Help Me Understand TAA - IFR Written Answer Seems Wrong

[Skid]

So I'm hung up on this question:

You are 27NM west of AJCIZ at 7,000 feet and have been cleared for the RNAV (GPS) RWY 30 approach. You should:

Answer: Remain at 7,000 feet until AJCIZ, descend to 4,700 feet in the holding pattern, cross AJCIZ and begin descent to cross BEMXI at 4,600 feet.

This is basically the approach: http://www.airnav.com/depart?http://155.178.201.160/d-tpp/1805/00292R30.PDF

Why?

From the AIM:

"Pilots entering the TAA and cleared by air traffic control, are expected to proceed directly to the IAF associated with that area of the TAA at the altitude depicted, unless otherwise cleared by air traffic control. Cleared direct to an Initial Approach Fix (IAF) without a clearance for the procedure does not authorize a pilot to descend to a lower TAA altitude."

From the IPH:

"Once cleared for the approach, pilots may descend in the TAA sector to the minimum altitude depicted within the defined area/subdivision, unless instructed otherwise by air traffic control."

The question states I'm cleared for the approach, so why wouldn't I descend immediately to the sector TAA altitude that I'm in?

 

[RussR]

You are correct. Assuming that the figure in the test is the same as the one currently published, that you linked to, and assuming you weren't given a crossing restriction, you would do just as you say.

Was this on the actual written test, or a test prep question? If the latter, contact the company that developed the test prep.

 

[EdFred]

I was taught you don't descend until you are cleared to a lower altitude. When did that change?

I know what the AIM says but what does part 91 say?

 

[jaybee]

The big problem with that question is that I believe the clearance is not in compliance with ATC 7110.65, that said I would definitely defer to someone who knows better but the clearance should be something like "proceed direct AJCIZ, maintain 4700 until established, cleared RNAV 30 approach"

 

[EdFred]

The big problem with that question is that I believe the clearance is not in compliance with ATC 7110.65, that said I would definitely defer to someone who knows better but the clearance should be something like "proceed direct AJCIZ, maintain 4700 until established, cleared RNAV 30 approach"

And that's what clearance I always get when cleared for an approach when I'm not at the initial approach fix altitude.

 

[Skid]

This was a test prep question, 2387

 

[Clip4]

So I'm hung up on this question:

You are 27NM west of AJCIZ at 7,000 feet and have been cleared for the RNAV (GPS) RWY 30 approach. You should:

Answer: Remain at 7,000 feet until AJCIZ, descend to 4,700 feet in the holding pattern, cross AJCIZ and begin descent to cross BEMXI at 4,600 feet.

This is basically the approach: http://www.airnav.com/depart?http://155.178.201.160/d-tpp/1805/00292R30.PDF

Why?

From the AIM:

"Pilots entering the TAA and cleared by air traffic control, are expected to proceed directly to the IAF associated with that area of the TAA at the altitude depicted, unless otherwise cleared by air traffic control. Cleared direct to an Initial Approach Fix (IAF) without a clearance for the procedure does not authorize a pilot to descend to a lower TAA altitude."

From the IPH:

"Once cleared for the approach, pilots may descend in the TAA sector to the minimum altitude depicted within the defined area/subdivision, unless instructed otherwise by air traffic control."

The question states I'm cleared for the approach, so why wouldn't I descend immediately to the sector TAA altitude that I'm in?

Without the other two options it is impossible to determine if that was the correct answer.

 

[Blatham489]

My check ride is scheduled for next week, so no expert but the answer looks right to me. You’re at 7000 with no instructions or clearance to descend. You’re cleared for the approach, which means you need to stay at your last assigned altitude until established on the approach. The TAA is not part of the approach. So once you cross the IAF and begin to start your hold, you’re established on the approach and you can descend, but not until then.

Am I right?

Edit: Re-reading your excerpt from the IPH I understand the confusion but I suspect I’m still “right” because your “instructions” were last given as 7000.

 

[dmspilot]

Could be an error by the test prep company. I've seen Gleim get quite a few wrong in recent years.

 

[Skid]

Without the other two options it is impossible to determine if that was the correct answer.

Here are the other two:

1) Descend to 5300ft, cross AJCIZ and complete the procedure turn, then cross BEMXI at 4,700

2) Descend to 4,700ft, cross AJCIZ and complete the procedure turn, then cross BEMXI at 4,600

Both of those also seem wrong too. For #1 crossing BEMXI at 4700 is incorrect, and for #2 descending immediately to 4700 would put you below the published altitude for that segment.

The answer in the original post is the most logical choice, but if I’m cleared for the approach, in the real world I’d naturally think I could descend to 5300.

