10 deg. Of flaps in a 6 /6A for take off and for short field take off. How ( for us dummies) do you determine 10 deg. ?
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10 deg. of flaps, take off and short field. How (for us dummies) do you determine 10 deg. ?
- Thread starter firemanken
- Start date
You can also measure the flap angle and apply tape, paint pen, or permanant marker to the flap to show when the leading edge of the flap extends past the trailing edge of the wing. That'll give you a visual reference.
Just for another data point, I had Fast Signs make up a black vinyl hyphen that I affixed to the left side flap near the aileron. I think it's about 1/2" wide by 1" long. In my case, it reveals itself at half flaps (20 degrees) so I can visually confirm at a quick glance the flap is where I think it is. You could do the same for 10 or 15 degrees. The one thousand one, one thousand two count--or one Mississippi, two Mississippi--should get you pretty close.
My flaps have stripes (as they become exposed from the trailing edge of the wing), 3" or so long, painted at 0, 10, 20 and 30 degrees. That works great during the day.
For night ops, I made a table in Excel showing how many seconds it took to go from 0 to 10, 10 to 20, 30 to 10, 20 to 10, 20 to 0 and 10 to 0. No need for x to 30 or y to reflex, as those are hard stops. If memory serves, I did the timing measurements three times for each interval--very consistent.
You can also realize that there’s almost no advantage to using flaps for takeoff on an RV…and you easily may get distracted and overspeed the flaps by failing to retract them in time, given how fast we accelerate. Only if it’s really muddy and soft, do I use flaps…and consider than a special circumstance…
If one has VPX you can use the "reflex" position as -10% flaps regardless, if you have a 10 or 14 wing. VPX gives one a CAS warning if overspeed but if one consistently uses 10 degrees for take-off it pretty intuitive to bump the flaps up before one overspeed's it. If I lose my engine at 200 ft at least, I've got some flaps in to fly it to the crash. 
This is what I did (the sharpie on the flap method), but also use the one one-thousand, two...method as well.
Yeah. It ain't rocket science. 12 degrees, 18 degrees? The difference doesn't matter enough to worry about.
I can agree with causing problems if you forget to retract the flaps. However, if you treat it as a standard operating procedure then you should be consistent enough to make it routine. I had only one experience early after first flight. That was enough for me to ingrain it in my standard operating procedure to make it a permanent part of every takeoff.
On the other hand, I disagree with your comment about “no advantage to using flaps for takeoff on an RV”. I have used flaps on just about every takeoff for the past 17 years flying my RV. In my initial testing I tested takeoffs with flaps and without. I also do some no flap landings and no flaps takeoffs for proficiency. There is a noticeable difference on my 9A with 180 hp engine and fixed pitch prop when taking off with 10-15 deg of flaps vs no flaps. If the best lift to drag ratio is basically at 10 deg of flaps for most aircraft why would an RV be different? When taking off don’t we always want the most lift we can generate? We want the plane flying as quickly as possible.
Measure the flap deflection and mark the position with tapr so you can see it when sitting inside your cockpit. Other people have programmed the EFIS but you need a flap position sensor which is difficult to install with an already built airplane. Even when it's programmed into my EFIS, I just glanced outside and know the deflection by looking at the tape.
