Landing Height System for Mooney

[hammdo]

Yep single panel GPS for IFR (I do have VOR/ILS too) and yes looking  for the LHS callouts. Thanks for the reply. I have a 496 so I could use that but was looking for something hidden. Thanks for the reply…

-Don

[ilovecornfields]

What kind of wiring do you need for the whole shebang (gps, audio output, power, gear sensor)? I’d like to get all the supplies ordered so I can make it easy on my installer.

[Microkit]

37 minutes ago, ilovecornfields said:

What kind of wiring do you need for the whole shebang (gps, audio output, power, gear sensor)? I’d like to get all the supplies ordered so I can make it easy on my installer.

If your installer already has aviation wire spools, let them take it from that, otherwise, he needs to tell you the length to get (then add 3 feet).

The recommended bundle to use is: 3 sets of 2-core 24 AWG shielded wires.

Set 1: 2-core shielded for Power & Ground, goes to the back of the panel to the power bus.  Use a ground point there rather than attaching ground to the airframe at the wing, though an airframe wing ground point works, but it is best to select the same ground bus where the Audio Panel ground is connected.

Set 2: For Audio only.  If the Audio Panel offers an Audio LO pin, then get a 2-core shielded wire, bring the Audio LO to the LHS Ground wire.  If the Audio Panel does not offer an Audio LO pin, but only an Audio HI, a single shielded 24 AWG works.

Set 3: 2-core shielded for both the GPS & Gear Warning hookup.  If not attaching GPS, then a single-core (un-shielded) is sufficient for the Gear Warning, as that wire is for detecting voltage only, no data being transmitted on that wire, hence the shield is not really necessary, but it's still recommended to be shielded even if it is a single wire with no data; to be consistent with the rest of the airplane and also if routing the wire through metal tight spaces then having it shielded will protect it from being grounded years later.

All shields to be joined (from one end) to any ground point (airframe, or LHS).  Other end of shields to be left unconnected but capped/heat shrink

Having said the above, we know of some who just used a single cable 5-core shielded and all good.   

[hammdo]

@Microkit Will NMEA @ 9600 baud be ok or must it be MAPCOM for GPS? The Garmin 496 does not have a MAPCOM selection. I do have the output from the 496 wired and on Monday we’re going to test but wanted to inquire if that will work.

-Don

[good2eat]

Any one in Central Oregon that has had the LHS installed? - looking for a quality installer.

[LANCECASPER]

7 hours ago, good2eat said:

Any one in Central Oregon that has had the LHS installed? - looking for a quality installer.

@Baker Avionics is in Oregon and a Mooneyspace member

[Microkit]

On 1/7/2023 at 11:43 PM, hammdo said:

@Microkit Will NMEA @ 9600 baud be ok or must it be MAPCOM for GPS? The Garmin 496 does not have a MAPCOM selection. I do have the output from the 496 wired and on Monday we’re going to test but wanted to inquire if that will work.

-Don

We are probably going to support NMEA 0183 later this year.  If this is your only option, I will schedule a firmware update for you right after we complete the VBox release.

The GPS feed interface currently decodes Aviation Output 1 and 2, sometimes called MAPCOMM.  Aviation Output 1 message includes GPS Altitude, while Aviation 2 does not include Alt, only the Ground Speed.

Here are some more info regarding the GPS feed:

The main objective of this feature is to set up a speed threshold.  The extra 4 announcements that are based on GPS altitude are really a byproduct.

Speed Threshold:

Normally it is set as “approach speed” + 10 knots or so.  Depending on the range between the airplane approach speed and cruise speed.  We are not talking here about the approach speed used during an instrument approach before reaching DA or MDA.  It's the IAS speed airplane should be at when reaching 200’ or below and intended to land.

When the LHS is receiving any speed value above the set speed, it ignores/mutes any AGL announcements (200’ callouts and below).  This makes muting the system during certain kinds of IMC conditions automatic, so there is no need to manually mute the audio channel and then remembering to put it back on before landing.

Some may even elect to put the threshold to be the same as landing speed as normally there is some kind of headwind component so in most cases, airplane ground speed is less than or equal to IAS.

Let's say an airplane approach to land speed is 80 kt, and cruises at 140 kt IAS, setting the speed threshold to 90 kt covers having a 40 kt headwind while cruising in IMC conditions.

GPS Announcements:

Currently, 4 callouts are added (if enabled), 3000, 2000, 1000, 500 ft. Note that these are MSL.  So if the airport elevation is 720 ft, then 500 ft should never be heard.     These callouts are announced regardless if it reached climbing or descending, and depending on the deviation settings, it can be announced again, and again.

If someone keeps the Deviation at +/- 50 ft and flying without an alt-hold autopilot, the moment you go +/- 51 ft and come back 1 ft, the announcement occurs again. This also depends on the type/model of GPS, some units only report the nearest 100 ft, while newer ones report in 1’s. 

Thanks

Nidal

 

 

[rbp]

1 hour ago, Microkit said:

The GPS feed interface currently decodes Aviation Output 1 and 2, sometimes called MAPCOMM.  Aviation Output 1 message includes GPS Altitude, while Aviation 2 does not include Alt, only the Ground Speed.

