Johnson Creek Fly In Videos, Photos, Reports Etc.

[ComputerAndPhotoGuy]

There are advantages to certified planes.
There are advantages to experimental planes.
For what we want to do, certified is better.
Knowledge is what we get paid to do.
If we were to go experimental, probably would go BearHawk which seems to be an experimental Maule.
Years ago I looked at Aerocomp or is it called compair. It is too heavy for our needs and there are some other issues. However, it might be ideal for some people.
This reminds me of another experimental I looked at. It was a neat flying boat called, I believe, a Teal. Getting the newsletters, real life Teals with full fuel had enough payload left for half a pilot. Also some pilots reported that parts of the tail fell off on landing. This did not seem like a very good “advanced feature”.
On the M9, Maule plans on having the 235, 260 and diesel certified and released at the same time. Only spring gear. Only standard wheels. Not even 8.50. However, AK BushWheels will have big tires.
They also plan on having a retrofit kit to change a M7 to M9. Do not understand how this could work at reasonable cost since the plane is beefed up in several areas.
I would think that one could hold it with brakes while the engine spooled up. However, need to see it in real life.
Cost is a factor. For ease of calculating, assume $50,000 difference. Say the value of money is 10 %. That is $5,000 a year. One can buy much fuel for $5,000. Have to see the advantages and the costs.
I think the future of AV gas is shorter than we realize. Not for sure how this will play out.
I will not comment on the FAA.

[maules.com]

Yes, aviation and all of life is a compromise.
I assume optimum conditions is around 6,000 to 8,000 feet. Is this correct?
Big tires probably knock off 5 to 8 mph.
VG and antenna probably another 3 mph.
So we are probably talking about 150 tas for the 235 and 160 for the 260 in normal conditions. Is this correct?
I assume this is max power. What was the fuel burn? There would seem to be other factors influencing the .44.
As one goes up, do the 235 and 260 lose power at the same rate?
At high mountain strips with a density altitude of 8,000 to 10,000 ft, what have you found to be the difference in take off distance between the 235 and 260?
For an educated guess, how do you think the 230 diesel would perform under these conditions (assuming the 230 happens)?
Thanks in advance for the info.

Optimum conditions vary according to the desired performance, ie, best loiter speed 45% hp and above, best range of 55% hp, power cruise of 65%, 75%, or 85%.
For the IO540 235 or 260hp use the .44lbs/hp/hr fuel figure and provided you have a sealevel temp of 59F and standard lapse rate with altitude, then hp loss is 3% for each 1000ft of Pressure altitude, of 160, 180, 235, 260 or whatever you have (thus loss is not the same), OR 3.5% loss for each 1000ft of Density altitude.
The SMA 305 diesel is planned to be 230hp for takeoff at sealevel diminishing to 200hp at 5000msl, however you have no control over the prop rpm. The 235 LYC loses power to 5000msl at the same rate but you can gain thrust by controlling prop pitch which you cannot do on the SMA, and the 260 of course does not drop to 200hp until about 7500ft.
The 230hp SMA is turbocharged and can therefore hold the 200hp to 10,000ft when it drops off at the same rate as before. Certification at this point does not allow it to be used as high as the Lycomings. I'm told the diesel fuel burn is .34 lbs/hp/hr.
Drag increases at a rate of the speed increase squared and so I have found that at a 68% cruise power the 8.50 will slow the 235hp by 5mph and the 31" by 15mph similar to a set of straight floats, BUT if you fly at a slower speed the drag reduction speed reduces dramatically which is why a 95mph cub on 31"normal does not experience a 15mph loss.
The drag factors of tyres, VGs, antennas etc do not all add up to a total loss as the square of speed is not applied in linear fashion.
With these numbers fuel burns and drag can be worked out for any horsepower at any altitude.
It appears the SMA with all it's ancilliarys may weigh 100lbs more than the Lyc.
Rule of thumb is that for every 10% increase in gross weight, increase ground roll by 20% and 10% landing roll.
Another rule of thumb might be, To maintain same hp effectiveness, reduce gross weight by 2.85% for each 1000ft Density altitude increase for constant speed and 3% for fixed pitch.
Primarily, each pilot should check his/her capabilities in the plane being used prior to going the max.

[ComputerAndPhotoGuy]

Thanks for the info.

I will study it.