FMC "HOLDING" Tutorial

[CrashEd 8]

Great work Fred - many thanks for your tutorial.

[Hawk570 0]

I have never done holds with the CDU on this aircraft before so I had to try it. I spent about 2 hours experimenting. I setup a flight from KLGA to KBOS with many waypoints in between and put it through the wringer. I wanted to familiarize myself with the CDU pages and wanted to see how the plane behaved. I tried every conceivable test.....hold at current pos, hold at waypoint, different holding courses requiring parallel, teardrop and direct entries (several of each left and right). The aircraft behaved perfectly making all the entries properly, acceleration/deceleration right on target every time. It only seemed to get confused one time during a teardrop entry but I have to admit I was pushing it to the limit giving it all kinds of wild orders. In all cases it kept me within the hold airspace. Great job PMDG! I now feel confident that I can put the ship wherever the controller asks me to. Thanks Fred for motivating me to familiarize myself with the procedures.

[mr_ramirez 1]

And when we have to do a paralel and teardrop hold enter, can the FMC and the LNAV do this type of entrance or do we have to do it manually using the HDG Bug?

[royski 0]

Captain Frederic, Thanks a lot for the useful information.

[RYR738 9]

And when we have to do a parallel and teardrop hold enter, can the FMC and the LNAV do this type of entrance or do we have to do it manually using the HDG Bug?

LNAV calculates the type of pattern entry (Teardrop, Parallel, Direct) from the difference betweenthe inbound course and the airplane's heading when you pass the fix.

Thank you Fred,I have another questio, if you will perform go around with pre-programed holding pattern how you would change the airplane mode following the go around procedures into the holding pattern ?Thanks

I think you are confusing this with a missed approach ? A pre-programmed holding pattern is normally part of a Missed Approach.They are the same as other holding patterns. The same rules apply.

[RYR738 9]

The " Making Waypoints Tutorial " is here.................. http://forum.avsim.net/topic/347242-making-waypoints-tutorial/ Enjoy ! Fred.

[Frank 737 0]

Hey Fred, greets from EDDF and thx for this nice Thread. Can you tell me what ist the correct method to decent in a hold? Editing the FL on the hold site in the CDU doenst help. Editing the legs page doesnt help either.Do i have to use LVL CHG? Greets Frank

Hey Fred, have you seen my post? Mayyou can help me here, THX

[RYR738 9]

Hey Fred, have you seen my post? Mayyou can help me here, THX

Hi Frank ! I did see your post but thought you had made a mistake. You do not climb or descend while in a hold !!If for example you are descending to the next waypoint, you could enter a holding pattern at your present position or at the waypoint when you get there. You can of course change the holding pattern speed.ATC would sometimes ask you to do that. Hope that helps. Fred.

[Frank 737 0]

Ah, ok. So it is not possible to decent wit LNAV in a hold. And in the RW you would do this. Thx

[skipjack 0]

Thanks Fred, an excellent Turtorial! Regards, Stewart Thompson

[HdG 0]

Hi Frank ! I did see your post but thought you had made a mistake. You do not climb or descend while in a hold !!If for example you are descending to the next waypoint, you could enter a holding pattern at your present position or at the waypoint when you get there. You can of course change the holding pattern speed.ATC would sometimes ask you to do that. Hope that helps. Fred.

Fred, are you serious on that?British ATC is notorious for keeping aircraft high on the STARs and put them in one of their stacks to descend there to an intermediate approach altitude. This is happening every day, their whole airspace management system is based on handling traffic this way.And, a published speed restriction for a particular hold is there for a reason: to keep the aircraft within protected airspace and clear of obstacles. The only reason I can think of a pilot wanting to alter holding speed is turbulence. But then, ATC has to approve that deviation first. Regards

[JC75 22]

Hi Frank ! I did see your post but thought you had made a mistake. You do not climb or descend while in a hold !!If for example you are descending to the next waypoint, you could enter a holding pattern at your present position or at the waypoint when you get there. You can of course change the holding pattern speed.ATC would sometimes ask you to do that. Hope that helps. Fred.

