Requirements for HOLD

[FlyerC3]

Hi all

I wrote a small LUA script to fly a hold starting at any chosen point. As you can see in the picture, it already works quite well. I haven’t compensated for wind drift yet, therefore there still may be a shift. In my script, I specify the heading of the leg as well as its duration in seconds. I set the bank angle to 25 degrees. The speed is manually set to 215 knots, and I define whether the turn should be to the right or to the left. In principle I allow any reasonable altitude and of course altitude changes.

The picture also shows a defined hold nearby, which seems to have a different size. Less bank angle ? Higher velocity ?

So I would like to ask, what instructions does ATC issue when they clear an aircraft to hold ?

And, by the way, does someone know how to write with LUA directly into the FMC scratchpad without "typing" every character via the keyboard.

Thanks a lot  

Edited 21 hours ago by FlyerC3

[Litjan]

Nice work!

Normally ATC will clear you for "published holds" - or they give you holding instructions consisting of a fix, an inbound course and a timing (how long in flighttime the inbound leg should be).

[mjrhealth]

If your talking about xplane ATC who knows if it works, Had people say they get told to hold but never to exit

[FlyerC3]

 

Is there a fix entry point for the HOLD, i.e. as shown here always LETKU ? Or can I enter the ring any place convenient for my situation ?

And what about the turn radius, i.e. is it a venial sin to overshoot when speed is to high ?

And one more : I assume,the FIX is alway the begin or end of the leg ?

 

Edited 19 hours ago by FlyerC3

[Litjan]

https://skybrary.aero/articles/holding-pattern

[FlyerC3]

@Jan : Thank you for the link. I assume IRL the pilot first manually goes into the circle due to the existing rules and then relies to the automatic  ?  With my 733 I joined "somehow" the circle and used timer and heading mode, but that keeps me quite busy especially when there are still other things to do during descend, since mostly the hold gives me additional miles when I was late for descend for the one or the other reason

@mjrhealth : no, I am using SI because of the very good voice interface, the astonishing AI model behind and the availability, that VATSIM et al. cannot match

Edited 4 hours ago by FlyerC3

[Litjan]

No, the FMS "knows" the correct holding entry and flies it automatically, too. 

I am no expert on holdings, though,  I can not remember the last time I had to fly one.

If you have to fly a holding with the IXEG, I would enter the holding fix on the fix page and then also enter the inbound radial - that way you have a pretty good depiction on the map. You could also do some quick math and calculate how far the plane flies at holding speed in one minute (usually about 4 nautical miles) and then draw a circle around the fix - that way you have a rough idea of when to turn inbound again (if you forget to start the timer on the outbound leg).

When flying a holding pattern, the important aspect is to fly in the area that ATC keeps "clear" for the holding aircraft, the holding area. That is why there are certain speed limits for holding patterns, they keep the planes within the holding area.