Circling minima on approach chart

[Boroda]

Here is one more silly question

For example, we make instrument NDB approach for RW36 and we use for it respective chart. Then we make circling for RW18. Is circling MDA on the chart for RW36 in right lower corner or should we refer for MDA to RW18 chart?

[Wingswinger]

The circling minima you want is the one for the instrument approach you will fly, in your example RW 36.

PANS-OPS criteria is that it is based on a 4.2 NM arc from each runway threshold and the arcs are connected tangentially to produce the circling area encompassing the whole airfield. The area is surveyed for obstacles and a circling minimum calculated which will give a minimum circling height of 600ft with a minimum obstacle clearance within the circling area of 400ft (for Approach Cat C aircraft). Thus the circling approach for the other end, RW 18 will usually be the same. However there may be different minima for circling in different directions, for example circling to the East of RW 36 may have a circling minimum of, say 1000ft while circling to the West may have a higher or lower minimum because of the obstacles in the respective sectors.

That's my understanding, anyway.

HTH,

WS

[Boroda]

Another one question do I have. According to FCOM A320 for 500 feet AGL we should fly 20 seconds from abeam RW threshold to base that is 4 secs for 100 feet, at the same time for visual 1500 feet - 45 seconds, that is 3 secs for 100 feet. How do you calculate base turn if MDA, for example, 1000 feet?

[Wingswinger]

In my company we use 20" for the first 500ft and 2" per 100ft above that. Thus for a circling height of 1000ft downwind timing would be 30" in still air from abeam the TDZ. Wind correction is 1" per 2kts head/tailwind - usually tail - that's why you are circling!.

Does that help?

[411A]

How do you calculate base turn if MDA, for example, 1000 feet?

I would suggest..that the aircraft Commander complete these types of circling approaches, then... properly describe it should/is done within the rrspective airlines operating procedures.

IF, said second pilot does not understand...ask the senior FD crew member....otherwise known as...The Captain.

A simple task.

[hetfield]

IF, said second pilot does not understand...ask the senior FD crew member....otherwise known as...The Captain.

Maybe he did already....

[ABO944]

I just look out the window

[Centaurus]

I just look out the window

And you are right. Timing based upon circling height means nothing if you lose sight of the runway. The problem is that many pilots design a pretty picture of a circling approach on their FMC MAP with various downwind, base and final approach waypoints and speeds. These are fed into the autopilot and flight director which means the pilot flies heads down without ever looking at the runway until turning final on autopilot watching the MAP and hoping to hell the runway appears in front out of the murk. This is accented in the simulator where all around vision is normally unavailable in the simulator design.

The circling manoeuvre is essentially visual flight. Of course you may have to scan the flight instruments on a dark no horizon night downwind and base but your eyes should also be scanning at the runway.

[411A]

The circling manoeuvre is essentially visual flight. Of course you may have to scan the flight instruments on a dark no horizon night downwind and base but your eyes should also be scanning at the runway.

Absolutely correct, however I suspect many new(er) pilots-of-the-magenta-line...were never told.
Pity.

[BOAC]

Originally Posted by wingswinger

The circling minima you want is the one for the instrument approach you will fly, in your example RW 36.

- how many airports are there where CM is based on a particular runway approach?

[Kirks gusset]

Centaurus, I'm sure you are aware that there is no requirement to keep the runway in sight in a circle to land, however, there is a requirement to keep the " aerodrome environment" visual. Personally, I would not want to loose sight of the landing runway.

[411A]

...I'm sure you are aware that there is no requirement to keep the runway in sight in a circle to land...

Tell (or demonstrate) that to an FAA inspector during a check ride will result in a fail notice, forthwith.
IF you doubt...try otherwise and...see.

[Kirks gusset]

Well 411A sadly I won't get the chance as we operate under a different regime, not the FAA.

[PappyJ]

For example, we make instrument NDB approach for RW36 and we use for it respective chart. Then we make circling for RW18. Is circling MDA on the chart for RW36 in right lower corner or should we refer for MDA to RW18 chart?

Back to the originial question, and a simple answer...

Example: Rwy36 has a instrument approach. Rwy18 does not have an approach. You complete an approach for Rwy36, then Circle for Rwy18.

Which of the only ONE available charts would you use, and which MDA is associated?

Simple enough answer?

[BOAC]

Boroda - can we try to sort out the confusion here?

Please tell us:
Which regulatory authority you fly under?
Which company you use for your 'charts'? Thales/Jepps/etc?
and
MDA R36 NDB
?MDA R18?? - which 'approach'?
Circling Minima on R18 'chart'
Circling minima on R36 NDB chart

The answer should then be simple................

[Centaurus]

s a requirement to keep the " aerodrome environment" visual.

I have often wondered how that is defined. If we are talking about the whole airport with associated approach lights, strobes etc then surely somewhere among that lot is a runway. But how far away from the boundary of a airport stops being "the aerodrome environment"? There may be a few local knowledge identifiable lights of a village not far from the aerodrome or a well lighted highway which skirts the aerodrome and so on. But can they truly be called the aerodrome environment? I don't know the answer. Seems to me if the visibility is so poor that you lose sight of the runway -apart from momentarily because one wing blocks your view, then maybe you should not be circling.

Navigating a circling approach based upon local knowledge street lights, villages, a moon lit river or lake or a brilliantly lit tennis court can never replace the comfort of seeing the runway on downwind and base. In addition, deliberately opting to descend below the circling MDA while on base (rather than when established in the splay on final) - and thus being entirely responsible for your own terrain clearance, will have the lawyers cheering if you crash into something while descending below the MDA.

[galaxy flyer]

I think I asked this before, Boroda, do you have a training department?

GF

[Fullblast]

FLIGHT PROCEDURES (DOC 8168) - ARRIVAL AND APPROACH PROCEDURES

7 VISUAL MANOEUVRING (CIRCLING) AREA

......
......
7.2.2 After initial visual contact, the basic assumption is that the RUNWAY environment should be kept in sight while at minimum descent altitude/height (MDA/H) for circling. The RUNWAY environment includes features such as the RUNWAY threshold or approach lighting aids or other markings identifiable with the RUNWAY.


FB

[Boroda]

BOAC

1. under russion authority
2. Jeppesen charts
3. just NDBing for 36 & circling for 18

GF

Do you have CRM courses nearby, high time you visited them.

[galaxy flyer]

Yes, I've been several, but some of your questions are pretty basic. Circling procedures are about day 4 of any instrument course.

GF