KLN-94 Gotchas

wilkersk

wilkersk

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KennyW
I'm getting ready for an instrument checkride in a C-172 with an IFR KLN-94/KMD550.

A couple of times, I've found myself scrambling to fix a gotcha on a GPS approach, or just using the GPS overlay as a back-up or DME substitute.

Beyond the NAV/GPS toggle on the instrument panel, what are some of the screwy things you all have found with this set up? And, what do you do to prevent them from happening?
 
To prevent that stuff ,I went to Garmin,however bendix king is becoming a competitor.good luck on the ride.
 
The KLN -94 will not have precision approaches in the data base, like ILS approaches.

Example, you can fly the LAS Rwy 25 ILS (Las Vegas NV) because the DME (not required but nice to have) is based on the LAS vortac which is in the data base. You cannot fly the LAS Rwy 1 ILS, the required DME is on the localizer freq, not loaded in the database.

Same for the VGT (North Las Vegas) Rwy 12L ILS, it's not in the database, the DME is associated with the localizer freq.

Know what approaches you need with the KLN and that the information you need is in the database, and that the database is current.
 
BillTIZ said:
You cannot fly the LAS Rwy 1 ILS, the required DME is on the localizer freq, not loaded in the database.
Click to expand...

Are you sure? I've put localizers (IXXX) in the KLN-89B before, it worked fine.
 
BillTIZ said:
The KLN -94 will not have precision approaches in the data base, like ILS approaches.

Example, you can fly the LAS Rwy 25 ILS (Las Vegas NV) because the DME (not required but nice to have) is based on the LAS vortac which is in the data base. You cannot fly the LAS Rwy 1 ILS, the required DME is on the localizer freq, not loaded in the database.

Same for the VGT (North Las Vegas) Rwy 12L ILS, it's not in the database, the DME is associated with the localizer freq.

Know what approaches you need with the KLN and that the information you need is in the database, and that the database is current.
Click to expand...
IIRC, the FAA allows you to use the GPS for DME as long as you can reference something on the approach (such as the IAF or MAP) and correlate the distance to the ones listed on the chart. Of course it's best if that's the same fix as the DME antenna as that eliminates any need to calculate the reading.
 
dmspilot said:
Are you sure? I've put localizers (IXXX) in the KLN-89B before, it worked fine.
Click to expand...

I think I've done it on the Moffett (NUQ) ILS or LOC DME Rwy 32R approach with a KLN-94.
 
Palmpilot said:
I think I've done it on the Moffett (NUQ) ILS or LOC DME Rwy 32R approach with a KLN-94.
Click to expand...

NUQ the DME is on the local VORTAC not on the localizer freq, so yes, you can load NUQ into the KLN-94 for DME data and the LOC freq into VOR1 reciever. That works. If the DME was on the LOC like the two I mentioned at VGT Rwy 12L or LAS Rwy1L it does not work.
 
gismo said:
IIRC, the FAA allows you to use the GPS for DME as long as you can reference something on the approach (such as the IAF or MAP) and correlate the distance to the ones listed on the chart. Of course it's best if that's the same fix as the DME antenna as that eliminates any need to calculate the reading.
Click to expand...

But you need to know the correction factor. Do you know the difference in distance between the two reference antennas to do the math? And only if they are in line with each other, if on different azimuth, good luck with that, in a moving airplane, in weather. Better figured out at GS=0.
 
dmspilot said:
Are you sure? I've put localizers (IXXX) in the KLN-89B before, it worked fine.
Click to expand...

The VGT Rwy 12L ILS or the LAS Rwy 1L ILS was not part of the KLN-89B database.

The LAS Rwy 25L ILS was not in the database either, but there the DME is (not required, there are crossing radials) but DME from LAS VORTAC can be used in the GPS and the LOC freq turned separately. That approach uses the VORTAC DME. the Rwy 1L approach needs the DME on the loc freq, the antennas are in different locations.
 
BillTIZ said:
NUQ the DME is on the local VORTAC not on the localizer freq, so yes, you can load NUQ into the KLN-94 for DME data and the LOC freq into VOR1 reciever. That works. If the DME was on the LOC like the two I mentioned at VGT Rwy 12L or LAS Rwy1L it does not work.
Click to expand...

If I remember rightly, the box displays all the stepdown fixes directly on the NUQ approach. Does it not do that on the approaches you mentioned?

I can't figure out why the source of the DME would matter, since the box can't receive DME anyway.

By the way, there's no VORTAC at NUQ, only a TACAN.
 
BillTIZ said:
The VGT Rwy 12L ILS or the LAS Rwy 1L ILS was not part of the KLN-89B database.

