Minivation

I think we're talking two different Trophy packages here. I'm not sure what exactly the Trophy 262 package entailed, but the package installed on the J model I fly is dubbed the "Trophy 221ES" and brings a normally-aspirated Continental IO-360-ES to replace the standard Lycoming IO-360 (whereas the M20K came from the factory with turbocharged Continental TSIO-360's, albeit with some differences between the 231 and 252). What's perplexing is that in the AMFS for the Continental conversion, the text specifically says "Speed and range are unchanged with the Continental 10-360 ES installed" with regards to cruise performance.

Wait, this gives me ideas. Why not certify a Mooney for 5 seats? Hmm. "Where's the fifth passenger?" "Oh, the kid? He's out in the back. It's gonna be a bit dark and cold back there, but we gave him a blanket. He'll be fine."

Welcome @Farmboy561 to the forum, and thanks for the follow-up! I've been flying a friend's Trophy 221ES conversion M20J and have been intrigued by the volumes and volumes of STCs the modification involved. The specimen I fly was converted in early 2000 and includes the Continental IO-360, speed fairings/seals, composite instrument panel, long-range tanks and the rest of the modification menu. This is the first Mooney I've actually flown seriously (I had a few minutes of stick time in short-bodies, but they were all when I was riding along on maintenance flights) and I realize that it's quite an oddball to get my first Mooney experience in, but it's been a great bird. Always wanted to ask ... what was the intent/rationale behind the Continental IO-360 conversion, as opposed to using a Lycoming IO-360? My best assumption is that the 6-cylinder Continental runs smoother than the 4-cylinder Lycoming, and the additional 10hp gives it a slight edge during takeoff.

Cantilever upper body (i.e. using your abdomen muscles alone to keep your waist-up held in place). But don't get me wrong - I'm no gym guy (quite far from it). I'm not sure if I'd have the strength and patience to install nutplates there though. In fact, from the picture it looks like the installation simply uses three screws held together by nylock nuts. That arrangement would be easily doable if you used an angle-drill and drilled out one or two holes at at time.

When you're an avionics tech, you learn to get verrrry familiar with this area. I like to call it Mooney's Cozy Home of Pain and Suffering. I usually access this area by leaning in forward then twisting my upper torso to the right to face the ceiling. If you're gonna be in there for more than a minute, it requires a ton of upper body strength in order to keep your upper body supported and to avoid resting your waist on the sharp sides on the battery access panel.

Sweet! Best case troubleshooting scenario. Hope the KMA24 serves you well for the foreseeable future.

I've never been a fan of the new LED post lights and Nulites as the PWM creates a strobing effect which for some of us is very noticeable and borderline nauseating. In addition, a lot of white LED's have a "cold" white balance (i.e. lots of blue) and the red LED's are eye-piercingly monochromatic. If I recall, Whelen still carries their A350 series of PMA incandescent post lights which are available in limited quantities. They're about $60-70 per light. Light bulbs used are 330 (14V) or 327 (28V). 14V, Long: A350CN06 (white), A350CN07 (red), A350CN08 (clear) 14V, Short: A350CN09 (white), A350CN10 (red), A350CN11 (clear) 28V, Long: A350CN12 (white), A350CN13 (red), A350CN14 (clear) 28V, Short: A350CN15 (white), A350CN16 (red), A350CN17 (clear). The Maxdim controller, as others here have pointed out, is a pricey but solid solution for controlling. As far as I know there are no dimmers that, using one knob, control two separate circuits - one in analog and one in PWM, but if you're able to get your hands on the Whelen A350 post lights, you won't have to worry about the PWM part anyway. I myself created my own analog dimmer using a 2N3055 transistor and 1kOhm linear pot with integrated on/off switch and it worked pretty well. If you purchase a dimmer other than the MaxDim or decide to fabricate your own, it is imperative that the potentiometer be a linear one instead of a logarithmic one, since using the latter type will make controlling your lighting feel like controlling your shower water temperature. Not sure why some avionics techs don't bother with properly hooking up the avionics to a lighting bus. Granted, some equipment (e.g. KX155) don't give you any other option except for the photodiode, but my thinking is, if the equipment gives you the option for a dimm bus and such a dimm bus exists for your aircraft, then use it...

