100 Above TDZE Prior to MAP on LOC/DME???

[eddie]

Although this crew may have been comfortable decsending to 100 above TDZE, the CVR transcript doesn't really address continuing below MDA.

I would like someone to touch on the fact that neither pilot discussed leaving MDA, the only altitude that was mentioned was MDA...why is it being assumed that they planned to continue to 100 above. Maybe they went below mins.

The Captain saw the lights 1 second before the radar alt. said 200 ft, and the FO didn't say he had the approach lights until after the radar alt. said 200ft. I'm having trouble buying the fact that they didn't just drop below mins because they were both outside.

Am I missing something really obvious here? I know your discussion on the board is about the fact that a lot of pilots believe they can continue down at any distance...but after reading that cvr transcript, I'm just not sure that is what happened here.

 

[Xav8tor]

Tony,


Did you even bother to read any other, or maybe even all of my posts? I am not trying to sound like a TIP/TERPS guru, but I would like to hear from a few. When I have finished analyzing the TERPS, AFS420 docs, and the myriad of other applicable regs, etc. on instrument procedure design, and talked to a few more guys in the 400 branches at the FAA, and integrated it with the opinions you and others have expressed, I will try and share the conclusion and see if it holds water with those of you here, and elsewhere, who have bona fide expertise in this particular area. Until, and if, that happens, I have asked, if not outright begged, for input from those who might have credible knowledge about the subject to help me (and pilots in general), not take cheap shots up my six for starting and participating in what I hoped would be a potentially meaningful thread concerning aviation safety.


The lack of a published VDP according to some is taken as a clue that there is an obstruction affecting an otherwise normal approach, a statement I took from a fairly well-known website written by a gentleman who, while maybe not infallible, did boil the question down into an understandable form when, at that time, I was looking for a quick answer to get the ball rolling and pointed in the right direction. I'll see if I can dig up the phone number of the FAA guy who is a supervisor in the region that designed that approach who, as I understood him, said something similar to what you are taking issue with, but below is the other quote I was referring to:


"You can use or make a visual descent point (VDP) as a landing aid. TERPs require a VDP for all straight-in non-precision approaches except for procedures with remote altimeter setting, where the descent path is below a required step-down altitude and where it would be between the MAP and runway. No VDP will exist where an obstacle exists. The absence of a VDP serves as an obstacle alert." (bold emphasis mine)


http://www.whittsflying.com/Page7.62All%20Other%20Approaches.htm


I'm not sure of his quals except that he says he is a 10K hour CFI who has taken the time to build a website with hundreds, if not thousands, of pages of great tips, tricks, and explanations on IFR (and VFR) flying. Some may be oversimplified, maybe even incorrect, but visit the site and decide for yourself. I admit I did quote it though and I will, after appropriate research, either back it up or correct (retract) it. As I said, my next move is going deep into the source and interpreting it myself, enlisting free help from the Feds where possible and getting some advice from a few ex TERPS retirees who I've worked with before. If you don't think all the answers to approach design are buried deep in the TERPS and other documents (i.e., beyond the reach and "teach" of most IFR pilots, then instead of taking cheap shots at someone who admits he isn't a TERP/TIP design guru, how about you explaining exactly how the LOC/DME 36 at IRK was designed, why controlling obstacles are charted on NACO but not Jepp, and what each and every entry in Form _ _ _ _ (you know the number of course) is, and how it was determined, and how it affects the design as a whole. Also, why was 91.175 written to allow descent from MDA solely only the basis of sighting an ALS if literally applied (which by the way, the cannons of statutory interpretation and construction defer to over "common sense".) What is the background history of the NPRM (if there was one), or the rationale for any alterations since its original publication? Also, could a controlling obstacle at 1059 feet, give or take a few, located on the localizer just off the end of the runway affect a VDP? If so, how? If not, why not? Does it affect the descent angle in any way, or is that just due to the triangulation of the three points that define it? (some of these ?'s are rhetorical, some not, a few have already been answered).


As for your last two questions concerning the witness statements I referenced, and posted elsewhere on this thread, what context are you speaking of? The pilots, check airmen, DOT, APOI, were asked if it was OK to leave MDA upon seeing the ALS? You saw the answers. Only a couple who said yes expressed concern about distance from the threshold. Did you read what the APOI said about the TERPS? Instead of crossing (as in cross-examination) me, spend a few bucks yourself and get the whole docket, or give me the URL of a place I can upload it and I might just do that, time permitting. Read all 35 pages and come to your own conclusions. Read the rest of the >500 page docket and attachments too. Then correlate the CVR with the FDR. After you do that, then you can talk about putting the question in "context."


