ILS or RNAV request

[aterpster]

Any downside to starting a timer at FAF?

More unnecessary work. The timing table is terribly inaccurate compared to the DA point.

The timing table is only for the LOC (G/S out) MAP. If you are planning for the extremely small chance that the G/S will fail between the FAF and DA, keep in mind any step-down fixes that may need to be factored into any such reversion. Reversion is your choice.

 

[poadeleted20]

Any downside to starting a timer at FAF?

None of which I am aware. But I've only been doing this for a few decades, so I may not have learned it yet.

 

[poadeleted20]

More unnecessary work. The timing table is terribly inaccurate compared to the DA point.

The timing table is only for the LOC (G/S out) MAP. If you are planning for the extremely small chance that the G/S will fail between the FAF and DA, keep in mind any step-down fixes that may need to be factored into any such reversion. Reversion is your choice.

Laws of Exercise and Recency. If you don't hit the timer every time you cross the FAF, then the day you really need it you are too likely to forget it. Takes about 2 seconds (maybe less) to do this, and if that's going to ruin your concentration on the GS, then you shouldn't be flying IFR solo.

 

[aterpster]

Laws of Exercise and Recency. If you don't hit the timer every time you cross the FAF, then the day you really need it you are too likely to forget it. Takes about 2 seconds (maybe less) to do this, and if that's going to ruin your concentration on the GS, then you shouldn't be flying IFR solo.

That is a bit strong, to say the least.

Rote is fine, but it doesn't mean a pilot will know how to revert on an ILS approach when once in 20 years, or whatever, the G/S fails inside the clock punch.

 

[TMetzinger]

Laws of Exercise and Recency. If you don't hit the timer every time you cross the FAF, then the day you really need it you are too likely to forget it. Takes about 2 seconds (maybe less) to do this, and if that's going to ruin your concentration on the GS, then you shouldn't be flying IFR solo.

Sorry, I call BS. It's not the hitting the timer that matters, it's the "oh jeez there goes the GS now what's my stepdown fix and what's my time what's my groundspeed" between the FAF and the MAP. Unless you've got an emergency, go missed and try again. There's no NEED to make it more complicated, the whatever-it's-named tribe isn't chasing you.

 

[poadeleted20]

That is a bit strong, to say the least.

Might be strong, but it's the reality in the owner/pilot world in which I work. I do a lot of instrument refresher courses with nonprofessional pilots, and the first time they have to fly a nonprecision approach without their GPS, most have to be reminded to hack the clock at the FAF.

Rote is fine, but it doesn't mean a pilot will know how to revert on an ILS approach when once in 20 years, or whatever, the G/S fails inside the clock punch.

Even if you don't plan to revert, how are you going to know when to start the turn on the missed approach procedure if you didn't hit the clock at the FAF if you don't have DME or GPS to help?

 

[tehmightypirate]

Might be strong, but it's the reality in the owner/pilot world in which I work. I do a lot of instrument refresher courses with nonprofessional pilots, and the first time they have to fly a nonprecision approach without their GPS, most have to be reminded to hack the clock at the FAF.

This makes a lot of sense to me. I could see that being a hard habit to develop and will definitely start flying ILS approaches with a reminder to hit the timer at the FAF. Bonus points because the G1000 makes it dirt easy to start the timer. As was said; why wouldn't I do it?

 

[poadeleted20]

This makes a lot of sense to me. I could see that being a hard habit to develop and will definitely start flying ILS approaches with a reminder to hit the timer at the FAF. Bonus points because the G1000 makes it dirt easy to start the timer. As was said; why wouldn't I do it?

It's an easy habit to develop if you learn it from the git-go in your IR training. :wink2:

 

[aterpster]

This makes a lot of sense to me. I could see that being a hard habit to develop and will definitely start flying ILS approaches with a reminder to hit the timer at the FAF. Bonus points because the G1000 makes it dirt easy to start the timer. As was said; why wouldn't I do it?

With the G-1000 what is a good reason for timing an ILS? It the GS fails you still have the LNAV missed approach up and ready to go.

 

[Jaybird180]

Laws of Exercise and Recency. If you don't hit the timer every time you cross the FAF, then the day you really need it you are too likely to forget it. Takes about 2 seconds (maybe less) to do this, and if that's going to ruin your concentration on the GS, then you shouldn't be flying IFR solo.

My question was tongue in cheek, but this IS the response I was seeking. Glad to know.

 

[DutchessFlier]

As noted above, the only thing that pushing the CDI to GPS will do at that point is take away your GS needle and generate a warning MSG on the GPS. Further, even quickly reloaded the RNAV(GPS) approach so you can use that instead of the ILS has a number of difficulties, starting with a lot of button pushing to select and activate the approach, and going to the probability that the programmed missed approach for the RNAV(GPS) procedure will be different than that for the ILS for which you were cleared, which could create serious problems if you miss -- controllers usually get really upset when you do something other than what they cleared you to do.

If you're cleared for an ILS approach and the ground based equipment or the receiver in your aircraft is faulty, don't you have to notify ATC and fly the missed approach, go out to a vector or a hold, request and reset to the RNAV approach (assuming you have the equipment in your aircraft) and play the do over? I was under the assumption that switching on the fly along the approach was verboten?

 

[bobmrg]

If you're cleared for an ILS approach and the ground based equipment or the receiver in your aircraft is faulty, don't you have to notify ATC and fly the missed approach, go out to a vector or a hold, request and reset to the RNAV approach (assuming you have the equipment in your aircraft) and play the do over? I was under the assumption that switching on the fly along the approach was verboten?

