I’m having a hard time setting up the following situation on the GNS 430:
flyig from Rochester to La Crosse (LSE) and center clears me direct nodine vor (ODI) and to intercept the 14dme arc for the ILS 18 approach.
Do i fly direct nodine using the gps mode then activate the approach once i intercept the 14 dme arc or is there an easier way? It would be nice to let the 430 fly the arc and monitor it with the 2nd radio in vloc mode.
Direct to ODI. Once on course sync HDG bug. Set HDG. Activate approach, bring up the FPL and set direct to the ARC. Hold HDG and press NAV twice. When you reach the DME ARC the GPS will sequence to your current position in the ARC.
Paul,
I’m having a little trouble understanding your clearance. They cleared you direct to ODI, then told you to intercept the arc?
That’s not a valid way to start the approach. I would have told ATC that I would like to either accept vectors to final or start the approach at an initial approach fix. You will NEVER intercept an arc as the way to “join” the approach. You must start every approach at an initial approach fix (IAF) unless you are being vectored to final.
So, I would have put ODI in the flight plan with LSE as the destination. Next, select the approach (ILS 18) and LOAD it (don’t activate it right away). When you select the approach, it will give you ODI as one of the choices (this is not an IAF, but instead a transition to an IAF MINDI).
Once you are sure you have been cleared for the approach, then activate the approach. This will take you from ODI to MINDI to start the approach. At MINDI you would turn outbound to perform the REQUIRED procedure turn.
Make sense?
Paul,
After looking at the approach more, ATC could certainly do what they did (although this is still a little weird since at ODI you should be headed on the transition to MINDI (not on the arc). The real question is should you do the PT once you arrive at MINDI from the arc or go straight in?
Well, needless to say, after rehashing this in my own mind and consulting a few other experts in the field, I must apologise for leading you astray. After thinking about it a bit, I realized that I had been vectored onto segments of the approach inside the IAF dozens of times. Sometimes you feel like a nut!
In a NON radar environment, the entire approach must be flown as depicted. The legal interpretation supports this since there would be no option for radar vectors (you are not under radar control or radar monitoring).
In a radar environment it is perfectly legitimate to receive vectors to the SIAP inside the IAF (see FAR 91175(i) below). So a controller can vector you onto an IAP at a point other than the IAF as stated in the AIM, para 5-4-7© at which time you should comply with the restrictions listed for that segment. If the controller vectors you onto the arc “inside” the IAF, fly the remainder of the approach from there, complying with the altitude that is appropriate for the portion of the arc that you are on at the time you become established, and all subsequent restrictions.
If you happen to be vectored onto a segment of the approach (including an arc) that is marked as a NoPT, then you would not be required or authorized to perform the PT. Just make sure it is a NoPT arrival route.
Just as a caution. Radar does fail, intercept angles can be great, add IMC, mountains, nighttime and an arc, and you’ve got a recipe for a very challenging approach. In an unfamiliar area, you might want to fly the entire approach beginning at the IAF.
Also care must be taken when setting up the approach on the Garmin 430, especially the one in the original question. If you set up the approach to begin at ODI, you will not be given course guidance or an arc on the display since the GPS database expects you to fly the transition to MINDI (057° radial) to begin the approach. In this case you would have to choose SHLGN as the IAF and then you’ll receive an arc and course guidance in the event of vectors to the arc. As you can see, it can be done and can get tricky.
Sorry for any confusion that may have resulted.
From the AIM, para 5-4-7©:
c. When operating on an unpublished route or while being radar vectored, the pilot, when an approach clearance is received, shall, in addition to complying with the minimum altitudes for IFR operations (14 CFR Section 91.177), maintain the last assigned altitude unless a different altitude is assigned by ATC, or until the aircraft is established on a segment of a published route or IAP. After the aircraft is so established, published altitudes apply to descent within each succeeding route or approach segment unless a different altitude is assigned by ATC. Notwithstanding this pilot responsibility, for aircraft operating on unpublished routes or while being radar vectored, ATC will, except when conducting a radar approach, issue an IFR approach clearance only after the aircraft is established on a segment of a published route or IAP, or assign an altitude to maintain until the aircraft is established on a segment of a published route or instrument approach procedure. For this purpose, the Procedure Turn of a published IAP shall not be considered a segment of that IAP until the aircraft reaches the initial fix or navigation facility upon which the procedure turn is predicated.