 

[TheGolfPilot]

So I'm hung up on this question:

You are 27NM west of AJCIZ at 7,000 feet and have been cleared for the RNAV (GPS) RWY 30 approach. You should:

Answer: Remain at 7,000 feet until AJCIZ, descend to 4,700 feet in the holding pattern, cross AJCIZ and begin descent to cross BEMXI at 4,600 feet.

This is basically the approach: http://www.airnav.com/depart?http://155.178.201.160/d-tpp/1805/00292R30.PDF

Why?

From the AIM:

"Pilots entering the TAA and cleared by air traffic control, are expected to proceed directly to the IAF associated with that area of the TAA at the altitude depicted, unless otherwise cleared by air traffic control. Cleared direct to an Initial Approach Fix (IAF) without a clearance for the procedure does not authorize a pilot to descend to a lower TAA altitude."

From the IPH:

"Once cleared for the approach, pilots may descend in the TAA sector to the minimum altitude depicted within the defined area/subdivision, unless instructed otherwise by air traffic control."

The question states I'm cleared for the approach, so why wouldn't I descend immediately to the sector TAA altitude that I'm in?

I don’t see why the answer they gave is wrong? You absolutely can stay at 7000 feet and wait to descend in the hold. There is nothing wrong with that unless the controller instructs otherwise. and I can think of various weather reasons why someone may opt for that.

What were the other 3 options

 

[Skid]

I don’t see why the answer they gave is wrong? You absolutely can stay at 7000 feet and wait to descend in the hold. There is nothing wrong with that unless the controller instructs otherwise. and I can think of various weather reasons why someone may opt for that.

What were the other 3 options

I think the confusion for me is the word “should”. The resources seem to indicate otherwise.

 

[TheGolfPilot]

I think the confusion for me is the word “should”. The resources seem to indicate otherwise.

Really bad answers because there is nothing wrong with answer #1 either... if they wanted you to cross bemxi at 4600, the plate wouldn’t say at or above

 

[EdFred]

If you are 27 West of the initial approach fix your minimum safe altitude is 5300 feet so if you immediately descend to 4700 feet that's a bust so the one that says immediately descend is out.

The one that says descend to 5300 and then cross the next fix at 4700 is wrong because the plate says 4600 however you could cross it at 4700 because there's no line above it to indicate you must cross exactly at 4600.

So all of the answers given the best one to choose from is remain at 7000 descend in the procedure turn to 4700 cross the next fix at 4,600.

In the real world ATC will 99% of the time especially in Nebraska clear you to the minimum vectoring altitude that keeps you above the fix altitude and clear you for the approach at the same time. Welcome to the world of test makers who don't actually fly in the real world.

 

[MauleSkinner]

I was taught you don't descend until you are cleared to a lower altitude. When did that change?

I know what the AIM says but what does part 91 say?

Part 91 says fly the altitude(s) in your clearance.

An approach is part of a clearance, and descending to appropriate altitudes on the approach without ATC giving you those altitudes one at a time is, well, appropriate.

 

[SbestCFII]

Typically you get "descend and maintain x000," or possibly "cross (fix) at of above x000," but these instructions will keep you at or above the MVA or MSA until reaching a fix where you will transition to the altitude guidance on a published procedure or airway segment.

 

[RussR]

You’re cleared for the approach, which means you need to stay at your last assigned altitude until established on the approach. The TAA is not part of the approach.

That not correct. The TAA certainly is a published segment of the approach. Ref the IPH quoted in the OP.

 

[flyingron]

Yep, the question is pretty horrendous. At 27 miles W of AJCIZ at 7000 and cleared for the approach (yes the actual phraseology should have reiterated maintain 7000 until established, thank you TWA) you may immediately descend to 5300, and the 4700 at 15 miles. You must fly the procedure turn and crossing AJCIZ coming out of that, you may descend to 4600 until past BEXMI.

I'm not sure I'm linking any of the answers more than others. Frankly, I'd have gone to the minimum alitudes as described above. At 120 knots you have 7 minutes to lose 1700', not an unheard of rate of descent, the next step down is only 600' as well. The course reversal really isn't necessary for altitude reduction so much as making the sharp turn back around to the FAC.

 

[EdFred]

Part 91 says fly the altitude(s) in your clearance.

An approach is part of a clearance, and descending to appropriate altitudes on the approach without ATC giving you those altitudes one at a time is, well, appropriate.

I have never gotten a clearance that did not include "cleared for the XXX approach, descend and maintain NNNN until established" whether it be a VOR/GPS/RNAV/LPV/ILS or whatever else approach.

 

[Skid]

So just to make sure I'm clear for real world flying, would being inside the TAA mean I'm established? I.e maintain 7000 until entering a segment of the TAA?