No, just a poor operating practice.

Bob Gardner

 

[John Collins]

No, just a poor operating practice.

Bob Gardner

Bob,

I think it is more than a case of a poor operating practice to fly an approach that you are not cleared for. Switching from flying a full ILS to the localizer version of the same procedure or from a RNAV LPV to an LNAV version of the same procedure is permitted, although I personally think it is a poor operating practice. However, switching from an ILS to an RNAV procedure without a clearance is not permitted.

 

[aterpster]

Bob,

I think it is more than a case of a poor operating practice to fly an approach that you are not cleared for. Switching from flying a full ILS to the localizer version of the same procedure or from a RNAV LPV to an LNAV version of the same procedure is permitted, although I personally think it is a poor operating practice. However, switching from an ILS to an RNAV procedure without a clearance is not permitted.

For good reason. The missed approaches are usually different and often quite different.

 

[John Collins]

For good reason. The missed approaches are usually different and often quite different.

Even if the missed approach was identical as is the case at ILM for these two approaches to RWY 6, a clearance for one (ILS Z) is not a clearance for the RNAV.

http://155.178.201.160/d-tpp/1401/00459IZ6.PDF

http://155.178.201.160/d-tpp/1401/00459R6.PDF

And because they are not the same procedure (ILS Z and ILS Y or LOC/DME), even though they have identical final approach segments, if you are cleared for the Z, you are not cleared for the Y if the GS fails and you want to continue on the Y LOC/DME option.

http://155.178.201.160/d-tpp/1401/00459IYLD6.PDF

 

[RotorAndWing]

Sorry, I call BS. It's not the hitting the timer that matters, it's the "oh jeez there goes the GS now what's my stepdown fix and what's my time what's my groundspeed" between the FAF and the MAP. Unless you've got an emergency, go missed and try again. There's no NEED to make it more complicated, the whatever-it's-named tribe isn't chasing you.

Yep

 

[MyassisDragon]

Third page, pretty good topic. Who would have thunk.
I do have a small tidbit to add.

The other night I was out practicing a few approaches with the wife unit cause she wanted to see a sunset, but that was only happening above the clouds so I thought I would help my currency and get her sunset.

Well here's the tidbit:
I was on an ifr flight plan requested vectors to rnav xx and was cleared and complied. It was a slow night and I was the only one on approach, then ATC came back and gave a final instructions

Turn xxx maintain 3000 until established cleared for ILS xx ???? WHAT!!!!!
So I queried back in a jovial manner and asked to confirm. Rnav or ILS...so the controller laughed and said cleared for vectors to straight in approach runway xx.
And asked how the approach would terminate. And laughed.

He opened that box a little so I thought I would kick it wide open and I asked if that would screw up tower if I went missed on either the rnav or ILS.

His reply was nope we will tell you your map climb out instructions so both you and tower will be on the same page before going missed. Regardless of the approach.

But he did follow up with cleared for rnav xx contact tower on xxx.xx.

Now I understand it was a slow night and there is nothing in this post claiming to what is legal or not...but i like being able to interact on slow nights with controllers ( they are real people too) and I wanted to share this exchange for what ever it's worth.




Sent from my iPad using Tapatalk HD

 

[aterpster]

Even if the missed approach was identical as is the case at ILM for these two approaches to RWY 6, a clearance for one (ILS Z) is not a clearance for the RNAV.

http://155.178.201.160/d-tpp/1401/00459IZ6.PDF

http://155.178.201.160/d-tpp/1401/00459R6.PDF

And because they are not the same procedure (ILS Z and ILS Y or LOC/DME), even though they have identical final approach segments, if you are cleared for the Z, you are not cleared for the Y if the GS fails and you want to continue on the Y LOC/DME option.

http://155.178.201.160/d-tpp/1401/00459IYLD6.PDF

That too.

 

[azure]

He opened that box a little so I thought I would kick it wide open and I asked if that would screw up tower if I went missed on either the rnav or ILS.

His reply was nope we will tell you your map climb out instructions so both you and tower will be on the same page before going missed. Regardless of the approach.

My understanding (and experience, FWIW) is that in a radar environment doing approaches to a towered field, you will usually not fly the published missed unless you ask for it. So yes, it probably doesn't matter -- as long as you can receive missed approach instructions. But what happens if you lose comms before they can give you your MA instructions? Normally that shouldn't happen since they give them to you at the same time as they clear you for the approach, but just say for the sake of argument that it did... then it would certainly make a difference. In the soup I'd be uncomfortable with a situation like you describe because it sounds like it wasn't totally clear that everyone was on the same page. When that happens I ALWAYS ask the controller for clarification, even if it annoys him.

 

[Velocity173]

Full stop vs practice approach are two different things in the controller world. If an aircraft is doing a full stop then the published MA is automatically authorized unless the controller issues alternate missed. The clearance for "cleared approach" allows the aircraft to do any instrument approach they want and the published missed for those approaches. Most likely the controller has nothing going on in that situation.

For practice instrument approaches the controller is required to issue climbout instructions before the aircraft begins final descent. This has nothing to do with executing a MA. The climbout might mirror the initial stages of a published missed but that's about it. Unless the pilot really wants to do the published missed, a vector and altitude will be issued instead.

If you get cleared for an ILS and the glidepath goes out, notify ATC and get recleared for a LOC. Most likely they're going to roger it. If you're not comfortable continuing then go missed. As Ron said, for those of us without DME, the clock is the only thing we have to find the MAP for a LOC.