Retractable Steps

[DCsr]

Has anyone installed a set of the Hendricks Retractable Steps on a -6A. Have opportinity to purchase a set but, would like to know a little more about the operation/installation before I do.

 

[10_Dreamer]

I posted the same question a week ago or so with no answer. I'd like to get a set for my 10. I'm guessing it would make some pretty cheap HP (wind drag) If someone can figure the drag on the steps at 175knots/200 that would be cool.
y

 

[Bob Axsom]

Well I can give one data point

In 2008 I modified my airplane (RV-6A) to allow complete removal of the steps for racing. The difference it top speed was approximately half a knot at 6,000 ft density altitude. I just removed them and installed the cover plates again for the race at Taylor, Texas but if I were not looking for every fraction of a knot I can get there is no way I would remove those wonderfully convenient and durable fixed steps.

Bob Axsom

 

[plehrke]

I agree with Bob. The only reason to retract the step is cool factor and aesthetics. What you are paying is weight (reduced useful load) and complexity (increased maintenance). I would stick with a fixed step. Many places it has been documented to cost less than a knot of speed.

 

[10_Dreamer]

Good info, point taken, Fixed step it is!

 

[DCsr]

Thanx for your input, guys. My good friend and T.C., Martin Sutter, added too that with my already built wing root fairings and plans to install Classic Aero's interior, the installation would - to say the least - be interesting. Guess I'll fall back to fixed steps or just no steps at all.

 

[robpar]

I would stick with a fixed step. Many places it has been documented to cost less than a knot of speed.

Is the instrumentation commonly available able to detect a 1 knot speed difference on a 160 knot or so speed? That is about 1/2 of 1%. We pay very high prices around here for instruments that give that kind of accuracy and few if any of them are that accurate on gas flow. Pitot tubes, the engineers here say are at best accurate to 1%. So if the speed difference with the step there or not is less than a knot it would seem that difference is lost in the noise of the measurement.

In astronomy they routinely pull data like that out of the noise but it takes a huge amount of data in order to do that. You can intuitively see that the step would cause drag and do calculations to estimate it, but if the difference is less than your ability to measure it is going to be difficult to prove it one way or the other. Keeping all the other variables between a flight with the step and one without to much less than 1/2% so that the step is the only change being monitored sounds really difficult.

I would be very interested to hear others thoughts on the ability to accurately evaluate changes that result in such small speed differences.

Bob Parry

 

[Bob Axsom]

GPS three way NTPS spread sheet 6,000 ft Density Altitude

GPS, three way per www.us-airrace.org handicap procedure, NTPS spread sheet, 6,000 ft Density Altitude - works amazingly well for me.

Bob Axsom