Time on ILS approach

[Dep676]

Do you normally worry about starting the time on an ILS approach for your MAP? I had examiner tell me he busted someone because he was starting the clock for his time and he went full deflection on his localizer needle. I don't remember the last time I used the time for an ILS. Just wanted to get some opinions. I have an interviewing coming up.

 

[FlyinBrian]

It's a good idea to start your time on an ILS. (I'm assuming you mean the timing for the GS out localizer only approach) If you start it and your GS goes nutty on the way down, you may be able to make it a LOC only. Even if you can't, you still have some sort of range info other than the marker beacons.

I'd be pretty pissed if I failed a checkride for starting the timer. UNLESS your buddy told him that he could time an ILS approach. Full scale on the LOC though, that's almost a sure bust. You might salvage the ride if you immediately and flawlessly execute a missed.

 

[ILLINI]

Many people feel the reason for timing an ILS approach would be so that you could switch from an ILS to a LOC only approach should the glideslope fail while you are inside the FAF. I don't think airlines would allow you to do this per their procedures manual. I've heard that they feel that if you should lose the GS while shooting an ILS approach, you should excecute a missed approach and get vectored for the LOC only approach. This would give you time to brief only one approach prior to shooting it, rather than trying to remember two different sets of minimums for both the ILS and LOC approach.

 

[GeorgeTG]

Sure you can

If there are LOC minimums on the ILS plate you can fly the LOC without glideslope.
The approach is an ILS approach, even with the glideslope out of service. ATC would clear you for the ILS approach "glideslope out of service".

LOC approaches are in addition to and distinct from ILS approaches.

If you brief both mins., some airlines let you land. Many require however when something fails you go missed, start your climb to missed apch alt and any turns after MAP.

 

[Tri-holer]

In my experience, we never timed an ILS approach. We briefed the ILS (usually with DME) and what to expect. If the GS went TU during the approach - which in the real world, it never did - then we would have gone missed approach after asking the controller to check his equipment.

If we then had to shoot the LOC approach, we would have briefed the approach, the times and the speeds. On a typical approach, the speed was bleeding off during the approach and was not stable enough to accurately use for a timed approach. Even on an approach expected to be down to mins, we would wait for the marker to do the final configurating. If we knew that we would be timing it, I would be on speed and configured at the marker when the clock started.

It would be a good backup to time every approach, and brief every possible scenairo, and every possible emergency, etc. But this is the real world of work-a-day pilots.

Flame away.

 

[bobbysamd]

Timing on an ILS

I was taught and trained my students to time on an ILS, as a backup for determining the MAP and to fly it as a LOC approach in case the GS goes out.

Illini and Batman raise interesting points, though, about whether you should complete the approach if you should lose the glideslope. I hadn't really thought about it before, but, I think, they're right. I'd take a miss and get a new approach clearance. I'd also report the GS outage to ATC. As George points out, correctly, you can be cleared for a LOC approach with the GS out of service.

Now, if you have an ILS/DME approach, you can time if you want, but you would determine the MAP with the DME. If you lose the DME during the approach, you have to take a miss and get a new approach clearance. The DME is a required component of the procedure.

Probably Dep676's friend busted not because he started the timer but because he went full deflection on the localizer. Assuming no other information, that sounds like a legitimate bust to me.

 

[cvsfly]

What he said. This subject was beat to death - sorry to continue it. It isn't to hard though. If you brief it fly it. Or do what your airline SOPs dictate. Develop your own SOPs if you are Part 91. If it something quits working, best to miss the approach and figure out why before continuing. Yes DME is a handy tool on an approach. Many ILSs do not have DME and DME may not necessarily be legal to identify the MAP on those that do. K.I.S.S. Fly safe.

 

[Dep676]

Thanks for all the reply's. I didn't have a buddy bust the ride. I had examiner tell me busted a guy for that. Just because he was to worried about getting the time started and not flying the approach. He was just making a point to me. Do we really need to start the time? Because we all know in the real world flying we do things different usually or do them our own way especially when you start flying 2 pilots.

