I included flaps on my Eros. But they were of my own design, being part of my pushrod & torque tube control system.
Bruce
Pushrods and torque tubes? Innnnteresting. Have you posted about this in another thread so I can read up (I admit to a preference to Pushrods and Torque-tubes).
If it flies, floats or fornicates.... rent it! Flight Leader
Posts: 181
Time Online: 3 days 18 hours 44 minutes
Bought my 'Max built but it has no flaperons (general choice in the UK) but it also has a push rod system. I was asked on here to publish details but the drawings/design intellectual property belong to 2 guys here in the UK and I didn't wish to breach that. I have a full set of drawings and I could ask the originators if they are prepared to share or if they want to sell licences if there's enough interest.
Flaps? Totally unnecessary on a low-mass high-drag aircraft like the Max. On final, in an extreme side slip, with the nose down 30-40 degrees and not really building up much speed, the concept of flaps becomes ludicrous.
Bill Metcalf, I agree strongly. Wayne Ison told me that the first 100 or so kits had the flaps. After that they were made an option. I bought a Max 103 project that has flaps. The best benefit the flaps provide is a couple of mph, when they are re-flexed. Most of the time I land with no flaps. Occasionally with flaps, and I've even landed with them re-flexed. They are mostly a gimmick on a Mini Max.
The best benefit the flaps provide is a couple of mph, when they are re-flexed.
After much consideration during building, I did the "flap/reflex" option just for the above reason. If it adds another 2-3 MPH during cruise that's about a 5% increase.....not shabby.
Pushrods and torque tubes? Innnnteresting. Have you posted about this in another thread so I can read up (I admit to a preference to Pushrods and Torque-tubes).
The system works very well. Main advantage is very light, smooth control feel. Also more inspectable than cables, but as I said in my thread, I'm not saying there's anything wrong with the teleflex system that's standard. Just I prefer pushrod & torque tube.
I incorporated flaps as much as a design exercise, & because I wanted a 6ยบ reflex position on the flaperons. This is the main advantage, & definitely gives a bit more speed. I rarely use the flaps for landing, but they do knock maybe 3mph off the stall. The Max seems to float more with flaps, but landing slower means you lose some control authority. Might be useful in an engine out rough field landing, though.
The best benefit the flaps provide is a couple of mph, when they are re-flexed. Most of the time I land with no flaps. Occasionally with flaps, and I've even landed with them re-flexed.
After much consideration during building, I did the "flap/reflex" option just for the above reason. If it adds another 2-3 MPH during cruise that's about a 5% increase.....not shabby.
Lynn
And that is why I actually asked. I flew in a Flight Design with Flap Reflexing, and was impressed with the speed gain. I was wondering if it would have any benefits for the Max family.
It is my understanding that the reason flaps were included on the Part 103 Mini-Max designs was simply to comply with the maximum landing speed under the part 103 rules. If strict compliance with Part 103 is important to someone they would probably want to use them. Otherwise I would think it is a matter of personal preference.
Tom's right. The flaps allow one to claim a maximum lift coefficient of 2 when using the graph determining stall speed. Otherwise one has to demonstrate stall speed compliance with flight testing.
I'm trying to figure out how I would retrofit reflexing flaperons to a completed Hi-Max (AFTER I get it flying... I'll fly it in basic config to get data, then I can observe the effects of my modifications).
I vote yes. Only for up, though. There's no need to lower them. Antoni's point about making the max slipperier is valid. Mine is very much happier with nothing more than a fillet of 2" wide electrician's tape around the wing root and it hangs on to noticeably more speed in the flare. (Jolly handy yesterday,as it decided to be a Rotax 223 1/2 immediately after takeoff, traced to a leaky plug cap after the precautionary landing.)
Logged
