Navigation control in the MAAM R4D

[dnunes 1]

This is a question I wanted to have put since long ago. Today, during another flight, I used a post-it in order not to forget about it.The question has to see with the switch on the left of the main panel, where are located the DME indicators. What is the use of this switch? It is by default in the VOR DME position. The two other positions, which have associated lamps, are RNAV and APPR. I do not understand what RNAV in this aircraft may mean. As for APPR, it seems to have no effect in following the ILS. Is there any use for this switch?I hope someone will clarify this.Regards,Domingos

[Dark Moment 0]

Hi DomingosI am sorry we are slow in answering your query; blame it on having to shovel snow!I didn't build the DME gauge, but as far as I am aware this is a dummy and the VOR DME position is the only one that works at present, even though the switch moves. Bill may confirm or deny this, but I think I'm right there. I can never get it to do anything myself, that's for sure!MarkMark "Dark Moment" BeaumontVP Fleet, DC-3 AirwaysTeam Member, MAAM-SIM[a href=http://www.swiremariners.com/cx.html" target="_blank]http://www.paxship.com/avsimlogo.jpg[/a]

[dnunes 1]

Thanks Mark for your reply. So you confirm what I have thought. What is strange is that, besides moving, the lights associated with RNAV an APPR are operational!Regards,Domingos

[rambow 0]

I had to crank up the wayback machine for this one! The instrument dates back to my very first R4D panel, before we even had an airplane to go with it, in 1999. FS98 had no way of modeling RNAV, which is area navigation. It was our intent to eventually go back to this unit and program the RNAV and Approach functions, but it got left by the wayside with the advent of the GPS in FS, and you are actually the first person I can recall ever asking about it. But like those modes of the unit, my memory may be non-functioning!Here, from the manual for the v2 R4D panel, is an explanation of these unprogrammed functions as they work in the real instrument:"MODESVOR DME mode. With the red knob in this position, the top readout will be Nautical Miles from the VOR station set on your Nav 1 radio, providing that station has DME capability. This is elementary radio nav and lessons can be had, if you need them, in FS98 Help files. When the VOR station is out of range, or has no DME capability, a red bar will appear across the number readout. This mode IS fully functional in this release of the gauge.R NAV, the second position, stands for Area Navigation. This is where things get interesting... The yellow light will be on when you are in R Nav mode. This allows you to enter the distance and bearing from a VOR to a point to which you wish to fly. In other words, you can create a "phantom" VOR station where none exists. This mode is NOT functional in this release of the gauge. In this release, the BEARING knob and readout adjust and mirror the setting of OBI #1, and the DISTANCE readout is DME 2. Its knob performs no function.For example, you want to fly IFR to your home station, Crowded Skies Aerodrome. CSA has no on-field nav aids, but there is a VOR, Whoopy, not far from your intended flight path in range of the field, and another on the other side of your track, Yippee, in range of your Point of Origin. Yippee is beyond the radio range of Crowded Skies, but it's range circle overlaps that of Whoopy. You, being the consummate (not to mention cheap) airman, want to fly a nice, economical straight line from POO to CSA. With RNAV, you can!(see the attached diagram)1. On your chart, plot the bearing (degrees true) and distance (nautical miles) from CSA to YPE. Enter these in the Bearing and Distance windows of the RNAV by rotating the black knobs. (Note this is bearing FROM the VOR) While you're at it, plot the numbers from CSA to WPY and write them down.2. Tune the frequency of YPE into the Nav 1 Radio.3. The OBI (VOR#1) should come alive. Center the needle on OBI 1 and fly a direct course to the phantom station you have created at CSA. (If you don't know how to do this, it's time to go back to flight school. See FS Help) The Nautical Miles (DME) top readout will register distance to the phantom station.4. Before you get too far, tune WPY's frequency into the Nav 2 radio. When you hear the identifier, theoretically when you are in the purple area which represents the overlap in the reception ranges of the two stations, switch Nav 1 to WPY.5. Enter the pre-plotted bearing and distance from CSA to WPY into the RNAV windows by rotating the black knobs.6. If you did everything right, the needle should still be close to center. Continue on your merry way to CSA.To repeat, this mode is NOT functional. APPR is the Approach mode. When in this position, the sensitivity of OBI #1 is increased by a factor of twelve. When in Approach mode, the red light will be on. This mode is NOT functional in this release of the gauge."You may be sorry you asked, after all that. :-)It's a useful little gizmo, never-the-less, as the bearing readout gives an exact digital readout of the course dialed in on OBI 1. The bearing knob or the OBI knob can be used interchangeably.Bill RambowMAAM-SIM http://www.fssupport.com/maam/hgrsm_blkani.gif

[dnunes 1]

Thanks Bill for your comprehensive reply. Both functions are of interest, but were they available in the original R4D? If not, I do not care if they are not available in the sim. When I fly the Level-D Boeing 767-300/ER for British Airways Virtual, I fully use the capabilities of the FMC. But when flying the DC-3 for DC-3 Airways, I like the challenge of using only what I have available on-board. This means I NEVER use the MAP or GPS buttons.I only wanted to make sure that the two switch positions were not functional.Best Regards,