Optimum Cruise Chart - From Benchmark

[testwest]

Hi everyone:

For background, read this thread:

http://www.mooneyspace.com/index.cfm?mainaction=posts&forumid=1&threadid=3273

The Falco guys are way ahead of everyone on modeling their airplanes in Benchmark. One of the builders has produced the attached gem.

He does have a couple of "nits"..he has a notation for no "oversquare" ops for greater than 75% power, and throttles the engine between 75% and 65% instead of WOT. Below 65% he does show WOT, but "economy" operation (not LOP).

But the cool thing is this no-wind optimum cruise RPM range. He shows 8000', WOT, 65% power, 2200 rpm. Result is 168 KTAS on 8 gph. My guess is that he has a 180hp parallel valve engine.

This type of cruise chart, adjusted in real time for cruise winds, would be a really nifty app for us Mooney drivers. We do need to create the model for Benchmark. Any Mac guys out there?

[carusoam]

Norm,

 

We used to have an iPad app guy here.

 

I tried to search... I think it was pie log mike?

 

He wrote a simple app that I believe did some basic engine hour log.  I think it may have calculated %hp also.

 

Unfortunately, the search function does not seem operational tonight.

 

Best regards,

 

-a-

[Ned Gravel]

Norm:

Don't know if this helps, but I have the IO 360 app on my iPhone and I think the guy that wrote it owns Air Dave LLC.  The website address for his app is:  http://www.airdavellc.com/AirDave/IO360_Power_Settings.html.  He has gotta know Mac.

Hope this helps.

[testwest]

I have that one, it is quite good.

However, Benchmark goes far beyond in being able to model any engine, but right now there is not an LOP model in Benchmark....which really should be a breeze since the hp is a straight function of fuel flow (15.1 * FF = hp for 8.7:1 CR).

Workin' on that. In the meantime, are there any Mac guys willing to download Benchmark and start plugging their M20 POHs into the program for their particular airplane?

[Magnum]

Quote: testwest

Workin' on that. In the meantime, are there any Mac guys willing to download Benchmark and start plugging their M20 POHs into the program for their particular airplane?

[testwest]

Once you have developed either a prop or airframe model in Benchmark, we can share the files on the Benchmark site, here:

http://www.seqair.com/benchmark/index.html#benchmark

Just e-mail the files to Alfred Scott at Sequoia and he'll post them on the site. You will find several models already posted.

What propeller do you have? My top priority right now is to get a blade activity factor number for a McCauley B2C34D212 and D214 prop. Hopefully someone will volunteer to email McCauley and get that. I have a Hartzell BA that will have a different BAF.

Failing that, it is possible to measure a prop and compute BAF with a simple spreadsheet. The procedure and downloadable spreadsheet is here:

http://www.avweb.com/news/airman/182418-1.html

Thanks for your interest, Magnum!

[Magnum]

Quote: testwest

Once you have developed either a prop or airframe model in Benchmark, we can share the files on the Benchmark site, here:

http://www.seqair.com/benchmark/index.html#benchmark

Just e-mail the files to Alfred Scott at Sequoia and he'll post them on the site. You will find several models already posted.

What propeller do you have? My top priority right now is to get a blade activity factor number for a McCauley B2C34D212 and D214 prop. Hopefully someone will volunteer to email McCauley and get that. I have a Hartzell BA that will have a different BAF.

Failing that, it is possible to measure a prop and compute BAF with a simple spreadsheet. The procedure and downloadable spreadsheet is here:

http://www.avweb.com/news/airman/182418-1.html

Thanks for your interest, Magnum!

[Magnum]

Testwest,

have you checked your POH against the IO-360 data in Benchmark? IMHO some power settings in my Mooney POH are around 5% too high. I have the Lycoming Operators Manual which is the source of the Benchmark data and there is no mistake in there.

Esp. with 2400 and 2500 RPM between 55 and 75% power the MAP settings Mooney suggests result in 5% higher power settings. It is ok (< 2-3% difference) for 2600 and 2700 RPM.

[testwest]

I'll definitely check on that, thanks Magnum. BTW, I do have the memory stick with all the J tech data from Mooney, which means I have the entire range of POHs.

[Awful_Charlie]

I'd be very interested in this too.  I have the TIO540 engine manual, and am happy to add flight test results (Longbody), but Magnum - if you could pick up the prop data for a McCauley B3D32C417/82NRD-7 whilst you are at MT that would be another task saved

Ben

[testwest]

Congrats to Magnus for producing the first Benchmork model for the Mooney, it is an IO-360 engine model that reflects the POH power settings. Well done!

[Magnum]

Quote: testwest

Congrats to Magnus for producing the first Benchmork model for the Mooney, it is an IO-360 engine model that reflects the POH power settings. Well done!

[Magnum]

I just came back from MT and have bad news. They don't have the data and doubt that McCauley will release them. But we can try. I asked them for the data of the MT props and they said that they have to check with the management first and are not sure if they want to release them either.

[testwest]

Ok, that should not be an issue as we can make measurements on an actual prop blade and compute the BAF using the spreadsheet I referred to earlier in this thread. Thanks for making the effort, Magnus!

KSMooniac has an MTV-12 on his J, Scott would you be willing to help? Magnus has a C214, I am going to write Hartzell for the BA prop info (or take measurements), we need someone to step up that has the older square-tip McCauley and also someone who has a 3-blade Hartzell. Any volunteers? No flying needed, just some precise measurements on your prop and the ability to put those measurements into a pre-done spreadsheet.

