MTV,
Specifically it's the wing on a Maule that limits the gross weight now. If they can increase the strength of the wing, the M-9 will have a higher gross weight limit. It is supposed to have an 1100 lb useful load. The M-6 and M-7 wing are limited structually to 2500 lbs. Idon't know about the M-4 or M-5.

It is my understanding that with the 182B the sales department wanted a service ceiling over 19,000 ft. The test pilots and engineers messed around with weight tell it got up to 19.

If this is true, what would be max gross if the sales folks only wanted it to go to 16K.

Tim

I believe that the gross weight on the airplane that starts with an "M", and is not a Mooney or Marchetti, in the M5, M6, M7 models is 2700# when on floats (M5 w/upgross kit).

Several aircraft have a higher gross weight when floats are installed. The Husky and Maule come to mind. There are varying "stories" as to why this is allowed.

One "story" is that the floats supposedly generate enough lift to carry their own weight. Personally, I don't buy that one.

The more likely logic is that the landing gear and/or its attach points are the limiting factor on setting the gross weight on the airplane. I believe this is the factor on the Husky, don't know about the Maule. Floats offer a very different load distribution and factor when it comes to a drop test.

MTV

donknee wrote:I believe that the gross weight on the airplane that starts with an "M", and is not a Mooney or Marchetti, in the M5, M6, M7 models is 2700# when on floats (M5 w/upgross kit).

You are right and it is supposedly for the reason that MTV won't buy. Since the wings don't carry the additional weight and since the wings are the limiting factor There is a gross weight increase egual to the lift generated by the floats. If engine performance, fuselage strength or another structure were the limiting factor, there would not be an increase in gross.

a64,

Note that I said that "I" don't buy that one. I didn't mean to suggest that the FAA might not . In fact, I have heard that story from a few folks.

My point was that I seriously doubt that floats, particularly as they were mounted on the earlier Maules (serious negative angle of incidence) could generate much if any lift.

The Husky floats are mounted at one degree AOI, by the way.

But, if BD could get the FAA to buy off on it...more power to him, and I don't doubt that it happened. Heaven knows, they've gotten a lot of other stuff approved that nobody else seems to have.

MTV

What do floats weigh? You get a 200 lb increase in gross, but they have to weigh more than that don't they? Maule Oleo landing gear strength is right at the 2500 lb gross weight limit as well, I think. I also think the spring gear are stronger, but there is no increase in gross with spring gear. They are about 60 lbs. heavier though.
It keeps coming back to the wings or fuselage being the limit for a Maule's gross weight. I know the reason the droop tip went away with the early M-6 is because they could lengthen the aileron without lengthening the wing by changing the tip. Lengthen the wing and you will re static test it. I know the M-9 will require a "new" wing to go to a higher gross weight.
The neat thing about Maule is that they are still open, This could be answered by a phone call to their engineering dept.

a64,

Don't know about weights of Maule floats, I'd bet they're around 200 pounds plus exchange weight (gear removed, floats added).

EDO 2000's on a Cub are 189 exchange, and the Baumanns on a Husky are 174 or something around that. That's one big difference between the Husky and Cub, if you're going to floats. Husky GW goes up, Cub's doesn't.

A lot of folks think the change from the Husky A-1 to the A-1B was mostly a paper exercise, but there were substantial changes, one of which was replacing the aft spar with one of a higher tensile strength aluminum on the B. And, several other more minor changes. As you say, sometimes it is the wing.

MTV

Just to add another source of nagging besides me, take a look at this site, and subscribe:
http://overtheairwaves.com:80/

He has a lot of good information, and sends out a weekly issue to remind us to stay honest with our flying and ourselves....

MTV

A little overgross in a 152 will get you, because it's performance limited (I think).

The 152 definitly has a performance limited gross. The 150/152 club published a very good history of the line a while back, including reasons for various changes. When Cessna went from the 150 to the 152 they changed from the O-200 to the O-235 primarily because it handles 100LL better and that was the most common fuel available at the time. But that and comfort and avionics upgrades increased the empty weight to the point that they had to reduce the flap extention from 40 degrees on the 150 to only 30 degrees on the 152 so they could increase the gross enough to still have a practical useful load and meet the Certification requirements for full flap go-around climb rate.

This sort of thing has happened throughout the 150's history. The old straight back, straight tail 150's only have a 1500 lb gross

The more common 150's, the "F" model on with rear window, electric flaps and swept back tail, have a 1650lb gross, but also have a 100 to 150lb higher empty weight than the 150 to 150C. I don't have all the specs but I'd bet these 150's have a lower service ceiling, or some other operating limitation different from the earlier models. Incidently, the tail was swept for marketing reasons, they wanted it to look more modern, more like a jet. The straight tails supposedly have better yaw stability/control authority and spin recovery (can't say from personal experience since I've never flown a swept tail 150).