The LAS Rwy 25L ILS was not in the database either, but there the DME is (not required, there are crossing radials) but DME from LAS VORTAC can be used in the GPS and the LOC freq turned separately. That approach uses the VORTAC DME. the Rwy 1L approach needs the DME on the loc freq, the antennas are in different locations.
Click to expand...

ICUA is not in the database?

It doesn't need to be anyway, you can use distances from FAF (NODIY in thise case) instead.
 
I have a KLN90B. Its similar. All the IFR GPS have to have an OBS mode. The way I do ILS's is to tune the ILS with the VOR/GS (seperate box). Then make the approach fix that is about 5 miles out (IAF, FAF outermarker whatever its called) the active waypoint, go to OBS mode and dial in the heading on the OBS dial. Now I have a line extending infinitly out both directions from the IAF at the correct degrees. If you can use the MAP as the fix its actually better because the distance will jive with the plate without subtracting, but you cant always do that. Depends on the approach. Then I fly the VOR/GS and just use the GPS info as backup and distance assistance.

If there is an ILS, just use the GPS for enroute and fly the ILS. Having that line gets you lined up for the approach fix ahead of time. Use your altitude for the MAP. Youre required to be able to indentify the FAF somehow regardless.

The hardest part to set up is the missed. Dont get caught fiddling with the GPS on the missed. Just do the initial part of the missed with the DG or a VOR if thats the case. Climb and turn as necessary. Too easy to get confused dialing the GPS at this point. Have the fix after the missed in the GPS flight plan though so you can get to it once you are turned, climbed and headed the right direction is my advice. If you have a 2nd GPS, put the missed in it (flight plan from the MAP to the MAHWP (the missed to the missed approach holding way point)), There have been some accidents on a missed in IMC caused by the pilot failing to climb and turn because he was dialing the GPS. Fly the airplane! If it says climb, CLIMB! If it says turn, you can just use the DG. The wind might blow you off a little, but you can compensate for that right?
 
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Kenny, if you are proficient with the KLN, you have nothing to fear.
If you feel you are not, time to spend a little more time with it (even on the ground is enough). You can also purchase the KLN simulator and practice at home. It helped me to some degree.

Good luck on your checkride!
 
I have been a KLN 94 for a decade and found it difficult to learn. I bought a docking station which helped immensely. If you would like to buy it I am all done using it. It is a little dusty but otherwise in great condition. I would part with it for $80.00+freight.
Walt Bell
303 886 4575 or bellw@me.com
 
Palmpilot said:
If I remember rightly, the box displays all the stepdown fixes directly on the NUQ approach. Does it not do that on the approaches you mentioned?

I can't figure out why the source of the DME would matter, since the box can't receive DME anyway.

By the way, there's no VORTAC at NUQ, only a TACAN.
Click to expand...

I'm saying that those approaches I mentioned are not in the database.
Everyone is using a workaround based on the FAF. But if the approach is not in the database, chances are the FAF will not either.

It's been a while since I've flown the KLN-89/94 models. But "percision approaches" (ILS) we're not in the database. Only non-percision approaches.
 
BillTIZ said:
I'm saying that those approaches I mentioned are not in the database.
Everyone is using a workaround based on the FAF. But if the approach is not in the database, chances are the FAF will not either.

It's been a while since I've flown the KLN-89/94 models. But "percision approaches" (ILS) we're not in the database. Only non-percision approaches.
Click to expand...

That's true of the 89B, but the 94 has the precision approaches. See section 6-2-12 of the KLN94 Pilot Guide, linked toward the bottom of the page I linked to in my previous post.
 
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The precision approach may not be in the database, but the FAF will be. All the 5 letter ids, the ones without dashes in them are in the database. That means all the IAFs and FAFs outer markers etc are in the database.

Also, an IFR GPS distance is legally and functionally acceptable as a DME. There is no "correction factor". The difference between slant distance and over the ground distance is too small to matter. Anyone who uses an IFR GPS should know it is acceptable to use GPS distance for DME. Im pretty sure its in the FAR or AIM somewhere, probably with a bunch of nitpicky details. But basic stuff like how far from the FAF, you can do that just fine.

Anyone have a citation?
 
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Thanks for all your suggestions and thoughts on this. I have the PDF of the Pilot's Guide and a Qref checklist for the KLN 94. I was looking for perhaps tips or tricks for remembering specific steps to avoid the dumb mistakes I seem to keep making (like selecting "Vectors to final", then forgetting to activate it).

I've learned a lot in the last few days. And, I think I've about got a handle on it now.

I found a PDF file of a slide-show presentation on the KLN-94 that is kinda geared towards answering my OP. So, I thought I'd post it here.

GACE Flying Club KLN 94 IFR Presentation,

presented by Michael T. Carrey (April 21, 2011); Accessed on 9/10/2015 @ http://www.gaceflyingclub.com/member download/GACE KLN94 IFR.pdf
 
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