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Operating on a Curved Runway & Performance Increase on a Hill

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General Aviation, Light Sport Aircraft

I am designing (and about to start construction) on a small strip on my property.  Unfortunately, the property is in southern Missouri, so there's no "traditional" optrion to make it straight and flat for thousands of feet.  Landings will be made on 07, and takeoffs from 25.  The first 800 ft. is almost perfectly flat and straight.  The remaining 350 ft. or so is a slight curve to the left, in total about a 30 degree bearing change.  (about 200 ft. of that turn is on a 13% gradient hill.) 

 

I have two basic questions:

1- Since I will be at the slowest point of decceleration/acceleration on the curved section, I'd assume it won't be all that hard to operate on.  I'm not expecting to be much quicker than 15 or 20 knots in those areas, so I don't foresee much of a control issue, considering I've turned off of high-speed runway exits at about those speeds before.  Am I correct in my reasoning?  Does anybody have some experience operation on curved runways?

2- Does anybody know of a calculation to see how the hill will afffect performance?  Obvisously, it will lower the needed runway length for both takeoff and landing, but I'd like to be able to calculate it.  What what I've heard and seen, the 200ft. of a 13% gradiant should act like about 500ft. of flat runway.  How close is this?  It shouldnt' be a factor when flying something like a Cub or some LSAs, but it would make a go/no-go difference for Skyhawk-type aircraft.

 

Any other input and/or suggestions would also be greatly appreciated!  Thanks!

(Here is a basic diagram of the strip that I made in Google Earth.  It is close to scale, being about 25ft. wide.)

Preliminary runway diagram

1 Answers



  1. Lucas on Nov 18, 2012

    Hey Jim
    If I understand everything correctly it would not be very wise to take a C-172 and land it at the proposed airfield. Well let me rephrase this, landing could probably be accomplished, but taking off again might become an issue since a fairly new Skyhawk loaded at 2300 Lbs with a temperature of 20 C at sea level will need 835 ft ground roll and 1490 ft to clear a 50 ft obstacle, add to that maybe a 5 kt tailwind and the distances are increased by 25% (1031 ft and 1862). Also if the runway is not paved add another 15%. And again this would be for a fairly new C-172 (most aren’t). Finally if you want to take a look at some studies for up slope and down slope runways you can check page 3-13 and 3-14 of the Mountain Search Pilot Guide that shows a formula to determine the break even point between runway slope and tailwind: http://www.capmembers.com/media/cms/mountainfurycourseguide_651EDE4593916.pdf

    On the other hand if you will be flying in and out of there on a Cub then you will have no problem.

    Lucas
    http://passfaaexams.com/

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