There's also an STC that allows a 10% gross increase to the 150's with an engine upgrade to 150 or 180 hp!* I've read the entire STC, the only structural changes are to the engine mount. Nothing behind the firewall gets changed except engine instruments.

All that said I've only ever operated over gross in my 150 once. I took off 20lbs over. It was a cool morning near sea level, and I still didn't like it. The climb was disturbinly slow. Any more I hate flying it if I'm within 100lbs of gross. Not because I feel the plane is unsafe at gross, I just really like light handling aircraft.

And and as MTV said, light weight is the real key to performance. I've had people ask if I have a 150 hp conversion in my 150 after seeing me take off in 400ft from grass and climb at 2000ft/min. It was just me and 1/2 fuel on a cool day. Add full tanks, survival kit and weekend camping gear on a hot day I'm easily up to the 1,000ft mark on takeoff and only climbing at 900ft/min.

Phil

*This particular STC is no longer available, but still valid. The holder just isn't in business any longer and hasn't sold the rights to it. The currently available 150hp upgrade STC's do not have the gross weight increase and typically leave the plane with about a 350lb useful load.

I've had people ask if I have a 150 hp conversion in my 150 after seeing me take off in 400ft from grass and climb at 2000ft/min. It was just me and 1/2 fuel on a cool day. Add full tanks, survival kit and weekend camping gear on a hot day I'm easily up to the 1,000ft mark on takeoff and only climbing at 900ft/min.

You sure on those numbers?

ravi wrote:

I've had people ask if I have a 150 hp conversion in my 150 after seeing me take off in 400ft from grass and climb at 2000ft/min. It was just me and 1/2 fuel on a cool day. Add full tanks, survival kit and weekend camping gear on a hot day I'm easily up to the 1,000ft mark on takeoff and only climbing at 900ft/min.

You sure on those numbers?

The runway I use is grass for 450ft from where I enter, then turns to gravel. I can easily tell from the sound of the tires when it transition from grass to gravel. Solo with 1/2 fuel I can consistenly be off the ground before I hit the gravel if the temp is below 60F. Granted I then spend 300 ft or more in ground effect getting up to Vx before climbing. My VSI only goes up to 2,000ft/min and I peg it climbing at Vy under the above conditions. At gross weight on an 80 degree day, climb is down to 800ft/min. I have the VSI checked with my encoder every 2 years, and it matches my calculated rate for a 3 degree approch on the PAPI. My plane is a 1963 150C (straight back version) and only weighs 1025lbs with 6 quarts oil and 3.5 gal unusable fuel (dry weight is 992lbs) . So with me at 215lbs and 10 gals fuel at 60lbs my take-off weight is only 1300lbs. It has the same wings and engine as the later, heavier 150's so performs better.

So, yeah, I'm pretty sure of those numbers.

Phil

Oh, and I have a 52" pitch Sensenich Cruise prop to boot!

Phil

Don't mean to pick a fight or imply anything, but if I had a 150 that would actually climb at 2,000 fpm for more than about three seconds at a whack, I'd be trying to market it to NASA or the military .

not many small airplanes, including the Super Cub, even kept light, climb at 2,000 feet per minute.

Might want to clean the bugs out of the VSI line .

MTV

You know he could weigh about 47 lbs. Seriously something's flaky. I don't think my Maule will climb at that FPM under any condition and that's with a 540 pulling on it. Try doing a timed climb for two thousand feet, it has to take more than 1 min.

Come on guys My old Texas Taildragger did that all the time.

Course it was only for the first 8-9 seconds then it settled on about 600fpm. With the 0320
I am a lightweight at 215lbs. I remember before the conversion many days when just getting a positive rate of climb was considered a blessing from above when taking off from 4000ft ele.

Hmmm...well my POH lists climb rate at 2500ft at gross weight as 760 fpm, so the 800 I'm showing at 1000ft at gross seems about right. Maybe my VSI is progressively further off the further I get from zero? Looks like a nice evening out there, if I get time I'll grab a stop watch and time a few climbs from 1000 to 2000ft at Vy.

Phil

mr scout wrote:Come on guys My old Texas Taildragger did that all the time.

Course it was only for the first 8-9 seconds then it settled on about 600fpm. With the 0320
I am a lightweight at 215lbs. I remember before the conversion many days when just getting a positive rate of climb was considered a blessing from above when taking off from 4000ft ele.

Just for my own curiosity, do you remember what the empty weight was before the conversion? And which year/model 150 it was?
Thanks

Phil

Phil

I seem to remember it was 1120lbs been quite awhile ago it was a 1969

If I recall correctly a 2000fpm climb is well beyond what Aviat claims for the Husky with 1/2 fuel and one pax...

900 fpm on a hot day with full fuel, plus camping gear, plus survival gear, with a cruise prop? Why the hell have I waisted all this time looking at Maule's, 180's and big engine 170's???