737 FMS NG questions

[N1 Limit]

hey guys
I've got couple of questions regarding the 737 NG:

1)What does Skid resistant on the take-off ref page 2 really means?

2)Say u're flying to a destination whose the elevatio is 3000 feet,and u've got the 240/10000ft,someone told me that it should be 240/13000 because the restriction is 10000feet to the elevation is that correct?

3)How can u build waypoints that u can assign names u want?i know it's on Nav status

Any help is greatly appreciated

[FlightPathOBN]

3)How can u build waypoints that u can assign names u want?i know it's on Nav status

You absolutely cannot and this is extremely dangerous and illegal.

[ReverseFlight]

How can u build waypoints that u can assign names u want?

Are you using Microsoft Flight Simulator ?

[FlightPathOBN]

Are you using Microsoft Flight Simulator ?

FUK..I hope so...

The other boxes allow you to randomly name and store them, but will prevent use of existing waypoint names already in the NDB.

No, No, No, and NO.........

manually inputting waypoints can/will cause conflicts with the database waypoints...

depending on what your navdatabase provider has been contracted to do...it may not error...

[HalinTexas]

WSR is a certification of a given airport runway. The airline (aircraft) must also meet certain criteria. Performance for that runway must be available.

It's a grooved and/or porous material that will disperse water from the runway, effectively giving near dry performance. Quite a few shorter runways are WSR rated in the US.

The speed restriction at altitude, i.e. 240/10000, is dependent on the regulatory authority of that airspace. In the US and many other countries it is 10,000'. "240/10000" is the default setting of the FMS as ordered from the factory by the operator. This setting can be changed.

Be careful using the "user defined waypoints" feature. I'm just sayin'.

[ImbracableCrunk]

You absolutely cannot and this is extremely dangerous and illegal.

Illegal, huh? Extremely dangerous?

Every time I've done ETOPS I've punched in my own nav points (EEP1, EXP1, etc.,) and the wings didn't fall off.

I hope you're just pulling the noob's leg.

[FlightPathOBN]

I've punched in my own nav points (EEP1, EXP1, etc.,)

waypoints are 5 letters, so either YOU are pulling my leg,
your flight simulator software on your Mac allows this,

or you do not know what you are talking about.

(good luck filing a flight plan)

[donkey123]

waypoints are 5 letters, so either YOU are pulling my leg,
your flight simulator software on your Mac allows this,

or you do not know what you are talking about

FlightPathOBN

I suggest you re read your Vol 2, or, next time you are out on line have a play and come back with your results.

There is a big difference between adding a WPT/APT through the NAV DATA page for reference only (ImbracableCrunk's example), compared with creating and executing a user defined waypoint in the legs page.

2 completely different things.

[b737NGyyc]

You can add user waypoints on the REF NAV DATA page using Lat/Long, reference from an existing waypoint in the NDB (Nav Database) or any temporary waypoint you may have created such as an along track waypoint. These waypoints are stored in the temporary database and are deleted after the aircraft lands and the FMC recycles back into departure mode. These waypoint names can be anything from 1 to 5 letters or numbers and do not have to comply with the standard 5 character naming convention.

These waypoints can be inserted into the active flight plan (not particularly recommended but can be done unless forbidden by your company SOPs) or inserted on one of the fix pages as a reference, this is how we do it for ETOPS, as flight plan modification on the oceanic portion is forbidden at my company.

They cannot and do not interfere with anything stored in the NDB. The NDB cannot be user modified without the use of a data uploader. We as pilots cannot corrupt the NDB by entering anything.

[FlightPathOBN]

Which was exactly my point...the original question posted was about waypoints...

3)How can u build waypoints that u can assign names u want?i know it's on Nav status

[FlightPathOBN]

FAA-AC-90-94

2. EN ROUTE (OCEANIC AND DOMESTIC) AND TERMINAL NAVIGATION.
b. All named waypoints are identified with a five-letter alpha character name provided by the NFDC.

Note: An aircraft is not authorized to fly any IFR approach using GPS unless that instrument approach procedure is retrievable from the navigation database.


4. THE GPS APPROACH OVERLAY PROGRAM.

c. Waypoints.
Note: User modification or entry of data associated with published instrument approach procedures is not possible, and not authorized.

[b737NGyyc]

You absolutely cannot and this is extremely dangerous and illegal.

You absolutely CAN and no it is not illegal or dangerous. Stop fear mongering. We are not talking about modifying approaches or existing NDB waypoints, just creating user waypoints in the temporary database. The first is illegal for obvious reasons and the second is not possible as an end user.

[aussiepilot]

FlightPathOBN,

I think you're getting a bit wound up about this.

Consider what you do when you get a long direct to from ATC. When I flew the NG, we would press the "abeam points" line select key and straight away there were new waypoints. It would appear as ABC01, but we would definately fly to it in LNAV.

There was another way to create waypoints based on a lat/long, but it's been too long and I can't remember how to do it.
We would have to do it for points on the flightplan that weren't in the Nav database due to the 8mb of memory not being large enough

[FlightPathOBN]

Aussie,

Concur...you can, but you cannot use these to fly IFR unless they are in the NDB. Perhaps what you do out in Oceanic Airways is loose, but the FAA regs seem to cover this.

I have significant experience creating new waypoints with the FAA and the significant time it takes to get one approved. I have tried to get custom waypoints for smaller aircraft, which seems fine, but the FAA will not approve them for IFR unless they are fully vetted and in the NDB.

The FAA will not approve a flight plan with custom waypoints, (go ahead and try to file one) nor will they approve a transition from custom to STAR or otherwise...nothing IFR, and even adding waypoints with GA VFR has met with resistance according to the rules noted in my previous post.