 

I am not hearing the GPS callouts which makes me think my installer just replaced the 100 with the 200, and did nothing else. I haven't tried a gear up low approach, so I don't know if the gear sensor was attached either. 

is there a low airspeed threshold as well? meaning, when the plane is rolling out below, say, 40kts, should it mute the callouts? 

[hammdo]

@Microkit, NMEA 0183 is what the Garmin 496 provides - Garmin also has their own output. Just let me know when the update is available…

Thanks for the response…

-Don

[Ryan ORL]

On 12/30/2022 at 12:40 PM, Microkit said:

Those who fly IMC a lot and in certain kinds of IMC conditions may hear the unit announcing a solid layer beneath them, why flying straight and level in IMC.  Most of our TBM customers just mute it manually from the Audio Panel and add a line in the approach checklist to re-enable the LHS audio channel.  Having that feed just makes the process automated. 

 

This is the first I've heard of this.  I was interested in one of these units but this would be kinda concerning.  How common of an occurrence is this?

[Microkit]

9 minutes ago, Ryan ORL said:

This is the first I've heard of this.  I was interested in one of these units but this would be kinda concerning.  How common of an occurrence is this?

This is a technology limitation, it also happens with the big airlines radar altimeter as well.  Depending on the kind of IMC, moisture, approaching freezing, the laser can reflect off ice crystals and if there are enough of these and the unit is not able to detect a massively larger object then it announces.  

Not an issue during actual approach as the unit is detecting a large solid object (the grounds below) and any small hits from rain droplets or snow is not counted.  Speed threshold eliminates this once in while occurrence.    

Initially, before the first certification, the FAA wanted us to specifically put a hard rule asking pilots to fully disable the system before entering IMC, but as we insisted that it's going to be an inconvenient operation, they accepted for us to mention that the pilot can ignore it or optionally mute it rather than being “required” to mute it. 

[Microkit]

6 hours ago, rbp said:

I am not hearing the GPS callouts which makes me think my installer just replaced the 100 with the 200, and did nothing else. I haven't tried a gear up low approach, so I don't know if the gear sensor was attached either. 

is there a low airspeed threshold as well? meaning, when the plane is rolling out below, say, 40kts, should it mute the callouts? 

@rbp I thought I replied to this, not sure why it did not show up on my end.   

Check WiFi pages to see if GPS and/or Gear Warning System are active/enabled.  Even within the LHS GPS Setup page, there is an option to mute the callouts so maybe it was set up but muted.  

Nothing muted below set speed (if used), if not setup (speed set to 0 or GPS feed is disabled), system works as usual.

[rbp]

2 hours ago, Microkit said:

@rbp I thought I replied to this, not sure why it did not show up on my end.   

Check WiFi pages to see if GPS and/or Gear Warning System are active/enabled.  Even within the LHS GPS Setup page, there is an option to mute the callouts so maybe it was set up but muted.  

Nothing muted below set speed (if used), if not setup (speed set to 0 or GPS feed is disabled), system works as usual.

it turns out that Sureflight in their infinite wisdom decided that “upgrade 100 to 200” did not include connecting the GPS and the gear wiring, since I had not told explicitly them to do so. I mean, yes, I didn’t explicitly tell them to do so. But why else would I want to upgrade? 

[Larry]

Those of you who installed the Height Finder in the left wing inside and behind the left main gear.  How did you route the cable to the panel?  Did you pull the side royalite or able to just remove the side carpet panel to get over the spar?

Thanks,

Larry

[jlunseth]

I had the occasional issue with callouts in IMC with the first unit that came out, the LHS100. As I understand it the new version of the unit, the LHS-200, takes care of this. It has a connection to the GPS that gives an airspeed input so when the airspeed is above a set level the unit won't give altitude callouts. I haven't had occasion to fly in IMC since it was installed so I have not verified. I also had the problem with not getting callouts below 200 & 100 when my new 200 was first installed. There is a Wifi settings menu and the company gives you very good instructions how to set up everything. I worked through that and the lower altitude call-outs worked. The only issue I have not resolved is that if I am doing, say, a missed approach and then climb to 3.000 for a hold, there are callouts at 1-, 2-, and 3,000 feet, and if you climb to one of those altitudes and stay there it will continuously call out the altitude like a broken record. Sometimes when that happens I do have to use the comm panel mute. There may be a resolution for it in the settings screen but I have not had time to look into it. The company has been very good about helping with issues. I really like the unit. The best part for me is that it really helps with landings. You get down to the one or two foot level, you just need to hold an attitude and let the plane settle to the runway, but you are not sure exactly how high you are or how fast the plane is falling so I sometimes have a propensity to pull up just a little, which messes everything up. When I start hearing 1 or 2 feet I know I am right where I should be and just hold the attitude. Makes for nice landings.

[Microkit]

23 hours ago, Larry said:

Those of you who installed the Height Finder in the left wing inside and behind the left main gear.  How did you route the cable to the panel?  Did you pull the side royalite or able to just remove the side carpet panel to get over the spar?

Thanks,

Larry

@Larry,

We did an install on M20J on left wing, access panel behind the gear well.  