I said earlier that this accident was merely an example of what is IMHO a broader system safety issue and I am looking for other similar misinterpretations. When I find them, I will post them. I say again, I am not a TERPS expert. I am however, an expert in other certain areas, and I do know how to properly investigate an accident, examine evidence, ID and address safety problems, and maintain "credibility" by citing reliable sources. In this thread, I am not however preparing an accident report, getting ready to do a research project, publish a paper, or prepare for an argument before the Supreme Court. If I was, I wouldn't be asking questions on this board or making comments purposely designed to elicit responses contrary to what I wrote, to stimulate productive debate, a technique I picked up both in law school, and as an accident investigator, and as a Director of Safety. I saw also it on CSI once and I too stayed at a Holiday Inn Express recently, but only because the Ritz was full.



In any event, asking questions, expressing opinions (my own, and those of others) seems to have backfired on me here. Sorry, I didn't mean to be such an idiot wannabee and/or troll, trying to toy with the minds of all the top guns and widebody Captains. I guess I should just shut up and listen (wait a sec, isn't that exactly what I was trying to do?). Please, give me a few weeks and I might figure it out (with the help of some members here), unless I get my priorities straight and focus on some other things I should be doing rather than persisting in trying to find THE answer to a potential problem that might hurt people I don't even know (and who probably wouldn't take a leak on me if I was on fire).



The FACTS I presented are from FACTUAL reports generated by a government agency, many of which were conducted in a manner that encompassed legal formalities. Everything else was an opinion and sometimes, pardon me, a guess. I thought that was the way people collectively identify a problem and arrive at a consensus solution via the free exchange of information, from pure facts to shot in the dark theories. I guess I should have known better after 12 years of higher education and almost twenty in aviation, half of that in safety. I deeply apologize for whatever the heck it was I did to offend you above and beyond my verbose, pointless, zeal over a trivial, common sense, irrelevant topic.



I plead guilty to repeatedly (about once a year) becoming absolutely obsessed with certain safety issues. I neglect my "day job," family, friends, "chores," and everything else when I get like this. The saddest part is, I never have anything to show for it, other than fatigue, lost income opportunity, and missing quality time with my small family and circle of friends, and large holes in my empennage. Why? Well, it is impossible to demonstrate that whatever I do (heighten awareness, present an argument that was the impetus for a change in a law, policy or procedure, even wrote a brief ten years ago that still gets attention and recently was the main subject of an NTSB Public Hearing on new safety measures they want Congress to pass) did one bit of good because you see, it is almost impossible to prove a negative (i.e., the accident that didn't happen).



Whether it is one's profession or a hobby, or just a nut with an obsession, the questions raised, the answers found, the solutions derived, all of that comes together and may save a life or prevent serious injury one day in the future. Most of time, you will never know if it made the difference, and in those rare instances where you think you do know, no one ever says thank you, there is no bonus in your check, if you get paid for it at all, and someone else ALWAYS takes the credit. Again I am sorry for asking such silly questions and suggesting such absurd possibilities on a subject I obviously have no business even being concerned about. Now that I think about it, you've made me realize I have wasted the past two decades of my life, missed out on irreplaceable time with the people I love, and gone neck deep in debt. I think I'll make an appointment with a shrink first thing in the morning to see if he can cure this obsession. I may still die poor, but at least I won't waste any more time fretting over the welfare of other people who couldn't care less about me, or my well-being. Thanks for directly and indirectly pointing all of this out to me Tony. You might not have meant to do so Captain Driver, but you did me a huge favor Massuh.



PS- In answer to your last question...Yes. And as I've said before, one is one too many.



PPS - Start a thread on anything related to CVR's if you really want to see my obsession and credibility.

 

[Xav8tor]

Eddie,

You've asked some good questions and those answers I have because they are right up my alley. I am limiting my participation on this board to the two questions about 91.175 and Jepp obstacle charting. I posted the OPS group #2 interviews because they perfectly illustrate the problem with the way 91.175 is being applied by a large (relatively speaking within a defined sample) group of pilots. The CVR transcript excerpt was posted to help illustrate the thought process (and everybody wants to see it anyway).

The issues you bring up require some very complicated explanations both technical and legal. I'd be happy to discuss CVR analysis either alone, or in conjunction with FDR/Radar data. I'm just not sure I want to do it about this accident and/or in this thread. It's after 0400. Let me sleep on it. I will say that even though you haven't accounted for time sync and NTSB transcription methodology issues, you are on the right track. Also, the CVR, FDR tab, ACFT Performance, ATC group reports, and more from OPS #2 have to be integrated.

I'll think about it and try to explain what I can tomorrow. I will say that at first blush, it looked like a constant 11-1200 fpm ROD until just before the first impact with no obvious level-off at MDA or 1064. The calls were a little off in more ways than one. BUT this is a first take looking at raw data with no time sysnc and a host of other caveats and that is coming from others who have seen the data, not my own in-depth analysis. I'm just not disagreeing with it, if for no other reason, than I haven't run it yet and it does look like it to me on the first take too.