From FAR 91.175(i):
(i) Operations on unpublished routes and use of radar in instrument approach procedures. When radar is approved at certain locations for ATC purposes, it may be used not only for surveillance and precision radar approaches, as applicable, but also may be used in conjunction with instrument approach procedures predicated on other types of radio navigational aids. Radar vectors may be authorized to provide course guidance through the segments of an approach to the final course or fix. When operating on an unpublished route or while being radar vectored, the pilot, when an approach clearance is received, shall, in addition to complying with § 91.177, maintain the last altitude assigned to that pilot until the aircraft is established on a segment of a published route or instrument approach procedure unless a different altitude is assigned by ATC. After the aircraft is so established, published altitudes apply to descent within each succeeding route or approach segment unless a different altitude is assigned by ATC. Upon reaching the final approach course or fix, the pilot may either complete the instrument approach in accordance with a procedure approved for the facility or continue a surveillance or precision radar approach to a landing.
Works great. Thank you.
That clearance may actually be a relatively common instruction:
The VOR/DME RWY 10 apch into Stateville NC (SVH) has 3 IAFs; 1 at Barrett’s Mtn. VOR (BZM), one on the 055 radial off BZM at 7 DME, and 1 on the 203 radial off BZM at 7 DME. The latter two IAFs mark the start of the northern and southern arcs, respectively. The two arcs meet and turn to the final approach course at ERIES intersection. (ERIES is on the 121 radial off BZM at 7 DME.) NOTE: There are no waypoint or intersection names that mark the start of either arc, just the radial and DME fix. (The Garmins label them as D055G and D203G respectively.) [see the attached graphic - its a .PDF file.] I have frequently been cleared for this apch with the following instructions:
ATL Center: “Cirrus 508JS, expect the VOR/DME runway 10 approach at Statesville. Cleared direct BZM. Intercept the north (or south) arc. Maintain at or above 4000 ft. until established on the arc. Report established on the arc. Cleared VOR/DME approach. Switch to advisory frequency at ERIES.”
A variation on this clearance I’ve gotten a couple of times was:
ATL Center: “Cirrus 508JS, cleared present position direct to the north (or south) arc of the VOR/DME runway 10 approach at Statesville. Intercept the arc at any point prior to ERIES. Maintain at or above 4000 ft. until established on the arc. Report established on the arc. Cleared VOR/DME approach. Switch to advisory frequency at ERIES.”
I use the NAV1 Garmin to fly the procedure in VLOC mode, and use the NAV2 Garmin in GPS mode, set up Direct BZM, to monitor my distance from BZM throughout the procedure (The #1 Garmin will sequence through all the intermediate fixes that define the procedure and give bearing and distance to the next fix, so you can’t get it to also maintain a DME readout from BZM at the same time.)
Scott, You are absolutely correct technically. However, as you know things don’t always go by the book. Had the approach been flown as you suggest it would have required a procedure turn and that takes up time and airspace. Most controllers like to avoid procedure turns in the radar environment as much as pilots do.
Basically I think what I would have done is exactly what Art suggested. I’m heading direct to ODI. When I get 14 from LSE I would follow the arc around to intercept the localizer. If the initial clearance specified a cleared for the approach I would descend to 3400 feet upon intercepting the arc, then to 2900 when intercepting the localizer. This seems faster and as safe as insisting on going to an IAF first. As a practical matter I think clearances like this are given fairly routinely and as long as the pilot understands how to fly them they seem to be quite reasonable, and, as long as you don’t descend until you are on a published segment of the approach, safe as well.
What you are saying is that you can begin the approach at some other point OTHER than an IAF, correct? ERIES is not an IAF and there are no IAFs after ERIES; both approach clearances are flawed and the second one is illegal and potentially dangerous. See the FAA Legal Counsel interpretation copied below that addresses this very issue.
