mooniac15u

PAR 36 has a diameter of 4.5 inches (115 mm) PAR 46 has a diameter of 5.75 inches (145 mm)

Unfortunately you have to disconnect your vacuum pump if you want to try it.

Exactly! At high altitude and/or cruise power settings it does nothing for you. Fortunately it works best down low at approach settings. If you have to go missed you can say goodbye to your vacuum until you are able to reduce power again. I've never used mine in actual IMC but I had a vacuum pump fail while VFR and it was a useful experience to see how it behaved at various power settings. If I ever have to use it on an instrument approach I will advise ATC in advance and request a nonstandard missed procedure with a straight-ahead climb.

This one is a little classier. From a test flight of a Boeing 787. https://flightaware.com/live/flight/BOE236/history/20120209/2100Z/KBFI/KBFI http://green.blogs.nytimes.com/2012/02/16/skywriting-with-an-airliner/?_r=0

Details available here: http://www.thevacsource.com/svs.php

The standby vacuum is an STC'd add-on. There should be a flight manual supplement. It runs off the difference between manifold pressure and atmospheric pressure. It is critical to understand the operational limitations before you try to use it.

Or maybe a retraction system like speedbrakes.

I still work in the industry but I haven't been near a lab in years.

-a- I wasn't insulted. Sorry if my reply suggested that. I'm often very direct with my questions and I forget that some may read it with tone that was not intended. I seem to recall you are chemical engineer. You must have had to deal with chemists and our lack of social skills.

Thanks for the input on the gauge. I had the UMA gauge on my M20D and it was very handy to have when attempting to use the Precise Flight backup vacuum. I only used the backup vacuum once but it was much easier to reference the gauge than to try to reference the table while setting power. I would not want to remove my warning light. I think warning lights for critical systems are very valuable, particularly in high-workload situations where you might not notice a change in a small gauge outside your core scan. Unfortunately the warning light doesn't really give me as much information as I would like. It sounds like I might be able to do this with just a logbook entry. I'll ask my A&P for his thoughts on this as well.

I wasn't asking whether documentation was needed, I was asking about what documentation was needed. Is it a 337 or just a logbook entry?

What paperwork was needed for that? Just a logbook entry?

Agreed, that the SFO ILS is a very complex example. Take a look at AOPA's discussion on this (http://www.aopa.org/Advocacy/Air-Traffic-Services-,-a-,-Technology/Air-Traffic-Services-Brief-Use-of-GPS-in-lieu-of-DME-ADF) particularly this part: "Caution: Pilots should be extremely careful to ensure that correct distance measurements are used when utilizing this interim method. It is strongly recommended that pilots review distances for stepdown points during preflight preparation. (See Figure B; a GPS receiver set to the FAF, AASON, would be counting up to 8.1 at the missed approach point, where as a DME would have counted down to 0.9 at this same missed approach point.)" The approach for Figure B is: http://155.178.201.160/d-tpp/1503/00129LDAD23.PDF You can see that you have to do exactly that kind of mental math when referencing AASON. I would in no way advocate trying that SFO approach without a Garmin style overlay to help you find those waypoints.

RW26 is not a waypoint and it does not have a DME reference distance. The distance from the MAP to RW26 is informational only. The purpose of these waypoints is that you may use them in lieu of DME. That is allowed. The whole point is that you are not required to load an entire approach. You may separately load one (or all) of these waypoints from your database and use them in lieu of DME.

From the IFH: "select either the named fix as the active GPS WP or the facility establishing the DME fix as the active GPS WP" " If selecting the DME providing facility as the active GPS WP, a pilot is over the fix when the GPS distance from the active WP equals the charted DME value"

Yes, there are GPS waypoints, but I was referring to specific mention of GPS, particularly in the title which would result in an official GPS overlay. Any approach that you find in your GPS that does not have an official GPS overlay is not an official approach and is for advisory purposes only. You can check your GPS manual and when you load the approach it will give you a warning that it is for advisory purposes only.

