Teardrop Procedure Turn as a Course Reversal

[_HAMMER_]

I would like to know how would you execute a Teardrop Procedure Turn. Letīs use the ILS/DME rwy 11 at TNCA as an example.

http://www.vatcar.org/charts/charts/...0(ILS-DME).pdf

I understand that we cannot perform the turn as a standard rate turn. The FAR does not tells you how to do it. It just state that you need to depart the IAF on the publish outbound course followed by a turn to intercept the inbound course at or prior the intermediate fix.

I read that is OK just to initiate a standard rate turn and then stop it in a manner so that you can wait and intercept the inbound course with 45 degrees angle. Other option is to anticipate the requiered bank by using the RMI.

Is there a techique or a formula to figure out how the required bank angle to make one continuos turn from the outbound course to finish the turn while intercepting the inbound course? How does airliners do it?

I know is not something you would use while being vectored in radar environment. But I still would like to know your opinion.

Thanks.

[Roger Greendeck]

A intercept 45degree may be too steep. 30 degrees works better but after a reversal this may put you too close. Cat C/D reversals cater for high speed in the turn which often mean that if you do a rate one turn to set up a 30 degree intercept you will intercept final too far along track.

The easiest option is to set up a 90 degree intercept and with 5 degrees to run on the VOR start a turn onto you final course. This is the same as you would do joining final off a DME arc.

[flyboyike]

If it's in the FMS, just hit NAV.

[Chris Scott]

I'm not familiar with this spec of chart, but am assuming the 'BEA' beacon is a VOR/DME, and not just a DME. Guess it must be, as the hold is based on it.

Mental arithmetic (using the one-in-sixty rule) puts "D10.2 BEA" about 4 nm south of "D10 IBE", implying a radius of turn (as drawn on the chart) of about 2 nm, giving a track distance of about 6 nm for a 180-deg turn. At TAS 180 kt, a rate-one turn (25 deg bank) through 180 deg (60 secs) covers just 3nm. That's in still air, of course. So you can see the curve they've drawn is more like a rate-half if you're doing only 180 kt.

Even if you fly it at a typical minimum-clean jet speed of 210 kt (about 30 deg bank for rate-one), you would still be well inside that curve. And you would probably need to slow down before completing the turn, because you want to be at final-approach speed when intercepting the GS at only 6 nm.

So Roger Greendeck is absolutely right to warn of the probability of intercepting the LLZ (ILS localiser) too close to the runway if you try a 30-degree intercept. I think his suggestion of flying a 90-deg intercept until 5 deg before the inbound track is a good one. That would be the BEA 288 Radial. In still air at 180 kt, that would be early enough to avoid shooting through the LLZ.

In a northerly or NE wind you might have to pause briefly on an intercept heading of about 080. In a southerly, on the other hand, you might need to start the turn a bit earlier if at 180 kt. Also, as always, VORs are only accurate to about 5 degrees, and any errors may not be consistent.

[aterpster]

I'm not familiar with this spec of chart, but am assuming the 'BEA' beacon is a VOR/DME, and not just a DME. Guess it must be, as the hold is based on it.

"D 113.8" is a major clue.

[bubbers44]

I have done this approach dozens of times and it is very easy. The hard part is getting a descent clearance at altitude. They don't have a clue how to get you down. I ask for descent fifty miles early and still have to descend in holding do to lousy ATC.

[aterpster]

bubbers44:

I have done this approach dozens of times and it is very easy. The hard part is getting a descent clearance at altitude. They don't have a clue how to get you down. I ask for descent fifty miles early and still have to descend in holding do to lousy ATC.

I know you know, but some of the readers may not. The holding pattern shown must be used in any case to align with the base leg course reversal unless you arrive at the VOR within 30 degrees of the base leg outbound course.

[reynoldsno1]

Teardrop Procedure Turn

It's officially called a 'Base Turn". For Cat C/D it will have been designed using a speed of 250kt IAS, unless a slower speed is specified. If you fly slower than that then you will probably turn inside the inbound course and have to adjust accordingly. The design also incorporates allowances for the effect of an omnidirectional wind -in this case, probably something a little over 50kts.

[bubbers44]

Aterpster, do you have any documentation of mandatory holding pattern entry? My neighbor who is an airline captain also says holding pattern is mandatory. I said no. I never did the holding pattern if number 1 for approach because it made no sense. I did it hundreds of times. I never had anyone question doing a direct outbound arrival from the vor with no hold entry. Why? I know I misspelled your name but this suck iPad is hard to type on.

[Fly3]

It is clearly marked PANS-OPS and therefore the speed during the procedure cannot be as high as 250kts. I think that it should be flown at 185kts IIRC and the intercept adjusted accordingly.

