Approach category

[West Coast]

If you’ve ever argued with a pilot, you know opinion doesn’t go as far as a solid reference, if one exists. As such seeking out a reference regarding at what point does one become governed by a particular approach category.

Assigned 180 kts to the FAF, released from ATC speed control inside of it. I say on an approach that has straight in minimums, that the minimums for a particular category apply from the FAF in. Other pilot says that once established on the FAC, even well outside the FAF that higher category minimums apply.

[172_driver]

Skybrary might not be the best reference but it's easier for Google to find than to find the relevant chapter and paragraph of PANS-OPS or TERPS. (The list is identical to my OM-C): https://skybrary.aero/articles/appro...categorisation

Speed ranges exists for all published segments from the initial approach fix to threshold speed and missed approach. Does that help settle the argument?
Are you thinking a scenario whether you have to fly maximum e.g. max 160 KIAS from the FAF if you're a Category C airplane?

[john_tullamarine]

If there is no subsequent manoeuvring to consider, turn radius and so on doesn't seem to be overly a concern ?

[West Coast]

Originally Posted by john_tullamarine

If there is no subsequent manoeuvring to consider, turn radius and so on doesn't seem to be overly a concern ?

In my mind, no. The other pilot, yes which is why I’m seeking a reference. I do accept such a granular level explanation of the requirements may not exist but figured I’d search just in case.

[B2N2]

Originally Posted by West Coast

Other pilot says that once established on the FAC, even well outside the FAF that higher category minimums apply.

Approach category is determined by final approach speed at maximum landing weights.
So if you fly 120 kts at minimums then you are Category B and if you fly 140kts you should apply the minimums for category C.
What your speed is outside of the final approach fix is irrelevant.

1.4.1 Aircraft performance has a direct effect on the airspace and visibility required for the various manoeuvres associated with the conduct of instrument approach procedures. The most significant performance factor is aircraft speed. Accordingly, categories of typical aircraft have been established.

1.4.2 The criterion taken into consideration for the classification of aeroplanes by categories is the indicated airspeed at threshold (Vst).

1.4.3 Aircraft categories will be referred to by their letter designations as follows:

• Category A: less than 169 km/h (91 kt) indicated airspeed (IAS)
• Category B: 169 km/h (91 kt) or more but less than 224 km/h (121 kt) IAS
• Category C: 224 km/h (121 kt) or more but less than 261 km/h (141 kt) IAS
• Category D: 261 km/h (141 kt) or more but less than 307 km/h (166 kt) IAS
• Category E: 307 km/h (166 kt) or more but less than 391 km/h (211 kt) IAS
• Category H: see 1.4.7, “Helicopters”.

Source: ICAO Doc 8168 PANS-OPS Vol 1, §4, ¶1.4

[Vessbot]

I'm not following what the debate is about. The minimums apply at... minimums. Not sure what can happen outside the FAF conceptually that bears on this.

[EXDAC]

Originally Posted by Vessbot

I'm not following what the debate is about. The minimums apply at... minimums. Not sure what can happen outside the FAF conceptually that bears on this.

It is relevant because, if no minimums are specified for the aircraft category, then the approach cannot (may not?) be flown.

Also, the aircraft minimum turn radius may be important on the published missed procedure.

[172_driver]

I'm not following what the debate is about. The minimums apply at... minimums. Not sure what can happen outside the FAF conceptually that bears on this.

This is not my area of expertise, but sure enough max (and min?) speeds may be relevant when any maneuvering (turning) is involved. Not all approaches are vectored straight in ILS. There are plenty of RNP (AR) approaches that will have you maneuver way below the mountain tops, I flew one with a 1,75 Arc RF leg in the final segment and 2,40 Arc RF leg in the intermediate segment, approved for Cat C/D aircraft. The OP asked when you're governed by your aircraft category. I would argue from the IAF, based on the table below (which is ICAO PANS-OPS). Will it work to fly most approaches faster? Most likely, they aren't edge cases.

[Vessbot]

Originally Posted by EXDAC

It is relevant because, if no minimums are specified for the aircraft category, then the approach cannot (may not?) be flown.