I think you are misreading that. It only says you can't create your own waypoint based upon place/bearing/distance. It has absolutely nothing to do with navigation. You are absolutely allowed to navigate based upon reference to any waypoint in your database. There is a good discussion of this in the FAA Instrument Flying Handbook. Starting on page 9-27 there is a section on GPS substitution that includes the following: To Determine Aircraft Position Over a DME Fix: 1. Verify aircraft GPS system integrity monitoring is functioning properly and indicates satisfactory integrity. 2. If the fix is identified by a five-letter name that is contained in the GPS airborne database, select either the named fix as the active GPS WP or the facility establishing the DME fix as the active GPS WP. When using a facility as the active WP, the only acceptable facility is the DME facility that is charted as the one used to establish the DME fix. If this facility is not in the airborne database, it is not authorized for use. 3. If the fix is identified by a five-letter name that is not contained in the GPS airborne database, or if the fix is not named, select the facility establishing the DME fix or another named DME fix as the active GPS WP. 4. When selecting the named fix as the active GPS WP, a pilot is over the fix when the GPS system indicates the active WP. 5. If selecting the DME providing facility as the active GPS WP, a pilot is over the fix when the GPS distance from the active WP equals the charted DME value, and the aircraft is established on the appropriate bearing or course. It clearly says you can select either the named fix or the facility as a waypoint.

I had a clogged #1 injector right after I bought my M20J.

A previous owner of my M20J used velcro strips to attach a couple of the long colored trim pieces. The extra material of the velcro strips in between the trim and the panel creates a noticable gap. It does not look good. Maybe it won't be as noticable under an armrest. Adhesive, or maybe carpet tape, would probably give a cleaner look.

I think we are talking about different things. When the FAA says "in lieu of" they typically mean a case where GPS isn't specifically listed. In that case the GPS overlay is not official and is for advisory purposes only. In that case you are not required to load it. This is what is outlined in that AOPA link. In the cases where GPS is listed on the plate there should be an official overlay that needs to be loaded. These should be distinguished in the list of approaches for an airport on your GPS unit. I believe this is what you were referring to when you pointed to that approach at SFO. In the posts that preceded our discussion The term "in lieu of" was mentioned without specifically mentioning GPS so I was focused on the first case.

It depends on the approach. If the approach has "GPS" in the name or lists GPS specifically (e.g. DME or GPS required) then you need to load it. If the approach is something like a VOR/DME with no mention of GPS anywhere on the approach plate then you may use GPS "in lieu of" the DME. In that case you only need to load the DME fix. If you have a Garmin 430 you should be able to tell the difference when you attempt to load the approach.

As far as the SFO ILS example I think the AOPA discussion covers this: "Caution: Pilots should be extremely careful to ensure that correct distance measurements are used when utilizing this interim method. It is strongly recommended that pilots review distances for stepdown points during preflight preparation. (See Figure B; a GPS receiver set to the FAF, AASON, would be counting up to 8.1 at the missed approach point, where as a DME would have counted down to 0.9 at this same missed approach point.)" The approach in question is the LDA/DME 23 at KEKO (http://155.178.201.160/d-tpp/1503/00129LDAD23.PDF). You can see that AASON is analogous to HEMAN in its relationship to the MAP. Yet the AOPA note clearly shows that you can subtract the two DME distances to find the MAP.

Well, your last example is a GPS RNAV approach so in that case you would have to load it, but that's not what we were talking about. In the 26 approach I don't see a RW12 fix. I suspect that is just the next waypoint that your GPS loads to help you sequence. I do see ZADBA which I can load as a waypoint. I agree that in some cases it is not practical and probably not a good idea. However, in other cases you just need your GPS in lieu of an ADF to identify the LOM http://155.178.201.160/d-tpp/1503/05958IL4.PDF In those cases you are not required to load the procedure. You may simply load the identifier and navigate accordingly.

Right, the fix has to come from the database. The approach procedure does not have to be loaded in order to load the fix. A simple "direct to" followed by entering the fix identifier will load the fix from the database and then you may use the distance information provided by your GPS in lieu of DME-based distance.

Also in table 1-1-6 on AIM 1-1-24 it shows that only en route and terminal certification is required for use in lieu of ADF or DME. If approach certification isn't required how can it be required to have an approach loaded in the system?