Subscriber question:
"What is a good standard go/abort point on a turf runway, high altitude, high density?"- anonymous
Wally:
“The answer to this question depends upon the obstacles you have after take off. Many pilots feel if they have rotation speed by ½ of the available runway, they are good to go. But that may not be enough if you have rising terrain or tall obstacles off the end of the runway.
Grass runways present a number of challenges to the pilot. While some pilot operating handbooks give a performance decrement for turf, others don’t. Then how high is the grass at your airport and how does that compare with the book numbers?
So even with numbers, you may not be able to compute an accurate distance. You need to add an abundance of conservatism when operating off of grass.
Some things you can do to improve your performance is to leave one or more passengers behind and shuttle to a longer hard surface runway nearby or plan your departure early in the morning for cooler temperatures.
In addition, on every take off, you need to know what you should be seeing on those engine gauges early in the take off roll to be sure you are getting full power.
So use your book numbers if you have them adding plenty of conservatism, plan your flight at the best time and abort the take off early if anything does not feel right.”