 

[ackattacker]

This is an excellent discussion, I think, with lots of good points all around and I hesistate to chime in with my regular old pilot viewpoint given all the technical talk being thrown around... but regs don't have to obey the laws of physics and lawyers don't get killed when they get it wrong.

Now, it appears to me that the regs do allow you to do the stupid thing and descend below MDA using the approach lights only on a non-precision approach. This is clearly idiotic. I question Xav8tor's statement that a lot of pilots seem to think this is OK. But I guess some do and some is enough to be dangerous. Apparently this company taught it, but they are hopefuly the exemption to the rule...

This whole descend to 100 HAT has always struck me as bit funny, even on a precision approach. You better know what you're doing. And just to let you know, I have shot more than my fair share of 1800 RVR VV001 approaches (ACK anyone?). The reg reads paraphrasing) "can't descent using ALS as the only visual reference unless red terminating side row bars also visible" and is a bit suspect. I mean, I've used this rule more times than I care to count to get down a little lower but I never really used the approach lights as a real reference to my aircrafts position, only just quick glances to verify lateral alignment. If you take your eyes off your scan for more than a second or so you've lost it for sure, until you get the REAL visual references (terra firma). I think this is pretty common practice, you don't see the ALS and go visual, you see the ALS and *continue*, as in "continue the instrument approach". This being safe because, with the ALS visible, you probably won't run into them. (and I've never seen an obstacle poking *through* the approach lights...) I know this is not exactly how the regs are written but practically that's how its done. Anyone disagree?

So, how do you apply this to a non-precision approach? You don't. I suppose, theoretically, that if you broke out of a non-precision approach and saw the approach light nearly underneath you then it might be tempting and perhaps legal to dive at them in hopes of getting the runway. The same general idea being that if you can see it and it's lit up then you probably won't hit anything between here and there. This is obviously dangerous, and the other way (seeing the ALS 3 miles out and dropping to tree-top level) is even more ridiculous. "Normal rates of descent" applies to both excessively slow and fast, as I believe most of us have been taught. Either way, there are other problems:

1. You can't very well be continuing any portion of an instrument approach at this point. You left all that behind at the MDA. You have no vertical guidance and no guarantee of any horizontal guidance either (depending upon the approach, or course, the location of the navaid, DME, etc.) Non-precision approaches are predicated upon essentially "going visual" to land. This is how we announce it in two pilot crews, is it not? "Runway in sight 12 O'Clock", "Going Visual". If you can't even see the runway, how can you possibly have enough visual reference to actually control the aircraft visually? So really, you have neither adequate instrument reference NOR adequate visual reference.

2. When you are visual you are taking responsibility for your own terrain clearance. I thought most pilots understood this. If you can't actually SEE the terrain than this is a pretty stupid thing to do, if you think about it, but of course we do it all the time since at night we often can't see the terrain when landing. In this case we are NOT relying on the TERPS to protect us we are relying on the same basic airmanship we learned when we got our VFR ratings and a little caution goes a long way. This is why the regs are so vague in this area. It's tough to regulate basic airmanship. I mean, there's no regulation which states "don't land if there's cows on the runway" but we pretty much use our common sense. This is no different on any non-precision approach, whether you see just the ALS, the runway, the whole damm airport--- once you've left the MDA it's entirely up to you to not hit anything and you have to use every trick up your sleave (knowledge of terrain, DME/VDP/GPS, avoiding black inky spots that could be either a lake or a mountain, etc). How could simply having the ALS in sight guarantee that you won't hit anything? Unless you're right on top of it? You can easily run into the ground on a clear moonless night with the runway in sight from 20 miles away. Or how could anyone believe that so long as you see the ALS you are "protected" at 100' (100 feet!!!! it gives me goosebumps!) above TDZE for an indefinite radius.

I guess my point it this, since I know Xav8tor that you are gathering a sort of survey/snapshot:

1. I was never specifically told to not use this rule on non-precision approaches. However, I was *never* taught to. I guess it seemed obvious.

2. It appears to me, that while the rule does seem to allow for a legal descent to 100 HAT on a non-precision approach, practically there is no legal way to do it, since you'd probably have to break some other regs to do so (operation below MDA without adequate visibility, not being in position to land using normal maneuvers and normal rates of descent, operation below VGSI for air carriers, I'm sure I could find some more).

3. Regardless of the legalities, its assinine. It's probably just an oversite on the FAA's part that it's legal at all. But then again, plenty of things are not prohibited but still stupid. It's not specifically prohibited in the regs to get up, spin around in circles 20 times fast, then sit down and try to land the plane, but it's pretty stupid.

