David, Tim and group.
Sorry for the slow response. Anita and I are recovering from our flu/covid
/omicron/delta =93breakthrough=94 cases. So, just a case of the flu for us
and simple over the counter medication keeps the symptoms in check. Not w
orth standing in line with the masses of travelers, government contract wor
kers and New Yorkers down here worried about their job or getting the Covid
from us Floridians. (Anita and I believe we had Covid at New Years 2020 l
ike many did in our area (there was no testing for antibodies available the
n), but we got the Covid shots =93vaccine=94 and we still got the flu/omicr
on of course.) Neither of us is normally affected much by the flu variatio
ns over the years other than just feeling under the weather for a few days,
so we are lucky.
For a Mono and conventional gear aircraft, ground clearance is 9 and a trig
ear is 7 inch clearance at full impact clearance. Duh. I should have been
more exact. The actual certified standard for aircraft is uniform across
the world at these values. Of course, regulations change so check in your
country. Here are the US/International certified basic requirement guideli
nes.
Sec. 23.925 =97 Propeller clearance.
(a) Ground clearance. There must be a clearance of at least seven inches (f
or each airplane with nose wheel landing gear) or nine inches (for each air
plane with tail wheel landing gear) between each propeller and the ground w
ith the landing gear statically deflected and in the level, normal takeoff,
or taxing attitude, whichever is most critical. In addition, for each airp
lane with conventional landing gear struts using fluid or mechanical means
for absorbing landing shocks, there must be positive clearance between the
propeller and the ground in the level takeoff attitude with the critical ti
re completely deflated and the corresponding landing gear strut bottomed. P
ositive clearance for airplanes using leaf spring struts is shown with a de
flection corresponding to 1.5 g.
The Woodcomp guys just used the original certified testing standard which A
irmaster met to assure they were in compliance with the LAA.
To be honest, I only got involved with the prop ground clearance when Bob B
erube made his conventional conversion years ago. The gear height was base
d on the 64 inch propeller with a minimum of 9 inches.
Story Time.
The gear length was set by Grove aircraft for the single beam gear and plac
ed to give 9 inches. Since it was a non articulated fixed beam gear leg, G
rove was sure to meet the criteria required by the FAA.
If I recall correctly, the plane was loaded IAW the FAA manual to full gros
s weight and a three foot drop test was made to determine gear flexing, str
ucture, and alignment. The Grove gear slid sideways a little off the cente
rline of the mounts and pins were fitted as standard to prevent recurrence.
Bending of the gear at the belly of the aircraft was only enough to just
touch the belly skin at the center. That was scary but I had seen it before
.
In college we went to MacDonald Douglas Aircraft and helped drop test the F
-4E with the USAF gear upgrades (different tires and wheels, some changes t
o the struts) I was a dumb freshman data taker. The plane was dropped 7
feet (USAF Test) on to a treadmill doing 150 mph. That was exciting, scary
and very noisy. That test was repeated many times over the week for fatig
ue testing. Mr. Mac was instant that the plane exceeded the testing design
requirements. Later the factory just spun the wheels up to speed for the
drop tests on the F-15 and 18 aircraft. Still a heck of a test. Navy requir
ements differ from Air Force for obvious reasons.
Have a Happy New Year
Bud and Anita Yerly
From: owner-europa-list-server@matronics.com <owner-europa-list-server@matr
onics.com> On Behalf Of davidjoyce@doctors.org.uk
Sent: Wednesday, December 29, 2021 10:03 PM
Subject: Re: Europa-List: Re: Propeller Sizing
Bud, Possibly the earlier versions of the SR3000 were 1600mm but my more re
cent SR3000 N W comes with its certificate stating 1625mm, or 64 ins as cor
rected by Paul. Regards, David
On 2021-12-29 22:42, Bud Yerly wrote:
David,
The Woodcomp has a larger twist hence it varies in exact length at the prop
s are made from 1600 (63") to 1738mm (68"). Woodcomp uses a 1600mm blade
for the Europa on their SR3000. On the Airmaster, the actual blade length
will vary from the 64 inch maximum based on the production mold used down s
lightly after production. For instance, at Woodcomp they don't cut a 1700
mm prop down to 1600. That is a different mold so measuring the prop provi
ded will not always be exact. 64 inches maximum meets the criteria for the
UK and US with the black rubber block (as the regs are basically the same)
. Europa 2004, Airmaster and I have supplied many props (even fixed pitch)
at 64 inches per the LAA. (Let's face it, it is only an inch longer at th
e tip than yours.) The Europa Club website indicates that the Airmaster wa
s considered to be the "standard" for the Europa. They are all nominally
62-64" maximum length. Unfortunately, the Europa Factory POH from 1998 sti
ll says 62 inches in the performance numbers because the original engine wa
s the 912. Those figures are based on the narrow chord blade. Note, from
my reading of the original test flights the fixed prop was set to a takeof
f static RPM of 4000 for cruise and 5500 for takeoff for testing like most
Rotax powered kit planes trick us with. Note the tip is really set high at
21degrees for the 912S. The 912S with the wide chord give better performa
nce from takeoff to cruise.
I'm forced to say that all our 64 inch props are not exactly 64 inch blade
lengths after mounting in the rotating barrel of a constant speed prop. It
seems there are no absolutes in aviation. By the time the blades are grou
nd to length, shaped and balanced, each prop is slightly different in lengt
h.
