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LeifApex

Orbit/Pattern Procedure

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Hello,

I've been flying some flights on VATSIM lately, and i remembered that i saw pilots executing an orbit procedure in a youtube video in the past. So, the thought of being instructed to do an orbit procedure came to me, but i don't know how to execute it.

It's not the same procedure as a standard hold, and i'm aniticpating that ATC would tell me "(Callsign) do a right/left hand orbit to (heading)", but how do i perform this procedure in the NGX? Can i do it in the FMC, or would i have to constantly turn the heading bug whil in HDG Select?

 

Also, does anyone know when it would be wise to start decelerating towards flaps and final landing speed when on approach?

If ATC were to tell me "(callsign) cleared ils approach rwy 22L, maintain 180KTS, and does not state further speeds. As i obviously would not be able to land the NGX with 180KTS IAS, would i just decel at my own discretion at some point, or do i constantly have to ask for a new speed clearances, i don't see anyone else doing this?

Regards


images?q=tbn:ANd9GcRDsyAYmTuFbxdJK4WUSUb

Nikolai Brandtberg

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1 hour ago, LeifApex said:

Hello,

I've been flying some flights on VATSIM lately, and i remembered that i saw pilots executing an orbit procedure in a youtube video in the past. So, the thought of being instructed to do an orbit procedure came to me, but i don't know how to execute it.

It's not the same procedure as a standard hold, and i'm aniticpating that ATC would tell me "(Callsign) do a right/left hand orbit to (heading)", but how do i perform this procedure in the NGX? Can i do it in the FMC, or would i have to constantly turn the heading bug whil in HDG Select?

 

Also, does anyone know when it would be wise to start decelerating towards flaps and final landing speed when on approach?

If ATC were to tell me "(callsign) cleared ils approach rwy 22L, maintain 180KTS, and does not state further speeds. As i obviously would not be able to land the NGX with 180KTS IAS, would i just decel at my own discretion at some point, or do i constantly have to ask for a new speed clearances, i don't see anyone else doing this?

Regards

When I need to make an orbit just do it in HDG select, I believe this is how it's done in real life when in A/P.

 

Usually ATC will tell you maintain 180 knots until XX DME or until established in the glide or any other point.  If no specific point is given you need to ask them until when they want you to maintain that speed.

 

 

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Chris Makris

PLEASE NOTE PMDG HAS DEPARTED AVSIM

You can find us at http://forum.pmdg.com

 

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Take this as an opinion for what I have learned, I am not a pilot.

Orbit is used in GA and in VFR condition and is normally a circle within the airport area over reporting point or in downwind phase.

With a 737 it's mandatory to use holding procedure but you train to do circuit pattern by following  Flight crew training Manual that came with the documentation from PMDG.

I never heard of a 737 flying in VFR procedure but only on visual for circuit pattern or landing.

Here the step for touch & go landings.

gY8h98B.png?1

Atc will instruct you to maintain speed just for separation but once you are cleared for visual or ILS you stick with procedure speed as flap step requirement. 

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3 hours ago, LeifApex said:

If ATC were to tell me "(callsign) cleared ils approach rwy 22L, maintain 180KTS

never will you hear this ..... as fabrizio wrote (have you been using PATC).

2 hours ago, Olympic260 said:

When I need to make an orbit just do it in HDG select, I believe this is how it's done in real life when in A/P

as instructed by atc in any pattern particularly if it's for weather, easier with the autopilot always.


for now, cheers

john martin

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2 hours ago, simbio said:

Take this as an opinion for what I have learned, I am not a pilot.

Orbit is used in GA and in VFR condition and is normally a circle within the airport area over reporting point or in downwind phase.

With a 737 it's mandatory to use holding procedure but you train to do circuit pattern by following  Flight crew training Manual that came with the documentation from PMDG.

I never heard of a 737 flying in VFR procedure but only on visual for circuit pattern or landing.

Here the step for touch & go landings.

gY8h98B.png?1

Atc will instruct you to maintain speed just for separation but once you are cleared for visual or ILS you stick with procedure speed as flap step requirement. 

At heatrhow you can be cleared for ILS 27L maintain XXX until 5 dme. This procedure is also done in other airports as well, ATC must provide a point after which you can decelerate more.

