Anatomy of a Slam Dunk (and what to do differently in the future)

[Ragsf15e]

1 hour ago, 0TreeLemur said:

Good catch.  Didn't mean MDA. 

I really have no idea why they had me at 4000.  You are correct, I don't know what their MVA is.

Who do I call about this?   How do I find the phone number to talk to someone at ABC approach?  Do I really want to do that?   Dealing with bureaucrats is NOT my hobby.  (first time I've used that face on MS).

I'm learning-   I anticipated it happening this time.    Next time I want to talk to the approach controller in a way that produces a better outcome .  Based on what @Ragsf15e wrote, I think I should request a vector to an IAF.   Yesterday, with storms SE of the airport, that would have sent me to IAF ALICE for the RNAV04 at TCL.  Alice was not that far out of my way.   Don't know why they didn't just do that.

I think my lesson here is this:  When the approach controller says vectors to FAF, suggest vectors to an IAF.

 

You will need to think proactively and tell them what you want.  Fight the tendency to just let them decide what you’re doing and how you get there.  Most of the time they will default to vectors to final.  If you want ALICE, ask for it by name (without asking for vectors).

You will give and take with the controller, but you need to make your wishes known.

[rbp]

 

7 hours ago, 0TreeLemur said:

I'm not established because they are vectoring me to the final approach coarse outside of the FAF. 

I see the VNAV glideslope indication appear at the top of the scale, and I pass through it.   I contact approach and tell them that I'm above the glide slope.  Meh.  The controller didn't seem to care or understand the implications, just a "Cleared for the approach once established, contact tower, good day."

 

I re-read your post and and I have more questions. 

you wrote that the glideslope indication appears "at the top of the scale." do you mean it was fully deflected at the top of the instrument? if so, that means you are below the glideslope, not above it. could you have been reading it "upside down?"  Where was the CDI at this point?

when you say: "I'm not established because they are vectoring me to the final approach coarse outside of the FAF" are you suggesting that with VTF you believe you are not established until you are at the FAF? you are established once the CDI is at half deflection, no matter how far out you are. you may begin your descent once the vertical indicator is half deflected (although its proper for it to be centered), and this should put you at the correct crossing altitude for the FAF.

 

[RobertGary1]

Reminds me of the vor approach into Santa Monica. You had like 1.3 miles to lose 1500 feet. Full slip in the clouds full dirty and hope to land by the end of the runway 

[Ragsf15e]

1 hour ago, rbp said:

 

I re-read your post and and I have more questions. 

you wrote that the glideslope indication appears "at the top of the scale." do you mean it was fully deflected at the top of the instrument? if so, that means you are below the glideslope, not above it. could you have been reading it "upside down?"  Where was the CDI at this point?

when you say: "I'm not established because they are vectoring me to the final approach coarse outside of the FAF" are you suggesting that with VTF you believe you are not established until you are at the FAF? you are established once the CDI is at half deflection, no matter how far out you are. you may begin your descent once the vertical indicator is half deflected (although its proper for it to be centered), and this should put you at the correct crossing altitude for the FAF.

 

One clarification that I’m sure you’re aware of, I’m just say so that someone else doesn’t get confused… 

you said:

“you are established once the CDI is at half deflection, no matter how far out you are.”

but you actually need to be on a published portion of the approach, so you need to check the distance from the waypoint as well.  It is definitely possible to be outside the furthest portion of the approach (ie, not on a published portion) and have the cdi centered. Very easy to do on an ils that has an arc, but you get vtf…

Does that make sense?

[MikeOH]

3 hours ago, 0TreeLemur said:

Good catch.  Didn't mean MDA. 

I really have no idea why they had me at 4000.  You are correct, I don't know what their MVA is.

Who do I call about this?   How do I find the phone number to talk to someone at ABC approach?  Do I really want to do that?   Dealing with bureaucrats is NOT my hobby.  (first time I've used that face on MS).

I'm learning-   I anticipated it happening this time.    Next time I want to talk to the approach controller in a way that produces a better outcome .  Based on what @Ragsf15e wrote, I think I should request a vector to an IAF.   Yesterday, with storms SE of the airport, that would have sent me to IAF ALICE for the RNAV04 at TCL.  Alice was not that far out of my way.   Don't know why they didn't just do that.

