?Hi Michael,?Thanks for helping.?The flaps were set by the former owner - Guy at Speedwing.? When in the up position, they are almost exactly even with the ailerons.? They are about 1/2 cm higher than the ailerons, which I set with the stick per your instructions. We align the flaps level with the underside of the wing - using planks of wood or similar to do the job.?I flew the plane by myself this afternoon.? It was a perfect day for flying.? The plane flies great with only me in it and 10 gal of fuel.? I was able to cruise from 50 to 65 mph (43? to 56 knots) It should be going faster, is the ASI accurate ??, can you check it with a GPS ?, depending on my power setting.? I could hold level flight down to about 5000 RPM (50 mph or 43 knots) 5000 rpm on the Rotax will do just over 50 on ours.? There was no adverse yaw.? It seems my problem was mainly with two heavy people in it.? Of course, I want to fly with two people at times.?I hope you are wrong about the Hirth having 5 HP less than book.? Since I get book RPM, I was assuming I was getting full HP, Is your tacho accurate ???? it may say your getting full rpm but it may be much less - therefore much less horsepower.... can you get a lend of a digital tacho for comparison. There is something major wrong and i dont know what ?? we just have to eliminate the obvious first but Matt from Recreational Power (distributor for Hirth) says the engine will pick up a few HP as it breaks in.? Perhaps that is some of the problem.?For your 582 engines:

• Do you load it up to full gross weight? We fly ours at 490kgs in Australia
• How does it perform with two heavy people? Very well - 582 900 feet/min at 450kgs
• What prop do you use? Make, size, pitch? Brolga three blade 68" diameter 17 degrees
• What gear reduction do you use? Rotax e box 3:1 ratio
• What is your cruise, stall, and climb speeds at full gross?? Cruise 55 to 65, stall 25ish depends on heat etc.. climb ? they like to climb out hands free at 50 knots but you can pull them back to 35 but i like to let them fly
• What is the 582's power settings at cruise and climb? We gear climb full power 6500 rpm cruise 5200 to 5400 for 55 to 60 knots - all day long

Thanks for your help.?Bill MagriniXair - Virginia/Maryland?-----Original Message-----
From: Michael Coates <xair@...>
To: Magrini, William J <william.magrini@...>; X-Air_Ultralight_Aircraft@... <X-Air_Ultralight_Aircraft@...>; Bertrand Cheval <randkar-ulm@...>
Date: Saturday, June 24, 2000 12:26 AM
Subject: [X-Air_Ultralight_Aircraft] X-AIR CENTRAL Re: Questions about the Xair F
?>I really don't know ??,? there are too many variables here for me to work out.
>We don't have any fitted with Hirth engines so i don't know about the engine,
>the speeds are in MPH and we work in knots (even though Australia is Metric) and
>i have never used or seen a powerfin propeller.? I am going to try and convert
>all your figures and see what i get.
>
>I am also going to post this on the eGroup bulletin board for other owners
>worldwide to have a look at as there may also be another owner out there with
>the Hirth. Finally i have forwarded this to the factory in France, as they have
>more exposure to different configurations.
>
>A big question before we chase ourselves in circles is, how did you set up the
>flaps and ailerons, i have found the wrong flap setting in the "F" will upset it
>considerably !!, it needs to be set up properly to fly at it's best. The other
>thing i have heard about the Hirth's (and don't quote me it is third hand) is
>that the HP figures quoted are not close to the true achievable performance....
>take 5 HP of it ?? i would like to know the answer to that one also
>
>Thanks Michael
>
>"Magrini, William J" wrote:
>
>> Michael,
>> I am running a Hirth 2706 on an Xair-F
>> I have a Powerfin F prop with a 3.16 reduction.? My 68" 3 blade prop is set
>> at 14.5 degrees pitch to give me 6000 RPM at climb and about 6200 max RPM.
>> The plane weighs 256 kilos with 7 gal of fuel and full gross or 450 kilos,
>> with one 210 lb. pilot and a 215 lb. passenger.
>> I calculated the CG as follows:
>> Nose = 13.634 kilos
>> Right = 125 kilos
>> Left = 117.3? kilos
>> 13.334 x 146 = 1991/255.9 = 7.77 cm. Forward of datum.? So my nose is light
>> due to the light engine, but for some reason, my overall weight does not
>> seem light.?? Is that acceptable?
>> My 13 lb. 18 amp battery is behind the seat as far forward as possible. I
>> guess I could get a lighter battery or mount it behind the engine.
>> My speeds are alot higher than Xair specs show.? The plane climbs at about
>> 500 fpm, at about 50 to 55 mph which, I guess is okay for a hot day, and a
>> heavy load.? Cruise is about 60 to 65 mph indicated at 5800 to 6000 RPM.
>> The plane stalls much higher than the 30 mph indicated in the factory specs:
>> about 46-48, no flaps.? The trouble I'm having is that:
>> 1. The flight numbers are higher than indicated by the manufacturer.
>> 2. When I throttle back to 5500, I quickly drop speed to around 55 or so and
>> I loose altitude.? I need about 5800 RPM to maintain level flight, and about
>> 6000 RPM for a slight climb.
>> 3. The engine overheats if I maintain 5800 RPM or better. I mean really hot.
>> 550+ CHT
>> EGTs are O.K. at about 1100.? I have an air dam on the front cylinder (as
>> recommended by Hirth because the plane is in a tractor congiguration) and
>> both cylinders read the same.
>> I talked to Stuart at Powerfin and he says I need more pitch to the prop, in
>> order to be able to have more thrust at lower RPMs.? He says myt static
>> thrust is good, but cruise thrust is probably inadequate to overcome the
>> plane's drag at cruise speed - especially when the plane is fully loaded.
>> He says I'll have to cut the prop from 68" to 66" to allow for more pitch
>> and allow the engine to develop full power. The Hirth 2706 is rated at 65 hp
>> at 6200 RPM.? Maximum torque is at 5700 RPM.? So the engine runs at a lower
>> RPM than the Rotax 582.? I asked Stuart if he thought I needed a lower ratio
>> gear box (like 2.59) and he said he didn't think that would help.
>> Questions:
>>???????? How does this compare with your 2 seat performance on the Xair at
>> gross weight using a Rotax 582 engine?? I know you like the 618, but how
>> does the 582 perform at Gross?
>>???????? Do you think the prop is running too slow because of the 3.16 gear
>> ratio? What ratio do you run with the 582. What prop pitch.
>>???????? What are your recommendations?? (I can't afford a 618 right now.)
>
>
>------------------------------------------------------------------------
>CLICK HERE AND START SAVING ON LONG DISTANCE BILLS TODAY!
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?
?