As a reminder, the procedure and downloadable spreadsheet are here:

http://www.avweb.com/news/airman/182418-1.html

Thanks, everyone!

[jezzie]

[Hank]

Norm--

I don't know my prop model number [any of the 12-18 character code], but I do have a 3-blade Hartzell and an assortment of calipers and mics that I know how to use. Below is a photo of the prop. Does is matter that it's on a C? I would think there would be little difference in prop, just in aircraft performance.

Send me a spreadsheet and I'll be happy to fill it in for you. Just recently finished my own MS Engineering, but thankfully in a non-thesis program. I just manufacture medical devices, not aircraft.

[testwest]

OK, here is where we are so far:

Magnus: Produced the IO-360-A, C, D series angle valve Lyc engine model, it is already on the Benchmark site, here:

http://www.seqair.com/benchmark/index.html#benchmark

Prop activity factor volunteers:

Eldon (jezzie) - McCauley B2C34D212 (original J prop, square tips)

Magnus - McCauley B2C34D214 (follow-on McCauley prop with rounded tips)

Hank - Hartzell three blade Top Prop STC (non-scimitar) HC-C3YR-1RF/F7282 (this is for C-J models, the STC is different due to the different spinner)

testwest (me) - Hartzell two blade Top Prop STC (scimitar) HC-C2YR-1BFP/F7497 (this covers A-G and J models)

J Props for which we still need a blade activity factor (BAF):

MT Propeller MTV-12 (KSMooniac?)

Hartzell 2 blade non scimitar Q-tip HC-C2YK-1BF/F7666A-3Q (anyone have one of these?)

Other props for other models? Awful_Charlie, are you in?

As a reminder, the procedure for measuring your prop and a downloadable spreadsheet that computes the BAF are located here:

http://www.avweb.com/news/airman/182418-1.html

After you enter the prop radius (not diameter), number of blades and clear the station widths, hit F9 to recaculate the station distances, then print the sheet for measuring.

Hank, check your e-mail for the files.

Also, if you are doing the measuring with the masking tape and marks per the above, get some pictures of you doing the measuring! I have an idea for an article for MAPA or AOPA, tentatively called "Flight Test in the iCloud".

Thanks again everyone.

[Awful_Charlie]

Yep - I'm in for a 3 blade McCauley B3D32C417/82NRD-7 (Bravo, maybe early Ovs too?)  Possibly this weekend if nothing gets in the way!

Ben

[testwest]

Right on, my friend. Let me know if you have any trouble with the spreadsheet.

[testwest]

Lopresti Aviation is picking up on the Benchmark activity, we are starting a "thing"...here is a letter from him to Alfred Scott, the author of Benchmark:

Alfred

I helped develop the installed power chart for the original 201 in 75 or 76. The data we used to develop the chart was based on in flight torque meter data which we felt was very good. I haven't seen the folder with that data for many years. After Roy pas[sed] we cataloged a lot [of] the data he had collected in 50 years or so. There are boxes and boxes of the stuff. I keep telling my self that when things slow down I will go through it, but as you have probably guessed things never slow down.

I am in the middle of a IO-360 project now. We are developing a new cowling for the Cessna 177RG. I am also installing a DeltHawk diesel in a Cirrus SR20. I would like to use BenchMark for the flight test programs on both of these jobs. How do I get a current copy?

Thanks
Curt

Curt LoPresti
President, LoPresti Aviation

Now what would really be cool would be to input the original, raw drag polar flight test data from 1975 into Benchmark!

[Hank]

Norm--

All you want is gross blade width at the referenced stations? No thickness or anything? Just measure the blade width perpendicular to the center line at the calculated distances from the tip? This all sounds far too simple . . . but hey, YOU are the Flight Test Engineer, I'm just the guy holding the calipers!     But then again, the hard part comes with what you are going to do with the numbers.

I wish you the best. I'll try to get everything back to you in a few days.

[testwest]

Yep, that's it, just the blade width. The thickness only matters at the tip, and then only if the tip is transonic. The back side of the older props is flat, so there are not any significant airfoil differences among the certificated props....except for the scimitars. I think the calculation of the BAF is more complex for the newer blended-airfoil (BA, or "scimitar") props than for the traditional designs.

I have written Mike Trudeau at Hartzell for info on the BA series. Will let you know.

[KSMooniac]

Late to reply, but I'm definitely on-board!  I got the spreadsheet via email, and will try to do some measuring this weekend for my MT prop as well my old McCauley that is still in the hangar.

[Magnum]

I measured my prop today. The Excelsheet calculated a BAF of 114.9. But something is not right, the figures Benchmark calculates are far away from the POH values. I'll have to dig deeper and hopefully I'll find the error. IMHO the data from the Drag Polar Flight Test is not accurate enough.

Has someone else measured the prop yet? It would be nice to have more data for comparison.

[testwest]

I haven't heard from Mike at Hartzell regarding the BA props.

KSMooniac had a McCauley in his hangar, think it is the same one as you. Hopefully he can measure his blades and come up with the smae number. The spreadsheet uses a standard numerical integration technique for the computation, but there are a few non-obvious items that need to be done to get the numbers, such as hitting F9 after entering the prop diameter to compute the correct stations for that diameter.

Did you look at the 2-blade Hartzell with the 7666 blades already modeled on the benchmark site? The BAF for that should be similar.

BTW, thanks for the effort!