 

[AggieMike88]

Assuming that the figure in the test is the same as the one currently published, that you linked to

This might be a key item in the discussion. The one linked is the current chart, but not the one in the testing supplement.

The testing supplements can be found at: https://www.faa.gov/training_testing/testing/supplements/ and the 2017 IFR test supplement is found at: https://www.faa.gov/training_testing/testing/supplements/media/instrument_rating_akts.pdf

A screen grab of the chart in question is below....

 

[AggieMike88]

This was a test prep question, 2387

Which test prep system? #2387 is likely unique to that system, versus an FAA generated number.

 

[EdFred]

Seems like a spot the difference game between the current and testing plate, but I can't see it other than the very bottom left corner that says 05Feb15 vs 19Sep13, a foot added to the runway and the TDZE vs THRE which wouldn't affect the question.

 

[flyingron]

So just to make sure I'm clear for real world flying, would being inside the TAA mean I'm established? I.e maintain 7000 until entering a segment of the TAA?

Yes. The entire TAA is a published part of the approach. In the proposed question, 27W of AXCIB **IS** in the TAA. Presumably if you have your GPS set appropriately, you're on the approach the moment the controller clearance.

The question just said you were "cleared for the approach," which is all you should need to answer the question. It didn't give you the actual controller instruction which, since the TWA 514 crash into Mount Weather has included the REDUNDANT maintain altitude until established. It has never been the case that being "cleared for the approach" was a clearance to descend to the first published altitude if you were not yet on a published segment. However, these guys were confused (as with most crashes, there were a bunch of things that lead up to this).

 

[PPC1052]

I never like it when I disagree with EdFred, cause he tends to know this stuff really well. And I have never flown IFR with GPS/RNAV, so this isn't my area of experience, either. But, what's the point of the TAA if you can't descend when cleared for the approach and your within the TAA?

 

[flyingron]

I never like it when I disagree with EdFred, cause he tends to know this stuff really well. And I have never flown IFR with GPS/RNAV, so this isn't my area of experience, either. But, what's the point of the TAA if you can't descend when cleared for the approach and your within the TAA?

You are correct. The TAA is an published segment and you are allowed to descend to the altitude in the sector as soon as you are cleared and within that sector. As stated the "maintan NNNN" stuff should be redundant. You're obliged to maintain your cleared altitude until you are an a published section of the approach when cleared.

 

[EdFred]

I think the biggest problem is, as written, none of the three answers are exactly correct.

 

[flyingron]

The reason you wouldn't descend to 5,300 then 4,700 is first and foremost that you were not cleared to do so. That is not a feeder route and therefore not considered part of the approach. Secondly MSA's only guarantee 1,000 foot of clearance, not adequate signal reception.

This is a TAA not an MSA. The TAA is a published segment of the approach and when you are cleared and established on it you may descend. This is a GPS approach anyhow, so there's not any signal reception to worry about in the approach design (though TAAs do exist on non-GPS approaches, we have one on an ILS here. But then the reception of the navaid is surveyed as part of it).

 

[Grum.Man]

This is a TAA not an MSA. The TAA is a published segment of the approach and when you are cleared and established on it you may descend. This is a GPS approach anyhow, so there's not any signal reception to worry about in the approach design (though TAAs do exist on non-GPS approaches, we have one on an ILS here. But then the reception of the navaid is surveyed as part of it).

I realized my error and tried to retract my post but you caught me ;-)

 

[bflynn]

I never like it when I disagree with EdFred, cause he tends to know this stuff really well. And I have never flown IFR with GPS/RNAV, so this isn't my area of experience, either. But, what's the point of the TAA if you can't descend when cleared for the approach and your within the TAA?

Warning, look out below. Having the TAA is informational, it is not an authorization.

Wasn't it just a month or two ago that someone posted about a commercial flight that narrowly avoided CFIT despite descending before the approach? As I recall, the problem there was that the enroute altitude was lower than TAA, so as they approached the IAF, they were seeing tree tops in the clouds.

 

[Grum.Man]

Warning, look out below. Having the TAA is informational, it is not an authorization.

Wasn't it just a month or two ago that someone posted about a commercial flight that narrowly avoided CFIT despite descending before the approach? As I recall, the problem there was that the enroute altitude was lower than TAA, so as they approached the IAF, they were seeing tree tops in the clouds.

My recollection of that instance was that the controller cleared them to an altitude lower than MOCA too early.

 

[Larry in TN]

It didn't give you the actual controller instruction which, since the TWA 514 crash into Mount Weather has included the REDUNDANT maintain altitude until established.

Isn't that only when you are on radar vectors or non-published direct routing? In this case the pilot is already on a published segment of the approach where, I think, the restated altitude is not required.