The approach must start at either of the two radial IAFs or at BZM (not before and not after). If the approach clearance were direct to BZM (an IAF), there’s absolutely no reason to intercept any arc. That would be a straight in approach using the 121° radial. In fact, if you select BZM on the Garmin and activate the approach, you would not be shown the arc on the approach. The next waypoint would be ERIES, not D055G or D203G. Besides the point I make above, the first clearance you mentioned is bad because you are being told to go direct to BZM and intercept the arc. Since this is not a published transition, how do you comply with the minimum altitudes for IFR operations? As a result, you would have to comply with FAR 91.177. They told you to maintain 4000, but you are not being radar vectored to the arc, you are under your own navigation. As a result, ATC is NOT maintaining terrain separation for you since you are not being radar vectored and you have absolutely no way to know what the minimum altitudes are in this area. That’s dangerous. In fact, the MSA is 5700 ft (which is an emergency only altitude and should never be used in this situation, but does drive home the fact that there are obstacle alligators out there to get you).
The second clearance is flawed and just as dangerous because you must always start the approach at the IAF (D055G or D203G). Instead, ATC should have given you radar vectors to either one of these points and cleared you to intercept the arc at the 055 or 203 radial. In fact, in order to be established on the arc you must be within 1 DME of the arc at this point (it may take you a couple of degrees on the radial to get established).
If you are getting a clearance that it is okay to intercept the arc after these points over and over, I’d speak to a supervisor at the center and let them know that this is incorrect.
Regardless of their willingness to correct their mistake, I’d file an ASRS form and also make that statement.
Remember that controllers are NOT instrument approach experts. Their job is simply to clear you to an IAF (maybe via a transition) or vector you to final (in a radar environment). When they clear you for the approach, essentially they are saying that the airspace is at your sole use and there are no other IFR aircraft to interfere. They DO make mistakes and will continue to issue the same bad clearances over and over if not told otherwise. Unfortuately, there are pilots that die because of these mistakes.
AIM 5-4-7 (e) -
Except when being radar vectored to the final approach course, when cleared for a specifically prescribed IAP; i.e., “cleared ILS runway one niner approach” or when “cleared approach” i.e., execution of any procedure prescribed for the airport, pilots shall execute the entire procedure commencing at an IAF or an associated feeder route as described on the IAP Chart unless an appropriate new or revised ATC clearance is received, or the IFR flight plan is canceled.
AIM 5-4-7(b) -
b. When operating on an unpublished route or while being radar vectored, the pilot, when an approach clearance is received, shall, in addition to complying with the minimum altitudes for IFR operations (14 CFR Section 91.177), maintain the last assigned altitude unless a different altitude is assigned by ATC, or until the aircraft is established on a segment of a published route or IAP. After the aircraft is so established, published altitudes apply to descent within each succeeding route or approach segment unless a different altitude is assigned by ATC. Notwithstanding this pilot responsibility, for aircraft operating on unpublished routes or while being radar vectored, ATC will, except when conducting a radar approach, issue an IFR approach clearance only after the aircraft is established on a segment of a published route or IAP, or assign an altitude to maintain until the aircraft is established on a segment of a published route or instrument approach procedure.
Nov. 28, 1994
Mr. Tom Young, Chairman
Charting and Instrument Procedures Committee
Air Line Pilots Association
535 Herndon Parkway
Herndon, VA 22070
Dear Mr. Young
This is a clarification of our response to your letter of August 23, 1993. In that letter you requested an interpretation of Section 91.175 of the Federal Aviation Regulation (FAR) (14 CFR Section 91.175). You address the necessity of executing a complete Standard Instrument Approach Procedure (SIAP) in a non-radar environment while operating under Instrument Flight Rules (IFR). Our response assumes that each of the specific scenarios you pose speaks to a flight conducted under IFR in a non-radar environment.
Section 91.175(a) provides that unless otherwise authorized by the Administrator, when an instrument letdown to a civil airport is necessary, each person operating an aircraft, except a military aircraft of the United States, shall use a standard instrument approach procedure prescribed for the airport in Part 97.
