IFR approach briefing

[triplese7en]

It seems to be the standard in flight training to teach pilots, when flying an ILS approach, to brief the timing to the MAP so that in the event that the GP or LOC fails, the pilot will transition to the LOC or NDB approach and use the timing as applicable.

I don't think this is a good idea for a number of reasons. What statistics are there of the failure rate of GP or LOC instruments while an airplane is flying an instrument approach? Has anyone here had a GP or LOC fail while flying an ILS?

Failures can happen either due to an ILS system failure or an airplane avionics failure. These failures can be sudden and clear (i.e., signal completely lost and CDI centers with flag shown) or it can be incremental and obscure (sudden CDI or GPI excursions and/or flags coming in and out of view), plus other failures.

The point is that failures in real life aren't going to be equivalent to your instructor dialing in another frequency for the ILS and red flags popping up immediately.

What about cold temp corrections? Are you going to brief all the cold temp corrections for every altitude on the entire approach plate, or will you decide to brief the cold temp corrections after the GP fails and you fumble to get some situational awareness and transition to the LOC approach?

Determining what has failed and what is still providing legitimate data should not be done in a high stress environment such as flying an instrument approach—i.e., flying towards the ground at a high rate of speed. The 'why' should be obvious I hope.

Do a go around, fly the missed approach, talk to ATC, figure out what went wrong, and try again.

I can see how this practice has entered the flight training environment. When flying an approach, the instructor wants to ensure the student is able to recognize a failure and do something about it. In their mind, flying a missed approach is a waste of time and money and so they insist that their student fly another approach to get the maximum amount of teaching into one lesson. How is a student who is wet-behind-the-ears going to argue with their almighty wet-behind-the-ears instructor?

When I was wet-behind-the-ears I also taught to brief the timing on an ILS, etc. as it was SOP at the place I worked.

We need to start training for the real world.

[DanWEC]

I think this probably depends on the instructor. I wasn't taught to brief timing on anything but a non prec NDB approach, nor do I teach my students to.
I agree in that is just creating unnecessary work in a potentially high workload environment. By that vein you'd have to brief all the non prec minima as well while doing a prec approach.
If there's a failure, go around and configure for the proper approach unless you're visual or have a very good chance of making the field on your current approach.

Now that being said, it could be done to easily switch to a non-prec approach, assuming you already have the NDB/VOR dialed in as a backup, which I would do. Could be a case by case basis depending on how the approach is going, but what's an extra 5 minutes to redo the approach properly?

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[Big Pistons Forever]

I am with you trip.

The silliness of briefing the timing on an ILS is a FTUism which should be stamped out. I tell students you fly the approach you briefed. If something changes then you don't change horses on the fly, you go around. For a scenario where there is a problem with the glideslope this is what I expect:

1) Immediate fly the missed approach starting with going to the MAP, as you are now not flying the briefed approach

2) Start troubleshooting as a lack of the glideslope signal may be the first sign that you have bigger avionics/electrical problems.

3) Analyse the options starting with considering whether going to another airport with a fully functioning ILS is the best course of action. If the decision is made that the problem is ground based and a reliable LOC signal is available then request LOC only approach from ATC and re-brief for that approach.

[esp803]

From a training stand point I don't understand why you wouldn't just go missed. Operationally I've seen an HSI fail while on the slope, and a continuation of the approach with a quick switch of PF/PM.

E

[AuxBatOn]

I had to revert to a LOC only on a couple of occasions because the GP went tits up. Happens quite a bit on older GP antennas. No biggy. Didn't have to go missed, just leveled off at the appropriate altitudes. I rarely fly an approach that required timings (no ADF).

[ahramin]

I do more go-arounds than anyone I know, but I'm not big on go-arounds for no reason. I'm a firm believer in doing as much prep beforehand as possible. In cruise I have a look at all the approaches at destination. I run through each approach in my head, try to find any gotchas, and try to remember the initial waypoint names. Once I've got the ATIS I completely brief myself on all the approaches in use, including LOC only approaches for any ILS I'm doing, and program the 2 most likely ones into the magic box. If I lose the glideslope, and I'm in a good position to switch to the LOC approach, I'll be ready to do so.

But hells bells! Every IFR Approach Briefing I've ever met was way too long and had way too many Useless Pieces of Information. Why Add More? Why brief the other pilot on something as likely as a glideslope failure with enough time to switch to a LOC but without enough time to rebrief the LOC.

Ready for the LOC if the glideslope fails? Excellent idea and go right ahead but be ready for real. In my opinion though throwing one item about it into the briefing to sound cool without actually being ready for it is just bad flying, and teaching students who are just starting to fly IFR to brief switching from an ILS to a LOC in the middle of an approach is just bad teaching.

[Big Pistons Forever]

27 years since I got my IFR rating and I have had 2 instances of glideslope failure. The first one was when I was pretty new at the IFR thing and the glideslope in the airplane failed at full fly down with no flag. I realized I had a problem when I had a big descent rate approaching the gp check altitude at the FAF (marked by an NDB) and the ADF needle was still pointing ahead with not a wiggle . I wasn't exactly sure what was wrong but I knew enough not to try to fix things on the fly. A go around was initiated and I went to an airport with better weather. The GS needle was still full down when the avionics guy removed the instrument.

The second one was caused by a total power failure at the airport. The FSS guy told us and around we went.

The bottom line is I have flown the approach I have briefed every time. In the extremely unlikely event I have to change the plan then I have no problem with a go around and resetting the airplane, the crew, and my own mind.