4. The reg probably should be changed. There are, unfortunately, people who spend a lot of time studying the regs trying to figure out ways to get away with stuff they probably shouldn't. We've all seen it. And if you have an operator who has an economic need to operate reliable service into an airport which is hard to get into on instruments, they just might decide they've found a "loophole", and teach it to their poor unsuspecting pilots.

 

[Xav8tor]

Ack,

The tech talk is a necessity I guess because it is the nature of the beast. Your plain old pilot viewpoint is exactly what I'd like to see 1000 more of, which is why I asked a while back that people link this thread to other boards that might find it interesting.

Legal isn't safe was something I had to tell management every single day as a DOS. When I said a lot of pilots seem to think this way of applying 91.175 I was (I think) referring to the ratio of people who said that in the NTSB report. As a ratio, it was a lot, but I was trying to be "PC" and not single out this one airline. Of the people I spoken to about it and the responses on this board, two have said it was "legal." The rest used words like idiotic, stupid, insane, retarded, etc.

I earlier alluded to my first ILS to real mins using the ALS to get in. I was the PF as a newly minted FO in a J32. We had held for 20 minutes when the Wx finally came up to 1800, then went back down to less after we were inside the FAF, then up again...you know the drill. Cap'n said stay inside until I tell you to look up. At 200 he said I've got the rabbit, keep on coming, stay inside. Out of the corner of my eye I saw a fuzzy glow. Very quickly we passed through another 100 feet and he said I see the bars, stay inside, keep on coming. I was a little scared, but trusted this guy completely, he was one of the best. About that time, the GS bar on the flight director shoots upward and I pitch up to it, the Captain says runway in sight - look up, which I did just in time to pitch up another 2 or 3 degrees, trying to get out the words "going visual" before the thing just started rolling on the runway, never even felt it touch down or a heard a squeak out of the wheels. He took the controls at 70 knots and I just ran the checklists and nervously smiled at him. I got out and went in the breakroom, sat down, chainsmoked about 3 cigs, and gulped down a quart of coffee before I stopped shaking like a leaf (inside anyway). Since then, I've shot a few more down to mins like that (handflown in the J32 you know) and understood at that point how the reg was meant to apply. We too were legal but also perfectly safe. We flew it by the book, as a team, and knew each other's capabilities and those of the plane and that particular ILS, and had done it in the sim a few times. But buddy you are right, you had better do it by the numbers and know exactly what you are doing, especially in a plane like that one.

Thanks again, Ack for your input and analysis. By the way, your "cow regulation" comment was pretty funny to me. I did some consulting for a regional down in the Caribbean a couple of years ago and that was a really big safety issue they asked me about. At one airport, a low pass was required on almost every approach to clear the cows and goats off the runway. They had a fence put up, and tried a few other things, but the locals kept cutting through to take a shortcut to get to the farmer's market in town. I came up with 3 or 4 solutions, but last time I heard, I don't think they'd yet done anything about it. The most laid back, easy-going, adaptable guy I know almost went nuts after about 18 months down there. Great place to visit, lousy place to live and try to run an airline. The answer to a safety issue you bring up down there is almost always "No problem Mon....ev'ryting be Irie."


Back on topic, still pouring over the design criteria looking for the definitive answer in "English." Hope to have something soon. Also, if anyone has some space on a server somewhere, I could upload the other docs, charts, pics, etc. PM me if you do. I don't have one I can use for this.

 

[TonyC]

Tony,

Did you even bother to read any other, or maybe even all of my posts?

I guess you don't know me too well. I wouldn't bother posting if I hadn't read the entire thread, including every word of every post. Before I comment on what you have to say, you can be sure I have reviewed all you have said. I even read all of this post in spite of the attempted cheap shot with which it began.

I am not trying to sound like a TIP/TERPS guru, ...

Then it would behoove you to refrain from making statements like this:

Also, everyone needs to be aware that the lack of a published VDP means there is an obstacle in your way that precludes using one. Of course, most pilots will never learn or know that because it is buried deep within the TERPS and one or two other obscure FAA documents.

Now, do you really think I was taking a cheap shot?

... not take cheap shots up my six ...

... didn't frag up my six ...

... instead of taking cheap shots ...

I criticized the authoritative way in which you presented your assertion about VDPs and obstacles, and the casual way in which you admitted it was just something you got off a website, not really from an actual study or knowledge of the depths of TERPS - - YOU SAID that EVERYONE NEEDS TO BE AWARE! A writer with more academic integrity, and an honest investigator in search of truth and knowledge might have said, "I've found a website that states ___________. Is this true?"

Cheap shot? Hardly. I'm going to assume that the pain meds are making you a bit sensitive. That's a cheap shot. I apologize if I offended you - - it wasn't my purpose.

