35 minutes ago, anavsun said:

Wouldn't it be better to move towards the middle of the lake or in the opposite direction to avoid unpredictable thermals coming from the mountains in the east?

Apart from the considerations that @sloppysmusic has mentioned, the existing approach already has you over water from before OBAVE, so mountain thermals shouldn't be an issue. Plus, on a day with strong thermal activity, ceilings should be high enough for a visual approach anyway.

20 minutes ago, sloppysmusic said:

The big picture. There's more going on than just your approach! If you read the airport info you will notice noise abatement, heavy bird presence and the mountain thermals mentioned. 

More important than that is that r18 is preferred landing and r36 takeoff. To avoid planes flying right at each other the only SID for ktvl takes your plane on a left turn after takeoff and underneath a jetway that passes high over the lake. The left turn is to avoid your approach that is routed close to the shoreline to keep you well clear of departures. 

Thank you for this. This makes a lot of sense. 

21 minutes ago, Stearmandriver said:

An LPV is a precision approach.  But 737s are not certified for LPV (minus the Max which can do it with its MMR nav receiver, but which almost no operator uses.). The airline world by and large went the RNP route instead, before LPV was really a thing.  An RNP .10 approach yields basically the same minimums as an ILS or LPV.

But no need to get too down in the weeds.  Just know that you cannot use LPV minimums in your 737 NG.  Even if you fit the MMR, your operator almost certainly has not paid to get it added to your ops specs 😉.  So, you need to use LNAV / VNAV minimums. 

In reality, if an airline was serving this airport in 73s, the operator would likely build a non-public,  tailored approach that only they can use.  We have dozens of these, even excepting SE Alaska where we've built an entire network of them.  SAN, DCA, SBA, etc etc.

A character fault of mine from decades of root cause analysis in a prior life. 🙂 Thank you.

3 hours ago, anavsun said:

I don't understand your statement that he has flown it all wrong since he's almost always landed the aircraft without crashing.

Pure luck. He did fly IAN Approaches without noticing. Not RNAV. Different minima, different prerequisits, different obstacle and terrain clearence. See @Stearmandriver 's response above.

4 minutes ago, Farlis said:

Pure luck. He did fly IAN Approaches without noticing. Not RNAV. Different minima, different prerequisits, different obstacle and terrain clearence. See @Stearmandriver 's response above.

Rhetorically speaking, a 99% success rate can't be pure luck. 🙂 Perhaps there is some other explanation?

9 minutes ago, anavsun said:

Perhaps there is some other explanation?

Why do you keep asking the same question over and over again if it has already been answered. Just read what Stearmandriver wrote about IAN approaches and there is your answer.

 

 

2 minutes ago, Farlis said:

Why do you keep asking the same question over and over again if it has already been answered. Just read what Stearmandriver wrote about IAN approaches and there is your answer.

 

Apologies. @Christopher Low mentioned that he selects RNAV approaches and apparently unbeknownst to him and according to you, he actually ends up flying IAN approaches by pure luck. That makes me think that in as far as the PMDG 737 aircraft is involved, selecting an RNAV actually selects an IAN approach. In other words, RNAV is IAN, It is one and the same?

But those two are supposed to be different?

I am under the impression that RNAV uses satellites whereas IAN uses navigational radios. Maybe I am wrong...

3 minutes ago, anavsun said:

he actually ends up flying IAN approaches by pure luck.

No he does not fly them by pure luck, he managed to land in one piece by pure luck.

 

And by now I'm done explaining basics to you. Use google if you want to know how IAN works.

2 minutes ago, anavsun said:

I am under the impression that RNAV uses satellites whereas IAN uses navigational radios. Maybe I am wrong...

IAN is Boeing lingo for "let's have the FMC build a virtual Glidepath that will take you from the FAF to the missed approach point". (The last part is key to understand, this is a non precision approach, No autoland here)

Is it satellite based? I guess you can say so since FMC position is heavily biased to GPS and you have everything you need in the FMC. Maybe you can fly IAN without GPS, that's way above my layman knowledge of a 737.

 

7 minutes ago, Farlis said:

And by now I'm done explaining basics to you.

I appreciated your time. Thank you.

54 minutes ago, anavsun said:

 In other words, RNAV is IAN, It is one and the same?

