Altitude preselector: M20K 231

[fatalflaw]

Hi there

Can anyone confirm whether the KAS-297A altitude preselector is compatible with the KFC-200 autopilot in my aircraft?

I know the KAS-297 was fitted originally in the factory. This is for a retrofit. I'm aware I need a KEA-346 servo altimeter as well. I have heard mixed views on the KAS-297A/KFC-200 combination. I don't know how to get a definitive answer.

This from the KEA-346 product info sheet:

Compatible with KAS-297A Preselector/Alerter option for KFC-200
Compatible with KAS-297B Preselector/Alerter option for KAP-150/KFC-150 (per Installation Bulletin No. 262)

And yet ... it would be lovely to be certain before I start on a major wiring job.

TIA,

Jim

[jlunseth]

Yes, but do you know what the cost is for the compatible altimeter?  Look it up, it will be a shocker.  You can probably go to www.seaerospace.com and get a price.  Somewhere in the 11-12 AMU range.  Then you will also have the cost of the 297 and all the installation.  I have the KFC 200 and it has altitude hold, not pre-select.  That works really well, I have looked at the pre-select option and it is just not worth the >15 AMU's to add everything you need.

If you are looking for presents for your airplane, the addition of a high quality GPS such as the 430W, and a moving map, if you don't have them, are far better more useful.  Another option, and the one I picked for my aircraft, is the Icarus SAM roll steering.  By properly initializing the SAM (putting in baro. pressure and a target altitude), the SAM will give you a voice annunciation when you are reaching your target altitude, whether you are ascending or descending.  It also gives you a roll steering connection between you GPS and your AP.  Cost is more like 3-5 AMU's installed.  The SAM can also be initialized to provide a DH voice annunciation.     

[Earl]

+1 on the addition of the 297.  You have to replace the altimeter and then try to find a unit and the cost is probably around $15K.  I looked into this in detail for my 252 (KAP-150) and decided it was not worth the cost.  Next plane will have it for sure.

[fatalflaw]

Thanks, guys. I am in the highly fortunate position of having the parts already. I just want to check that the 297A will actually work.

The Icarus roll steering unit is really interesting though - something to seriously think about. I have a GNS430 WAAS, and the ability to execute procedure terms and holds without knob-twiddling (if you'll pardon the expression) sounds a real workload-reducer.

[jlunseth]

That is indeed an enviable position.  I do not have the alt. preselect, but I did check it out thoroughly in anticipation of installing one and the two A&P's I talked to verified that your intended installation is the one for the KFC200.

The SAM is a good unit, I like mine.  I wanted all the voice alerts I could get.  There are other ways to get the roll steering though, if you do not need or want the voice alerts.  I am pretty sure it is built into the Aspen products for example, and they are compatible with the KFC 200.  DAC also makes a roll steering unit.

The 200 is a really good unit.  I just read an article in Aviation Consumer and it was highly rated particularly because of its ability to handle difficult conditions (turbulence or heavy aircraft) without disconnecting.  I sure like mine.

[mooney231]

Quote: ehscott

+1 on the addition of the 297.  You have to replace the altimeter and then try to find a unit and the cost is probably around $15K.  I looked into this in detail for my 252 (KAP-150) and decided it was not worth the cost.  Next plane will have it for sure.

[Earl]

Quote: fatalflaw

Thanks, guys. I am in the highly fortunate position of having the parts already. I just want to check that the 297A will actually work.

The Icarus roll steering unit is really interesting though - something to seriously think about. I have a GNS430 WAAS, and the ability to execute procedure terms and holds without knob-twiddling (if you'll pardon the expression) sounds a real workload-reducer.

[jlunseth]

There is a little "knob twiddling, actually button pushing with the SAM, in order to fly a procedure.  To take an RNAV as an example, the SAM will fly the entire procedure hands off except for altitude changes, all the way to the FAF.  The way the SAM works is that it disables the Hdg. bug, and "fools" the AP into following roll steering commands with the AP in HDG mode.  However, to couple to a glide slope, whether an ILS or RNAV glideslope, it is necessary to put the KFC 200 into APPCH mode.  APPCH mode does not follow roll steering commands.  So at or before the FAF it is necessary to dial in the DTK (Desired Track) on the HSI, and then press the APPCH button while the glideslope indicator is still a little high.  The unit then couples to the GS and flies right down to DH or whatever altitude you want, your only job is to manage MP and, of course, get the gear down.  An ILS can be flown using the GPS and roll steering in exactly the same way, except that the 430/530 has to be set up properly to automatically switch to VLOC to follow the ILS signals.  Pretty easy. 

I don't have the Aspen, so am not sure how that works with the KFC 200, but probably pretty much the same way.  Glideslope coupling occurs inside the KFC 200, so am pretty sure it needs to be in APPCH mode at the FAF with the Aspen also.

I think the 700 does all this completely seamlessly, but that is another story.

[fatalflaw]

Thanks for the advice guys. I will go ahead with the installation and let you know how it goes.

[fatalflaw]

Guys there'a a nice KEA-346 on ebay at a good price.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=150565815049