lml@lancaironline.net Mailing List Archive

I like Bob's restrictor on the retract idea. flap retraction on a IV can be "startling" if built per plans.

to Dico's question though, arguments in favor of using flaps:

- you'll need them on a short runway so you should get used to what performance you should expect and be ready to make a quick decision if you are not getting expected performance.

- take it easy on your gear. 100 mph on little tires is quite a bit of exercise on those tires

- flaps let you get positive rate sooner which means you can get cleaned up sooner which means you are set up for maximum glide sooner.

- in theory you should be able to get to a safe altitude sooner.

On Aug 9, 2013, at 7:49 PM, Robert R Pastusek wrote:

Dico,

I use about 20 degrees of flaps on takeoff…extended to when they have moved all the way aft, and just before they start tilting down. For me, this occurs when the flaps align with a fully deflected aileron. I also have a flap position indicator, but looking out the window works better, even at night.

I also installed an adjustable restrictor valve in the line that “free-flows” in one direction, but can be modulated in the other. I adjusted this to allow the flaps to retract in about 5 seconds on the ground. They come up just a bit faster under air loads during takeoff, but I never get that “sinking feeling” at any time.

This, along with the original restrictor valve in the down-flow direction allows me to control the flap operating speed in both directions. A great improvement to the original design.

The McMaster-Carr specs and part number for the brass version:

1/8"

1 15/16"

0.28

0.125"

4982K71

$36.71

Works like a champ!

Bob

Hi All,

I am wondering how many people use flaps on take off with the IVP? I was told to use about 15 degrees of flaps. I've also discovered that I don't like retracting the flaps unless the IAS is about 135knots IAS. No real reason other than I notice that you don't really feel the retraction as much as you do at the lower speeds.

So I guess I am wondering, if you only have a couple people on board (or even a full load with lots of runway), do you use flaps?

-Dico