This is the second time I have this issue:

I have the Hold page correctly set for the hold, I execute it and now is active.

When I reach the entry point ...instead of a right turn (as programmed) the NGX turns left.

It happened either having the entering path perfectly aligned with the inbound leg....either having it with a steep angle.

What am I doing wrong?

Thank you

Hard to tell because I am not looking over your shoulder.  You provided no specifics.  Hold left or right distance or time and inbound course?  Heading entering the pattern?

you are right...but I did not take a screenshot...I will test do and post it.

Anyway I am quite sure I have set the hold pattern correctly (inbound leg, R/L turn, altitude, ...) but as soon as I have reached the waypoint simply the NGX turned into the opposite way.

Same thing happened yesterday to a VA friend during the same flight, same hold.

it was SAMOS  ...we were arriving from south and had to hold over the SAM VOR. Once over SAM instead of a right run...the aircraft turned left (opposite of the FMC setting that said to hold R)

http://

(I hope I did not violate any forum rule by posting this partial image. If I did I apologize)

 

 

Hi Stefano,

That's absolutely correct. Entering the hold, inbound 087 RH turns from a track of 357 requires a parallel entry, involving a left turn, outbound for one minute then another left turn back to the fix and in to the hold.

Correct. The 737 obeys ICAO standard entry definitions for holding. You'll have to look them up but the traditional cross line at 110' drawn onto holding fixes on older charts is the clue.... You can enter a hold using direct, parallel and teardrop entry. 

Basically with a 090 radial on the holding fix, right hand turn and entry TRACK that is from West of a line 020' to 200' inbound to the fix should be a direct entry. (it's been so long since I looked this up!).  From 200 to 270 would be a teardrop and 271' to 019'  Parallel entry. Apologies for the messy link. Pictures speak better than words.

  https://www.google.com/imgres?imgurl=http%3A%2F%2Fwww.pilotsweb.com%2Ftrain%2Fart%2Fhold02.gif&imgrefurl=http%3A%2F%2Fwww.pilotsweb.com%2Ftrain%2Fpattern.htm&docid=Sg9WJfJ-MvLdpM&tbnid=hXTQsN5SZm_s-M%3A&vet=10ahUKEwiNuOSw1uLdAhWKHsAKHcgcAvsQMwhIKAowCg..i&w=232&h=242&bih=674&biw=1536&q=standard icao holding pattern&ved=0ahUKEwiNuOSw1uLdAhWKHsAKHcgcAvsQMwhIKAowCg&iact=mrc&uact=8

Edited September 30, 20187 yr by MarkJHarris

5 hours ago, MarkJHarris said:

Pictures speak better than words.

LOL yeah, I earned my instrument rating in the 80s.... no GPS or glass cockpits then!  My instructor taught me to put lay a pencil on the chart at the pattern to visualize that 110 deg line.  After you do it ten times the pencil is no longer required.

OOOhhhh...thank you all folks for the answer...I knew I would have found it immediately here.

I will test it immediately....!!!!!

I am testing now...both the tear drop and the parallel entry.

but now I have another question to ask.
Suppose there is already another plane in HOLD.
If my entry is parallel, I will have a leg in the opposite direction to the direction of rotation of the hold.
In order not to collide with the other plane I will imagine both a vertical separation and an entry order in hold by the ATC. or not?
Or does the vertical separation suffice and can the entry also be parallel?

The hold entry is designed to keep you within the protected holding airspace (remember that the hold does not exist as a standalone entity -- there will be other airspace around that may need to be used for other traffic, or terrain might be a consideration).

Aircraft in a hold will ALWAYS be vertically separated by at least 1,000ft, so no additional lateral separation required.

Don't take what the ngx does as gospel on hold entries... I've seen it do some very weird things when entering a hold. (I'm referring to this sim, not the airplane which behaves as expected).  It gets there eventually, but sometimes the entries are entertaining ;-).