I think my lesson here is this:  When the approach controller says vectors to FAF, suggest vectors to an IAF.

 

Yes, I think you should call.  The numbers are listed in Section 4 of the AFD (excuse me, the Chart Supplement). They have a QC department and if they are routinely violating the 1000 fpm 'rule' they will want to know.  You may also learn there is a reason they keep you high and if there is an alternate way to request a milder descent.

Also, be polite but take charge and 'request' what you want; don't just suggest, or 'let ATC worry about getting you to a decent place', that's YOUR job.

[rbp]

11 hours ago, Ragsf15e said:

One clarification that I’m sure you’re aware of, I’m just say so that someone else doesn’t get confused… 

you said:

“you are established once the CDI is at half deflection, no matter how far out you are.”

but you actually need to be on a published portion of the approach, so you need to check the distance from the waypoint as well.  It is definitely possible to be outside the furthest portion of the approach (ie, not on a published portion) and have the cdi centered. Very easy to do on an ils that has an arc, but you get vtf…

Does that make sense?

not on vectors to final. you can be established up to +10nm outside the gate (which is 5nm from the threshold) for a non-precision approach, so long as you are navigating on the final approach course

these are from JO7110, section 5-9

 

[rbp]

I managed to find your flight https://flightaware.com/live/flight/map/N202Y/history/20230309/1530Z/KTMB/KTCL

here you are intercepting the final approach course 041 @ 8nm from the threshold (You can't see it, but my cursor on the threshold of 04). 

at 14nm out, you were at 4900' on a heading of 030, and at 10nm out you were at 4400' on a heading of 038, and you only descended 500'. might have also been going faster than you thought.

it seems to me that the CDI should have come off the stop further out than 8nm, but you were still pretty high. CAPOG is 11.1nm out, and the crossing altitude is 2400.

they definitely did a crappy job of descending you. the should have brought you down to 2400 @CAPOG

if you're going to call ATC, then you might want to offer to send them the link for the flight 

[Ragsf15e]

1 hour ago, rbp said:

not on vectors to final. you can be established up to +10nm outside the gate (which is 5nm from the threshold) for a non-precision approach, so long as you are navigating on the final approach course

these are from JO7110, section 5-9

 

No, the example with your red box is exactly what I’m talking about.  You are established on the approach course but not established on an approach segment.  You have to be very careful and specific about saying “established” because if you’re cleared for the approach and “established on a published segment” you can descend to the published altitudes.  If you’re “established” on the course, that doesn’t mean you are established on the approach.

The key is knowing when you are established on a published segment and which segment it is.  Both require looking at the distance to the waypoint (faf).

[AIREMATT]

It is up to the PIC to decide what is acceptable for the operation of the airplane. ATC isn’t flying your airplane and making decisions for it. 
Tell them what you need I.e. I need lower or I will need a 360 to lose altitude before the FAF. They are there to keep you from hitting another plane and to provide the services you tell them you need. If you don’t tell them, they don’t know.

Since you are concerned about future flights with the same issue, weather permitting, request the approach via an IAF/IF or tell them you need lower to get down for the approach if you want to follow the VNAV profile or keep a reasonable descent rate. ATC isn’t monitoring your glide slope or concerned if you are going through it, but if you say you need lower to make your crossing altitude, they can make it work usually for both of you.

Sometimes we as pilots defer to ATC’s instructions thinking ATC is doing what is best for our operation. Until they hear something to the contrary from the Pilot, they assume it is acceptable and continue doing what they Think you need. Communication goes along way towards resolving issues before they become issues.

I wouldn’t lose much sleep over the whole thing at this point. Call the facility and ask them why you are brought in high on the approach if you want , but when flying, tell them what You Need and I’d bet you will get what You want 99% of the time.

[rbp]

1 hour ago, Ragsf15e said:

No, the example with your red box is exactly what I’m talking about.  You are established on the approach course but not established on an approach segment.  You have to be very careful and specific about saying “established” because if you’re cleared for the approach and “established on a published segment” you can descend to the published altitudes.  If you’re “established” on the course, that doesn’t mean you are established on the approach.

The key is knowing when you are established on a published segment and which segment it is.  Both require looking at the distance to the waypoint (faf).

yes, you're correct. you can only descend on a published segment of the approach -- a solid black line -- regardless of whether or not you have intercepted the inbound course or GP/GS

[jlunseth]

21 hours ago, Shadrach said:

How is it hard on the engine? Genuinely curious?