First you ask whether an arriving aircraft must begin the SIAP at a published Initial Approach Fix (IAF). A pilot must begin a SIAP at the IAF as defined in Part 97. Descent gradients, communication, and obstruction clearance, as set forth in the U.S. Standard for Terminal Instrument Approach Procedures (TERPs), cannot be assured if the entire procedure is not flown.
You also ask whether a Distance Measuring Equipment (DME) arc initial approach segment can be substituted for a published IAF along any portion of the published arc. A DME arc cannot be substituted for a published IAF along a portion of the published arc. If a feeder route to an IAF is part of the published approach procedure, it is considered a mandatory part of the approach.
Finally, you ask whether a course reversal segment is optional “when one of the conditions of FAR section 91.175(j) is not present.” Section 91.175(j) states that in the case of a radar vector to a final approach course or fix, a timed approach from a holding fix, or an approach for which the procedures specifies “no procedure turn,” no pilot may make a procedure turn unless cleared to do so by ATC.
Section 97.3§ defines a procedure turn, in part, as a maneuver prescribed when it is necessary to reverse direction to establish the aircraft on a intermediate or final approach course. A SIAP may or may not prescribe a procedure turn based on the application of certain criteria contained in the TERPs. However, if a SIAP does contain a procedure turn and ATC has cleared a pilot to execute the SIAP, the pilot must make the procedure turn when one of the conditions of Section 91.175(j) is not present.
If you have any questions regarding this matter, please contact Patricia R. Lane, Manager, Airspace and Air Traffic Law Branch, at (202) 267-3491.
Sincerely,
/s/
Patricia R. Lane
for Donald P. Byrne
Assistant Chief Counsel
Regulations Division
Jerry,
You simply don’t have the option (see my post below to William). You can’t take any shortcuts when flying IFR. You’ve signed up to follow the rules EXACTLY as they are published. You cannot worry about what ATC wants or needs. That’s too bad if you have to do a procedure turn. You must do the procedure turn (you don’t have the option unless you are being radar vectored to final or are on a NoPT segment). If ATC wants to expedite traffic, they will radar vector you. Intercepting the arc at any other place other than the IAF is a violation of FAR 97 (see the FAA legal interpretation in my other post).
If what you say is true, then we should never fly direct any where as we are off the published airways and don’t know what MEA is. However, we do know what the min safe altitudes for the different sectors are. As long as we stay above that we are okay. So, if the controller and i both know that i’m safe at 4000 and i don’t descend below that until established on the approach, it stands to reason that this is safe. You are never cleared below a safe altitude even if a controller is sending you to an IAF.
Now, i agree that controller can make mistakes so always know your min safe altitude
The letter refers to a NON radar environment, so it seems to me that your AIM references are the only ones that apply to either of these situations. It also looks like radar vectors to anywhere on the arc would be legal, but cleared to ODI would not be vectors to a published segment, therefore not legal.
Paul
pilots shall execute the entire procedure commencing at an IAF or an associated feeder route as described on the IAP Chart unless an appropriate new or revised ATC clearance is received,
So if the ATC tells me to intercept the ARC at other than an IAF I would consider it “an appropriate new or revised ATC clearance”, and follow the instructions.
I’m not saying you CAN begin the approach at other than an IAF, I’m only saying that I have been INSTRUCTED to do so. (BTW, if being vectored to final, you CAN begin an approach at other than an IAF, but that’s a whole different scenario…) One point of clarification, though. ATL Center is the approach facility for this airport, and I always ASSUMED, based on the instruction sequence (in the first example I gave), that the instruction to intercept the arc was a FURTHER CLEARANCE past the clearance to BZM, so I never questioned it. Also, ATL Center does provide radar coverage all the way down to the ground in that area. This is only speculation, but the controller may be assuming radar control for the entire approach…
In the future, I’ll always ask for clarification if I get the same instructions again!
This is an interesting thread. I agree completely that in a non radar environment one needs to start at an IAF and fly the procedure as published. What’s not really clear to me is whether the scenario presented is a non radar one. If is in a radar environment then I don’t see how flying that clearance is dangerous.