As for your last two questions concerning the witness statements I referenced, and pasted elsewhere on this thread, what context? The pilots, check airmen, DOT, APOI, were asked if it was OK to leave MDA upon seeing the ALS?
...
Instead of crossing me, spend a few bucks and get the docket, or give me the URL of a place I can upload it. Read it and come to your own conclusions. Read the rest of the docket and attachemnts too. Then correlate the CVR with the FDR. After you do that, you can talk about putting the question in context.

Oh, I see. I have to meet certain standards before I can question your conclusions? Sorry, but I don't see it that way. Here's what I mean about questioning the context:

If you were to ask me if it's legal to descend to 100' HAT using only the approach lights as a visual reference I would say, "Yes." As far as I can tell, that may be just the way the question was asked. So, you go quoting Tony who says it's OK to descend using only the ALS, but now you use the quote in a discussion about descending to 100' HAT immediately after the FAF. Well, the context has changed, and so the answer would change. It seems to me a decent lawyer would have asked me, following the initial answer, "Are there any conditions that must be met in order to descend to 100' HAT using the ALS as the sole visual reference?" I would have answered in the affirmative.


Finally, I'll conclude this post with the same question that concluded my previous.

Your second sentence claims "a lot of pilots are under the impression that, upon seeing the approach lights during a non-precision approach, it is permissible to continue descent from MDA to 100 feet above the touchdown zone – REGARDLESS of the aircraft’s distance to the threshold." Have you found any pilots on this forum that have that impression?

 

[Xav8tor]

Tony,

How many times have I said I don't have the answers and instead asked others if they do?

OK, I initially failed to say someone else who seemed to know what he was talking about said "No VDP will exist where an obstacle exists. The absence of a VDP serves as an obstacle alert." Until I know that is not true, if there is any truth in it, yes, I think every IFR pilot should be aware that that may be a possibility. It is called erring on the side of caution. I admit after reading that I had the same knee-jerk reaction the FAA does when they put out an emergency AD or other instruction (like after 5481).

Bubba, don't even begin to question my integrity. That is about the only thing I have of my very own to be proud of. Them’s fightin’ words in my book. Besides, lighten up man, this is an informal public discussion forum, not a peer reviewed journal, and if it were, I am not even close to being at the rough draft stage - just circulating ideas and opinions asking for CONSTRUCTIVE criticism. I'm not delivering a lecture or writing a flight dept, memo. I’m not rendering a legal opinion either. However, I am tossing out ideas posting on an aviation board, something I am seriously considering quitting. Lurking was just as informative and far less frustrating. As far as my investigative skills go, I don't care what you think. My past and current superiors/clients have all been quite satisfied (except for a bean counter or two). In any case, I am not conducting an investigation here. Pay me 150 to 300 an hour (depending on the task/subject area), plus first class expenses, 5 grand non-refundable retainer up front, and I'll think about it.


How many times does my question and concern(s) have to be repeated? I don't care why 5966 per se went down. The crash is what brought the question to light. There are enough FACTS made public to ask the question: How many pilots interpret 91.175(c)(3)(i) to mean that descent to 100 above TDZE is permissible without any other visual reference, and at what point may that descent SAFELY begin, if permitted? Assume there is no charted VDP and you are using a Jepp for the LOC/DME 36 at IRK.

Continuing to respond to your questions of me:

Yes, I do believe that the vast majority of pilots don't have a clue about how instrument procedures are designed and those criteria ARE buried deep in the TERPS and a dozen other places.

Apparently I have to meet a very high standard before I so much as open my mouth or type a single word, but you can fire off the round of your choice in responding to my posts. And by the way a cheap shot followed by an apology is still a cheap shot, and last time I checked my PDR, NSAID's don't appreciably affect emotional status. But yes, uncalled for personal attacks gripe my rear end on a bad day. Usually I try to just ignore it. Notice I said “try.”

Read the entire docket before you question the context and get some experience in NTSB, legal procedure, and accident investigation, before you accuse me of jumping to an unwarranted conclusion. Don't you understand that that is why I started this thread in the first place? I wanted to know if what I read in the factuals on 5966 is indicative of a broader problem and isn't just an aberration. The approach profiles and procedures at that operator are basically cut and pasted from the GOM/FOM's at the airline I flew J32's at for four years and also similar to the ones used at two other J32 operators where I was DOS. So, I have integrated the rest of the reports with that knowledge before arriving at the question and yes, I stated in the affirmative that, based on the interviews conducted by the NTSB, a large percentage interpret the reg in question literally and a lesser number qualify their answer with concern about distance from the threshold. I would think the APOI's statements are clear enough.