Also, the aircraft minimum turn radius may be important on the published missed procedure.

But if this is the case, you know it before taking off. Or if you missed it there, you catch it at the approach briefing. Or at whatever other point you learn this, you simply don't fly the approach.

[B2N2]

Originally Posted by 172_driver

This is not my area of expertise, but sure enough max (and min?) speeds may be relevant when any maneuvering (turning) is involved. Not all approaches are vectored straight in ILS. There are plenty of RNP (AR) approaches that will have you maneuver way below the mountain tops, I flew one with a 1,75 Arc RF leg in the final segment and 2,40 Arc RF leg in the intermediate segment, approved for Cat C/D aircraft. The OP asked when you're governed by your aircraft category. I would argue from the IAF, based on the table below (which is ICAO PANS-OPS). Will it work to fly most approaches faster? Most likely, they aren't edge cases.

Your posted documentation clearly reads ‘range of speeds’.
Which means you can be well above your max category speed at the IAF and still be at the correct threshold speed for your category.
So no, speed at IAF does not apply
Now if a non normal condition increases your Vref then you need to apply the higher category minimums if applicable.
Could also mean you’re no longer legal to fly that approach if it’s a A/B only.

[galaxy flyer]

Westie,

This FAA InFO Letter (link below) should answer the question. Also, FAA AIM 5-4-7 as reference, which says and I quote,

If it is necessary to operate at a speed in excess of the upper limit of the speed range for an aircraft's category, the minimums for the higher category should be used. This may occur with certain aircraft types operating in heavy/gusty wind, icing, or non-normal conditions. For example, an airplane which fits into Category B, but is circling to land at a speed of 145 knots, should use the approach Category D minimums.

“Should” being the operative word, it’s not mandatory.



https://www.faa.gov/sites/faa.gov/files/InFO23001.pdf

[172_driver]

So no, speed at IAF does not apply

If the approach plate has published minimums for Cat A/B only, do you not read it as you have to be within the range of speeds for initial approach (and reversal and racetrack procedures) passing the IAF?

[galaxy flyer]

Under PANS-OPS, yes; TERPS, no. The AIM only says the initial segment should be flown at 200 KIAS.

[172_driver]

Okay, I did not know that galaxy flyer.

My point is that you have start with checking the plate and see what Category the entire approach is designed for and comply with the speeds accordingly (accounting for differences between TERPS and PANS-OPS). If 99 % of your approaches are vectors to a straight final segment the only relevant restriction is perhaps the minima.

[EXDAC]

Originally Posted by galaxy flyer

The AIM only says the initial segment should be flown at 200 KIAS.

Would you please provide the reference. Many category A aircraft couldn't fly that fast.

[galaxy flyer]

FAA AIM 5-4-9, subparagraph 3 says.

3. When the approach procedure involves a procedure turn, a maximum speed of not greater than 200 knots (IAS) should be observed from first overheading the course reversal IAF through the procedure turn maneuver to ensure containment within the obstruction clearance area.

The speed being the maximum should have been obvious

[B2N2]

As is common…we’re going down the rabbit hole of chasing minutiae.
We’ve provided ICAO and FAA references.
At the end of the flight what really matters is what the STAR and approach plates dictate as far as altitudes and speeds.

[EXDAC]

Originally Posted by galaxy flyer

FAA AIM 5-4-9, subparagraph 3

Thanks for the reference.

How often in a radar environment would you expect to fly a procedure turn even if one is depicted on the plate?

If, as I suspect, the answer is seldom then the initial statement "The AIM only says the initial segment should be flown at 200 KIAS" seems to have implied a restriction that seldom actually exists.

[galaxy flyer]

It’s all minutiae and written exam trivia until it’s not…

https://www.icao.int/APAC/Meetings/2...%20-%20Bali%20[Compatibility%20Mode].pdf

[galaxy flyer]

It’s all minutiae and exam trivia until it’s not…. Air China 129 circling at Busan, Korea.

There’s an excellent ICAO ALAR presentation from 2012 but I can’t copy/paste the link.

172_driver,

The 99% case is where the problem lies—the 1% that catches the crew out.