Yes this is wrong! Hold speed is set under ICAO rules unless published otherwise - Holds are somtimes allowed to be extended either in time or leg distance - but only by prior approval from ATC as holding at a speed or leg distance outside of this could result in a loss of seperation from other holds, or flight tracks (if a hold is based on leg times and you flew faster than published speed you would fly bigger holds) normal request is to fly 1.5 or 2 min holds, but at standard speed (210kts - below FL140 in UK) Descending in Hold is what happens - when an airport is too busy to handle or the arriving traffic (or for weather etc) aircraft HOLD and are bumped down a 1000ft at a time as aircraft at the bottom of the stack leave the hold. Dont qoute me completely here but a VS of 500/1000ft a minute would be the mode used normally to descend in the hold - this way you are less likely to set the TCAS off of any aircraft in the hold below you - VNAV descent in hold(which not entirely sure is completly possible without FMC manipulation also) could result in a high rate of descent (especially if you had more than a 1000ft drop to do) and likely to set both aircraft TCAS and also ATC's STCA (short Term Conflict Alert) on their radar off. (using VS at a low amount 500/1000ft would also ensure you dont have any signigicant speed increase) One final note the FMC on the PMDG occasionaly gets mixed up with some holds - not always but on occasion it seems to not be able to hold correctly or do the correct entry!

[RYR738 9]

Fred, are you serious on that?British ATC is notorious for keeping aircraft high on the STARs and put them in one of their stacks to descend there to an intermediate approach altitude. This is happening every day, their whole airspace management system is based on handling traffic this way.And, a published speed restriction for a particular hold is there for a reason: to keep the aircraft within protected airspace and clear of obstacles. The only reason I can think of a pilot wanting to alter holding speed is turbulence. But then, ATC has to approve that deviation first. Regards

Yes this is wrong! Hold speed is set under ICAO rules unless published otherwise - Holds are somtimes allowed to be extended either in time or leg distance - but only by prior approval from ATC as holding at a speed or leg distance outside of this could result in a loss of seperation from other holds, or flight tracks (if a hold is based on leg times and you flew faster than published speed you would fly bigger holds) normal request is to fly 1.5 or 2 min holds, but at standard speed (210kts - below FL140 in UK) Descending in Hold is what happens - when an airport is too busy to handle or the arriving traffic (or for weather etc) aircraft HOLD and are bumped down a 1000ft at a time as aircraft at the bottom of the stack leave the hold. Dont qoute me completely here but a VS of 500/1000ft a minute would be the mode used normally to descend in the hold - this way you are less likely to set the TCAS off of any aircraft in the hold below you - VNAV descent in hold(which not entirely sure is completly possible without FMC manipulation also) could result in a high rate of descent (especially if you had more than a 1000ft drop to do) and likely to set both aircraft TCAS and also ATC's STCA (short Term Conflict Alert) on their radar off. (using VS at a low amount 500/1000ft would also ensure you dont have any signigicant speed increase) One final note the FMC on the PMDG occasionaly gets mixed up with some holds - not always but on occasion it seems to not be able to hold correctly or do the correct entry!

My little tutorials are just based on normal procedures and do not take into account the thousands of different ATC possibilities that can arise. I am sorry that they do not cover everything but they are meant to be Basic Tutorials for people whomight find them useful in learning more about the FMC. Fred.

[RYR738 9]

What if asked by ATC to hold at a fix that is NOT part of the route ?

That is a good point !! I will make a short tutorial on that next ! Fred.

[JC75 22]

Fred yes they are excllent turorials for those who find the depths of the FMC a bit midboggling - I was just merely trying to not let the poster who asked about descent in holds get confused about what might happen, as your answer may have lead to confusion. All posts that are helping everyone enjoy this excellent sim fully are always a great thing - reading manuals is fine for those of us who know what we are looking for in the first place - simple guides like this are a great help to those newer to complex sims - so keep them up Fred.