I second Rudy Aircraft Instruments! We used them 2 years ago for a friend's attitude indicator and heading indicator overhaul on his Cherokee. The turnaround time was about a week and a half (from us sending it out to getting it back in the mail) and if my memory serves, we paid little over $350 or so for each gauge. Their workmanship is excellent; I cannot find a thing to complain about. I've recommended them for other vacuum gauge operators in need of overhaul.

I'm afraid I don't have the manuals for the KA-134 in my library. I see that Texas Air Salvage has a handy pinout reference for it though: https://www.texasairsalvage.com/PinnoutPDFfiles/KA134.pdf If you really need the full thing, you could pay $20 and download it here: https://www.eflightmanuals.com/ITEM_EFM/SDETAIL_EFM.asp?mID=10852 I've used eFlightManuals for a few other manuals (King KY92, etc.) in the past and on all occasions they've delivered what I needed.

I realize I may have spoken a bit too soon about the lift detector "taking the prize" for the highest markup (plenty of horror stories about voltage regulators and prop heat control units I see) ... even within my own experiences I think the one that takes the grand prize for the highest markup (although the end price isn't too expensive) is the Cessna solenoid surge protection diode (P/N 0770783-*). Behold, the true pinnacle of cutting-edge technology, backed by millions of dollars of R&D, countless weeks of testing, and most important of all, a shiny new Form 8130-3: a 1N4007 rectifying diode terminated on both ends by TE Connectivity PIDG series ring terminals. For just $55, you too could enjoy this marvelous piece of tech... ...or you could fabricate one yourself for literally $0.52, $0.02 (for the diode), $0.15 (for the #10 ring terminal) and $0.35 (for the 1/4" terminal). That aside, I got the lift detector reinstalled in the airplane, ops test good. The weather here in the east coast has been absolutely dismal (going on 20 days of straight rain and sleet - I haven't seen the sun for more than 2 weeks) so I'll have to wait till next weekend (fingers crossed) to bring the plane up to make sure the switch is aligned so that it activates at the right AoA.

I'm surprised nobody has mentioned the TX-1 yet. Also known as the MT20. In the early 1980s the USAF was looking for a replacement for the Cessna T-41 (militarized 172/175) so Mooney created a variant of the M20K with a sliding canopy and some hardpoints on the wings. The project was not a success and ultimately the USAF opted to continue with further variants of the T-41 at this time, resulting in the T-41D, basically a military Hawk XP. Sometime down the road however, the USAF shifted over to the "Enhanced Flight Screener" concept, so Mooney created another oddball airplane that I'm sure a lot of MSers know about - the M20T Predator (N20XT) - as their entry in 1991. Ultimately, the Slingsby T67 Firefly won the competition but that type was withdrawn from service in the early 2000s after a series of fatal accidents and the USAF's philosophy change to discontinue the whole ab initio thing. As for the M20T, it was kept with Mooney into the 2010s but last I heard was Don Maxwell bought it and is supposedly restoring it in Longview. Regarding aerobatics - legal issues aside, given the fact that Mooney was able to whip out not one, but two military contenders without any crazy redesign hints at a good possibility that the structure of the airframe is suitable for mild aerobatics. (The TX-1 even had hardpoints, which implies that the wing was capable of taking on additional loads and withstand extended positive/negative load factors). Another testament to the (surmised) structural capability of the M20 design is that the type has gone from 2450lbs max gross to almost 3400lbs max gross with minimal changes apart from extending the fuselage and slight increase in wingspan. That said, I think the biggest concern would be, as others have already pointed out, (1) roll performance, (2) spin characteristics, and (3) the slipperiness of the plane. (1) The M20 features short-span, wide-chord ailerons that do not provide clean rolling characteristics. I've worked on a few Helios (notorious for their huge barn door ailerons) and although I haven't flown one, their turning characteristics are ... interesting, enough to the point that Helio had to design interceptors (sort of like spoilers) into the wing to counter adverse yaw (and to provide additional control at low speeds). So although we have that video of someone "aileron rolling" their Mooney, we can see that it's a pretty terrible one that involves a lot of nosing up before even getting to the roll itself in order to avoid ending the maneuver at a -40 degree attitude. The Mooney's flight controls are another thing - (a) the controls are spring-loaded, which prevents the pilot from "feeling" the aerodynamic state of the aircraft, and (b) the aileron/rudder are correlated, which sort of defeats the purpose of certain aerobatic maneuvers. (2) Many others here have pointed out that M20s have relatively nasty spin characteristics. Not the worst, but not like a Cessna or Piper where one can simply let go of the controls and the plane starts flying again. I suspect this has a lot to do with the M20's relatively small vertical stabilizer size, coupled with limited rudder travel. Note that the M20T Predator utilizes a noticeably longer vertical stabilizer and rudder assembly compared to a standard M20J, likely in order to combat this issue. (3) Lastly, the very thing that makes the M20 such a crazy good personal X/C machine is also what likely makes it a terrible aerobatics machine - forward aerodynamic efficiency. Coming from flying Citabrias, 172s and PA-28s where you could easily chop the power 5 miles from your destination and drop from 5000ft AGL down to traffic pattern altitude, the single most disruptive characteristic during my checkout on the M20 was descent planning, simply because the airplane is so clean that a standard -300ft/nm profile is enough to keep the speed up. I can only imagine what the airspeed would do at -50 degrees nose down. Perhaps with careful planning and excellent execution the plane may be able to pull off some basic loops, but I wouldn't be surprised if that's about it.

