Expert: David Bidwell - 1/27/2005

Question
One of my flight instructors I am flying with in the 1969 Piper Cherokee Arrow. He tells me that Vx is 80 MPH for a certain amount of time for right off take off and then Vx is 90 MPH afterwards. I looked up on the POH and it says Vx is 90 MPH while Vy is 100 MPH. Rotation is 70 MPH. Which Vx do I use for short field t/o clearing 50 ft. obstacle?

Also, cessna has a kind of minimum equipment list in there poh. I know its technically not a mel, but it is like that. I was looking in the poh and did not find one for piper. Is there one?

Answer
Hi korey,
You might want to discuss this with your instructor.  There is only one Vx for any airplane.  However, be aware that different year of manufacturing use different numbers.  A ten mph difference does not ring true to me. You should be going by the POH. You might want to ask if the 90 mph value represents a "cruise climb" speed.

As for the POH, they were not standardized until 1979.  You can always contact Piper for a suggested mel.
Dave