Stall Speed

[danweseman]

Glen,
We did glide ratio test back May and June when the weather here in FL was probably the worst.(thought I posted back then ...sorry) Even early in the AM the air was unstable and hard to get accurate data. The weather is getting much better this time of year for accurate testing.
I got average rates of descent at 80 mph around 500 ft. per minute which is a little over 14.1 ratio. Bob tested and at one time light on fuel had under 400 fpm. That was prop idling. I couldn't get accurate repeatable information to detect weather prop stopped or idling was better. I will put better GR testing on the list of test for smooth air,im interested to know also.
Just looked up initial design predictions from 2 years ago.
1030 lbs.
73.65kts (85 mph)
15.15 L/D
432 FTPM descent rate
pretty close ,now I really want to get some good numbers!
Dan Weseman

[GlenNJ]

Dan,
When I asked for Panther glide ratio and sink rate performance, I'm not asking you to shut the engine off. Flight idle information would be fine.
Glen

[GlenNJ]

Dan,
Can you put engine out glide ratio, and sink rate at this speed on the flight test list to?
Glen

[danweseman]

Tony ,excellent point. I will be honest that our low end stall speed test were all centered around the US LSA clean stall speed verification. I took 5 min and played with the lift formula ,and with the current flap length and 40 degrees we are very close to 45 MPH. I will put landing configuration stall speed and the list for flight testing in coming weeks and see what gross weight will meet the rule. I believe this would be helpful in other countries as well! Thanks

[Mike]

Interesting points, Tony. I'm not exactly sure if the builder can decide the gross weight in Canada, but I can't find any evidence that says otherwise. IMHO, the basic ultralight category is perfect for a single-seat design like the Panther. I'll keep an eye out for further flight testing results!

Thanks,
Mike

[rlweseman]

Good points Tony!

[Tony Spicer]

Mike,

Don't be too quick to dismiss the Panther! Just for grins, let's have a look at the Sonex. Max gross with the 3300 is 1150 lbs, and stall speed in the landing configuration is listed as 40 mph. The Panther, with 5 sq ft less wing area would have a slightly higher wing loading and has a max gross of 1115 lbs. The Corvair package is about 240 lbs; the 3300 about 185, so there's a path to weight reduction. In the US, the builder sets the gross weight. Don't know how it's done in Canada. Lighter gross equals lower stall speed. Also, it will be interesting to see what happens to stall speed when Dan gets a full 40 degrees of flap deployment.

Tony

[Mike]

Yes, that helps. Thanks. I was hoping the Panther might qualify as an ultralight under Canadian rules, but it looks like the stall speed might be just out of reach.

an aeroplane having no more than two seats, designed and manufactured to have a maximum take-off weight of 544 kilograms (1199 lbs) and a stall speed in the landing configuration (Vso) of 39 knots (45 mph) or less indicated airspeed at the maximum take-off weight.

-Mike

[danweseman]

Mike documented "dirty " stall speed is about 48 mph CAS at 1115 lbs. our current (GRT EFIS)ASI is well calibrated above 1120 mph. but reads high below this. The Previous MGL and wing mounted static source was close above 100 but read VERY low at hi AOA. It would read 35 mph in "dirty" stalls. In a recent Magizine article the Onex with the MGL also posted very low and unrealistic IAS stall speeds.we worked with the staic /pitot to get it as close as possible. Hope this helps

[Mike]

Hi,

I can't seem to find any information about the Panther's stall speed in the landing configuration. Is this data available yet?

Thanks,
Mike