MD83 flight crew is dispatched with the number one GPS on MEL and flies an RNAV arrival to las witho...

Narrative:

There was a MEL 34-08 situation 1; which deferred the number one GPS. The release had us filed to las on the sunset 2 RNAV arrival. We flew the RNAV with no problems. It was before the next leg when we had another write up (also associated with the GNS MEL) that we realized that we could not fly RNAV. From discussion with the mechanic on second write up; we discovered we only had one GPS. We did not know there was only one GPS installed on the aircraft and not knowing our navigation limits on the aircraft; flew the sunset 2 RNAV into las. It seems that the dispatcher should have known that with the GPS MEL'd that the aircraft was no longer RNAV capable and could not fly an RNAV arrival. Also we were given a takeoff alternate that was not required. The release was generated 3 hours prior to departure and the weather was greater than 6 miles visibility with an overcast of 1;800 ft. The takeoff alternate at our estimated time of arrival if we needed to go there; the forecast was for 1/2 visibility; freezing fog; and 200 ft ceiling. We discovered the alternate was not legal when enroute to las. With the weather good at the departure airport it wasn't required.there should be a list available to pilots; dispatchers and mechanics as to what equipment is installed on the aircraft. I also think better training on all our different types of navigation systems for all the different aircraft would be helpful. Also; the asm only lists how to operate one type of FMS navigation while our ops spec lists 3 different types of usable navigation radios. On our flight in question; the aircraft system manual did not have a specific operational manual for our type of FMS. This would have made it much easier to find/figure out which buttons/keystrokes to determine how many GPS units we had on board.

Original NASA ASRS Text

Title: MD83 flight crew is dispatched with the number one GPS on MEL and flies an RNAV arrival to LAS without difficulty. Prior to departure from LAS it is discovered that this MD83 only has one GPS and is not RNAV capable.

Narrative: There was a MEL 34-08 situation 1; which deferred the number one GPS. The release had us filed to LAS on the Sunset 2 RNAV arrival. We flew the RNAV with no problems. It was before the next leg when we had another write up (also associated with the GNS MEL) that we realized that we could not fly RNAV. From discussion with the mechanic on second write up; we discovered we only had one GPS. We did not know there was only one GPS installed on the aircraft and not knowing our navigation limits on the aircraft; flew the Sunset 2 RNAV into LAS. It seems that the Dispatcher should have known that with the GPS MEL'd that the aircraft was no longer RNAV capable and could not fly an RNAV arrival. Also we were given a takeoff alternate that was not required. The release was generated 3 hours prior to departure and the weather was greater than 6 miles visibility with an overcast of 1;800 FT. The takeoff alternate at our estimated time of arrival if we needed to go there; the forecast was for 1/2 visibility; freezing fog; and 200 FT ceiling. We discovered the alternate was not legal when enroute to LAS. With the weather good at the departure airport it wasn't required.There should be a list available to pilots; dispatchers and mechanics as to what equipment is installed on the aircraft. I also think better training on all our different types of NAV systems for all the different aircraft would be helpful. Also; the ASM only lists how to operate one type of FMS NAV while our ops spec lists 3 different types of usable NAV radios. On our flight in question; the Aircraft System Manual did not have a specific operational manual for our type of FMS. This would have made it much easier to find/figure out which buttons/keystrokes to determine how many GPS units we had on board.

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.

Attributes
ACN	983011
Time
Date	201112
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Aircraft 1
Make Model Name	MD-83
Operating Under FAR Part	Part 121
Flight Phase	Parked
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Deviation - Procedural Published Material / Policy Deviation - Procedural MEL

MD83 flight crew is dispatched with the number one GPS on MEL and flies an RNAV arrival to las without difficulty. Prior to departure from las it is discovered that this MD83 only has one GPS and is not RNAV capable.