Microkit

Let me describe how the Gear Warning System works: The Gear Warning System is an opto-isolated voltage sense. So it looks for voltage vs ground (or open). It does not detect ground itself, it just detects if > 6v is in the wire, so Ground or open circuit is the same state for the system which is: No voltage present state. The settings on the WiFi setup page for the GWS are basically two choices, you are telling the system if voltage is present on the wire, then consider the gear is down, or if voltage is present in the wire, consider gear is up. This to accommodate various airplanes/setups and hookup methods. So for the Mooney M20J with the annunciator panel (the one we did and provided details on Page 16 of this thread here: https://mooneyspace.com/topic/36596-landing-height-system-for-mooney/?do=findComment&comment=747501), all 3 limit switches which are connected in series, so when all are clicked when gear is down and locked, it provides +VE voltage to the Down light on the annunciator panel. So we spliced into that wire going to the Down light pin and set up the LHS to consider gear is down when the voltage is present on the wire. More details on that at the link above. I think most Mooney (if not all) use that method (provide +VE voltage) to indicate the 3 limit switches for the gear to a light and the 2nd wire of the light is permanently hooked up to ground. There are some airplanes in the Comanche fleet for example that do it the other way around, the permanent side of the light is hooked up to +VE power, and the limit switches provide (trigger) ground of the light to make it work. So first, you need to determine which side of that light is the control side (trigger side) and which side is permanently connected. If the trigger side provides +VE, connect the GWS yellow wire to that. If the trigger side provides ground, you can still use it, but you will need to use a small mini relay to make the relay trigger +ve to the yellow wire when it is triggered with ground. If unsure, best to have the airplane on jacks and check, even to check when with the unit installed, as when you set up the unit for the GWS, visit the WiFi page again, and it should say Gear Down (at the bottom of the page) if it was set up correctly and the gear is down and when you put the gear up, the page will show Gear Up. Remember to test the GWS every time the airplane comes out of annual or panel work/major maintenance or upgrade. There was a case where someone wanted to demonstrate the GWS to a pilot buddy (two months after the airplane had a major panel upgrade) and it was considering gear down all the time as someone did not know the wire or the need for it and they connected it permanently to a +VE source, so the owner flew the airplane for two months thinking the GWS was enabled and working while it was not. It is recommended to also check it out in-flight once in a while, by doing a low approach with the gear up or at least every bi-annual with an instructor.

The show special is currently active, promotion through Sunday, July 28th. https://landingheight.com/shop/ Also, I would like to introduce our new FAA Certified product, the Audio Checklist. Promotion price $335. For those with LHS already installed, share the same power/ground/audio channel wire with the LHS. Unit designed to share the same audio channel, making installation simple and fast; just find these three wires from the back of the panel, splice the audio checklist connector to these wires, done. I am going to copy and paste some of the points from the product page here, and I am looking forward to answering any questions. The Microkit Audio Checklist is a digital device that plays pre-stored audio files checklists using the airplane intercom or audio panel. The unit can also connect directly to a headset providing the headset can amplify the audio output of the unit. The Audio Checklist unit comes with a remote control to trigger playing a checklist, and it offers an interface for up to 3 external push-buttons such as on the panel to trigger playing any checklist. These 3 optional push-buttons can be installed then configured to trigger a specific checklist such as the Emergency Checklist, GUMPS, or Landing (on final) Checklist with a single push. Owners/Operators are able to upload their own checklists using the built-in WiFi interface. The remote control offers direct access to specific checklists such as the “Emergency Checklist” using a single dedicated button. Several emergency checklists can be stored and accessed. Direct access to the next checklist once the previous one is already played, such as the PreStart checklist then the next checklist the unit will play is the Taxi for example, as Owners/Operators decide the order sequence of the checklists when uploading the audio files to the unit. - Listen to the checklist over the headset or cabin speaker. - Up to 9 standard checklists and up to 6 emergency checklists. - Dedicated button to hear the emergency checklists. - Optional panel/yoke/stick push-buttons; configure up to 3 push-buttons to be associated with a checklist or to navigate through all checklists. (Push buttons are not included) - Handy remote control that can be placed anywhere such as the panel, yoke, window, side trim. Co-pilot can have a remote on their own side as well. (One remote control included) - Accepts standard MP3 audio files. Record your own or use freely available online Text-to-Speech sites to create your own checklists. (checkout the User’s Guide) - Logical transition between different checklists with a single button, once the first checklist is heard, the next checklist plays in sequence till the end of the flight. - Fully configurable to listen to all items in a specific checklist with a customizable pause (for example PreStart Checklist), or to step through it one item at a time with a dedicated button (STEP). - Upload shared checklists for your own make/model airplane in a single ZIP file. - 2 configurable custom remote buttons that give direct access to a specific checklist. - Simple to install, only requires power, ground and an audio channel on the audio panel. If the Landing Height System is installed, share the same power wires and use the same Audio channel used for the LHS for even faster installation. Check it out here: https://landingheight.com/product/audio-checklist/