Ah yes of course . Thanks for the heads-up! Yes, I am an A&P with an avionics tech background. I used to do quite a few bench tests and even some component level repairs when I used to work at a 145 shop. As for the legalities, the work done on the switch, a "component part", is a minor repair, minor alteration done with reference to AC43.13-1B (accepted practices), much in the same way someone might repair a nav light bulb receptacle, for example.

A bit of light reading if you're bored over the weekend. TL;DR: Stall switch failed on me, and the $2500 price tag for a new replacement is downright stupid. A few months ago I noticed that the stall switch (lift detector) on the 201 I'm currently flying didn't work too well - in that the stallhorn might or might not activate even as the airplane entered imminent stall condition during the last moments of flare during landing. Interestingly, around that time I also noticed that during descent (in excess of 500fpm) in clouds/rain I would hear a distinct, but faint, high-pitched tone from the ceiling area. A few days ago I returned home after a rather challenging X/C trip that mostly took place in the soup, even with a "fun" encounter with light icing too. Upon arrival late at night, I hangared the plane and plotted -D-> to MYBED. The next morning I returned to the hangar to take care of a few things, and at this time I turned the master on to check the voltage since I had it trickle charging overnight. As soon as I flipped the master on, the stall warning came on in full force and wouldn't quit. Playing with the lift detector vane didn't help (although I could hear a very faint pitch change in the stall warning tone) but pulling the STALL WARN circuit breaker stopped the madness. I searched this forum and found out that I was not the only one to encounter this issue: https://mooneyspace.com/topic/17546-stall-warning-stuck-on/ https://mooneyspace.com/topic/15399-stuck-stall-warning/ I opted to leave the airplane alone at that time and to see if any supposed moisture buildup in the stall switch would clear up in a few days. It didn't. After letting it sit for 4 days the horn was still blaring as soon as I turned the master on, so I removed the switch from the airplane (not the worst, but not easy either) and confirmed with a multimeter that even when not activated, there was only 1.2kOhms between N.O and Common. The Mallory Sonalert SC628 (the generic P/N of the 201 stallhorn) has a current draw of approx. 7mA at 13VDC using data interpolated from the datasheet. This roughly translates to a roughly 1.8kOhm impedance assuming no other resistance in the circuit. When a 1.2kOhm "resistor" (i.e. faulty switch) is added in series with this device, the voltage differential across the Sonalert drops to 4.6V, but the thing about these smaller Sonalerts is that despite their listed operational voltage of 6~28V, they actually activate around 1V and are quite loud even at 3V. I have disassembled the switch as much as I can. The Safe Flight lift detector system is attached to the leading edge curved piece via 2 MS20470AD4-3 (or -4?) rivets which can be drilled out with a 1/8" dia. drill and punch. The lift detector assembly itself is basically a custom-order variant of the Honeywell BA or BE series SPDT microswitch housed inside a custom formed sheet aluminum cover then secured via two long MS20470A4-?? soft rivets, although the rivets are bucked so that the bucktail looks identical to the head. One could try drilling these out too, but they are prone to rotating with the drill bit, so I found the best method of removal was to carefully use a file to shave off one of the heads, then to use a 1/8" dia. punch to press/pull the remains out. The vane lever (constructed of stamped stainless steel) is secured at its fulcrum using a pin, which also can be pressed/pulled out of its place using a very small diameter punch or some other improvised device (I used an awl to expose enough pin on the other side, then carefully pulled the rest out with a needle-nose plier. It appears that the switch itself is not one of Honeywell's hermetically sealed types, which in my opinion is a huge no-no given the fact this switch is literally exposed to oncoming air/rain/debris. Thus, the plastic plunger slips right out of its place, so care should be taken not to lose this part in addition to the aforementioned lever pin. The Honeywell (or rather, its subdivision "Micro Switch" in Freeport IL) switch can be opened up to reveal its conductive innards by separating the upper "roof" from the main body, albeit with much difficulty. Safe Flight uses some sort of yellow electrical tape in an apparent attempt to seal this joint but I have found the tape's material to age very poorly, peeling unevenly and leaving an unsightly pattern of sticky residue upon eventual removal. Alcohol and/or brakleen easily removes this though. The "roof" is secured to the switch body via a combination of press fit and 3 tiny pins, 2 located on the LH and RH sides, and one at the rear. I learned this after-the-fact when the roof separated from the body and 3 