Remove pilot seat, remove pilot side panel to expose the wiring already there, remove the bottom two big panels to make it easier.  Get plastic tubing similar to the ones used for Pitot/Static, slightly larger dia though, pass the tubing starting from the pilot side, then through the back and there is an opening in the wing to get to that access panel, use a fish tape or even a solid core wire to pull all wires through the plastic tubing.   

Once you actually have all panels out, you will be able to locate the opening the wing to that access panel aft of the gear well.

 

[Microkit]

2 hours ago, jlunseth said:

The only issue I have not resolved is that if I am doing, say, a missed approach and then climb to 3.000 for a hold, there are callouts at 1-, 2-, and 3,000 feet, and if you climb to one of those altitudes and stay there it will continuously call out the altitude like a broken record. Sometimes when that happens I do have to use the comm panel mute. There may be a resolution for it in the settings screen but I have not had time to look into it. 

@jlunseth  The GPS deviation (in the LHS GPS settings) is probably set to +/- 50 ft.  Put it to +/- 150 ft.  The LHS keeps announcing the 500,1000,2000,3000 if you deviate and come back.  If you hand fly the airplane, you either deviating to 51 ft and back 1 ft (to reach 50) or your GPS model is reporting in 100's and not in 1's with some models reports the lower alt (-100) even if you go down 10 ft as a safe buffer.  So depending on the GPS itself, some will report 2900 when you are in fact 2990, and report 3000 when 3000 to 3090 and so on.   A note in the manual to "know your GPS".   Though setting it to +/- 150 ft. should solve it for those who hand fly.

The main advantage of the GPS is the speed threshold which solves the IMC operations technology limitation. The extra 4 callouts are just a by-product of connecting to a GPS source.   You can keep the speed, and mute the 4 callouts from the GPS setup within the LHS.

Thanks

 

 

 

 

[Larry]

@Microkit -

Thanks for the detailed response!

Larry

[rbp]

shout out to @Microkit for their ongoing support with my install via phone & email

my issue has been that connecting to the LHS wifi access point only works within a short distance from the access panel that its mounted into, and the microkit team has been very responsive

[dfurst]

1 hour ago, rbp said:

shout out to @Microkit for their ongoing support with my install via phone & email

my issue has been that connecting to the LHS wifi access point only works within a short distance from the access panel that its mounted into, and the microkit team has been very responsive

Same problem.  Please let me know what the solution is when you get it fixed.

[dfurst]

@Microkit, to be clear, if you hook up GPS, the 3,000, 2,000, 1,000 is AGL?  Not sure how useful it would be landing in Denver it is MSL.

Great product!

Thanks.

[Microkit]

44 minutes ago, dfurst said:

@Microkit, to be clear, if you hook up GPS, the 3,000, 2,000, 1,000 is AGL?  Not sure how useful it would be landing in Denver it is MSL.

Great product!

Thanks.

 

@dfurst  It's what ever your GPS reports, some GPS can report Above Terrain Altitude based on the internal terrain database, most are MSL.  For sure not useful in high elevation airports, again it is just a byproduct of the Speed.  We will consider adding more callouts in the future.

 

[rbp]

1 hour ago, dfurst said:

Same problem.  Please let me know what the solution is when you get it fixed.

since the device is properly configured now, and I have a workaround, I'm not going to mess with. but 2 weeks before annual, I will drop the access panel and send the LHS in to micro kit to have them take a look at it.

[Microkit]

4 minutes ago, Steve Parker said:

Uh, what?  You want the system to call out AGL, as in 200 feet above the ground, 100, 50, 20, 10, 5, 3, 2, 1 as my unit does. As a PIC landing the MSL readout over the threshold and in the flare is useless.  If your touchdown zone is 5,280 MSL, especially at an unfamiliar airport, who wants a system calling out "5,300 feet"? You'd be forever trying to remember the TDZ altitude and doing math in your head during a gusty, rainy crosswind landing. 

This system, thank God, calls out AGL, which is immediately useful and incorporated unconsciously in my flare. I love it. I get my Mooney to "one" foot AGL and hold it off until the times rumble.  @Microkit, your laser uses a verbal AGL readout. Why would you think of adding "new callouts"? 

To clarify, we are talking about the GPS feed feature of the LHS.    Late last year we introduced an upgraded edition of the LHS-100-B to the 200-C which adds two more features, a GPS feed from external GPS source, and a proper physical check Gear Warning System.  The chat above is regarding the GPS side of the LHS.   There are no changes on the AGL (laser based) side of the LHS, this is still the same.   The optional GPS feed provides 4 additional callout (MSL), which can be disabled from the LHS GPS Setup page.   200 ft and below, the system is laser based.  Higher callouts are GPS based.

[exM20K]

Question for @LANCECASPER @donkaye and the other long body LHS owners: 

I purchased a system and will have it installed at annual this month.  My landing technique is 70-75 KIAS Vref, cross the threshold at 1.2 Vso, roll in up trim and roll out throttle in the flare.  How do you make use of the altitude callouts in landing? Day/night differences?

looking forward to experimenting.

-dan