Most probably induced noise. If the audio wire is routed next to high load wire, such as if the battery is under the back seat and the wiring from the unit at the wing is routed along or near the same bundle, then some noise comes in. Or audio wire shield is connected to ground from both ends or not used at all.

Yes, no changes in the system regarding AGL callout. 100-B (which is your current model) to 200-B or 200-C, it just depends if you want the Gear Warning System (then you need 200-C) or you want to upgrade the 100-B to 200-B which is without gear related functions. In your case, if you want the Gear Warning System, your only option is 100-B to 200-C. The 200-B (and -C as well) adds GPS feed compared with the 100-B. A wire connects to an available GPS in your airplane which can output Aviation Output 1 format via RS232 port. The main reason for this addition, is to allow speed threshold settings within our system, it is for those who fly IMC a lot, where at certain types of IMC (high content moisture or near freezing) the unit may see a solid layer and report the range; with the Speed Threshold setup, you set it 10kt or 20kt above your approach speed, and the unit will auto-mute any callout once it sees the aircraft speed (coming from your GPS) exceeds that set threshold in the wifi setup. Many don't hookup the GPS, and just mute the unit via their audio panel when they are in IMC and put it back on during downwind check or when they leave IMC.

The "Check Landing Gear" audio message is only heard if the gear is up, in fact, the height call it ourself will be omitted to give you further notice that things are not normal. Basically, the Gear Warning System is a single wire gets attached to the Gear Lever itself or to a single indicator that shows gear is down and locked, our wire is just an opto-isolated voltage sense, it just senses if there is a voltage on the wire versus no voltage (open or ground) and based on that, you can set it up to assume gear is down when voltage is present or visa-versa, this setup is done through the wifi setup menu. Once the system is told what voltage on the wire means (gear is up or down), then once it sees the ground below starting 220 ft AGL, it checks the condition of the gear based, and if the gear is still up, it keeps repeating "Check Landing Gear" every 4 seconds until either a positive rate of climb is registered or the gear is extended. Here is link for the upgrade offer. https://landingheight.com/product/lhs-upgrade-options/

John, you do have the 100-B (since Nov 2020). Upgrading requires the unit back (though; one day turn around), and the 4-pin connector to be changed to a 5-pin connector, a new airplane-side 5-pin connector will be sent along with the upgraded unit, at least one more wire will need to be pulled to the location of the unit and to be connected to your down and locked light. Adding to what dkkim73 said, we intentionally removed the "gear reminder only @ 200 ft" in the 200-C model so it's not tuned out, the Check Landing Gear message will be repeated every 4 seconds, without any height call out until either a positive rate of climb is registered or the gear is down. Maybe you can upgrade the unit 10 days or so before your annual or extended period of downtime. If you fully satisfied with the P2 function to get your attnedeton during high-load or fully distracted scenarios, I am guessing no need to upgrade.

The 200-C model includes an extra wire for the Gear Warning System. It is basically an opto-isolated voltage sense circuit, for airplane that use a single down & locked light, our wire can connect to that, for others, the wire can connect to the gear lever itself. Previous series (100-B model) does not have that feature, there is a low-cost upgrade path for those with 100-B wanting to upgrade it to 200-C, the Upgrade offer is online. We do recommend checking the Gear Warning System in flight, like a low-approach with gear up, down to 150 ft AGL, no need to go lower. It is also highly recommended you re-check the Gear Warning System after each annual or after any maintenance/upgrade work that included wiring or back-of-the-panel work jus to make sure the new work did not affect the Gear Warning System as its a very critical function which you want it to work.