I have personal experience with this. Had to idle the engine and do a long dive from 19k once upon a time. Engine was not happy after that and we eventually did an IRAN. The diagnosis was “piston slap.” The rings, esp. the compression rings require compression from the operating engine to seat properly against the cylinder walls. If the rings do not seat, this allows the rings and pistons to scar the cylinder walls. This is a different thing from the placarding of some models as I understand it. The placarding is because of vibration, not piston slap. My situation was pretty extreme. I have done lots of reduced power descents since then without a problem, but low power is not no power.

On the OPs “slam down” issue, I always set the “desired descent” algorithm in my 430 so I know when I am at about 450 fpm to make my desired altitude. I then ask for a “slow descent” to the airport. On occasion that may start 125 miles from the airport if I am in the flight levels with a nifty tailwind. I use 450 because when I tip the nose over the plane is going to speed up and my target descent rate is 500. I fly many Angel Flights and/or have passengers on board who are not used to rapid descents, and 500 is easy on the ears. ATC does not always give me what I want, but most of the time they put me in the queue and eventually I get a reasonable descent. If I don’t get a reasonable descent I use the speed brakes. Very rare in my experience to get an actual slam down where you need to get to the GS from a high altitude. Have had to do it a few times, and at that point it is time to stop worrying about a long stabilized descent and weather ATC did something to you. Fly the airplane. Stabilize your descent and airspeed with all available weapons once you get on the GS. By that time you should have flaps and gear down and that will slow your speed pretty good.

Edited March 11, 2023 by jlunseth

[Marc_B]

https://www.ifr-magazine.com/technique/what-is-established/

Not exactly the situation faced by the OP, but still a great review of exactly how do you define "established" and how you can anticipate the course to make sure you're starting your decent at the earliest possible time (plus realizing that the terps were designed to maintain obstruction clearance with plenty of berth around the centerline for this).

To the OP's case, if pointed out/requested from ATC, would they have approved vectors to CAPOG to get established on final approach course and better manage altitude?  Sounds like the moral of the story is, if you rely on ATC to put you where you need to be it's easy for ATC to get us way behind the aircraft.  My thought is if way too high to be feasible, worst case you could go missed and have ATC bring you back around and hopefully give you more time to get better sequenced.  Which interestingly enough the missed approach is climb to 2500' for hold...

[201Steve]

I have called controllers several times to chat it out with them. Just find the clearance phone number in ForeFlight, call them up and tell them you’d like to talk to a supervisor or someone familiar with the local ops at the airport. Heck I’ve even told them I wanted to talk to the specific controller who was working me. Assuming they are still at work. Tell them what happened. Ask why. Tell them your position. It’s just a conversation. No need to worry about “bureaucratic mess”, the intent shouldn’t be to get someone in trouble or the like, just talk it out. They are usually super helpful and very down to earth. If unsatisfied you can do whatever you may from there but each time I’ve talked to a tower or approach, it all makes sense and case is closed. 

[GeeBee]

We had FOQA, "Flight Operations Quality Assessment" data that detected about 250 parameters on a recorder, not FDR, but a dedicated optical disc recorder. When we would see a lot of flap overspends at a given airport, we would look at the descent profiles and if warranted have a discussion with ATC facility concerned about what they were doing to trigger these problems. ATC was always helpful and responsive, in some cases not realizing what they were doing was backing pilots into a wall. A call to the facility is and talking to the managers is always a good place to start. It needs to be timely so they can pull their data and look at what they did.

[Will.iam]

As previously stated tell them you need lower, as you wait for their response slow to approach speed then when they give you lower you can trade more altitude for airspeed than you could if you are still at top of flap speed. Besides at 75 kias or what ever your min approach speed is you are so slow you are not going to have air driving your engine at that low of speed if you goto idle and that will really help your decent rate compared to keeping 18” MP. If no response within a min, tell them you need a 360 to lose alt or vectors back to the iaf as this approach is now unstable for you. No need to waste time and gas continuing on this approach that is unsafe to you anyways. 

