If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
|
Thread Tools | Display Modes |
|
#1
|
|||
|
|||
Missed approach (?) when glideslope fails
You are on an ILS approach, DH 200'. The localizer-only MDA is 500'.
You are at 300' in IMC when the GS fails. Assuming you are timing the approach, is it legal to climb to 500 and continue the approach? |
#2
|
|||
|
|||
It's rather academic, since if you can't see the runway at 300 feet, you're
unlikely to climb to 500, see it, and then be in a position to descend down for a normal landing. But to answer your question, no it's not legal according to 14 CFR 91.175(e)(1)(i) since you'd be operating below the MDA for the LOC approach. Section 91.175: Takeoff and landing under IFR. (e) Missed approach procedures. Each pilot operating an aircraft, except a military aircraft of the United States, shall immediately execute an appropriate missed approach procedure when either of the following conditions exist: (1) Whenever operating an aircraft pursuant to paragraph (c) or (l) of this section and the requirements of that paragraph are not met at either of the following times: (i) When the aircraft is being operated below MDA; or "Yossarian" wrote in message oups.com... You are on an ILS approach, DH 200'. The localizer-only MDA is 500'. You are at 300' in IMC when the GS fails. Assuming you are timing the approach, is it legal to climb to 500 and continue the approach? |
#3
|
|||
|
|||
"Yossarian" wrote:
You are on an ILS approach, DH 200'. The localizer-only MDA is 500'. You are at 300' in IMC when the GS fails. Assuming you are timing the approach, is it legal to climb to 500 and continue the approach? I don't know of any rule which explicitly says it is illegal, but my personal opinion is that it's a stupid idea. It's a stupid idea in the general sense because the middle of an approach is no time to be changing plans and diagnosing instrument failures. Go around, sort things out at a safe altitude, and figure out a new plan when you have time to consider all your options. It's a particularly stupid idea in the specific scenario you described. If you're still IMC at 300 feet, what makes you think climbing to 500 will put you in a position where you can see the runway? Consider also how inaccurate timing is. In a typical GA airplane, 100 feet above DH on the GS is about 10 seconds away from the ILS MAP; what makes you think your FAF-MAP timing is accurate to within 10 seconds? Plus, another thing. Transition from descent to climb profile involves power changes, pitch changes, and trim changes. And all those again as you level off at 500. Are you going to be doing all those things, and peering out of the window at the same time trying to see the runway (all the while paying attention to your timer counting down the last few seconds)? And then more power/pitch/trim changes (plus get the gear up this time) a few seconds later as you finally decide to go missed? Low, slow, and IMC is the wrong place to be doing all these things. |
#4
|
|||
|
|||
"Yossarian" wrote in message
oups.com... You are on an ILS approach, DH 200'. The localizer-only MDA is 500'. You are at 300' in IMC when the GS fails. Assuming you are timing the approach, is it legal to climb to 500 and continue the approach? Legality-wise, the only offence someone could really try to prosecute you for would be that of breaking the approach constraints of the equipment available to you. Your defence (which I'm 100% sure the court would accept) would be that the approach was legal until the equipment broke and immediately switched you to a situation which was (strictly speaking) illegal, but which you expeditiously got yourself out of by climbing to the new MDA. Theory notwithstanding, though, the sensible way to go is execute a missed approach, go back to the start, get the other approach plate out, remind yourself of the minima, and have another go. As others have said, I suspect this example is hypothetical - if you're at 300' on the glideslope of an ILS, you're a mile from touchdown and you'll probably be over the runway by the time you've realised what's going on and have climbed. It's not inconceivable, however, for something similar to happen when (say) an airfield has published ILS (precision) and NDB (non-precision) approaches, where the difference in DH is only a hundred feet - you could in theory embark on the ILS approach, the glideslope could fail at 350 feet, and you're still within the legal limits of an NDB approach. Again, though, this doesn't necessarily mean it's a sensible way to go. D. |
#5
|
|||
|
|||
David Cartwright wrote:
"Yossarian" wrote in message oups.com... You are on an ILS approach, DH 200'. The localizer-only MDA is 500'. You are at 300' in IMC when the GS fails. Assuming you are timing the approach, is it legal to climb to 500 and continue the approach? Legality-wise, the only offence someone could really try to prosecute you for would be that of breaking the approach constraints of the equipment available to you. Your defence (which I'm 100% sure the court would accept) would be that the approach was legal until the equipment broke and immediately switched you to a situation which was (strictly speaking) illegal, but which you expeditiously got yourself out of by climbing to the new MDA. Theory notwithstanding, though, the sensible way to go is execute a missed approach, go back to the start, get the other approach plate out, remind yourself of the minima, and have another go. Not exactly. There is always the catch all "reckless" operation violation. All it takes is an FAA guy to find out about this and consider it reckless. Matt |
#6
|
|||
|
|||
Is it safe or prudent given your level of skill? That is the question.
