okay fellas.. keep it in your pants for a few here...
Whats everyone who's riding behind a good ol R985 running at in cruise?
MP and RPM?
Hot Beaver?
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Driving Rain
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Vortex_driver
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I forgot to mention that our Beavers are Viking 5600 lbs. upgross machines, that and they're on amphib Whips. 28-18 works fine for <5100 lbs. We flew an Advance Wing Tech Beaver last year with a GTOW of 6000 lbs and that was a 30-20 cruise airplane.
No wonder I don't like to fly the Beaver: they're a joy when there not 1000 lb.s over design weight.
No wonder I don't like to fly the Beaver: they're a joy when there not 1000 lb.s over design weight.
Our three company Beavers are full mk2000 Baron machines with Viking 5600lb high gross weight mods and the Sealand cabin extension on Wippy amphibs.
The wiplines are alright on the piston Beaver. They are a fast float compared to Edos and they have nice big tennis court decks on them. Their biggest drawback is the short struts: the props eat a lot of water no matter how careful you are. We run them off gravel quite a bit and they're holding up to that as well. I guess some people will argue that Edo amphibs are better at this or that but to me it's more the pilot flying them that matters. I ran them out of some 4000' lakes last year with four hunters and gear without any problems.
One of the best mods you can do to the Beaver is the Alaska door: http://www.sealandaviation.com/sealand-alaskadoors.htm
Our engines on the beavers go to 1600 hours (that's the highest tbo you can get and still haul pax) no problem. We get so many overhauls our engine shop gives us a 985 spare just in case we need to change one. We have 13 985s in the fleet flying 500+ hours/year plus whatever we end up leasing for the summer.
The wiplines are alright on the piston Beaver. They are a fast float compared to Edos and they have nice big tennis court decks on them. Their biggest drawback is the short struts: the props eat a lot of water no matter how careful you are. We run them off gravel quite a bit and they're holding up to that as well. I guess some people will argue that Edo amphibs are better at this or that but to me it's more the pilot flying them that matters. I ran them out of some 4000' lakes last year with four hunters and gear without any problems.
One of the best mods you can do to the Beaver is the Alaska door: http://www.sealandaviation.com/sealand-alaskadoors.htm
Our engines on the beavers go to 1600 hours (that's the highest tbo you can get and still haul pax) no problem. We get so many overhauls our engine shop gives us a 985 spare just in case we need to change one. We have 13 985s in the fleet flying 500+ hours/year plus whatever we end up leasing for the summer.
Gorgeous looking beast! Are my eyes deceiving me or does it have both the finlets on the horizontal stab and a skeg?
Are they running the 2 blade or 3 blade props? Looks like she sits fairly low on those floats too.
You folk up island also drive the geese around right? How many? Also a beauty of a machine IMHO.
Drove around today at 28-18... sure is quieter!
Are they running the 2 blade or 3 blade props? Looks like she sits fairly low on those floats too.
You folk up island also drive the geese around right? How many? Also a beauty of a machine IMHO.
Drove around today at 28-18... sure is quieter!
The planes do have both the finlets (Viking) and the ventral fin (wipaire). They all have two blade props as the three bladers don't make enough static thrust to work at the gross weights we're running.
We have four Gooses (that's what their called don't ask me why) online and one coming out of overhaul for July. It's my favorite airplane and I've got close to fifty types in my logbook.
We have four Gooses (that's what their called don't ask me why) online and one coming out of overhaul for July. It's my favorite airplane and I've got close to fifty types in my logbook.
I would like to know if anyone flies by the POH. Here's the numbers for 2000 feet.
HP RPM MP
240 1650 29
260 1750 29.2
280 1900 28.7
300 2000 29.2
The way I look at it if you would balance the jump from 260-280-300 that would put 280 at 1875 and would probably give you the same 29.2 MP as the others. Does anyone know, where did 1800 28 come from? Nothing close to that in the POH. I use 1750 29.2 empty and 1875 29.2 loaded. The POH states that higher boost lower RPM gives better fuel efficiency.
HP RPM MP
240 1650 29
260 1750 29.2
280 1900 28.7
300 2000 29.2
The way I look at it if you would balance the jump from 260-280-300 that would put 280 at 1875 and would probably give you the same 29.2 MP as the others. Does anyone know, where did 1800 28 come from? Nothing close to that in the POH. I use 1750 29.2 empty and 1875 29.2 loaded. The POH states that higher boost lower RPM gives better fuel efficiency.
Philly, why would you worry about my tach accuracy at 1875 more than yours at 1800? But you miss my point. I will attempt to unpack the numbers from the Beaver Manual. You will notice the common thread in the list is 29 inches Manifold Pressure regardless of the RPM's. According to that you keep MP at 29 and select the RPM that suits your requirements. Now, I was also trained at the age old conventional wisdom setting of 28 18 but when the POH differs from conventional wisdom I go with the manufacturer until I can be convinced that there is a good reason to go with conventional wisdom.
Page 43 of the Manual states that maximum engine efficiency and prop efficiency are oftained by: Max permitted MP and reducing RPM to the lowest possible to maintain desired cruise speed. This reduces engine losses and gives maximum fuel economy. What more could you want?
