I looked up my docs and there is no reference of any option regarding fasten seat belt annunciation. Unless this option has been added in last three or four years, there is no other functionality than described.

Functionally speaking, there is nothing "digital" in the system, there are switches, relays and wires.An altitude option will require a unit able to detect the altitude from the ADIRUs and will give a "ground" to power the relays.I'm not aware of such a unit, but I cannot exclude a company option for that.

The Auto position is not realistic at all anyway. Maybe on climb when it dings at 10,000 but on descent the signs are on at TOD.

For safety reasons most items will chenge during airplane life, companies will also update some systems to add more features and so on.Manual will be updated each time a modification is applied.However, if the modification is mandatory, a FAA, EASA, Boeing (and so on) documents will be released for that.Now, I think that passengers signs are not part of a mandatory modification, so it is something related to newer aircraft options or only company option.

The Auto position is not realistic at all anyway. Maybe on climb when it dings at 10,000 but on descent the signs are on at TOD.

Switching on the FSB-sign at TOD does not happen automatically, but is part of the SOPs at most airlines. In the NG, when the switch is on auto, they will switch on when the flaps and/or the landing gear lever is moved.

Switching on the FSB-sign at TOD does not happen automatically, but is part of the SOPs at most airlines. In the NG, when the switch is on auto, they will switch on when the flaps and/or the landing gear lever is moved.

Have you flown the NGX lately? Because that's not true. That's the point of the first 5 or so posts.

Probably not the answer you're looking for, but when I flew the classics, if the switches were in Auto, the seatbelts signs would go on when either the flaps were extended or the gear was down or both. The smoking sign would illuminate only when the gear was down.Not sure if this applies to the NG, not even sure if it still applies to the classics as it's been 18 years since I've flown them so there may have been some changes.Capt. Rónán O Cadhain [Former B737CL F/O].

I though the Ding at 10000 ft was to remind you that the landing lights should be off or shut them off if they are on.....I guess not.

This is really strange, I always hear the ding at 10.000' but according to 1.40.5 In the FCOM 2 it clearly says the exact same description as Rónán said. But when I was a passenger on the all SAS NG's the belts come off at 10.000' feet since you can feel the aircraft pitching down for acceleration, but it might have been that they manually turned it off.Manfred

Woops, should have specified I was talking about real life, not the NGX, my bad.

In AUTO, seatbelt sign is: - illuminated when flaps or gear are extended - extinguished when flaps and gear are retracted(Ref: FCOM Vol. 2, chapter 1.40)Prior to pushback, select ON.Climbing through 10000FT, select AUTODescending through 10000FT, select ONOnce fuel is cutoff, select OFFAUTO is used so that if we forget to turn on the signs on descent, they come on automatically with flaps/gear. In all other situations, we force the lights to what we want them to be.

but they do not ding with flaps and gear, they only ding below 10,000 feet

The signs always make the Ding if the staus of the light changes.This means, that in AUTO will ding if gears are extended or retracted, in OFF will ding if lights were previously lighted, in ON will ding if previous the lights were off.The Ding is intended to alert passengers and crew about the changed light status. It has nothing to do with the AUTO or not AUTO position.If at 10000fts the Ding sounds, it means that the lights are passing from ON to OFF, this either in auto (if there is an option for that) or manually by putting the switch to OFF.If you are on ground, with flaps, the switch is in AUTO, the lights are ON, if you now move the switch to ON the lights remain on and no DING will be played as nothing changed for passengers. Same results if at 10500 fts you move the switch from auto to OFF or viceversa. At least if you are still in clean configuration (no flaps)

Probably not the answer you're looking for, but when I flew the classics, if the switches were in Auto, the seatbelts signs would go on when either the flaps were extended or the gear was down or both. The smoking sign would illuminate only when the gear was down.Not sure if this applies to the NG, not even sure if it still applies to the classics as it's been 18 years since I've flown them so there may have been some changes.Capt. Rónán O Cadhain [Former B737CL F/O].

Alright, I can now confirm that this is also the case on all RYR 737-8AS aircraft in operation today, so it hasn't changed since my day. I would take that to assume it is the same across most of the NG aircraft in operation worldwide today....I'm sure one of the PMDG team could pipe up though and just confirm the parameters they used while designing the NGX, but I'd expect them to be as above given the highly accurate nature of the sim...Capt. Rónán O Cadhain [Former B737CL F/O]

The Fastend Seat Belt Sign will illuminate when the FASTEND SEATBELT Switch is ON. When the FSB switch is in AUTO position the Fastend Seat Belt sign will illuminate when the Landing Gear Lever is down."Not the Gear it self". Or when the Landing Gear Lever is NOT DOWN and the Flaps are NOT UP than also the seatbelt sign is ON.The NO SMOKING sign is always Illuminated on most airliners because smoking is prohibted on most airliners only the low chime works. If not the NO SMOKING sign operate the same as the FSB sign's. This is how the Real Airplane works. I notice that the NSFSB sign's on the PMDG 737NGX only operates in AUTO when it passes the 10.000 FT marker.

Looks like we got there in the end. Thanks to all for responding (or should I say responDING!) and for clarifying this.Iain Smith