Amphib Performance At High DA

[UtahMaule]

Has anyone operated an amphib M-7 260 at high DA? A friend of mine is looking to operate here in Utah and wondering how the performance would be?

Any other models operated at high DA routinely?

Thanks for any info.

[aero101]

What are you calling high DA? The biggest problem with the amphibs will be the legal useful load as performance will match most anything that's not turbo'd or supercharged....

[UtahMaule]

He understands the useful load limitations. Wondering about getting off the water at 4000-8000 DA. 2 people and half tanks. Don't any of you guys go splash in high lakes? Thanks.

[aero101]

2 People half tanks will probably put him just below max gross... at 4K he'll do very well, will probably need 1/4 mile to get off water (not clearing obstacle), at 8K probably just a little over double that assuming light 5-12knot winds. If lakes are good sized, he can always roughen up with step taxi, smaller lakes he can get into places he might not be able to get out of! So much depends on wind conditions (wind being your best friend on floats in tight areas up to a point) and pilot technique that he'll just have to get to know his airplane and his own limitations/skill level. Glassy water will add considerable distance and require good technique. Most guys I know up here that do high lakes are either turbocharged, round engines with superchargers, or turbine conversions which allow for getting in and out of the smaller lakes.

[maules.com]

I believe I had mentioned to him that I had a customer with M7 235 IO540 operating of Lake Tahoe at 6200msl and could get off with 3 people and 2 hours fuel useing straight floats.
Alternative test is find a Maule on amphibs, and then to equal 8000 ft DA, take off with 21.4"MP from land and then on water at sea level or any altitude, then try loading people or weight till it won't get off.

[aero101]

Good idea Jeremy, we quite often use the same kind of procedure on supercub owners float training to similate high load and high altitude to make them work a little to get it off the water at our low altitudes in this area... Works quite well...

[UtahMaule]

He got home with it. I got a ride this morning. Seems to perform real well with two on board, half tanks. Did a few landings on a lake at 4200 with a DA of 5600. Light winds.

[dbross]

Does anyone have any experience with an M5 235C on amphibious floats at lakes around 4500' elevation? Just new to this forum so if this has been discussed sorry. looking at half tanks, 2 guys with camping gear.

Thanks


Dave

[aero101]

Will probably get off with good technique, but will require considerably more room with the shorter wings / flaps. Would suggest try technique with reduced power settings Jeremy suggested earlier this post.... Just don't see that many amphibs up here, mostly straight floats..

[maules.com]

The M5-235C on EDO 2500 amphibs will get off at 4500msl with two and full mains.
Performance will depend which prop, whether VGs and gapseals are fitted.
I have not flown the M5 on Wipaire or Bauman amphibs at 4500ft but suspect there will not be a problem.
High temperature can raise the Density altitude a few thousand feet.

[dbross]

Thanks. Do you find VG's and elevator gap seals very beneficial? My plane has neither.

Dave

[maules.com]

Yes, the gapseals are required on the M5 and VGs enhance aileron and elevator control especially on floats.

[TomD]

Yes, the gapseals are required on the M5 and VGs enhance aileron and elevator control especially on floats.

Amen!