Page 43 of the Manual states that maximum engine efficiency and prop efficiency are oftained by: Max permitted MP and reducing RPM to the lowest possible to maintain desired cruise speed. This reduces engine losses and gives maximum fuel economy. What more could you want?
Abuelito.. I was more curious as to what people were running around at power setting wise not what the books say as I'm sure we all have the manuals or have easy access to them. I also don't think you're going to have any luck trying to peg 1870 rpm and 29.2MP even with recently calibrated instruments! Looking at the gauges in the two machines here you'd be lucky to get within 30 or 40rpm! or .5MP
The buckey eighty has a plate that says "RPM only accurate within 40rpm"
Take care!
Rowds
The buckey eighty has a plate that says "RPM only accurate within 40rpm"
Take care!
Rowds
I flew a really fast beaver once; the MP gauge said 26" when the enginge was shut down at sea level and it used full throttle at takeoff... true story. 
The reason for the decimal power setting was to achieve the even HP numbers for the power charts and thus give flight planning numbers for fuel burn etc.
But before everyone bashes Abuelito too bad, he's right. We should all be carefull not to run airplanes one way just because someone told us too. There is a lot of wisdom out there but it's mixed with plenty of BS.
A little history about the R-985: most current day operators have a vastly increased TBO over the original (I think it was like 900 hrs). On top of that the engines are working harder that was intended for the TBO increase (when was the last time you cruised at 26-1600 for three hours straight?). There are times I'm doing eight to ten full power cycles in an hour at work and I'm sure many float / spray operators aren't much different.
The 985 was (and still is) built to run on 80/87 fuel and in theory should be capable of higher than book manifold pressures without worry of detonation. However, a known weak spot on the engine are the cylinder hold down studs; these are most often found pulled after someone over-boosts the engine (and a good thing to check during a DI). Break Mean Effective Pressure (BMEP) is the pressure inside the cylider during the power stroke. Though you might think the highest BMEPs occur at static TO power, higher values can happen at hard over-square cruise settings; or more commonly when someone ham-fists the power and the prop gov surges to keep up, or when someone is too quick on the prop lever coming back. It's good to remeber the that prop weighs over 200 lbs and has inertia to spare: imagine the forces acting through the end of your crankshaft when it's turning 2300 rpm!
If you where worried about nothing else but effieciency you would open the throttle, pull the prop lever back to min and lean the thing out untill it hardly ran. Your specific fuel burn would be great, but you engine wouldn't last very long (Read more about the Doolittle raiders).
Probably the most common cause of inefficient engine operation these days is poor leaning technique (most 985 had automatic mixture control carbutators replaced with manual types due to lower maintenance of the later). After several thousand hours behind some very well instumented R-985s I can say that many of the common practices have no basis in fact, and that different power settings have small changes in fuel burn while choosing an appropriate altitude and properly leaning the engine will result in the best increase in efficiency.
http://www.lycoming.textron.com/support ... SP700A.pdf
Put that in your pipe...
The reason for the decimal power setting was to achieve the even HP numbers for the power charts and thus give flight planning numbers for fuel burn etc.
But before everyone bashes Abuelito too bad, he's right. We should all be carefull not to run airplanes one way just because someone told us too. There is a lot of wisdom out there but it's mixed with plenty of BS.
A little history about the R-985: most current day operators have a vastly increased TBO over the original (I think it was like 900 hrs). On top of that the engines are working harder that was intended for the TBO increase (when was the last time you cruised at 26-1600 for three hours straight?). There are times I'm doing eight to ten full power cycles in an hour at work and I'm sure many float / spray operators aren't much different.
The 985 was (and still is) built to run on 80/87 fuel and in theory should be capable of higher than book manifold pressures without worry of detonation. However, a known weak spot on the engine are the cylinder hold down studs; these are most often found pulled after someone over-boosts the engine (and a good thing to check during a DI). Break Mean Effective Pressure (BMEP) is the pressure inside the cylider during the power stroke. Though you might think the highest BMEPs occur at static TO power, higher values can happen at hard over-square cruise settings; or more commonly when someone ham-fists the power and the prop gov surges to keep up, or when someone is too quick on the prop lever coming back. It's good to remeber the that prop weighs over 200 lbs and has inertia to spare: imagine the forces acting through the end of your crankshaft when it's turning 2300 rpm!
If you where worried about nothing else but effieciency you would open the throttle, pull the prop lever back to min and lean the thing out untill it hardly ran. Your specific fuel burn would be great, but you engine wouldn't last very long (Read more about the Doolittle raiders).
Probably the most common cause of inefficient engine operation these days is poor leaning technique (most 985 had automatic mixture control carbutators replaced with manual types due to lower maintenance of the later). After several thousand hours behind some very well instumented R-985s I can say that many of the common practices have no basis in fact, and that different power settings have small changes in fuel burn while choosing an appropriate altitude and properly leaning the engine will result in the best increase in efficiency.
http://www.lycoming.textron.com/support ... SP700A.pdf
Put that in your pipe...
Sorry, forgot to answer in my last post. Probably not enough caffine. Anyway, yes it is capable of operating in very rough water though we try to avoid it as the newest one we have is 62 years old. Picture waves breaking across the front window...Rowdy wrote:Ahhh Okay! Gotcha gooses it is!
Very cool and rugged looking machine. Heard they're quite capable in all kinds of water/seas?
where do they do the majority of work?
I'm full of questions!