pieces of plastic debris fell out with it. In my case, the breakage was clean and CA glue (aka superglue) did the trick. The switch innards are very simple; in the image above, the switch's Common conductor (on the far right) is connected to a springy copper arm that extends from the right to the far left. The arched shoulders on this arm bias the arm upwards as such to normally make contact with the upper electrode (the gold colored rectangular tab on the left) which is connected to the N.C. port, but this port is not threaded/used in this switch. When the vane at the wing L.E. lifts during high AoA, the opposite end of the vane lever pushes down on the plastic plunger, and the bottom end of the plunger pushes this copper arm down, causing it to detach from the N.C. electrode and to make contact with a similarly-shaped N.O. electrode below. A distinct clicking sound can be hear d during this operation. I rinsed down the switch body with liberal amounts of contact cleaner and then tested the contacts again with a multimeter; the check was OK. Chances are some conductive debris got lodged between the Common and N.O. electrodes. Reassembly of the switch consists of reattaching the "roof", securing it with the 3 tiny pins, inserting the plastic plunger (flat end goes into the switch), then reattaching the vane lever with the securing pin. I have taken the liberty of securing the switch to the Safe Flight housing using 2 sets of #6-32 screws, AN960-6L thin washers and MS21044N06 nylock nuts, and likewise for securing the assembly to the leading edge curved piece as well. Especially disappointing (and frankly, anger inducing) is that this switch was removed, factory repaired, and reinstalled according to a logbook entry dated 15 January 2016, which means this switch only lasted just over 5 years and about 150 hours T.I.S. before failing again. (The previous owner apparently didn't fly much) According to a Cessna 170 forum thread, a factory overhaul for an unheated lift detector (which basically involves Safe Flight switching out the Honeywell switch and putting it back into the housing) cost $400 in 2007 and according to another MS thread, $1200 in 2017. That is f***ing outrageous. Mind you, the price above is for overhauls/repairs. Aircraft Spruce lists a new Safe Flight Model 164 switch at $2575. A Honeywell BE-2R-A4 switch costs $12 on Sager Electronics. Even if, say, a custom-order variant of the BE series switch was batch-produced with an MOQ of 10,000 for $1,000,000 ($100 ea.), FAA PMA certification efforts cost $400,000, the aluminum housing cost $50 per unit, and the labor to assemble one was a generous 2 hours at $100 per shop-hour, this amounts to a valuation of $390 per switch, which translates to a 660% markup. During my days as an avionics tech, I've seen some unremarkable products sold at absurd prices (such as the Astro-tech LC-2 clock, a $10 Walmart kitchen timer sold at $400) but the Safe Flight lift detector takes the prize for the dumbest piece of s*** sold at the most d e n s e markup considering it's tech straight out of the Industrial Revolution of the 18th century. I've seen TSO'd comm radios sold for less than this switch. I understand that businesses need to generate profit to stay afloat; I may have given the lift detector a pass if it incorporated some ingenuity or special attribute that reflected some sort of significance in its R&D. My day job involves selling industrial electromechanical devices with a comfortable (but fair) markup because they're some of the best performers on the market and I know the engineers put in so much effort designing and refining them in years past and present. But the lift detector is nothing more than a custom-order microswitch from the 1940s with no meaningful R&D since, probably, the 1950s or 60s. To sit on decades-old tech and offer them for a markup so high that it might as well get RVSM is beyond my comprehension. Well, maybe it's not that much beyond comprehension. I know Safe Flight has some pretty technically advanced products such as their powerline detectors and helicopter pedal shakers, and I can only assume that their lift detectors contribute only a tiny portion of their revenue portfolio at this point, so all things considered, they couldn't care less about these relics of the past. Normally, the nature of the market would dictate that someone else would pick up the slack to offer reasonably-priced competition, but given the current rate at which new airplanes are produced and the relatively high entry barrier of PMA certification, such a venture is unprofitable and unattractive. If anything reflects painfully well the shattered remnants, the empty shadows of a once-hopeful general aviation industry, it is the flat-out unimpressive Safe Flight lift detector and its ludicrous pricing. At the end of the day, this is just one of my biggest pet peeves that I know is beyond my personal control, but one that I still can't help but be frustrated about. If you've made it this far, kudos to you for actually sitting through this entire monologue. Thanks for coming to my Ted talk.