 

Also orbits can happen to airliners as well. If you can watch Pilots Eye Shangai episode where the A340 is asked to do an orbit on departure for seperation. Orbits can be done on all aircraft types, airliners or non airliners if needed. Much easier than entering a hold


Chris Makris

PLEASE NOTE PMDG HAS DEPARTED AVSIM

You can find us at http://forum.pmdg.com

 

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1 hour ago, Olympic260 said:

Also orbits can happen to airliners as well. If you can watch Pilots Eye Shangai episode where the A340 is asked to do an orbit on departure for seperation. Orbits can be done on all aircraft types, airliners or non airliners if needed. Much easier than entering a hold

4

Sorry, Is this is the video you are talking about?

 

 


 

 

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15 minutes ago, simbio said:

Sorry, Is this is the video you are talking about?

 

 

Yes


Chris Makris

PLEASE NOTE PMDG HAS DEPARTED AVSIM

You can find us at http://forum.pmdg.com

 

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As “orbit” isn’t an FAA term, I’m over here like “the NG isn’t not certified for orbit - it’s ceiling is FL410.”

Currently on my phone - more in a moment when I get to my desk (for those thinking “put the phone down and drive” I’m on the subway, which has wireless now - hello future).

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Kyle Rodgers

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1 hour ago, vadriver said:

never will you hear this ..... as fabrizio wrote (have you been using PATC).

As Chris says, you will most certainly hear this in certain parts - as Chris states, Heathrow regularly give speed restrictions in the Radar Manoeuvring Area (RMA).  Generally, heading in there you'll be given a speed of 220 knots, then on turn towards a base leg, you'll be asked to slow to 180 knots with a further reduction on turning to establish on the ILS of 160 knots until 4DME.

While it's not used at other UK airports as a rule, depending on traffic levels it does get used (I've listened to it at others including Edinburgh and Inverness).

 


Trevor Hannant

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Back...

First, I want to point out that you always want to bias toward the least complex method of addressing a task. Too often, simmers get this wild impression that EVERYTHING needs to go through the AP and FMC. If you're in visual conditions, why not just kill the AP and hand fly it? If not that, then HDG SEL on AP is probably the way to go. The simmer thought that everything has a procedure, and everything has a place in the FMC will hopefully die off over time, else I shudder to think about the upcoming crop of pilots (says every generation of pilots, ever - though there is some merit to the argument that pilots of today are over-reliant on automation).

Seriously: keep it simple. There's no need to Rube Goldberg the automation into doing something as simple as "go in a big rectangle around the airfield."

 

 

To add some clarification to the speed question:

***FAA Rule Discussion***

When previously assigned a speed, receiving an approach clearance cancels that speed, unless a speed is restated as part of the clearance. As such, the earlier clearance of "cleared [approach], maintain [speed]" isn't incorrect, however, the speed usually has some sort of limit, such as "...until 5DME," or "...until [fix]." If there is no limit, then it is expected that the controller will come back with a cancellation. This can be prompted with a simple "did you still want us at [speed]?" if it seems that you're getting closer than you'd like while staying so fast.

In general, though, IFR is predicated on the concept of lost comms, so it's rare that a contingency is not provided. This is the reason for controllers providing Expect Further Clearance (EFC) times for holds, for example (many assume it's simply a courtesy, but it's a core concept of AVEF: Assigned, Vectored, Expected, Filed). In the case of lost comms, if I was assigned "180 knots until ENEDE," and my radio died, I could - in the absence of any other direction - reduce speed at ENEDE. Without that "until ENEDE" though, there's ambiguity in a lost comms situation, on both sides. When I reduce speed in a lost comms situation would be a judgment call that I'd have to make, and the controller would have to react to with less clarity.


Kyle Rodgers

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2 hours ago, Trevor Hannant said:

While it's not used at other UK airports as a rule, depending on traffic levels it does get used (I've listened to it at others including Edinburgh and Inverness).

 

Actually it very much is used at at least one other airport in the UK, Gatwick is 160 until 4 dme.

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32 minutes ago, nawarren said:

Actually it very much is used at at least one other airport in the UK, Gatwick is 160 until 4 dme.

Haven't had the pleasure of being there with the scanner (yet....)  🙂


Trevor Hannant

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I thought an orbit (in this case) means to fly a circle, usually where you are but sometimes they might say "next time over Ockham perform one right hand orbit and then leave heading 340 degrees". Either way, when you get to the requested point in space, fly in a circle. In my understanding, to fly a circuit around the airfield is just that, a circuit, an orbit is like the orbit of a satellite, round (ish).

I've never flown the 737 so I can't comment about that specifically but there are a few ways to do this in general. Off the top of my head...