I get approach clearances without an altitude to maintain quite regularly. Last one was going into DEN. Descending via the JAGGR 3 arrival, clearance was, "[callsign], at QWIKE, cleared RNAV Z Runway 17R" No altitude mentioned.

 

[flyingron]

Warning, look out below. Having the TAA is informational, it is not an authorization.

I disagree. It is a published segment. If you're cleared for the approach, you can descend to the TAA altitude if you're within the appropriate sector.

Wasn't it just a month or two ago that someone posted about a commercial flight that narrowly avoided CFIT despite descending before the approach? As I recall, the problem there was that the enroute altitude was lower than TAA, so as they approached the IAF, they were seeing tree tops in the clouds.

As I stated before, the classic is the TWA 514, which occurred on December 1, 1974.

The flight was headed for Washington National, but weather there had closed down arrivals there. So the pilots, already at the end of a long day were now headed for an airport that was going to be a long way away from where their cars were parked. After further communications with the company dispatch they got rerouted to IAD. They had been cleared down to 7000' and then the controller clearance (proper for back then) was just "TWA 514, you're cleared for a VOR/DME approach to runway 12." The captain (having briefed the approach previously stated that "1800 is the bottom" and the FO confirmed with "We're out here quite aways. I better turn the heat down."

Then as the approach progressed, the captain observed "You know, according to this dumb sheet it says 3400 to Round Hill is our minium altitude." The FO started "Well but..." and the captain completed "When he clears you, that means you can go to your initial approach altitude."

In addition to being wrong about what the meaning of "cleared for the approach" meant with respect to altitudes, they had misplaced the fix the captain was talking about as well. Round Hill isn't 11 DME, it's 11 miles from the next fix and actually about 17.6 DME from the ARMEL VOR it is based of. Of course, that mistake would have just told them to stay higher closer.

Attached is the plate from that approach.

 

[flyingron]

Isn't that only when you are on radar vectors or non-published direct routing?

Correct, the "MAINTAIN" qualification on the approach is only required for aircraft "operating on unpublished routes and NOT already established on a published part of the procedure."

In the case of the test question, unless they were on an airway (which it didn't indicate), the actual controller approach clearance should have included the MAINTAIN 7000. Again, the question just states you were cleared for the approach, it doesn't give the text of the clearance verbatim. Again the MAINTAIN is actually redundant.

If they had arrived via an airway or the controller knew they were established on the approach (i.e., they'd been previously reported established on a published segment), then the MAINTAIN can be omitted. Most controllers tend to give it anyhow.

 

[Noah Werka]

Read about TAAs from Bruceair.

Noah W

 

[denverpilot]

Warning, look out below. Having the TAA is informational, it is not an authorization.

Wasn't it just a month or two ago that someone posted about a commercial flight that narrowly avoided CFIT despite descending before the approach? As I recall, the problem there was that the enroute altitude was lower than TAA, so as they approached the IAF, they were seeing tree tops in the clouds.

My recollection of that instance was that the controller cleared them to an altitude lower than MOCA too early.

Their clearance was a decent “at or above” to a MVA that was lower than the MVA further ahead on their planned route and lower than they should have started the approach.

 

[MauleSkinner]

I have never gotten a clearance that did not include "cleared for the XXX approach, descend and maintain NNNN until established" whether it be a VOR/GPS/RNAV/LPV/ILS or whatever else approach.

that's exactly what you get with a TAA...maintain NNNN until established. That clearance allows you to descend to the TAA altitudes published.

 

[flyingron]

Again, Larry had it right. The "Maintain NNNN until established" is only mandated when you are arriving off airway/published segments, but it is true that a lot of controllers pretty much give them out all the time (especially in the areas where most arrivals don't come in on airways).

Anyhow, it's entirely redundant. Cleared to approach gives you the authority to descend as the approach allows once you're on a published segment (this includes TAAs and it includes published feeder routes). If the "Maintain NNNN" altitude was different than what you'd previously been cleared for, ATC is required to give you a specific climb/descend instruction. Prior to being cleared AND on the published segments, you'd maintain your assigned altitude anyhow. About the only time you don't is if you lost comms and for some reason there's a higher altitude in the Minimum/Expected/Assigned sequence, which is pretty unlikely in the space between being cleared for the approach and getting on the published segments.

 

[benyflyguy]

Good example of selecting the best choice available...not necessarily the absolute nuts right answer. But given the details of this question, you’ll recognize the question on the test. I remember it from my prep and I took my test over a month ago

 

[denverpilot]

Someone more confident there wasn’t a correct answer, will report the bad question at the end of their test, and it’ll get pulled.