Edited March 12, 2023 by Will.iam

[Mcstealth]

Controllers are supposed to vector to the final below the GS so you don't have to dive.  But of course the MVA ( minimum vectoring altitude) must allow for that.    You just fly along level until it becomes active, then follow it.  If you are above they must ask if above is OK.  Your intercept is supposed to be at least two
miles outside the approach gate.  That's a point two miles from the FAF or five miles from the runway.  And they have to give you your position with the clearance.  They can turn you on at the FAF with your concurrence.  As to what happened I can think of a couple of things.  First the controller may have been busy and couldn't take the time to vector you out farther to intercept below.  He just wanted to get rid of you to lessen his workload.  I understand.  I've been there.  Most of the time intercepting a bit above doesn't hurt and he was betting it wouldn't here especially if he knew the bases were high.  And you sounded like a proficient pilot so he figured you could do it.  We always listen to the voice.  If you sound like a rookie we don't expect as much.  Second, with T in the area maybe he was turning you in close to avoid one that he saw.  None of us always get all of our i's dotted and our T's crossed and the system still works.  That's what flexibility is for, not to excuse an error, but that's life.  What to do??  If your set-up doesn't look right ask for what you need.  If you think you'll be high ask for a farther vector though it could change your sequence and take longer.  He may make you last instead of first.  He's not god.  You have rights.  It's a partnership.  Do what he says, but don't let him walk on you.  Be honest.  Tell him if you need something.  Go missed if you have to.  He'll hate that.  He has to work you again.  Maybe he'll do better then.

[EricJ]

24 minutes ago, Mcstealth said:

Controllers are supposed to vector to the final below the GS so you don't have to dive.  

Also so that the autopilot will capture it, and so that you don't get GS reversal from a reflection on an ILS.   

[Pinecone]

Also due to false glide slopes that only appear above the real one.

[0TreeLemur]

1 hour ago, Pinecone said:

Also due to false glide slopes that only appear above the real one.

The first time I got slam-dunked here I was shooting the ILS 04 and ^^^^this happened.

[rbp]

On 3/11/2023 at 11:47 AM, rbp said:

yes, you're correct. you can only descend on a published segment of the approach -- a solid black line -- regardless of whether or not you have intercepted the inbound course or GP/GS

after a discussion with a friend who is a long-time corporate pilot/ATP/CFII, I am reversing my position on this, and here is why.

he said many airports that don't have radar coverage low enough to descend you below the MVA to the glideslope/path intercept altitude. so they give you a clearance to maintain the MVA altitude "until established" so that you will intercept the final approach course inside an intermediate fix aligned with the runway. Once you turn inbound, you are actually on an intermediate segment (note the thick black line), which is a published segment of the approach and you can then descend in protected airspace to the altitude at the FAF.

in the case of TCL RNAV RWY 4, we know from the ADS-B track that @0TreeLemur intercepted the final approach course at least 8nm from the threshold at 4000, which puts him inside CAPOG (11.1nm), heading 041 (note on the chart that this is specifically the final approach course) for  BUPGY, and he can therefore descend in compliance with 91.175(i) to cross at 1800, and capture the glidepath

The reason they don't clear you to the IF is because you're talking to TRACON and getting vectors to final, which means they send you to the FAF. If you want to fly the full approach, you have to ask for it, in which case you'd have to go to an IAF, not CAPGY because CAPGY's crossing altitude is below the MVA

So, in actuality, @0TreeLemur had at least 3 miles from when he intercepted the final approach course until BUPGY to lose 2200 ft. Still not a great descent rate to capture the glide path, but certainly better.

here's another link to the plate: 

[0TreeLemur]

13 hours ago, rbp said:

So, in actuality, @0TreeLemur had at least 3 miles from when he intercepted the final approach course until BUPGY to lose 2200 ft. Still not a great descent rate to capture the glide path, but certainly better.

 

Live and learn, and learn to live...  Appreciate all the comments.