Given the thousands of waypoints and the associated names, including 3,4,and 5 letters, and all combinations, as noted by other posters, most airlines forbid the crew from adding custom waypoints.
The incident in South America prompted this, where the crew thought they had entered their own waypoint, and the NDB found an existing and they didnt realize it. The aircraft flew directly into a mountain on IFR.

I get excited, because I have to deal with all of the rules, cost, and headache associated with all of the people who insist on adding custom data without understanding the issues. ( I have to pay the FAA a cost per waypoint to add a new one to a procedure, pay to validate that point, and pay to maintain that point in the NDB cycle)

[donkey123]

FlightPathOBN

With respect, I think you are missing the point.

Most people on this thread are talking about adding a temporary waypoint into the FMC to illustrate certain 'critical' points along the flight plan (eg EDTO ETP's etc). It is purely a point on your ND nothing else. I can't see any operator anywhere in the world having issues with this.

As I said before it is an entirely different beast to creating your own random waypoints and executing them within the legs page (which I agree is fraught with danger).

[Denti]

You can also add permanent new waypoints or even NAVAID entries on the ground into the supplemental navigation data base, those won't auto-delete after landing. You have to be careful of course, but sometimes it is useful to store new NOTAMed waypoints until the next AIRAC cycle comes around. Not all countries give sufficient advance information to allow NDB suppliers to put them into the database in time.

The supplemental nav data base can also be filled via datalink if you happen to have to fly unplanned into an area which is not covered in your normal database set, of course only if your OPS or NDB supplier supports that. It can also be downloaded via datalink from the aircraft to your OPS, for whatever reasons.

[ImbracableCrunk]

waypoints are 5 letters, so either YOU are pulling my leg,
your flight simulator software on your Mac allows this,

or you do not know what you are talking about.

(good luck filing a flight plan)

That's offensive. I would never use a Mac for my flight sim!

[Capn Bloggs]

this is extremely dangerous and illegal.

Rubbish...

[cosmo kramer]

N1 Limit:
3)How can u build waypoints that u can assign names u want?i know it's on Nav status

FlightPathOBN:
You absolutely cannot and this is extremely dangerous and illegal.

Indeed it's possible. And I can't see any reason why it would be illegal or dangerous. Sometimes it's very useful, which is probably why Boeing put the feature there, readily available and well described in the FCOM volume 2.

How to put a waypoint in the temporary database with a name selected by yourself:

Go to INIT/REF on the CDU keypad. From the Line Select Keys navigate to the subpages INDEX, then NAV DATA.

Input the waypoint name you want to create (1 to 5 letters). I don't know if you can use names of official waypoints that are in the permanent database, I didn't try. My guess is that it's not possible in the temporary database, but maybe in the supplementary database (I'll explain how to access it below).

But useful names could be LEFT or RIGHT to put in the FIX page for your engine out procedure. Or e.g. BASE if you want to prepare some point to put in the legs page for visual circuit.

Now you can put in a lat/long. But much more useful is the option in the bottom of the screen called REF IDENT (reference ident). Type an existing waypoint in the scratch pad and line select it in there. To the right in the field RADIAL/DISTANCE you can now put in a radial and distance from the reference point in the format "XXX/YY".

For example, you have a engine out procedure that says:
"maintain runway heading until 2.5nm from ABC VOR, then turn right heading 250".

Put ABC in the FIX page and find out which radial from ABC VOR that intersects your extended centerline at 2.5 nm (trial and error with your ND in plan mode). If you fly there often you'll probably remember this radial and can skip this step. Let's say you find it's radial 096.

Create a point called RIGHT with reference to ABC VOR and in RADIAL/DISTANCE put in "096/2.5".

Now you have a waypoint at the exact point where your engine out procedure requires you to turn right. Put your new waypoint RIGHT in the fix page with a radial of 250. You now have your procedure nicely represented on the ND.

It sounds complicated, but it really doesn't take more than 30 seconds. I do this myself if the combination of airport/terrain/weather and special procedure is sufficiently complicated. I guess in the odd case of an engine failure in that situation it would be quite helpful to reduce the stress.

You can use any waypoint from the permanent database and previously created waypoint from the temporary database as reference points. Example with the base waypoint, let's say the Outer Marker for the ILS runway 27 seems reasonable to use as a final turn for your visual approach. The Outer Marker would then be OM27 in the legs page. Make a BASE waypoint with reference OM27 and 180/2 for radial distance. You now have the possibility to quickly put in a visual left hand pattern in the case you are cleared for a visual approach.
Before someone comes with a rant about visual approach has to flown out the window: I agree. But that doesn't mean that the FMC can't correspond as well. Furthermore it's not the topic of this tread.


The waypoints you create in the temporary datebase are automatically deleted upon "completion of flight" according to Boeing. I didn't check when it occurs, if it's air/ground sensor related, engine shutdown or turning the IRSs off. However, presuming you do all of those things, they are gone when the next crew takes over and you don't have to worry that it will cause confusion for the next crew.

To put something in the supplementary database I would strongly advise against, unless it's some official change that didn't made it into the FMC database. Never the less, you have to be on ground to access the supplementary database and do it by writing SUPP in the scratch pad prior to selecting NAV DATA.
Here I completely agree with FlightPathOBN that it's dangerous, since whatever you put in there will be there to possibly confuse the next crew. Don't put anything in there unless it's an official revision.

[BOAC]

At one point in my airline time some silly chaps were carefully positioning waypoints (nb 2-5 letters) in SUPP so they gave a clear message about a certain **** as you approached the LGW area from the south.