Thanks Again

 

[runtofthelitter]

Had this discussion a month or two back with two of my instrument students they were curious as well.

I asked them why would you not time the approach?

It’s a simple thing and should not result in task saturation of even the newest of students. As you are beginning to set up for the expected approach just note the time to the missed app point and the straight in LOC mins as well. Have your stopwatch either on the yoke or on the clipboard and start timing at the final app fix.

If you break out prior to DH or higher no problem, if the G/S stays put to DH another no “problem-er” but if you lose the g/s before the Loc minimums then you can at least continue to the published loc mins with a reasonable level of safety.

Personally, even if I was timing and lost the glide I’m getting my backside out of there and sort things out. Is the problem on your end or there’s.

runt

 

[ventus]

An interesting article I ran across a while ago about timing the ILS:

DON'T Time that ILS Approach

 

[WIDGETBOY]

In an airline enviroment it is pretty much usless to time an ils since usally slowing down and not holding a constant airspeed and the times are based on a constant groundspeed. If you loose you gs on an ils just go-around re-brief for the loc so you don't miss a step down fix or something and take a chance of becoming a smoking hole. Remember safety first.

 

[Tim47SIP]

Start the Time!

Guys, there are reasons that many people start the time at the LOM or FAF for the non precision point on the ILS. It is not to convert over to a Loc only approach or just incase the GS is lost. The TERP's manual and the AIM's both state when and where you may start the missed approach. This is very clear. At the missed approach point. Most of the time the reason for this is full scale deflection. Whenever full scale deflection occures, you have to try to get back to the loc course and then to the missed approach point. When DME is not present, the only means you have to get there is time. If you get full deflection, you dont continue to descend untill you are back on course because of obsticle avoidance. So, you may not be able to get back on the GS once back on the localizer and you dont know precisely how far out you are. I have seen many a student and recurrency pilot try to get down only to find that they have allready passed the MAP and I have them look up before they hit the ground or run into something. They are believers after this session. You just cant start a missed approach proceduer 4-5 miles out from the MAP and expect to have obsticle avoidance. No it is not required at all to start the clock on a precision approach, but any examiner that will bust an individual for starting the time on an ILS is a moron and needs to be reported.

 

[Wiggums]

Another problem with timing approaches is that quite often the timer will start going off just about the time the student will need to roundout. I've seen students try to flare and stop the timer at the same time, it doesn't work out so well.

Changing from an ILS to LOC approach after the FAF is beyond my personal limits in actual. I train my students like I fly.

 

[willi7]

gs

I have found that using the good old five t's works real well. by ommiting a t (time) you train students as well as yourself to skip steps. this can lead to an error on an appoach. It sure doesn't hurt to start your time even if you won't be needing it.....

 

[runtofthelitter]

Re: gs

I have found that using the good old five t's works real well. by ommiting a t (time) you train students as well as yourself to skip steps. this can lead to an error on an appoach. It sure doesn't hurt to start your time even if you won't be needing it.....

Maybe it’s just late, maybe it was that second Corona I had with supper but would you mind explaining just a bit further what you mean?

Maybe I’m just not receiving what you are saying, has happened before.

 

[willi7]

when I teach an instrument student, I try and keep it monkey simple. At every fix they must do the 5 t's(turn, time,twist,throttle,talk.) They may not need to do one, but they have to say it out loud. If you do this you will not miss a 10 degree turn at a final approach fix or forget a time on a ndb or forget that you can descend. All those fun things that can get you. hope this explains things better.

 

[runtofthelitter]

Okay

I only teach the five T’s in relation to the hold, never crossed my mind to teach them at every fix passage.

 

[willi7]

Works real well although it gets old listening to it. Just insert twist as twisting any new radials or bearings and throttle with power settings for your descent.