If you assume that a controller can clear you directly to a point (in this case the ODI VOR), it would seem that he could clear you to that point (via direct) and ask you to intercept a segment of a published procedure (the 14 mile DME arc) on the way to the VOR. The clearance certainly needs an altitude that is safe and in accordance with the Minimum Vectoring Altitude. Once you are on the arc descending to the arc altitude keeps you quite safe from terrain. I don’t know if it’s legal but I can’t see how it wouldn’t be safe assuming the initial clearance to ODI at a safe altitude is a legal, valid and safe clearance.
The question really is interesting. I’ll ask one of the local FAA guys for his interpretation as to 1) legality and 2) safety
Paul,
That’s right. When you are direct (off-route), you must comply with the FAR 91.177. This is true regardless of whether you are being vectored or under your own navigation. Either case, the controller only knows one thing: Minimum Vectoring Altitude (or Minimum Instrument Altitude for Center). Actually, the MIA is used by center less for vectoring and more to monitor off-route “direct-to” progress. Also, the only time ATC can vector you below the MVA/MIA is when you are on a DP or missed approach. Even in this case, ATC must vector you away from prominent objects.
But you still need to be aware of the terrain around you (think about losing comm on a vector below MVA and headed for a hilltop?) You’ve got to be on your toes.
When direct, you are directly responsible for terrain separation. When being radar vectored, both you and the controller are responsible for terrain separation. Don’t get me wrong, if you request (while direct) an altitude lower than the MVA in the area, it is likely ATC won’t approve it (even if it is above the MORA or OROCA for you FAA chart guys).
Direct routes are great, just don’t get caught without knowing what your required separation with terrain needs to be. That includes enroute and terminal ops.
Paul,
Yes, the legal interpretation doesn’t speak about radar environments because the question specifically addressed non-radar. However the AIM is clear. You must begin ALL approaches at an IAF unless you are being radar vectored to the FINAL approach course. In the SIAPs mentioned in this thread, neither arcs are the final approach course. So, you cannot get vectors to intercept the arc. You must always begin the approach from an IAF or feeder route to the IAF.
The reason for this is simple. All of the FAR 97 approaches are predicated on the fact that the approach begins at an IAF. That’s for our safety. ATC is allowed to vector us to the final approach course, but again, this is flight tested and authorized as vectors to FINAL. Intercepting anywhere else is not flight tested and therefore you are taking risks of hitting something solid.
Good try. ATC has no authority to change or revise the instrument approach chart. You must follow it is as depicted since the SIAP is an amendment of FAR 97. The only thing that comes close to this is that ATC does have “secondary” missed approach procedures that you may not be aware of for some approaches. These missed approach procedures are valid FAR 97 amendment procedures. Other than that, you MUST follow it as charted beginning at the IAF unless you are radar vectored to the FINAL approach course.
Yes, it is an interesting thread. I’m generally in the “do it if the controller clears you (in a radar environment)” camp. But the argument about non-standard approaches not being flight tested has some merit too. Maneuvering to intercept the arc could, theoretically, take you outside the protected airspace in terms of terrain clearance, especially if the intercept angle is high, you are going fast, etc. (overshoots, and all that).
Jerry,
In a radar environment, the rules are the same (in this instance). The FAA guy will likely point out FAR 91.177 and AIM 5-4-7(e). (To be perfectly honest, I’ve gotten a lot of bad advice from the local FAA folks). The AIM doesn’t (on purpose) specify a radar or non-radar environment and is VERY clear “…pilots shall execute the entire procedure commencing at an IAF or an associated feeder route as described on the IAP Chart…” This statement does not allow for any other choices (and it does so on purpose).
Now, if the controller wants to vector you to intercept the arc SOONER than the IAF, that’s acceptable. And you can be vectored to intercept (in the middle of) a feeder route (prior to the IAF). Once established on the feeder route and cleared for the approach, you can descend to the altitudes listed on the feeder route (unless ATC has assigned a higher altitude to maintain for a crossing restriction). However, if the route is “inside” an initial approach fix, ATC cannot vector you to intercept the route after this (some approaches will have multiple IAFs along your cleared route of flight) initial approach fix.