1 - Drop the autopilot and honk on some (type/weather specific) bank and hold it on until you're facing the same way again. Sounds like a great idea (and in the sim it really wouldn't hurt for practise) and to cries of "pilots are over reliant on the AP and can't fly for toffee!" it's great ("I'll whip out the stick and finish her off by hand!" as we used to say on the Airbus) but with fare paying, real life people behind you and assuming you've been flying for 12 hours through the night beforehand (longhaul) or you're on sector 3 of 4 after a 3am wake up call (shorthaul) at night in IMC with CB's around in busy airspace while descending and changing speed, it does expose the flight to quite a bit more unnecessary risk, especially if it's done unannounced and unbriefed to your colleague. There's an awful lot that could go very wrong very quickly and frankly, pilots are there to operate the flight safely and not to prove how great they are (or otherwise) at flying!

2 - Hit Heading Select and wind it round in the direction you want to go. In some types if you go more than 180 degrees to your current heading it will try and turn the other way so you'll have to have a few goes at adjusting the heading to get round. In other types, you won't, and can just spin it round the whole way, much easier.

3 - Enter a hold with a leg length (or time) of 0. This is a bit heads down and sometimes a bit fiddly to do but if you are already in the hold then changing the leg length of that hold to 0 (which it will do the next time over the fix) will have the correct effect and is pretty straightforward. In my experience, despite 0 being in leg length/time it may well roll the wings level for a second or so before putting it back on so you still fly a sort of hold shape in the sky but it's normally good enough for ATC (I've often done it this way as most orbits I fly are over the holding fix at LHR where they're just trying to get the 2.5nm spacing right, and I've ususally been there a good 5 or 10 minutes already).

As a member of the crew you are free to decide the best way to accomplish this orbit depending on your circumstances. I would guess that 2 is the most common with 3 being effective in certain circumstances while 1 would be used very rarely but is a perfectly acceptable way of achieving it.

As everyone else has said, if you're given a speed restriction on the approach, it normally comes with a point at which you can resume own speed. Yesterday (into LAX), we were given 170 to JETSA (about 10 miles from the runway). It's highly unlikely they won't give you that point and if they don't, ask them. In the US (as Kyle has already mentioned), if you have a speed restriction and you're then given an approach clearance then that speed restriction is lifted unless given again.

LHR usually gives 160 to 4 and this is usally the fastest I like to be at this point (unless we have a stonking headwind), I can normally recover from that but much more and you're into very careful energy management and need to be thinking about the very real possibility of a go around. The A380 gets either 160 or 170 to 5 (I'm not sure, I don't fly it). As previously stated, LGW has adopted the 160 to 4 procedure as well now.

This can be quite an issue for pilots, approach speed restrictions are there for spacing and hence safety but if you don't allow enough time/space to slow down you won't make your approach stability criteria and have to go around. I try to include in the brief the sort of restriction we're prepared to accept so in the heat of battle we don't take something that commits us to a go around early on.

JFK are famous for that and on receipt of an approach speed restriction we can't do (or aren't prepared to accept), just tell them, along with what you can do and I've always found them quite helpful. In the US you need to be very careful as many of their ILS DMEs don't read 0 at the threshold, sometimes thery are as high as 2nm at the threshold so your waypoint that says 5.5D on the chart could actually be only 3.5 from the threshold which is usually just over 1000ft above the airfield which is pretty much our approach stability point (it's actually when it first says "1000" on the rad alt so depending on the terrain, it could be earlier - see LGW 08R).

Hope this helps,

Ian Webber

 

Edited by iwebber
Typos and avoiding "word not allowed"
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No clue about the orbit but as far as maintaining 180 kts you will often here that with something like, “UAL180 cleared ILS 22L approach, maintain 189 kts until DOOIN or simple 5 dme. Rarely will you not hear the later part on final approach but if you don’t get clarification or as the PIC set the aircraft up for a safe landing 

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18 minutes ago, jmwill1228 said:

No clue about the orbit but as far as maintaining 180 kts you will often here that with something like, “UAL180 cleared ILS 22L approach, maintain 189 kts until DOOIN or simple 5 dme. Rarely will you not hear the later part on final approach but if you don’t get clarification or as the PIC set the aircraft up for a safe landing 

Listening to LiveATC, specifically JFK Tower, I've heard pilots ask the tower controller, and the tower controller would clarify this. Some pilots have told the tower controller that the approach controller never specified.


Captain Kevin

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Air Kevin 124 heavy, wind calm, runway 4 left, cleared for take-off.

Live streams of my flights here.

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