Thank you for the feedback, Will. One note to keep in mind to all; whenever the airplane comes out of annual or any wiring/panel related maintenance; make sure you test the Gear Warning System again, the best test is to do a low-approach with the gear up, then perform a go-around, the unit announces “Check Landing Gear” every 4 seconds until a positive rate of climb is registered, or the gear is extended. We did get a report from a pilot who handed over his airplane for a GPS/EFIS upgrade, the shop temporarily removed part of the panel along with some wiring to assist with their installation and when they put it back together, they ended up connecting the GWS wire to a permanent +VE source; unaware of its functionality or why it was there in the first place; this effectively made the LHS unit sees the gear as always down. He only found out about it when he wanted to demonstrate the GWS feature to another pilot, so we asked him to troubleshoot the location of the GWS wire after he told us the airplane just got a huge panel upgrade. Apparently; system failures and issues after maintenance is a hot topic at the moment. It is a good idea to have an “After Maintenance checklist” with first flight to be around the pattern and check all critical systems such as the Gear Warning System, autopilots and such.

No practical or safety reason at all, hence the limitation is only mentioned in the installation guide rather than the approval letter/certification itself. We are the first one to use LIDAR technology instead of Radar Altimeter for height callout during landing, and its on NORSEE rather than STC, allowing us to offer it at a much cheaper price point compared to other STC equipment.

The LHS unit is shipped with the default settings to allow 2 & 1 to be announced. Some installers go on the LHS unit WiFi pages and click on the button, so 2 & 1 are not announced. We are aware that some users go back into the LHS menu (details available within the online guide) and disable that mode, so they can hear 2 & 1. I guess they are reading between the lines. Here is a 3 years old (Nov 2020) reply on the same question with more info. https://mooneyspace.com/topic/36596-landing-height-system-for-mooney/?do=findComment&comment=627163

Some newer GPS may have an AGL output message based on their internal terrain database and current location; we don't think it will be in the Aviation Output message itself, but rather a new message format. Sorry Jim, unfortunately there are no coupon codes at this time.

The GPS callouts are MSL, this is because the GPS sends as MSL in the Aviation Output message. As mentioned previously, the main objective of having a GPS feed is the speed threshold. The extra 4 announcements that are based on GPS altitude are really a by-product, and there is a dedicated option within the WiFi setup of the unit to mute these 4 callouts. The main function of the LHS unit is laser-based AGL starting 200’, then of course the added value of the audio based Gear Warning System

Don, I sent you an email with a firmware update to check out the NMEA 0183 option for the 200-C model. Anyone else in need of this firmware, please do email us (let us know if it's 200-B or 200-C model), we will probably keep it in Beta until we get confirmation from more than one pilot that NMEA is working at their end.

It is scheduled before the middle of March. I will email you a firmware update to check it out soon.

Your field elevation seems to be right at the border of the +/-150, and it's not exactly 2000 ft. LHS repeats callout based on whatever is coming from the RS232. You can see the data coming if you open the GPS Setup page and watch at the bottom (when the GPS has a fix). There is an option within the LHS configuration to only announce 50 ft and below and not announce height. The default is to announce 200 ft AGL and below, this is called Standard in the drop-down list. If you only get 50 ft and below, that's what it is set to. LHS does not call gear down. It only calls Check Landing Gear and keeps repeating it if it sees the ground below and the gear is up. We recommend everyone to do the test flight we presented here (see Page 17 on this thread) right after installation to confirm the Gear Warning System is operational. It is also recommended to perform this test flight after each annual or panel work, a customer discovered the Gear Warning System wire was removed during an annual.

The deviation is probably set to +/- 50 ft (default) in the GPS Setup page within the LHS unit. Set it to +/- 150 ft. When you deviate 50 ft and come back it will announce again. Try it with +/- 150 ft, and you can also disable GPS callouts while taking advantage of the Speed threshold for IMC operations. We may release a firmware upgrade that allows selecting certain ones, and add more GPS callouts (4000, 5000, 6000). Also, it depends on how your GPS is reporting it to the LHS. Some GPS models report only in 50 ft increments, others report the lowest of nearest 100, (in 100 ft increments), others in 1’s and so on.

VBox on a Mooney. YT Audio during the flight was actually taken from the VBox as he forgot his GoPro!

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.

@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.

@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, 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.

@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.

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.

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