Video of an ILS failure and CRM

[wrxpilot]

The link:
http://www.youtube.com/watch?v=0qaDVaKQSkQ

 

[deemee boosgkee]

Wow, glad they saved the day!! Hate to think what would have happened if one was flying single pilot IFR down to 200 ft as freight dawgs often do!! I am always a pesimist myself and have thought about what I;d do if I did get a false ILS as this crew did and certainly they did the right thing by going missed!! I ALWAYS check the VS compared to the GS and make sure the two matchup. The VS should be approx 1/2 the GS times 10. If I have any intuition that this doesn't match, I go around. PERIOD!! Certainly a good lesson for all of us!

 

[Way2Broke]

Very interesting video. I learned a thing or two from this. Well worth the watch. But what was wrong with the GS, and how would that make them close to the island.

 

[epic!]

thats strange, i wish they would have said what exactly was wrong with the ILS

 

[Amish RakeFight]

Although not mentioned, intercepting the GS too high can cause excessively high descent rates and lead to false indications.

Has anyone ever encountered this phenomenon?

 

[SPilot]

Couldn't it be a vehicle or something momentarily interfering with the signal?

 

[Instinct]

http://www.caa.govt.nz/Occurrences/00-2518.htm

 

[wrxpilot]

I've got a dumb question... What does it mean when a navaid such as the ILS is unmonitored? Does that mean appch control is not going to keep an eye on your glideslope?

EDIT:
Ok, I just found the definition:

5-3-5. UNMONITORED NAVAIDs​

a. All VOR, VORTAC, and ILS equipment in the NAS have automatic monitoring and shutdown features in the event of malfunction. Unmonitored, as used in this order, means that the personnel responsible for monitoring the facility have lost aural and visual monitoring capabilities and cannot observe the status of the facility. It does not refer to the automatic monitoring feature.​

b. When a navigational aid's operational status cannot be monitored at the controlling or monitoring facility, but all indications or reports are the facility is operating normally, issue a NOTAM placing the aid in an unmonitored status.​

c. When issuing a NOTAM describing a facility as unmonitored, do not use the category of monitor, only the contraction UNMNT.​

EXAMPLE-
!DCA LDN VOR UNMNT ​

d. If the NAVAID is reported as being out of service, the unmonitored NOTAM shall be canceled.​

 

[Amish RakeFight]

A little trivia, the reason some aiports are unusable as an IFR alternate (N/A) is that the facility the approach is based upon is unmonitored.

 

[PositionandHold]

Although not mentioned, intercepting the GS too high can cause excessively high descent rates and lead to false indications.

Has anyone ever encountered this phenomenon?

During my IR training Night X/C, intercepted above and got the wrong gs indication. My CFII knew it, but let me take it until I caught it when I crosschecked altitudes on the plate at the fix. Classic false gs scenario.

 

[Amish RakeFight]

During my IR training Night X/C, intercepted above and got the wrong gs indication. My CFII knew it, but let me take it until I caught it when I crosschecked altitudes on the plate at the fix. Classic false gs scenario.

Was your descent rate excessive on the VSI? I'm wondering what it actually looks like and how high above the minimum GS int. alt. were you?

It's one of those things you read about but never really experience. I should go out and try it one day.

 

[Learsforsale]

Although not mentioned, intercepting the GS too high can cause excessively high descent rates and lead to false indications.

Has anyone ever encountered this phenomenon?

Its been awhile since my Instrument class but I remember something about false glideslopes that can be encountered above the normal glideslope. IIRC that is one reason that the altitude at FAF on GS is printed on the chart, so you know you are on the correct GS (in case you couldn't figure it out before).

 

[PositionandHold]

Was your descent rate excessive on the VSI? I'm wondering what it actually looks like and how high above the minimum GS int. alt. were you?

It's one of those things you read about but never really experience. I should go out and try it one day.

It's been some time so I don't remember exactly what happened, but I think I got distracted with something and waited too long to descend to the intercept altitude and I reacted by descending (probably steeper than normal) to catch it instead of going missed; and ended up catching what I thought was the GS but what was actually a false GS. In retrospect, going missed would have been the best option right away.

A couple of weeks after getting the ticket, I flew into an airport and was given "bad" vectors to intercept the glideslope, in and out of IMC and runway not in sight. As soon as I was given an intercept hdg and clearance for the approach, I already had full above GS Deflection on the CDI (i.e. needle was all the way down). I could have descended to catch it but why? So I asked for new vectors to re-intercept. Not worth the risk, especially in and out of IMC. If it was clear, I would have taken it fine.

 

[Gorilla]

The VS should be approx 1/2 the GS times 10.

?? Did you mean X 100? Otherwise you're looking at 15 fpm.

V/S is totally dependent upon approach speed. Your rule of thumb will vary, of course, with the type of AC you are flying. At 150 knots in a 737, V/S is going to be 700 or 800 fpm, not 1/2 GS X 100 which would be ~ 150 fpm for a 3 degree slope.

 

[wrxpilot]

?? Did you mean X 100? Otherwise you're looking at 15 fpm.

V/S is totally dependent upon approach speed. Your rule of thumb will vary, of course, with the type of AC you are flying. At 150 knots in a 737, V/S is going to be 700 or 800 fpm, not 1/2 GS X 100 which would be ~ 150 fpm for a 3 degree slope.

He meant GS = groundspeed, not glideslope... So for your example 150/2 = 75; 75x10 = 750 FPM. Just a nomenclature thing, I know you're already aware of the rule. Just thought I'd clear it up for everybody.

 

[CoATP]

false glideslopes will be at multiples of the angle of the "real" one. Usually you will see one at twice the angle (about 6 deg) so descent rate will be x2 (or about 1500 fpm) anything in excess of 600-900 fpm should be suspect.

 

[Morettis]

Had the same thing happen to me after I had an engine lose oil pressure on climbout. I tuned in the ILS and it bounced around a little then showed on glidepath but it was really the glideslope reciever in the plane quit and that's where the needle defaults to. Not so much fun to switch to a localizer approach using a separate vor for your stepdown fixes...

 

[Gorilla]

He meant GS = groundspeed, not glideslope... So for your example 150/2 = 75; 75x10 = 750 FPM. Just a nomenclature thing, I know you're already aware of the rule. Just thought I'd clear it up for everybody.

I stand totally corrected, TY.