts that this MEL is a little screwy. We contacted maintenance control. After describing aforementioned events; he sent me to a 'MEL guru.' this 'guru' told me when there is no specific MEL referring to switch; you move out to the next affected system; in this case; LNAV. Dispatcher advised me that a new release was coming to reflect a new arrival into our next destination. Release showed up right at departure time. En route; I hashed out the particulars of these discussions with my first officer. Noted on the release that I signed; MEL states 'RNAV ops are not conducted yet we are filed as a /left.' on the ground; a new release said; 'RNAV ops are not conducted and we are filed as /left.' I contacted dispatcher and asked; 'if RNAV operations are not allowed; why are we filed as /left'? The answer is; 'the person who reviews the mels and assigns the proper designator.' I asked; 'doesn't /left reflect RNAV capability'? Answer: 'yes it does' 'what is going on here'? I informed this new dispatcher of the events of the day and told him; 'I'm just going to call my chief pilot's office and run through this with them.' dispatcher connected me with the chief on call and I explained all of this to him. He asked if we can get maintenance control. Dispatcher said; 'no; it won't let me;' at which time; we apparently lost the connection to the chief pilot. Dispatcher then connected me with maintenance control whom I briefed. I said; 'while I realize that I can leave the VOR/ILS; navigation switch in VOR/ILS; and fly all over the country; this MEL does not address the fact that my HSI won't display LNAV data. It seems as though we are trying to 'backdoor' our way into an MEL that we otherwise couldn't use.' maintenance control said; 'sure we are.' I about fell over! I said; 'if we don't have relief; we need to fix it.' maintenance control said; 'call maintenance and see if they have a HSI they can swap out. If not; call me back and we'll take it from there.' two gentlemen showed up and began discussing where they thought the problem was. They swapped out the hsis and the daas. An ops person on the airplane asked how long they think the delay would be. Maintenance said; 'are you holding off boarding because of us'? I said; 'yes; because if you can't fix this; I'm not taking it.' I then explained my concerns of how the stated MEL does not reflect the true issue. He said he deferred one of these a few days ago. He began dialing a number on his phone and asked me for the north number of the aircraft. I heard; 'yeah; captain's HSI won't show LNAV data. We got any relief for that? We don't? Wanna down the airplane then? Ok. Bye.' I called dispatcher to verify the aircraft was down. We walked to the next jetway and took an aircraft from an inbound crew. The flight departed 42 minutes late.

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Original NASA ASRS Text

Title: A B737-300's Mode Control Panel was MEL'ed because the VOR could not be selected as an input to the Captain's HSI. RNAV was disabled but the aircraft was continuously filed as a /L because LNAV operated but could not be displayed. The Captain refused the aircraft after two legs.

Narrative: Unscheduled aircraft swap. First Officer proceeded to originating aircraft while I shut down our aircraft due to scheduled arrival of next Crew. Arrived at gate; looked at release and noticed 'MEL 22-15 Mode Cont Pnl' L NAV 0-1 RNAV operations are not conducted. I looked back through the logbook and saw the #1 NAV radio had been removed for troubleshooting; reinstalled; and the aircraft returned to CAT IIIA status the previous evening. Noticed 3 days prior that aircraft was written up for Captain's HSI not displaying LNAV data. [I] noticed white MEL sticker next to Captain's VOR/ILS; NAV switch. Selected switch to NAV and HSI responded correctly. Cycled again; Ops normal. Went out into the jetway and called station Maintenance. I told them the aircraft appeared to have been worked on the previous evening; but the MEL was not cleared. They said they would send someone out. [I] went back to the cockpit to continue setup. Discussing the write up with my First Officer; I selected my VOR/ILS; NAV switch again; and the HSI showed a red flag; no CDI movement; and no auto-tuning on #1 NAV radio. Called Maintenance on the radio and told them; 'Never mind; it's still broken.' We pushed from the gate and blasted off to our destination. Enroute; I began to review in detail; MEL 22-15. Of all the panel switches/paddles it refers to; it does not mention the VOR/ILS; NAV selector switch. It does mention LNAV. Aircraft had GPS; WAAS (Wide Area Augmentation System). It does not require auto-tuning. LEGS page shows RNP (Required navigation performance) of .03. LNAV is indeed selectable on mode control panel; just can't see it on my HSI. On the ground; I contacted Dispatcher and conveyed my thoughts that this MEL is a little screwy. We contacted Maintenance Control. After describing aforementioned events; he sent me to a 'MEL guru.' This 'guru' told me when there is no specific MEL referring to switch; you move out to the next affected system; in this case; LNAV. Dispatcher advised me that a new Release was coming to reflect a new arrival into our next destination. Release showed up right at departure time. En route; I hashed out the particulars of these discussions with my First Officer. Noted on the Release that I signed; MEL states 'RNAV ops are not conducted yet we are filed as a /L.' On the ground; a new Release said; 'RNAV ops are not conducted and we are filed as /L.' I contacted Dispatcher and asked; 'If RNAV operations are not allowed; why are we filed as /L'? The answer is; 'The person who reviews the MELs and assigns the proper designator.' I asked; 'Doesn't /L reflect RNAV capability'? Answer: 'Yes it does' 'what is going on here'? I informed this new Dispatcher of the events of the day and told him; 'I'm just going to call my Chief Pilot's office and run through this with them.' Dispatcher connected me with the Chief on Call and I explained all of this to him. He asked if we can get Maintenance Control. Dispatcher said; 'No; it won't let me;' at which time; we apparently lost the connection to the Chief Pilot. Dispatcher then connected me with Maintenance Control whom I briefed. I said; 'While I realize that I can leave the VOR/ILS; NAV switch in VOR/ILS; and fly all over the country; this MEL does not address the fact that my HSI won't display LNAV data. It seems as though we are trying to 'backdoor' our way into an MEL that we otherwise couldn't use.' Maintenance Control said; 'Sure we are.' I about fell over! I said; 'If we don't have relief; we need to fix it.' Maintenance Control said; 'Call Maintenance and see if they have a HSI they can swap out. If not; call me back and we'll take it from there.' Two gentlemen showed up and began discussing where they thought the problem was. They swapped out the HSIs and the DAAs. An Ops person on the airplane asked how long they think the delay would be. Maintenance said; 'Are you holding off boarding because of us'? I said; 'Yes; because if you can't fix this; I'm not taking it.' I then explained my concerns of how the stated MEL does not reflect the true issue. He said he deferred one of these a few days ago. He began dialing a number on his phone and asked me for the N number of the aircraft. I heard; 'Yeah; Captain's HSI won't show LNAV data. We got any relief for that? We don't? Wanna down the airplane then? Ok. Bye.' I called Dispatcher to verify the aircraft was down. We walked to the next jetway and took an aircraft from an inbound Crew. The flight departed 42 minutes late.

Data retrieved from NASA's ASRS site as of April 2012 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.