-----Original Message-----
From: Michael Coates <xair@...>
To: X-Air_Ultralight_Aircraft@... <X-Air_Ultralight_Aircraft@...>
Date: Saturday, June 24, 2000 8:17 AM
Subject: Re: [X-Air_Ultralight_Aircraft] X-AIR CENTRAL Re: Questions about the Xair F

?

Bill Magrini wrote:

?Hi Michael,?Thanks for helping.?The flaps were set by the former owner - Guy at Speedwing.? When in the up position, they are almost exactly even with the ailerons.? They are about 1/2 cm higher than the ailerons, which I set with the stick per your instructions. We align the flaps level with the underside of the wing - using planks of wood or similar to do the job.?I flew the plane by myself this afternoon.? It was a perfect day for flying.? The plane flies great with only me in it and 10 gal of fuel.? I was able to cruise from 50 to 65 mph (43? to 56 knots) It should be going faster, is the ASI accurate ??, can you check it with a GPS ?, depending on my power setting.? I could hold level flight down to about 5000 RPM (50 mph or 43 knots) 5000 rpm on the Rotax will do just over 50 on ours.? There was no adverse yaw.? It seems my problem was mainly with two heavy people in it.? Of course, I want to fly with two people at times.?I hope you are wrong about the Hirth having 5 HP less than book.? Since I get book RPM, I was assuming I was getting full HP, Is your tacho accurate ???? it may say your getting full rpm but it may be much less - therefore much less horsepower.... can you get a lend of a digital tacho for comparison. There is something major wrong and i dont know what ?? we just have to eliminate the obvious first but Matt from Recreational Power (distributor for Hirth) says the engine will pick up a few HP as it breaks in.? Perhaps that is some of the problem.?For your 582 engines:

• Do you load it up to full gross weight? We fly ours at 490kgs in Australia
• How does it perform with two heavy people? Very well - 582 900 feet/min at 450kgs
• What prop do you use? Make, size, pitch? Brolga three blade 68" diameter 17 degrees
• What gear reduction do you use? Rotax e box 3:1 ratio
• What is your cruise, stall, and climb speeds at full gross?? Cruise 55 to 65, stall 25ish depends on heat etc.. climb ? they like to climb out hands free at 50 knots but you can pull them back to 35 but i like to let them fly
• What is the 582's power settings at cruise and climb? We gear climb full power 6500 rpm cruise 5200 to 5400 for 55 to 60 knots - all day long