My 02 cents: Concentrate on the killer items on the approach you intend to fly and don't clutter your mind with numbers for some other approach with a tiny chance of you actually needing.

[photofly]

It seems to be the standard in flight training to teach pilots, when flying an ILS approach, to brief the timing to the MAP so that in the event that the GP or LOC fails, the pilot will transition to the LOC or NDB approach and use the timing as applicable.

I was taught NOT to do that, for all the reasons mentioned.

[Colonel Sanders]

I was taught NOT to do that

It's funny, how things change. Decades ago,
TC insisted that you do the "navaid failure dance"
which was fly the ILS, and when the GS failed,
drop to LOC MDA/timing, and when the LOC failed,
you kept on trucking in using NDB MDA/timing.

If you did not do the above, TC would fail you
on the instrument rating flight test, because
according to them, it was the ONLY way to
fly IFR. So you did it, or else.

It's funny, how things change. It shows you
how many things that we take for granted as
solid as the Rock of Gibraltar, are just fashion,
and as one generation of TC Inspectors retire,
we see a new wave of fashion from the new
wave of TC Inspectors.

Like watching hair styles change.

[Trematode]

I think I'm pretty firmly in BPF's camp when it comes to flying the approach you started, and not switching in the midst of it. The idea of simply falling back to a LOC without knowing exactly what happened to cause the GS failure makes the hairs on the back of my neck stand up, especially if I were in IMC, relatively close to the ground. Why not go missed, and re-evaluate?

The First Air, Resolute Bay crash comes to mind, and the possibility that they may have been set up for an ILS approach with the VOR tuned erroneously (hypothetically speaking, here): ahramin, no disrespect intended, but what if the crew in that hypothetical scenario shared your thoughts about being prepared to fall back on any other approach -- when they tuned in what they thought was the LOC, and didn't get a proper glide slope, but still had what seemed to be valid lateral guidance, perhaps they were too eager to change plans and fly down to LOC minimums?

Not saying one shouldn't be ready for all possibilities, but wouldn't simply going missed incur the least amount of risk?

[triplese7en]

Well said BPF and Trematode.

Not saying one shouldn't be ready for all possibilities, but wouldn't simply going missed incur the least amount of risk?

That's pretty much it.

[AuxBatOn]

I can think of many scenarios where it would be safer to land from a back up approach than going around. Flight in icing is one of them..,

The beauty if a LOC back up to an ILS is that you can almost always maintain the same ROD if you have the GS failure because the GP check altitude is almost always higher than the non-precision FAF altitude. Maintain the ROD till FAF then increase slightly ROD to descend to the next altitude (more often than not, MDA).

[triplese7en]

AuxBat... you're assuming that this failure is going to be as clear as a bell and light flashing to tell you that the GP is gone and to switch to LOC minimums...

Also, how often have pilots ended up covered in ice where their de-ice equipment hasn't been able to catch up and then had a GP or LOC failure while flying an approach in IMC? Something tells me the chances of that are extraordinary small..

[ahramin]

Trematode, I'm not advocating it for everyone. In the situation you describe (ancient avionics with lots of gotchas and suicide switches) I completely agree with you. But in a modern aircraft, loading a different approach can be as simple as two button pushes.

What I think is obvious from what everyone here is saying: This is not something you would want to include as part of every briefing for student IFR pilots.

[careerpilot?]

I was just thinking through this scenario, and came up with a possible gotcha. If you are flying an ILS (no DME) and had a failure of the glide scope, then decided to execute a missed approach because you didn't brief the FAF timing for the LOC, how do you know where the missed approach point is without timing?

If you execute a missed prior to the MAP, you can (and should) execute an immediate climb, but still need to fly to the MAP before you continue with the procedure (laterally). Reversal of the LOC won't occur until 1000' past the end of the runway, in most (all?) cases that is well past the MAP. How do you determine when to begin the missed approach procedure without the FAF timing?

Makes me think that, maybe in an ILS no DME situation, we should always brief the timing, regardless of whether we plan to execute a backup approach or not... Unless I've totally missed something, in which case please bring it up for my own edification/learning value!

[glass1/2full]

Very recently within the last few months, had the GP go on the approach, just prior to faf.
Problem was, no GS flag was down, on either side, and we did have a capture initially. it all happened as we were coming up on FAF crossing. after cross checking the” FAF GP crossing altitude” and a quick cross check of both altimeters and settings, good freq and good tones, we quickly ignored the GS telling us to fly down on full scale down.

Rather than just descending to the LOC-Mins, since it happened pretty quick, I elected to go missed. That was my first gut feeling, and yes I know they are independent /LOC/GS, but I couldn't be certain at that moment that, It wasn't A/C equipment malfunction that was causing the issue
We called the missed and asked radio for the RNAV approach on the same runway VIA the corner post.
Radio asked if all is well.
Once we had a minute and got things squared away, we explained to radio what had happened and asked if he can check the equipment lights were all indicating all greens on his end.

This is the part that got me a little pissy.
He mentioned equipment were all indicating greens at his end for serviceability of the ILS but " and RJ had the same issue very recently" WTF…….
Maybe worth mentioning………………… !!!

So it does happen but like other posters had mentioned some might elect to just go missed and try something different.
that was at the end of a long ass day, just shy of the 14th hour of our duty and leg 7 of the day.
For me that was the best choice given our condition as a crew at the end of a long day.