Yossarian wrote: You are on an ILS approach, DH 200'. The localizer-only MDA is 500'. You are at 300' in IMC when the GS fails. Assuming you are timing the approach, is it legal to climb to 500 and continue the approach? |
#7
|
|||
|
|||
IMHO, there are far too many CFII's teaching students to transition
from an ILS approach to a LOC approach midstream, if the glideslope fails. Human beings are very habit oriented. Things are much more consistent if we do things the same way every time. (Watch a professional golfer getting ready for a drive a few times, and you'll see that they do it the same way every time.) The prudent (in my opinion) action, when the glideslope fails inside the FAF, is to go missed and then get your head around the LOC approach, regardless of where you are on the Final Approach segment. If you have yet to reach the FAF, brief the LOC approach if you have time. Otherwise, ask to hold at the FAF (if available) or take another action that will give you the time. Just my two cents. -Rob ---- Rob Montgomery www.scarylittleairplanes.org |
#8
|
|||
|
|||
Don't try to convert an ILS into a LOC in midstream. Go around and try again
(this assumes that radar is not available). Bob Gardner "Yossarian" wrote in message oups.com... You are on an ILS approach, DH 200'. The localizer-only MDA is 500'. You are at 300' in IMC when the GS fails. Assuming you are timing the approach, is it legal to climb to 500 and continue the approach? |
#9
|
|||
|
|||
On 6 Sep 2005 19:29:14 -0700, "Yossarian"
wrote: You are on an ILS approach, DH 200'. The localizer-only MDA is 500'. You are at 300' in IMC when the GS fails. Assuming you are timing the approach, is it legal to climb to 500 and continue the approach? That's how I was taught. You time the ILS approach, even though it's not necessary, in case the GS fails and you can climb to the MDA and continue as a LOC approach. I've read several articles advising that. I was even told that not timing the ILS approach was a failure item on the checkride, so I did as I was taught and timed the approach. I guess it's good practice against the possibility of forgetting to time the approach when it really does matter. My GS is included in one radio, the Narco NAV122. The LOC and GS share some components so if a common component fails, the whole thing is suspect. In fact, the one time the radio did fail it was the multiplexer that quit, though the failure was discovered on the ground and not on approach. I suspect that other installations may also share components in unexpected ways, particularly antennas. If something fails, you don't need to be puzzling about whether you can trust what's left while you're 300' and barrelling down the glideslope. A miss allows you to evaluate your condition from a safe altitude. Unless your tanks are empty and you have seconds to get it on the ground before the power fails. But then that's a whole different scenario. RK Henry |
#10
|
|||
|
|||
RK Henry wrote
I was even told that not timing the ILS approach was a failure item on the checkride, so I did as I was taught and timed the approach. You received incorrect information. A miss allows you to evaluate your condition from a safe altitude. A procedure required in the airline industry. Bob Moore ATP CFI |
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Nearly had my life terminated today | Michelle P | Piloting | 11 | September 3rd 05 02:37 AM |
VOR/DME Approach Question | Chip Jones | Instrument Flight Rules | 47 | August 29th 04 05:03 AM |
Approach Question- Published Missed Can't be flown? | Brad Z | Instrument Flight Rules | 8 | May 6th 04 04:19 AM |
Missed approach procedure... | [email protected] | Instrument Flight Rules | 39 | November 11th 03 03:46 PM |
USAF = US Amphetamine Fools | RT | Military Aviation | 104 | September 25th 03 03:17 PM |