Thanks for your help.?Bill MagriniXair - Virginia/Maryland?-----Original Message-----
From: Michael Coates <xair@...>
To: Magrini, William J <william.magrini@...>; X-Air_Ultralight_Aircraft@... <X-Air_Ultralight_Aircraft@...>; Bertrand Cheval <randkar-ulm@...>
Date: Saturday, June 24, 2000 12:26 AM
Subject: [X-Air_Ultralight_Aircraft] X-AIR CENTRAL Re: Questions about the Xair F
?>I really don't know ??,? there are too many variables here for me to work out.
>We don't have any fitted with Hirth engines so i don't know about the engine,
>the speeds are in MPH and we work in knots (even though Australia is Metric) and
>i have never used or seen a powerfin propeller.? I am going to try and convert
>all your figures and see what i get.
>
>I am also going to post this on the eGroup bulletin board for other owners
>worldwide to have a look at as there may also be another owner out there with
>the Hirth. Finally i have forwarded this to the factory in France, as they have
>more exposure to different configurations.
>
>A big question before we chase ourselves in circles is, how did you set up the
>flaps and ailerons, i have found the wrong flap setting in the "F" will upset it
>considerably !!, it needs to be set up properly to fly at it's best. The other
>thing i have heard about the Hirth's (and don't quote me it is third hand) is
>that the HP figures quoted are not close to the true achievable performance....
>take 5 HP of it ?? i would like to know the answer to that one also
>
>Thanks Michael
>
>"Magrini, William J" wrote:
>
>> Michael,
>> I am running a Hirth 2706 on an Xair-F
>> I have a Powerfin F prop with a 3.16 reduction.? My 68" 3 blade prop is set
>> at 14.5 degrees pitch to give me 6000 RPM at climb and about 6200 max RPM.
>> The plane weighs 256 kilos with 7 gal of fuel and full gross or 450 kilos,
>> with one 210 lb. pilot and a 215 lb. passenger.
>> I calculated the CG as follows:
>> Nose = 13.634 kilos
>> Right = 125 kilos
>> Left = 117.3? kilos
>> 13.334 x 146 = 1991/255.9 = 7.77 cm. Forward of datum.? So my nose is light
>> due to the light engine, but for some reason, my overall weight does not
>> seem light.?? Is that acceptable?
>> My 13 lb. 18 amp battery is behind the seat as far forward as possible. I
>> guess I could get a lighter battery or mount it behind the engine.
>> My speeds are alot higher than Xair specs show.? The plane climbs at about
>> 500 fpm, at about 50 to 55 mph which, I guess is okay for a hot day, and a
>> heavy load.? Cruise is about 60 to 65 mph indicated at 5800 to 6000 RPM.
>> The plane stalls much higher than the 30 mph indicated in the factory specs:
>> about 46-48, no flaps.? The trouble I'm having is that:
>> 1. The flight numbers are higher than indicated by the manufacturer.
>> 2. When I throttle back to 5500, I quickly drop speed to around 55 or so and
>> I loose altitude.? I need about 5800 RPM to maintain level flight, and about
>> 6000 RPM for a slight climb.
>> 3. The engine overheats if I maintain 5800 RPM or better. I mean really hot.
>> 550+ CHT
>> EGTs are O.K. at about 1100.? I have an air dam on the front cylinder (as
>> recommended by Hirth because the plane is in a tractor congiguration) and
>> both cylinders read the same.
>> I talked to Stuart at Powerfin and he says I need more pitch to the prop, in
>> order to be able to have more thrust at lower RPMs.? He says myt static
>> thrust is good, but cruise thrust is probably inadequate to overcome the
>> plane's drag at cruise speed - especially when the plane is fully loaded.
>> He says I'll have to cut the prop from 68" to 66" to allow for more pitch
>> and allow the engine to develop full power. The Hirth 2706 is rated at 65 hp
>> at 6200 RPM.? Maximum torque is at 5700 RPM.? So the engine runs at a lower
>> RPM than the Rotax 582.? I asked Stuart if he thought I needed a lower ratio
>> gear box (like 2.59) and he said he didn't think that would help.
>> Questions:
>>???????? How does this compare with your 2 seat performance on the Xair at
>> gross weight using a Rotax 582 engine?? I know you like the 618, but how
>> does the 582 perform at Gross?
>>???????? Do you think the prop is running too slow because of the 3.16 gear
>> ratio? What ratio do you run with the 582. What prop pitch.
>>???????? What are your recommendations?? (I can't afford a 618 right now.)
>
>
>------------------------------------------------------------------------
>CLICK HERE AND START SAVING ON LONG DISTANCE BILLS TODAY!
>
>------------------------------------------------------------------------
>
>
>
>
>
>
?
?