Having completed 15 semester hours of doctoral level research design and statistics, I understand there may be issues with the sample size and demo’s. That is why, to repeat, I wanted to know if other pilots thought that way? If so, why? VNAV/Stab ROD aside, without a VDP, where is the safe point using only the ALS, if there is one? And don't forget the same thing nearly occurred the night before and the issue was talked about in the crew room. If I had been DOS there, even though pilots had 24 hrs. to submit an ASR, if a crew had to perform anything close to an evasive maneuver to miss a tree, I would have expected a phone call before the props stopped spinning and I would have put out an alert to the affected crews before the next flight left the gate. The one final conclusion I have reached is: there is a serious safety problem. The answer I want to know is: how widespread is it?

I did NOT say anything about going to 100 HAT immediately after crossing the FAF. In fact, a few pages ago, I pointed out that for the first mile or so, you'd better not even come close to MDA because you aren't protected at that point (that is buried way down there in the TERPS too). If you look at the FDR over a plate and topo, and roughly sync up the CVR, you'll see that they went through MDA about 1.8 or 1.9 out, kept on going, and penetrated 100 approx .5 further on. Between those two points (I have not calculated the FDR/CVR time diff yet), the CA said he had the lights, the FO then responded in sight CONTINUE, which they did. (Didn't I post that already too?).

As I have already stated, they did not use a VDP. As far as I am concerned, VDP's are not even an issue in the analysis at hand. Of course they are the primary solution to preventing this general type of CFIT/NP approach accident due to premature descent from MDA.

I think I know the IIC on 5966, if memory serves me correctly, he is the same one that was on 3379, which I was on the Go Team for. The NTSB as a whole, and one IIC in particular, is not known for going too far past "pilot error" before turning in the final. Look at the BS PC on 587. And if it hadn't been for some slick work by a few people on 427 and especially 261, they would have hung at least a chunk of it on the crew on those. Frankly I am pleasantly surprised, no, make that SHOCKED, that they are looking at this 91.175 thing as hard as they seem to be.

Now, can we please kiss and make up and try to work together to understand why a 100 foot clump of trees isn't charted and why on this, or similar approaches, the risk of a CFIT is so high? Or is it?

Thanks.

 

[TurboS7]

I had no idea aviation was so complicated. I guess you know that you are a redneck when you see the lights you stay on the VASI and land. The runway is there to land on, get your stuff or people, then go to the next place. What is so hard about that.

 

[TonyC]

Now, can we please kiss and make up and try to work together to understand why a 100 foot clump of trees isn't charted and why on this, or similar approaches, the risk of a CFIT is so high? Or is it?

I don't fly intrument approaches using topos. I use IAPs published on Jepps plates. I don't need to know where every clump of trees is, and I already told you why. If I descend no lower than the MDA until I reach a point from which I can make a descent using normal procedures and normal descent rates to the touchdown zone, I need not fear any clump of trees or stray utility pole. It's that simple. If every clump of trees, utility pole, farmer's grain elevator, office building, and hill were charted on the Jepps plate, it would become unreadable and therefore useless. It's unnecessary.


You claimed "a lot of pilots are under the impression that, upon seeing the approach lights during a non-precision approach, it is permissible to continue descent from MDA to 100 feet above the touchdown zone – REGARDLESS of the aircraft’s distance to the threshold." How many is "a lot"? Have you found any pilots on this forum that have that impression?

 

[TonyC]

Did he really call me "Bubba"?










.

 

[enigma]

Did he really call me "Bubba"?










.

Yea, he did. But you should cut him some slack. After all, he can spell. And his grammar's pretty decent too.

enigma

And another thing, this string beats reading an endless head butting session between Delta and AirTran.

 

[Xav8tor]

Well at least "Bubba" isn't as bad as impugning a person's professional honesty and integrity in writing on a public forum, nor is it libel per se, which your statements about me come dangerously close to being. But I probably don't know jack about that subject either. So much for my make-up kiss.

I didn't know we were only taking a poll. I thought we were discussing the issues too. Certainly this thread isn't a good place for an academic study (survey) conducted with "integrity" for any number of reasons. For instance, if a subject reads the thread before answering, the results will obviously be skewed. On the other hand, one could assume that members here possess a higher level of interest, and possibly, greater skill than the average IFR pilot. There are way too many variables to make any concrete conclusions based on the quantity of responses so far. A general impression is, however, possible to form already, and could, along with other sources, be the launchpad for a controlled, formal survey. Based on the responses so far, I'd say it is clearly worth pursuing. In fact, a controlled poll is a great idea.

