Sorry but didn't get an answer in the prev topic.

[744pilot 0]

I asked in a topic if someone know how to calc. slope of a rwy.But that post is lost in all the other reply's so that why I ask this in another topic. :)So, does anybody know how to calculate slope???? ;)Goodnight from Belgium,

[Gary_Hayes 60]

it should be on the airport plateGary HayesLevel-D Simulations Development TeamNo im not a "real" pilot, but I did stay at a Holiday Inn Express last night.P4 3.0ghz w/HT & FSB..GeForce FX 5900 ultra 256MB..1 gig PC3200 DDR RAM..Sound Blaster Audigy w/5.1 THX

[Mike S KPDX 598]

In the US, the FAA mandates what is called a level 2 (somtimes referred to as a 'sub mod 2') civil engineering survey of all public use airport 'controlled' surface areas. This will include runways and taxiways and somtime aprons if they are considered 'controlled'. This is not the same as have ATC control, it is a different definition.This site survey is very exacting and concise. Part of this survey is both the run slope and cross slope of these surfaces. This information is provided to the FAA as part of the final deliverable.I assume you are refering to the slope selection key on the CDU? If so, this information is published specifically for each US runway that had had this type of survey done. It is not calculated by the flight crew, cabin crew, dispatch, airline or even the FAA. It is provided as part of the record set to the FAA by the consultant.I dont even think it is maintained within the FMC database, and is rarely referenced. If it is to be used (Airline SOP) then it is looked up in a special publication.

[Guest psaul]

Yes, as Gary said it is on the airport diagrams. If you look at the ends of the runways (on the NACO charts at least) you will see<-.5% DOWNthis means that from the end of the runway until the half way point of the runway averages half a percent downwards.

[744pilot 0]

Ok thank all of you.But I mostly use Jeppesen charts and they don't have slope assignment on the charts.

[Guest BoeingFreak]

If its for some really strange reason not on the plate work out the change in height from both ends of the runwaym you know the distance so use a bit of triganomtry (sin-1 opp/hyp), ie the angle whos sin is the change in vertical height over runway length

[Guest PittsburghII]

Does the sim model this? That is not only the entry into the FMC, but does it have any effect in the sim? What effect does this have in real world situations?Thanks,Boaz

[Guest N401SS]

I don't know if runway slope is modelled in the sim, but in real life, runway slope can have a profound effect on performance.I don't have my POH handy for any of the planes I've flown, but particularly for large aircraft even minor slopes should not be disregarded in the real world.

[Guest Pittsburgh]

Ok, will take your word for it :-) Can you explain what the effect is?

[SAS263 1]

Nope, the rnuways in MSFS are level and nice. Too bad as most runways always have some ondulations, not to mention those exciting ones on mountain sides which have pretty narly (sp?) slopes

[Gary_Hayes 60]

"Can you explain what the effect is?"lol pretty obvious. You will find it harder to go uphill rather than downhill.Gary HayesLevel-D Simulations Development TeamNo im not a "real" pilot, but I did stay at a Holiday Inn Express last night.P4 3.0ghz w/HT & FSB..GeForce FX 5900 ultra 256MB..1 gig PC3200 DDR RAM..Sound Blaster Audigy w/5.1 THX

[Peter Clark 21]

That's strange, the NOS plates give the slope right on them. For Jepp charts you have to take the difference between the two runway TDZEs and the length of the runway and calculate it yourself.To calculate it you can take the elevation change (in feet) divided by length of runway, multiplied by 100 to get the percentage slope.So, KBOS 04R:19' (04R end), 14' (22L end), 10005' runway:((19-14)/10005)*100) = .0499, or -.05% (down) slope.Even the NOS plates don't show every slope, but I don't know what the low threshold is. Lawrence, MA (LWM) has a runway with +.7% slope and that's shown on the plate, so it's somewhere between .05 and .7 ;)Enjoy.

[Guest N401SS]

Instead of just providing merely anecdotal explanations, here's the best I could find on short notice.http://www.planeandpilotmag.com/content/pa...feb/uphill.htmlThe article quotes an approximate 10% increase in take-off roll for every 1% of upslope on take-off, which I have heard before.The general idea is this: Imagine that you're running up a hill. Since you're not just translating horizontally but going vertically as well, you are expending more energy. The same is true in an airplane, and not only are you moving that way at a constant speed but you're also trying to accelerate to take-off velocity. It simply takes more energy to get it done, and that translates fairly directly into a longer ground roll.

[Peter Clark 21]

Augh, my head just exploded......I was never very good at trig in school.

[Guest Pittsburgh]

Ok, feeling pretty stupid now :-) That is almost to easy to grasp...