TERPS circling protected area
 

Hi everyone, a quick question for you FAA TERPS experts: as long as I can recall the protected area for Cat D circling aircraft was based on a 2.3 nm radius from the runway and 300' obstacle clearance. Recently whilst reviewing for a checkride I noticed my company Operations Manual now states that the protected area under TERPS for Cat D is 3.7 nm.

Has there been a recent change I was not aware of, or have I found an error in our sacred book? :)

MD

In a previous thread (I think the AirBlue) Aterpster indicated that a review of Terps circling areas was being looked at. Perhaps it has been? I don't think it has yet been published, though, but maybe your company has either jumped the gun or just decided it needs to change?

main dog:

Quote:

---

Hi everyone, a quick question for you FAA TERPS experts: as long as I can recall the protected area for Cat D circling aircraft was based on a 2.3 nm radius from the runway and 300' obstacle clearance. Recently whilst reviewing for a checkride I noticed my company Operations Manual now states that the protected area under TERPS for Cat D is 3.7 nm.

---

It hasn't happened yet. At the last FAA/Industry Charting Forum they have finally agreed on the charting symbology that will be placed on an IAP that is in compliance with the new criteria, because the transition will likely take years (10 years in my estimation).

But, some housekeeping tasks remained to be done on the details of the chart symbology and how to best inform the aviation community.
So, for the time being (a very long time being in my view) it remains 1.7 for CAT C; 2.3 for CAT D.

When it does happen incrementally the areas will increase somewhat with airport elevation, thus a table explaining that in the AIP has to be finalized. 3.7 is a good ballpark figure for the incrementally future Cat D circling area.

Also, I am jaded, and still believe FAA internal politics will keep any of this from happening. I hope I am wrong.

Thanks gentlemen, sounds like someone has indeed jumped the gun...

A sensible jump, however, but the question you need to ask is from where do they get the new minima to reflect the enlarged circle?

BOAC:

I suspect the answer would be, "From the FAA's TERPs manual." The "new" CTL criteria were published with Change 21 a few years ago then placed on hold. The handbook is up to Change 24 now, so someone reading without knowledge of all the circumstances could reasonably conclude that the "new" CTL criteria are in effect.

Interesting, thanks, but I still think I would ask! Not all the managers making rules I have worked under are necessarily clever.

BOAC:

I agree. My history was hopefully to point the OP in exactly that direction.

- this is the really worrying part. Some circling minima (altitudes) must change in this situation. IF main dog is 'unaware', where is the 'Special Notice' or whatever to all crews and where does he/she find the new Circ minima - if on the charts, which provider has the new surveys??

Main Dog?

The first I was aware of this "new" protected area was when I recently noticed the number 3.7 instead of 2.3 nm in our manuals. Since I had not heard of this before, and there were no relevant notices to crew or any other such communication, I started looking online and couldn't find any FAA reference either. Thus I turned to you esteemed gentlemen!

Next step, ask Line Ops what they're on about...

Not being a jet pilot I googled the topic and found this article from last year..

Dangerous Approaches | Flight Safety Foundation

- yup! I would also suggest NOT using the new area until you are sure the minima apply.

An excellent article Cwatters - hadn't seen it before. A good example of the problems it highlights is one of our regular destinations - Busan in Korea. Terps minima, fatal if flown to PANSOPS - as an Air China crew found out in 2002. it doesn't help that some airports in Korea use PANSOPS (Incheon and Gimpo) and others such as Busan use TERPS. Not all understand that. When our larger neighbour bough us a few years ago, we adopted their Ops manual which confidently stated that all airfields in Korea use PANSOPS. They only flew to Incheon!

Busan now has a giant checkered board on that terrain north of the airport as well as a series of lead-in lights.

Busan now has a giant checkered board on that terrain north of the airport as well as a series of lead-in lights.

This seems to be an odd safety response – the hazard still exists (short of bulldozing a mountain).
Wouldn’t the use of a PANSOPS procedure and higher circling altitude be more effective?

This is a “How can we do this”’ solution opposed to “Should we be doing this” safety response.

PEI:

I agree with you.

Even at 2.3 miles radius, the circuit height is 1100'. At the PANSOPS radius of 4.6 miles, you will have to fly round finals at about 2000'! It's just not feasible as the hill in question is on the centrline.

Re the TERPS/PANSOPS argument:

You first need to eliminate the 'Arizona/John Wayne' state of mind that TERPS circling is for real men.only and 'if you cannot stand the heat'..............

It does sound as if commonsense is lurking in the cactus bushes in the US of A, however. No-one is suggesting that PANSOPS is the 'best' solution but it is certainly safer.Having done a few TERPS circles the last thing I want in difficult weather in a circle is the added pressure of having to stay within a very tight area.

Agree. To fly a 737 and keep inside 1.7 nm from the runway while allowing for drift and at the minimum vis for circling, can be bloody dangerous. The critical obstacle that defines the published MDA for circling may not be displayed on the instrument approach chart that led to the circling manoeuvre in the first place. It could even be just outside the approach landing splay and invisible at night.

Received wisdom is you don't commence descent below the circling MDA until lined up on final hopefully with a VASIS or PAPI available. But with circling MDA's varying greatly for example from 1500 ft agl to as low as 700 agl, then in order to keep within the protected area for a 737 category, the pilot may be forced to commence descent below the MDA well before he is lined up.

The danger of that is obvious unless the pilot is familiar with the local terrain. The ICAO published protected area around an airport allows a much safer operation; even though occasionally it may result in a higher circling MDA than closer in. A small price to pay for a significant safety factor increase.

BOAC:

The NTSB and the FAA reached a conculsion sort of like that when an American Airlines 707 crashed on the downwind leg of a circle to land at a relatively flatland airport, KCVG. (1965 or thereabouts.)

And, within a few years the FAA prohitbited circle to land for commercial operations unless specific training is provided.