?Thanks Michael,?Your stall is 25 knots?? That is pretty much book.? Mine is way higher.? I hope we can figure this out.? If it were my ASI, then the top speeds would be high too. right? Not really..... i have seen an ASI where someone blew into the end of it only read correct from about 35 to 50 knots over that it would go up to 90 knots and under 35 it would show about 15, so it can happen? If my revmeter (tach) was reading really low. then my engine wouldn't start getting hot at 5800 rpm.? But I should check them out. Your engine should run at max revs without overheating for a considerable period of time eg? our 503's air cooled will run for over 1 hour flat out 5600 rpm without any problems, just to try and keep up with the 618's / 582's.?I have a digital light tach that I tried.? It registered 1100 to 1700 RPM when I was showing 3000 on my engine tach.? I thought the digital tach was wrong. All i can suggest is eliminate the obvious first, replace / borrow a new tacho and check it out first because overreving the engine will cause it to destruct, once that's right check the ASI. Use a GPS and fly four legs, say a big square, go North for say 2 minutes and check your ASI against your ground speed then turn East and do the same, after completing the four legs average the ground speed and you have your average taking into consideration the wind direction by flying all four directions. Do this three times once at say 40 knots and them at 50 and again at 60 and it will tell you if its out an a particular range. Otherwise send it to an instrument tech and get him to check it.

Finally - where is your ASI pickup located this is also very important.

Thanks Michael

-----Original Message-----
From: <xair@...>
To:
X-Air_Ultralight_Aircraft@...<X-Air_Ultralight_Aircraft@...>
Date: Saturday, June 24, 2000 11:06 PM
Subject: Re: [X-Air_Ultralight_Aircraft] X-AIR CENTRAL Re: Questions
about the Xair F

Bill Magrini wrote: Thanks Michael, If it were my
ASI, then the top speeds would be high too. right? Not really..... i have
seen an ASI where someone blew into the end of it only read correct
from about 35 to 50 knots over that it would go up to 90 knots and
under 35 it would show about 15, so it can happen But
I should check them out. our 503's air cooled will run for over
1 hour flat out 5600 rpm without any problems, just to try and keep up
with the 618's / 582's. I thought the digital tach
was wrong. All i can suggest is eliminate the obvious first, replace /
borrow a new tacho and check it out first because overreving the
engine will cause it to destruct, once that's right check the ASI. Use
a GPS and fly four legs, say a big square, go North for say 2 minutes
and check your ASI against your ground speed then turn East and do the
same, after completing the four legs average the ground speed and you
have your average taking into consideration the wind direction by
flying all four directions. Do this three times once at say 40 knots
and them at 50 and again at 60 and it will tell you if its out an a
particular range. Otherwise send it to an instrument tech and get him
to check it. Finally - where is your ASI pickup
located this is also very important. It is not exactly
parallel with my flightpath. It is pointed up about 15 degrees.
Again, thanks loads for your help, Michael

-----Original Message-----
From: Peter Stuy <pstuy@...>
To: X-Air_Ultralight_Aircraft@... <X-Air_Ultralight_Aircraft@...>
Date: Tuesday, June 27, 2000 12:40 AM
Subject: Re: [X-Air_Ultralight_Aircraft] X-AIR CENTRAL Re: Questions about the Xair F

G'day Bill,

?

I have doors on my XAIR and find that the cabin pressure is definiteliy lower that outside pressure. This affects my ASI reading and altimeter readins, as I do not have a static line. Do you?

I did the same? Pitot tube tilted up. But that means that as you put thte nose down for higher speeds, the ASI will over read more, than with the nose up at low speeds. If not done yet, do fit a static pickup and dine to your instruments.

?

Cheers,

?

Peter Stuy

My experience with the Hirth 2706 corroborates yours:
if you assume that a 582 produces 65 true BHP, I would
rate the 2706 at 59-60 only.
Regards.
Joel

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