[Ragsf15e]

14 hours ago, rbp said:

after a discussion with a friend who is a long-time corporate pilot/ATP/CFII, I am reversing my position on this, and here is why.

he said many airports that don't have radar coverage low enough to descend you below the MVA to the glideslope/path intercept altitude. so they give you a clearance to maintain the MVA altitude "until established" so that you will intercept the final approach course inside an intermediate fix aligned with the runway. Once you turn inbound, you are actually on an intermediate segment (note the thick black line), which is a published segment of the approach and you can then descend in protected airspace to the altitude at the FAF.

in the case of TCL RNAV RWY 4, we know from the ADS-B track that @0TreeLemur intercepted the final approach course at least 8nm from the threshold at 4000, which puts him inside CAPOG (11.1nm), heading 041 (note on the chart that this is specifically the final approach course) for  BUPGY, and he can therefore descend in compliance with 91.175(i) to cross at 1800, and capture the glidepath

The reason they don't clear you to the IF is because you're talking to TRACON and getting vectors to final, which means they send you to the FAF. If you want to fly the full approach, you have to ask for it, in which case you'd have to go to an IAF, not CAPGY because CAPGY's crossing altitude is below the MVA

So, in actuality, @0TreeLemur had at least 3 miles from when he intercepted the final approach course until BUPGY to lose 2200 ft. Still not a great descent rate to capture the glide path, but certainly better.

here's another link to the plate: 

I agree with most of your comments, but here’s a couple nit picks…

1. You said “Once you turn inbound, you are actually on an intermediate segment (note the thick black line), which is a published segment of the approach and you can then descend in protected airspace to the altitude at the FAF.”

However, you still need to look at the distance to the faf to see which intermediate segment you’re on.  This approach it didn’t matter, others it does.  See example below.  You need to fly the segment you are on, not just to the FAF. It is easy to get vectors out past DIYSA (4.5 to the FAF) and then turn inbound and bust the step down if you descend to the FAF altitude.

2.Also, getting direct to the IF is definitely possible.  You may get “cleared direct to CAPOG, maintain 4200 (mva) until established. Cleared the approach.” Depends on the mva where you are.  You have 6nm after CAPOG to descend which will be a little over 4 degrees, not terrible, and better than what he actually had to do.

 You can start an approach at an IF, but ATC has limits to the maximum angle of your direct course to the IF, 90 degrees I think, but we’ll have to check my source.  An IAF allows more flexibility for that initial turn, but an IF is fine if you’re roughly aligned.

PS. I have the same exact background/certifications as your friend, did we talk?! 

[Ragsf15e]

22 hours ago, rbp said:

after a discussion with a friend who is a long-time corporate pilot/ATP/CFII, I am reversing my position on this, and here is why.

he said many airports that don't have radar coverage low enough to descend you below the MVA to the glideslope/path intercept altitude. so they give you a clearance to maintain the MVA altitude "until established" so that you will intercept the final approach course inside an intermediate fix aligned with the runway. Once you turn inbound, you are actually on an intermediate segment (note the thick black line), which is a published segment of the approach and you can then descend in protected airspace to the altitude at the FAF.

in the case of TCL RNAV RWY 4, we know from the ADS-B track that @0TreeLemur intercepted the final approach course at least 8nm from the threshold at 4000, which puts him inside CAPOG (11.1nm), heading 041 (note on the chart that this is specifically the final approach course) for  BUPGY, and he can therefore descend in compliance with 91.175(i) to cross at 1800, and capture the glidepath

The reason they don't clear you to the IF is because you're talking to TRACON and getting vectors to final, which means they send you to the FAF. If you want to fly the full approach, you have to ask for it, in which case you'd have to go to an IAF, not CAPGY because CAPGY's crossing altitude is below the MVA

So, in actuality, @0TreeLemur had at least 3 miles from when he intercepted the final approach course until BUPGY to lose 2200 ft. Still not a great descent rate to capture the glide path, but certainly better.

here's another link to the plate: 

Here's a couple of pages from the controller handbook about getting cleared direct to the IF for an approach.  Angle less than 90 degrees and you must be held at MVA until the IF.

[rbp]

16 hours ago, Ragsf15e said:

PS. I have the same exact background/certifications as your friend, did we talk?! 

so you have the same background, but disagreed when I originally took the position that OP could have descended after turning inbound.   

looking forward to seeing how you will justify taking both opposite positions, without admitting that one was wrong in one

 

 

[Ragsf15e]

2 hours ago, rbp said:

so you have the same background, but disagreed when I originally took the position that OP could have descended after turning inbound.   

looking forward to seeing how you will justify taking both opposite positions, without admitting that one was wrong in one

 

 

I only disagreed with you saying that you didn’t need to check distance as well as course to verify being established on a specific segment of the approach.  Blanket statements like that make it look like that’s acceptable on any approach and it’s not.