Best Regards,
Bud Yerly
From: owner-europa-list-server@matronics.com<mailto:owner-europa-list-serve
r@matronics.com> <owner-europa-list-server@matronics.com<mailto:owner-europ
a-list-server@matronics.com>> On Behalf Of davidjoyce@doctors.org.uk<mailto
:davidjoyce@doctors.org.uk>
Sent: Wednesday, December 29, 2021 3:47 PM
Subject: Re: Europa-List: Re: Propeller Sizing
Mike, for what it is worth I have a Woodcomp 1625mm (=62" as near as damm
it) prop on my 914XS mono. I am not aware of prop limitations differing bet
ween Classic and XS. I have always understood that this was the max size th
at the LAA would approve. The clearance is fine on hard runways, but on rou
ghish grass strips you wouldn't want any longer blades than that, as you mi
ght find the tips getting stained green. Regards, David Joyce, GXSDJ
On 2021-12-29 12:03, Mike wrote:
Hello Tim
Thanks, this is what I was after the only problem is that sadly for me you
are in NZ and I suppose governed by different regs!
Here in the UK we are subject to something called CS-VLA 925 (easily google
d) which makes minimum prop clearance demands.
However glad to hear that you are getting good results, what brand of blade
s are you using?
Thanks
Mike
From: owner-europa-list-server@matronics.com<mailto:owner-europa-list-serve
r@matronics.com> [mailto:owner-europa-list-server@matronics.com] On Behalf
Of timward
Sent: 29 December 2021 10:45
Subject: Re: Europa-List: Re: Propeller Sizing
Hi Mike,
I have 64" prop blades on my Mono Wheel Classic #292. Prop clearance is not
a problem.
With the Airmaster CSU, Rotax 912ULS 100hp, it provides excellent performan
ce.
Upgraded to 64" from 62" after a prop strike, on recommendation from Airmas
ter.
Cheers,
Tim
Sent from my iPad
Tim Ward
12 Waiwetu Street,
Fendalton,
Christchurch, 8052
New Zealand.
ward.t@xtra.co.nz<mailto:ward.t@xtra.co.nz>
021 0640221
On 29/12/2021, at 11:29 PM, Mike <mike@nyumba.co.uk<mailto:mike@nyumba.co.u
k>> wrote:
umba.co.uk>>
Thanks Bud for your usual excellent reply.
I have been in contact with Dirk who has indeed suggested a replacement
blade of 64" and been most helpful but the issue remains, can I fit a 64" t
o
a classic mono. The LAA have provided me with a spreadsheet of calculations
to determine prop tip clearance at Max AUW which I will carry out but they
were unable to find out easily if any other classics were operating with a
64" prop so this is why I asked the community if anyone was operating with
one.
Thanks for the pointer to your website I will certainly have a look.
Thanks
Mike
-----Original Message-----
From: owner-europa-list-server@matronics.com<mailto:owner-europa-list-serve
r@matronics.com>
[mailto:owner-europa-list-server@matronics.com] On Behalf Of
budyerly@msn.com<mailto:budyerly@msn.com>
Sent: 28 December 2021 16:44
Subject: Europa-List: Re: Propeller Sizing
m>" <budyerly@msn.com<mailto:budyerly@msn.com>>
Mike,
My website has how to select a prop for your Rotax.
The 62 inch Warp Drive Taper blade is fine for most 80HP Rotax powerplants.
The Rotax 912ULS 100HP has significantly more torque and the 62 inch tapere
d
blade is not very efficient. My US folks were very disapointed with trying
to use this short tapered blade on the 912ULS in both the Airmaster and the
fixed pitch versions.
The blade angle will be quite high and takeoff will be shortened, climb wil
l
be less and the cruise will be about 5 knots slower. The 80HP Rotax won't
spin a wide chord 64 inch without lugging the engine down. There is just
not enough torque. The tip at takeoff is not able to bite for good
performance.
The LAA recommendations is for the Warp Drive Standard (wide chord) blade o
f
64 inch for the Europa (which limits the length for the airframe to 64
inches) and was the standard Airmaster for a number of years. The 100HP
Rotax has the higher torque and can spin the wider and longer props with
authority.
Also available for the cost of a blade change is the Sensenich high speed
blades. Whirlwind has a blade but due to Covid lockdowns in California lea
d
time is many months. Sensenich and Warp Drive are made in free States so
production and labor issues are not a major problem for delivery at this
time. Airmaster will build you up a set of blades and ferrules ready to
mount. It will cost you but it is worth it.
Contact: Dirk Oyen
Oyen CTR (Europe Sales and Service)
Hemelrijk 61
Heusen-Zolder
Limburg 3550
Belgium
E: dirk.oyen1@telenet.be<mailto:dirk.oyen1@telenet.be>
M: +32 477 25 80 28
Website: www.propellor.com<https://na01.safelinks.protection.outlook.com/?u
rl=http%3A%2F%2Fwww.propellor.com%2F&data=04%7C01%7C%7C8b8f037b9a6847ba
2a3308d9cb41a5f8%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C6377643051047
47497%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6I
k1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=Gpp9mRbpFwIIQ5HYgdjcbYz%2B9gJIP2ryiHF7
ZH4wXuo%3D&reserved=0> your European Airmaster Dealer. He has the
experience you will need to draw on in the UK (See the Airmaster Contacts
section for resellers.)
I have been happy with all the US manufactured blades in the Airmaster Hub.
And NO, you personally can't change the blades yourself.
Best Regards,
Bud Yerly
US Airmaster Dealer
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=505507#505507<https://na01.sa
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iewtopic.php%3Fp%3D505507%23505507&data=04%7C01%7C%7C8b8f037b9a6847ba2a33
08d9cb41a5f8%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C63776430510474749
7%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1ha
WwiLCJXVCI6Mn0%3D%7C3000&sdata=ihxfMqjdpPURyetl0k8uCbkf7fNYwoXqAlgqAAquzQ
0%3D&reserved=0>
<====================
<sp; -Matt D=============
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