Please refer to the excerpts from the NTSB OPS group attachment (interviews) to see the basis for my initial question and concern. If you insist, I can post the entire 35 page document, you can read it all, and do the math. My position is that if even one line Captain, Check Airman, Instructor, Manager, or Inspector thinks the dead horse procedure we have beaten is safe and legal, then that is one too many. Read (and comprehend) what I posted from the docket and draw your own conclusions. A relatively large portion of the people interviewed are operating under some very unsafe assumptions as a direct result of the misapplication of 91.175. For a 121 sked carrier code-sharing with AA, that number in effective terms (not absolute value) just got much bigger. Good Lord man, can you not understand my question that asked if this was a widespread misconception, or confined to a single operator? Given that a lot of those guys came from other places, many from AE, the finest regional in the country in the early 90's when the procedures were developed, and the fact that one of the accident crew attended and another graduated from one of the best aviation schools in the world, there are clues that the problem may not be isolated to 3C.

As for your repeated question, this time I assume is screaming, as they say in the legal biz, "asked and answered." Are you sure you read this whole thread? Did you comprehend it? There are some really strange answers in the beginning on the first couple of pages. The answer is YES!

The way you fly approaches is fairly SOP. The question before us is about pilots who think seeing the ALS on a non-precision approach means drop down to 100 above TDZE as soon as you see them, without regard to distance from the threshold and having no charted VDP.

I may very well be wrong and sorely disappointed in how the NTSB treats this issue in the bluebook. It has happened before. But the conclusion of the NTSB investigation is not the end of the story. My bet is that when this is all over, many of the questions and issues I raised here will be seen again, in a prominent way. If not, it will happen again and I will be in a better position if I am still in the business. Most of the work will have already been done. But like I said Captain C., if you keep thinking I am off base, crying wolf, saying the sky is falling etc., you might want to ask your wife if she has a good recipe for crow. I think you are going to need one in about 4 to six months.

PS- I may not like the way you post, but I sure do envy your flight experience. I still think the 707 is one of the nicest aircraft ever built. I wanted to get a flight navigator ticket in that bird just for the fun of it, but that will never happen.

 

[TonyC]

Libel ?!?

..., nor is it libel per se, which your statements about me come dangerously close to being.

You're kidding, right? I thought you went to law school.


I'd like to return again to the post that began this thread.

http://forums.flightinfo.com/images/icons/icon20.gif Do you go 100 Above TDZE Prior to MAP on LOC/DME?
I read a copy of the factual reports (Operations, FDR, CVR, etc.) on the J32 accident last year in IRK. According to investigation interview statements made by pilots, managers and an FAA inspector, a lot of pilots are under the impression that, upon seeing the approach lights during a non-precision approach, it is permissible to continue descent from MDA to 100 feet above the touchdown zone – REGARDLESS of the aircraft’s distance to the threshold. In other words, after crossing the FAF and doing the old chop and drop to MDA, for example, at two miles DME from the runway/MAP you see the ALS, (but not the VASI or runway lights), they thought it was permissible (and safe) to go ahead and keep on going down to 100 feet while still that far out.



I know how I have always understood, applied, and taught that reg and related procedures, but I am curious to know what you guys (and girls) think and how you interpret and apply it, assuming you use standard 121 (i.e., airline "style") profiles and procedures.

Two questions:

1) You state that "according to investigation interview statements ... a lot of pilots are under the impression ..." Would you please tell us the exact number of pilots whose interview statements indicated they were under that impression? In other words, would you substitute an actual number for the phrase "a lot"?

2) You state that you're curious to know what [we] "guys (and girls) think and how [we] interpret and apply it, assuming [we] use standard 121 (i.e., airline 'style') profiles and procedures." Can you produce an example of a post that indicates a participant in this thread shares the view you cited in paragraph 1?


The closest I can find is DrewBlows:

There is always a minimum visbility published for any given approach. I like to think that in a senario where you are shooting an approach to minimums, when you are at minimums, you can descend without any worry, after all you have the approach lights in sight which are about 1500' from the threshold. I really have a hard time believing that you could start a descent to 100' above TDZE at a distance so far away from the threshold that you would risk hitting an obsticle (assuming on a visual approach you fly a standard three degree approach). I may be wrong, but I have always been under the impression the the TERPS took into account this senario (not the visual senario, but the poor visability senario).

Even his answer is qualified by distances, so I don't consider his answer as meeting your criteria. Furthermore, it's not altogether clear (based on his profile which, I realize, may be completely misleading or even false) that he meets your criteria of "us[ing] standard 121 (i.e., airline 'style') profiles and procedures."

So much for my make-up kiss.

I'm not into kissin' guys, thanks.

I didn't know we were only taking a poll. I thought we were discussing the issues too.

Funny, I thought that's exactly what you were asking for when you said, "I am curious to know what you guys (and girls) think and how you interpret and apply it, ...". I believe the issue at hand is pretty straightforward. First, is it legal, safe, AND smart to descend below MDA prior to reaching a point from which a normal descent can be made using nromal procedures to arrive at the runway? And, second, if it is not legal, safe, OR smart, are there pilots operating under the mistaken impression that it IS?