But those two are supposed to be different?

I am under the impression that RNAV uses satellites whereas IAN uses navigational radios. Maybe I am wrong...

IAN is confusing.  Believe me, you aren't the only one it confuses 😉.  I'll give you the breakdown on what it is and why it exists, but in general, yes... IAN is a specific mode of the avionics that can be used to fly a limited number of non-precision (to include some RNAV) approaches, using data from the FMCs.  IAN does NOT use nav radios. 

First, basics.  There are two general types of instrument approaches: precision and non-precision.  We've actually taken to calling these ILS and non-ILS approached in our manuals, as that is functionally what it amounts to in the airline world.  The only approach most airliners fly that meets the technical definition of a "precision approach" is an ILS.  So there's an ILS, and a non-ILS.

In the non-ILS bucket are several types of approaches.  Some of them are based on radio navaids (VOR, Localizer-only, NDB) etc.  Some of them are purely derived from satellite nav data (RNAV, GPS, RNP (AR)).  

An important point: a 737 crew is almost ALWAYS going to fly ANY type of non-precision approach using data in the FMC, utilizing the autoflight modes of LNAV and VNAV.  If there are underlying radio navaids, they are required to be monitored, but in an airplane with all equipment operational, if the approach procedure exists in the nav database and can be loaded in the FMC, then LNAV and VNAV will be the preferred modes.

So.  You've got ILS (for which the nav radios are used and Approach mode is selected), and "other", for which FMC data is used and LNAV / VNAV selected.  Easy enough.

But, that's two different approach profiles to train, and regularly evaluate during pilot continuing qualification (annual) check rides.  Training time is expensive, and airlines are cheap.  Some are cheaper than others. 

So, some airlines asked Boeing for an automation mode that would allow them to fly a limited number of non-precision approaches using the ILS profile (a profile is just a standard way of flying a type of procedure, configuring at certain gates with certain standardized call outs etc.).  That way, they only had to train and evaluate one profile. 

This mode is IAN.  It is using FMC data (if you do not load an approach in the FMC, you will never end up in IAN.), but providing instrument indications that mimic an ILS.  

In reality, IAN is very limited - it can only handle the simplest type of non-precision approach.  It cannot handle an offset approach course beyond a few degrees, and so I don't know if in reality it could handle your Tahoe approach.  I also don't know if PMDG has modeled these limitations correctly, so it may work in the PMDG in circumstances it would not in reality. 

These are explanations as to why a simmer could use it and it would work every time in the PMDG - functionally, in IAN you are flying an RNAV approach, and the PMDG may be able to use IAN mode in circumstances that the real airplane cannot.

Again, other than making training marginally cheaper, IAN serves no actual purpose.  It is always operationally limiting, never beneficial.  But on a simple straight in non-precision, it'll get you there.

 

1 hour ago, Stearmandriver said:

But, that's two different approach profiles to train, and regularly evaluate during pilot continuing qualification (annual) check rides.  Training time is expensive, and airlines are cheap.  Some are cheaper than others. 

So, some airlines asked Boeing for an automation mode that would allow them to fly a limited number of non-precision approaches using the ILS profile (a profile is just a standard way of flying a type of procedure, configuring at certain gates with certain standardized call outs etc.).  That way, they only had to train and evaluate one profile. 

Thank you. ILS at a discounted price. 🙂

When do pilots typically 'clock' in and out for their logbook?

1 hour ago, anavsun said:

When do pilots typically 'clock' in and out for their logbook?

I worked for two airlines. One had a meter built into the aircraft systems than started counting time to the nearest 1/10 minute whenever an engine was turning. When that meter was running, the pilots were earning pay (and logging time).

The other airline tracked OOOI times, which stands for Out-Off-On-In. Those times correspond to out of the gate, off the ground, on the ground, and in to the gate. The OOOI times were recorded automatically and sent to the company. Pilots were logging time from Out (leaving the gate) to In (stopping at the gate after the flight).

 

 

Edited February 17, 20251 yr by prolixindec

The important question is, when are you getting PAID?  😉

From Out (doors closed, brakes released) to In (brakes set, L1 door open).

Edited February 17, 20251 yr by Stearmandriver