Hello guys!

 

Today I had to do a circling approach and had to face the fact that I had no idea how to correctly setup the FMC for this.

What is the correct way to do? The FCTM doesn't say anything really interesting about this.

 

I had programmed the ILS approach to RWY 13, flown it manually to circling minima, then started my circling maneuver to RWY 31 as usual. But of course, when I passed abeam the MA (Missed Approach) waypoint, the FMC started thinking I was going around.

 

How do you do that correctly?

 

Thanks!

Which airport are you flying into?

 

Usually circle to land approaches are hand flown. I know coming into Chicago Midway when they're using 22L, ILS 31C is used to circle minimum then the aircraft is turned to the north to complete the circle procedure for landing.

 

Section 5.73 in the FCTM explains how to set up for a circle approach but there is no use of the FMC.

Nothing airport-specific here ;-) I am not searching for a way to keep the airplane under LNAV control, just make it aware I am not going to land on the runway associated with the instrument approach i'm doing.

 

I wonder how it's done in real life, but my searches aren't successful ;-(

 

Thanks,

Hey,

 

Why don't you set RWY 31 for arrival instead of 13? Maybe use some points of the RWY13 ILS approach but not the entire approach.

 

To fly it, maybe this helps.

 

http://www.smartcockpit.com/pdf/plane/boeing/B737/diagrams/0010/

 

Bert Van Bulck

I could select RWY 31, but you cannot select RWY 31 while keeping the ILS 13 programmed.

 

Thanks for the document, very nicely explained!

 

Thomas

Nothing airport-specific here ;-) I am not searching for a way to keep the airplane under LNAV control, just make it aware I am not going to land on the runway associated with the instrument approach i'm doing.

 

I wonder how it's done in real life, but my searches aren't successful ;-(

 

Thanks,

 

They would be hand flown in real life....

Try to setup your landing Runway in the secondary flight plan. When you pass abeam the threshold of your approach rwy just activate. You can now also follow the missed app of the landing rwy when needed.

 

Cheers

 

Edit: that's the way we do it in the Airbus. Not sure if there is a sec fltplan at all in the NG...

They would be hand flown in real life....

 

Maybe you should re-read my post ;-) I said I am *not* searching for a way to circle in LNAV. ;-)

 

Try to setup your landing Runway in the secondary flight plan. When you pass abeam the threshold of your approach rwy just activate. You can now also follow the missed app of the landing rwy when needed.

 

Cheers

 

Edit: that's the way we do it in the Airbus. Not sure if there is a sec fltplan at all in the NG...

 

You can define multiple routes, but I never tried to activate the secondary route while in flight. Not sure it is possible.

However, it is possible to re-select the appropriate runway from the ARR/DEP page of the MCDU while circling, but I was searching for a way to avoid dealing with the FMC while circling.

 

Thanks everyone!

You would not do anything to the FMC for a circle to land approach. The circle manuever would be done using HDG SEL or hand flown. You would not want to edit the approach as the missed approach procedure is the same if you are landing straight-in or circling.

OK I tried with the VNAV Circling Approach procedure of RyanAir (published on SmartCockpit).

Landing field is LFOT [IAC]. The ILS 20 was programmed, TUR being the IAF. LOC was intercepted in VOR/LOC mode, the vertical mode was VNAV PTH stable at 1900' until the FAP. MAP was set to the circling altitude (1230'), MCP Altitude was set to 1300', MCP heading was set to 151º.

 

At the MDA, it leveled in VNAV ALT, I engaged HDG sel, started timing to join the downwind leg. As soon as I passed the RWY 20 threshold, the FMS sequenced the next waypoint to TURNB, as part of the published missed approach procedure. VNAV disconnected, and the Vref speed was deleted.

 

Did I messed up somewhere?

 

Thanks guys

To me, it seems that things are being made much more difficult than they need to be.

 

The FMC is set for the approach being flown, not the runway being landed on.

 

If I'm flying into IAD on a really windy day and they're using ILS 1R Circle to Land 30, I will set the ILR 1R approach into the FMC and not bother with it from there. I'll let the thing think I'm landing on 1R the whole time. It really doesn't matter. The reason you set an approach into the FMC is in order to fly that approach via the automagic linked to the FMC. Otherwise, in the 737, I could just dial in the freqs on the nav radios and the courses on the course knobs and not even touch the FMC. A circling procedure is a non-standard procedure that varies based on the runway, controller instructions, weather, and so on. Computers don't do contingencies very well, people do.

 

So, circling procedures for the FMC are as follows:

Enter the approach you will be flying based on your expected approach instructions ("Expect ILS 1R Circle to Land 30," means you select the ILS 1R approach).

Fly said approach.

At your discretion, break off aforementioned approach and hand fly the circling procedure.

Land the plane.

 

This only differs from a normal procedure in the fact that you break off the approach at some point and land on a different runway.

I'd like to add to Kyle and Joe and others that advocate a hand-flown maneuver. The FAA requires that visual contact with the airport be maintained during the circle to land so you need to keep the eyeballs outside the cockpit and not on a computer screen. Stated another way, the approach becomes a visual instrument procedure when you break out and begin the circle to land.

2 things to remember when circling.

1. Fly the missed app for the approach flown, this is the procedure you briefed prior to the app. You may have to do some maneuvering over the airport to remain protected as you intercept the course.

2. Stay with in your protected radius. Depending on your approach speed and circling flaps used, you could be cat C or D. Example, cat C is 1.7 miles from each arrival end.

The FMC would not be used for the circle, but can help you figure the distance from the runway. If cat C, you want to start the circle no earlier than 1.7 miles, but have enough spacing to set your self up.

I love circling, and we do them all the time on proficiency flights. Some of the airports that we fly to get annoyed when a G-5 shows up, and request circling approaches.

You would not do anything to the FMC for a circle to land approach. The circle manuever would be done using HDG SEL or hand flown. You would not want to edit the approach as the missed approach procedure is the same if you are landing straight-in or circling.

 

Good point you made! Even when circling, you follow the missed approach procedure of the instrument approach. In this case the missed appraoch procedure for RWY13. (or get ATC instructions)

 

Bert Van Bulck

 

2 things to remember when circling.

1. Fly the missed app for the approach flown, this is the procedure you briefed prior to the app. You may have to do some maneuvering over the airport to remain protected as you intercept the course.

2. Stay with in your protected radius. Depending on your approach speed and circling flaps used, you could be cat C or D. Example, cat C is 1.7 miles from each arrival end.

The FMC would not be used for the circle, but can help you figure the distance from the runway. If cat C, you want to start the circle no earlier than 1.7 miles, but have enough spacing to set your self up.

I love circling, and we do them all the time on proficiency flights. Some of the airports that we fly to get annoyed when a G-5 shows up, and request circling approaches.

Question: is it correct that for a 737 you should always elect the minima and protected area of a CAT D (although it's a CAT C ACFT) or is it depending of your circling speed?

 

Bert Van Bulck

Question: is it correct that for a 737 you should always elect the minima and protected area of a CAT D (although it's a CAT C ACFT) or is it depending of your circling speed?

It is speed driven. Normally you will circle at flaps 15 at flaps 15 maneuvering speed. If that speed puts you at CAT C, use it if you want. The BBJ guys in my company use either C or D based on the speed. You can also be conservative and use CAT D. Just keep in mind that this could limit you if the weather is below CAT D but above CAT C.