On the first question, I believe the concensus of thread participants believe the answer to the first question is NO. The preponderance of posts, I believe, supports that view.

To the second question, it appears you may have a case where at least two pilots might have held that mistaken impression. I say "may" because I don't believe it has been definitively determined that such was the case. Initial review of the accident data suggests that might be the case, and that's all we really have with which to speculate at this time. Yes, I said speculate. We don't have the tools at our disposal to investigate the question further. All we really have is what the NTSB releases. Wouldn't it be nice if we could interview the people who trained these pilots so we could probe their understanding of this particular aspect of instrument flying to a satisfying depth? Alas, we cannot.

On the other hand, one could assume that members here possess a higher level of interest, and possibly, greater skill than the average IFR pilot.

That would be an extremely dangerous assumption. While there are a number of experts "here," there are as many beginners, affecianados, and friends. We're just as likely to be discussing how to taxi a 172 in a straight line as how to transition from instrument to visual procedures.

My position is that if even one line Captain, Check Airman, Instructor, Manager, or Inspector thinks the dead horse procedure we have beaten is safe and legal, then that is one too many.

I agree. Where we seem to disagree is on your assertion that "a lot" do think that. I'm not convinced that "a lot" of people think that way. I could be convinced otherwise, but I've yet to shown convincing evidence.

..., you might want to ask your wife if she has a good recipe for crow. I think you are going to need one in about 4 to six months.

You supply it, I'll cook it!

PS- I may not like the way you post, but I sure do envy your flight experience. I still think the 707 is one of the nicest aircraft ever built. I wanted to get a flight navigator ticket in that bird just for the fun of it, but that will never happen.

Don't get too green. It's listed with ratings, not airplanes I've actually flown. The type was for the RC-135, and it just shows up to the FAA as B-707 B-720. The RC-135 was close, but not quite a 707.

 

[Xav8tor]

Tony,

I don't want to kiss you either, it’s a figure of speech you know. The unproductive semantic games you are playing, and my biting the bait and responding, have added nothing but maybe entertainment for some people, but zilch to the original goals of the thread. Perhaps that is one reason the response level has dropped off.

There is no point in repeating myself. A few replies early on in this thread were not all that dissimilar to those in the witness interviews, but the split was different. I posted enough of the witness interviews to show, that considering the size of the place, a surprisingly large proportion were interpreting the subject reg and procedure in a manner that the NTSB apparently feels almost led to at least one accident, and 24 hours later, did. They typically don’t put things in the report that they don’t consider relevant. All I ever wanted to know was whether or not this misconception was widespread or isolated. Secondary to that issue is the uncharted controlling obstacle and how that might affect a do it yourself VDP.

I guess this, or any other board, isn't the best place to get that kind of information. I am quite sure that if I had spent the same amount of time doing the research myself i/o asking for opinions, and trading barbs, I would have most of my answers by now.

Yes I went to law school and yes, of course, I am kidding in that I am not a litigious person and I expect that sort of comment on a place like a message board. But, I am not kidding about how easy it is to cross the line and the kicker is damages can be presumed in some of those cases. At least that is one of the useful bits of wisdom as I barely remember it that I got for my 125K.

What I have taken from this discussion is that the reg is worded in a way that it makes it subject to being misapplied in real world flying. Chasing the rabbit as I call it down an ILS to mins (PF staying on the gauges of course) by hand is pure fun and as long as you are proficient and the plane properly equipped, it isn't particularly risky. Using the ALS as a cue to descend on a non-precision approach generally seems like a major ingredient in a recipe for disaster absent a charted VDP or VGSI in sight, etc.

If I get an answer that supports the system safety problem I "smelled" when I read the docket, supported by a few other misconceptions expressed elsewhere, I'll post it. Hopefully the NTSB will do that for us. I would have liked to spot a serious safety issue and played a part in fixing it, both for personal satisfaction, and to fatten my CV, which based on the way biz is these days, and some news I just got this morning, I may need to do sooner, rather than later.

Thanks to all for the input.

Xav8tor...missing it more than ever.

 

[TonyC]

The unproductive semantic games you are playing, ...

I don't know what games you're talking about. I've asked simple questions and failed to get straight answers. Perhaps my posts are too long. I'll keep this one short.

I asked:

2) You state that you're curious to know what [we] "guys (and girls) think and how [we] interpret and apply it, assuming [we] use standard 121 (i.e., airline 'style') profiles and procedures." Can you produce an example of a post that indicates a participant in this thread shares the view you cited in paragraph 1?

Do I take this to be your answer?

A few replies early on in this thread were not all that dissimilar to those in the witness interviews, but the split was different.

.