I can confirm this.

Assuming you have a separate intercom panel and given the fact that both pilot and copilot stations are having difficulty hearing both radios, my prime suspect is the headphone amplifier circuitry is at fault inside the KMA24. Reference the basic block diagram of the KMA24 circuitry below: In order to "mix" various audio sources (i.e. marker beacon, comm 1, nav 1, comm 2, nav 2, etc.) into one headset output, these audio sources are passively mixed through a network of resistors, which has the side-effect of attenuating each respective signal. In order to bring these signals back up to original amplitude, the mixed audio is then run through an amplifier before being sent out to the headphone jacks (or perhaps, in your case, the "radio" input of the intercom unit). The cabin speaker and headphones use separate amplifier circuits, which may explain why your cabin speaker still works OK. As for resolving this issue, my suggestion is to take it to an avionics shop that is knowledgeable with old-school avionics (i.e. won't throw new boxes at it right away). There exists an adjustable potentiometer (R201) which controls the amplification level of the Headphone Amp, so perhaps an attempt could be made first to see if that makes any difference. If adjusting the R201 potentiometer doesn't make any appreciable difference, there is a good chance the voltage regulator that supplies power to the amplifier itself is at fault. (If this is the case, then this might explain why you're still able to *faintly* hear the radios - the amplifier is inop and is operating at 1:1) Reference: King KMA24 Maintenance Manual 006-05180-0001 Revision 1

The LO pins should be connected to airframe ground, preferably along with the KX170B's power ground or as physically close as possible to to the KX170B's power ground in order to avoid annoying ground-loops. I've attached a wiring diagram of an installation I did between a KX170B and a PS Engineering PMA8000 I did a few years back. With the LO->GND arrangement shown, the audio quality was excellent. Within the scope of Comm1/Comm2/Nav1/Nav2 audio wiring, the pinouts between the PMA8000 and GMA340/345 are identical. Be advised: The KX170B requires its speaker output to be utilized one way or the other. If your airplane has a cabin speaker, then chances are it will be interfaced to the audio panel's speaker output, not the KX170's. In such a case, the KX170's own speaker output (P171 Pin 6) will need to be connected to a load resistor, preferably 16-Ohms, 3W (or greater) otherwise, damage to the radio may occur. Example load resistor suggestion: https://www.alliedelec.com/product/vishay-dale/cw00516r00je12/70204759/ KX170B PMA8000 Interconnect Excerpt.pdf

