ILS, with or without the Glideslope

[C-5 MEM]

I have been taught that while on the ILS you back it up with timing in case the glide slope goes out. There is nothing saying you must go missed or continue with the approach. I have lost the glide slope before and continued with the LOC mins. As long as you have the mins there is nothing wrong with continuing.


C141

 

[skippy22]

Hey

Is there a legal definition to what you can do if the GS fails.
Thats what we need written information telling us what we can and can't do. All we know is that if we go missed we cannot go missed till the MAP, so where does it say we can't revert to a LOC only approach?

I need proof, not technique. I have always taught to continue at LOC mins if above, if below then go missed.

Maybe someone out there has the TERPS guide?

 

[C-5 MEM]

As for the GS going out, I don't know of any written info saying you must go missed or continue the approach. AS for the only place you can go missed approach. You can go missed approach anywhere you want.

 

[skippy22]

OK

But you do have to climb to the MAP altitude first. As one of the previous posts stated.

 

[C-5 MEM]

Yes you do. You must climb to the alt. to clear any obsticles.
The reason I said you can continue the approach is for this reason. If you are doing the ILS and the GS goes out. If you back your self up either by timing or DME you can be set up to continue the approach. When you do you briefing you should make that statement about the GS going out. This will allow you to land instead of going back out getting vectors again.

 

[skippy22]

OK

I totally agree, again this is our technique. It is not a published procedure.

 

[avbug]

Skippy22,

What do you mean by climbing to the missed approach altitude? When executing a missed approach, you must remain at or above the applicable minimums for the approach being conducted, until the missed approach point. At that point, the missed approach must be commenced. You may climb before that point, but may not turn.

No requirement to climb above MDA/DH exists until the MAP, nor is there any requirement to stay at MDA or DH. If one experiences a glideslope loss while operating below MDA for the localizer-only approach, one must at a minimum climb back up to the nonprecision minimums. This being the case, and the approach having become destabliized, in most cases going missed is the wise action.


"Hey Is there a legal definition to what you can do if the GS fails.
Thats what we need written information telling us what we can and can't do. All we know is that if we go missed we cannot go missed till the MAP, so where does it say we can't revert to a LOC only approach? I need proof, not technique. I have always taught to continue at LOC mins if above, if below then go missed.
Maybe someone out there has the TERPS guide?"

If the glide slope fails, you are still flying an ILS approach, sans glideslope. You must use the applicable minimums, as specified in the proceedure. This is basic.

You CAN go missed before the MAP; you just can't turn before the MAP, barring specific clearance to do so from ATC under specific circumstances.

This isn't technique. It's basic instrument proceedure. It doesn't require reference to TERPS. You're not reverting to a LOC approach. It's still an ILS approach. Loss of glideslope doesn't change that. You're flying the ILS without a glidesslope; you're flying the same proceedures, but need only select the appropriate minimums.

Sometimes multiple stepdown fixes or other special considerations may make continuation of the approach impractical, even with a prebriefing. If you have the fuel, often it's best to come back and try it again.

You do have the option of continuing. Your timing, the type of approach, the distance, the circumstances, and weather your fingers are crossed the right way make the difference. Sometimes it's practical and appropriate to contineu, and other times it isn't. In most cases, going missed approach is appropriate.

 

[skippy22]

I agree

I agree, but wheres the proof. Written FAR/AIM references. What do we use to justify it if we are pinned in a situation with the FAA.

And also you should not really do the LOC unless you are briefed for it.

 

[trainerjet]

As Avbug stated, more than once I might add...you are NOT flying a LOC approach in this case. You are still flying an ILS, just without the GS. The only thing that changes are the minimums. If it makes you feel better, add the GS inop minimums to your briefing. Everything else in the procedure remains the same.

I don't think you would ever get "pinned" by the FAA on this point. BTW, if they try to tell you otherwise, I'd ask THEM to show me in writing where it says so.

 

[pilotyip]

NPA

ILS without a gs is a NPA, just like the LDA w gs

 

[avbug]

Ahhh...very good. Nothing to do with this thread, but you're right. Once the electronic glideslope is no longer available, it becomes a nonprecision approach.

However, it still remains an ILS...it never changes from being an ILS, even with the glideslope inoperative.

Skippy, I'm not sure where the demand for proof on how to execute a missed approach comes from. It's very basic, the quote from the AIM has already been posted on this thread. This is a very basic part of being an instrument rated pilot; it's not a trade secret. When executing a missed approach, one may commence the climb immediately (unless instructed otherwise by ATC), but may not turn prior to the MAP.

Reference AIM 5-4-19(b):

b. Protected obstacle clearance areas for missed approach are predicated on the assumption that the missed approach is initiated at the decision height (DH) or at the missed approach point and not lower than minimum descent altitude (MDA). A climb of at least 200 feet per nautical mile is required, unless a higher climb gradient is published on the approach chart. Reasonable buffers are provided for normal maneuvers. However, no consideration is given to an abnormally early turn. Therefore, when an early missed approach is executed, pilots should, unless otherwise cleared by ATC, fly the IAP as specified on the approach plate to the missed approach point at or above the MDA or DH before executing a turning maneuver.

 

[172driver]

Thus the reason for starting your timer on every ILS. How else will you know when you've arrived at the MAP? People always seem to want to argue this one but it seems clearcut...

 

[LR25]

I always thought that if the glideslope fails and you did NOT start the time without DME, you better go missed. Better reason to start the clock on all ILS's that require it.

And as far as climbing immediatly executing the missed approach, there is an altitude on the published missed, if it says 2200ft, you go to 2200ft. It doesnt say climb to 2200ft only when passing the MAP, unless there are obsticles or specific instructions.

 

[avbug]

LR25,

Going missed is often the best option. However, without time to backup other sources, identifying the MAP may be a problem in some cases. By uniformly always starting time, one is in the habit of having this additional resource available. If the only identification of MAP is DH on the glideslope, and there is no glideslope, one needs the timing to know when to start turning...to identify the MAP.

 

[KC-10 Driver]

Always use common sense...

As "GooodLaaa" says, "Climb, But No Turns." If you are prepared to fly the localizer-only procedure, do so. Otherwise, go missed approach. Climb to the MAP altitude, but wait to fly the routing until at the non-precision MAP.

On an ILS, if you can't identify the MAP due to GS failure and you didn't time, identify the approach end of the runway by the best means available. You are being paid for your judgement.

There may be specific examples where this may not be the best course of action. But, overall, it is good advice.