[eflowj]

Since it is a PANS-OPS procedure, look at ICAO DOC 8168. It is also in the Jeppesen Airway Manual, Air Traffic Control tab. Spells out when you can go straight into the Base Turn and when you cannot.

[reynoldsno1]

It is clearly marked PANS-OPS and therefore the speed during the procedure cannot be as high as 250kts. I think that it should be flown at 185kts

It (the base turn) is an initial approach procedure - initial approach speed for Cat D is 250kt(PANS OPS) 185kt is a UK limitation applicable to all approach procedures, istr. Cat A/B is limited to 140kt (PANS OPS).

[Sonny Hammond]

80/260 if theres nothing published and you are above the msa?

[Chris Scott]

reynoldsno1,

I've never flown to Aruba, and that wide-radius turn could probably be folllowed at 250 kt. But maintaining 250 kt until 10 miles from touchdown on an instrument procedure is plainly not to be recommended.

Also, if you start the turn at 250 kt, and then decelerate, you will start to creep inside the bend (unless there's a strong southerly wind). Therefore, you will need to choose an intercept heading, on the lines that Roger Greendeck and I have suggested.

[aterpster]

bubbers44:

Aterpster, do you have any documentation of mandatory holding pattern entry? My neighbor who is an airline captain also says holding pattern is mandatory. I said no. I never did the holding pattern if number 1 for approach because it made no sense. I did it hundreds of times. I never had anyone question doing a direct outbound arrival from the vor with no hold entry. Why? I know I misspelled your name but this suck iPad is hard to type on.

This forum really sucks big-time. It is the only aviation forum I attend that doesn't allow attachments.

Anyway, it is in PANS-OPS 8168. Here is a link to my website with an excerpt from 8168 in PDF format. Also, as someone else stated, it is in the Jepp legend.


Index of /8168

[reynoldsno1]

But maintaining 250 kt until 10 miles from touchdown on an instrument procedure is plainly not to be recommended.

I could not agree more, but the purpose of PANS OPS is to design procedures and subsequently assess the resultant drawing or template to determine clearance from obstacles/terrain. 250kt is the 'standard' initial approach speed (maximum) for Cat D, and all calculations are based on that - it does not mean you must fly at that speed. Anything less is fine, and you will be contained within the procedure depicted, but appropriate adjustments will be required as you suggested.

[aterpster]

ReynoldsNo1:

I could not agree more, but the purpose of PANS OPS is to design procedures and subsequently assess the resultant drawing or template to determine clearance from obstacles/terrain. 250kt is the 'standard' initial approach speed (maximum) for Cat D, and all calculations are based on that - it does not mean you must fly at that speed. Anything less is fine, and you will be contained within the procedure depicted, but appropriate adjustments will be required as you suggested

Well stated, but the premise is "the old way."

Eventually, performance based navigation will replace all this old stuff.

RNPA AR already has, but that is both a technical and political club dictated by already existing air carrier equppage.

[galaxy flyer]

Sonny

Maybe that's so in Idaho, but it ain't so in ICAO Doc 8168 land.

[Fantome]

Dear Mr Hammer . . .. .. As you see, there is much detailed and expert advice here which should clarify for you some fairly basic principles and practices.

By the way, you say in another forum -

I am just looking foward to build a solid career as a prossional pilot. Any comment would be appreciated.

Thanks a lot

May I suggest that before you fire off your posts you reread what you have written a little more critically. If you have a struggle with English
for the reason that it is not your native tongue, please do not be offended by anything posted here.

Another thing, looking back to that first post of yours in one of these forums, I must say I am a little puzzled as to why you appear to be fretting about the salary you expect to earn when you qualify. But I digress. Here you ask how to execute "a procedure turn as a course reversal". In the thousands of procedure turns I must have made over many years I cannot think of a single instance where such a turn was made for any other reason than a reversal, a means of doing a one-eighty.

Is a procedure turn the only way? No. A Pitts can easily do a one-eighty.
The manoeuvere is called a 'roll off the top'. Or an 'Immelman'.

Alright, so why so pedantic? Because the career you aspire to is
populated with people who will train and check and assess the knot you make in your tie.

Wishing you every success with your studies and satisfaction in your career, at whatever flight level that may be. As Captain Chesley Sullenberger wants the reader to know in his brilliant book 'Highest Duty', there is no other occupation on earth that comes within a bull's roar. A message he imparts with pride, humility, grace and simple unaffected modesty. Truly a man to look up to.

[Zeffy]

flyboyike

If it's in the FMS, just hit NAV.

The alignment holding pattern won't be in the FMS database.

As others have stated, unless the aircraft is arriving at the facility from the Entry Sector, the alignment hold is required.