Well, it appears I certainly got myself into a rabbit hole with this one. I am referencing the following documents: Garmin GNS480 installation manual, 560-0982-01 Revision M Garmin G5 Part23 AML STC installation manual, 190-0112-10 Revision 24 Garmin GI-275 Part23 AML STC installation manual, 190-02246-10 Revision 7 [quote]Does anyone know if it is possible for the GI-275 to work by splitting the ARNIC 429 NAV and GPS Outs that are also going to the GAD 29B[/quote] TECHNICALLY speaking, this technically should work. The GNS480 features 3 A429 inputs and 2 A429 outputs. When connecting to an EFIS (including the G5 via GAD29) both of the outputs are occupied, one in GPS "GAMA429" format (GPS position, navigation waypoint info, etc.) and the other in Nav "VOR/ILS" format (lateral and vertical HSI deviation info). (I am not sure if the GI-275, when configured for MFD mode, would even make use of the VOR/ILS info, though) In addition, one input is used under "EFIS" format (selected course, airdata, etc.) [quote]while not using the ARNIC 429 return?[/quote] Since the EFIS input INTO the GNS480 pertains to information generated by an air data computer (see GNS480 IM Page 2-34, Table 2-9, Column 3) the GI-275 need not (and should not) need to provide a return to the GNS480. The G5 is sufficient. Note that the flight plan info, including the proverbial magenta line, is communicated to the G5 / GI-275 separately via an RS232 channel in "MapMX" format. Whatever RS232 output from the GNS480 to the existing G5 HSI using this format will need to be spliced to run to the GI-275 as well. As @McMooney mentioned, A429 specs call for enough current to drive up to 20 receivers. Of course, there is a wire run limitation of something like 150ft, but that's way beyond the scope of GA aircraft. As per a previous conversation I had with Garmin, each RS232 output can only reliably drive 2 devices, maybe 3. Alternatively, the GI-275 has a built-in GPS receiver, so maybe installing a separate GPS antenna and running a coax cable to the GI-275 may be an easier solution, but surely less elegant. == Other Considerations == That said, the LEGALS are what I'm not quite sure on. I can only reasonably assume the GNS480 and G5 (and its associated LRUs) were installed under STC, and so will the GI-275. The GI-275 install manual explicitly mentions the GNS480 as a "compatible GPS source" under Appendix C.4 Table C-5, but this table also explicitly mentions an ARINC429 output (i.e. GI-275 -> GNS480) in "GAMA429" format. Of course, technically speaking, this functionality is already covered by the G5 as mentioned above, and while I am personally inclined to consider this arrangement a minor deviation from the STC, but it is a well-established fact that different FSDOs have wildly varying temperaments when it comes to these kinds of matters. Another point of consideration is how useful your GI-275 installation would be. If you're purely interested in a separate MFD through which you could view a nice moving map, this would be a suitable arrangement. However, other functions from ADS-B In (TIS-B traffic and FIS-B weather) won't work since, as far as I can collect, you do not have a compatible panel-mount ADS-B In device. (You may be able to display TIS-A traffic from the GTX330ES via an A429 line from the GTX330ES to the GI-275, but I can't confirm this as the Garmin Dealer Portal went inop while I was typing this reply). I hope this info offers some help. I've attached scans of excerpts from the sources I mentioned above along with my annotations.

I am absolutely in love with the Monroy tanks in the 201 I fly. Most of my flights are single-pilot IFR for business purposes, so I can safely fill the tanks to the brim and comfortably carry a suitcase and a box of pre-prepped lunch and dinner. (I have a horrible habit of not drinking much water, so I can easily wait out 9 hours of not going #1) Recently I completed a trip from Kerrville to Charlotte NC. I was originally planning to make it all the way home to Norfolk VA in one shot but decided to split it up as I was starting to encounter some nasty winter weather (feat. ice), the deviations were getting annoying, and I figured I'd give myself a break. However, this leg really highlighted the capability of the plane - 17000ft, 195~205 kts groundspeed (155 true), and all at 7.5gph. It is a HUGE upgrade compared to the 172's and PA-28's I used to fly - the Mooney consumed a total of around 65 gallons for the whole trip (Kerrville-Charlotte-Norfolk) while an equivalent trip in a PA-28 would have consumed 80-90 gallons due to the fact that it (1) cruises 30-40% slower on the same GPH and (2) can't take advantage of the winds aloft at 17000. Thus, one could argue that in some respects, the Mooney saves both time and money. I've got a few friends from my college days that live up in the Oregon/Washington/Idaho area. I hope to take the plane there to visit them during the summer - now that would be a little trip! Looking forward to it.

I'm quite late to the party, but ... WOW! Kudos to you @Microkit for getting this done and Norsee certified! I've actually wanted this exact device for a very long time - back in 2017 when I was a mx officer for a club with two 172's I was looking at taking a Garmin V3HP Lidar and interfacing it to an Arduino board (along with barometric pressure sensor and OLED screen) to create a poor man's radar altimeter callout device and cruise altitude alerter (with C chime and everything). Unfortunately I don't know jack about computer programming so that never took off beyond concept. I don't own the Mooney I'm flying but if it were, I'd pick this up in a heartbeat. I occasionally fly into my old home airport (where the abovementioned flying club is at) at night but the runway is flanked by trees and has a very pronounced bowl shape (downhill slope on both ends) which makes the touchdown somewhat an affair of luck. Perhaps I'll convince the owner to get one.