What about HP-14's---Why wouldn't I want one????????
Clarence A. Hurd
After reading this article I think I like the design and am giving
serious thought to buying an HP-14.
http://www.iac.net/~feguy/soaring_symposia/70-synop.html
So what should I be aware of? When I see some ads they specify that the
wings are filled. Is that a departure from the original design? How
does the epoxy hold up over the years?
I would like any first hand info or where to find it.
Looking forward to finding more GREEN AIR.
Mike Muncey
Thankyou so much for the pointer to that article. I’ve printed a
copy for myself and my friends.
I’ve owned the HP-14 I currently have for almost 10 years. This
is the second HP-14 I’ve been involved with-- I sold my 1/2 share
of my first when I bought this one. My first was a “T”; this one is
a “V”. I currently base my HP-14 at Hemet CA. There are
probably 5 or more flying HP-14’s at Hemet today.
First, the good points about the HP-14. It is very rugged, very
strong and a great climber with most having wing-loadings in
the 5.0 to 6.5 range. It offers very good (when you consider
the price) low-speed glide performance-- some top 40:1. It can
land VERY steeply and in a short field. The all metal construction
allows it to be tied-out if you desire. All of the critical structure
is rivetted-- not bonded or glued; so they don’t have any problems
with delamination. I would recommend the ship to someone who
doesn’t have competition or 1,000 K ambissions, doesn’t have
$30K for something nicer, and who has good flying skills.
Now lets discuss some of the potentially negative issues. The HP-14
is a difficult ship to fly-- in particular on take-off and landing.
It lacks “rudder” authority for yawing (especially the “V”) on
take-off and handling x-winds for both take-off and landing.
The HP-14 rolls SSSSSSLLLLLLOOOOOWWWWWW. It feels
like an open-class ship in this respect so you have to anticipate
thermal corrections a bit. This also makes it a challenge to keep
your wings level during take-off roll.
Landing with the flaps is quite different from spoilers and will take
a lot of practice, but once you have it figured out you’ll probably
like it better-- I do. Its high-speed glider performance leave a bit
to be desired as glide ratio drops quickly above 90 mph. Claimed
performance is 24:1 at 90 mph. Above that speed, the stiff wings
and light wing-loading combine to beat the pilot into submission! :-)
The lack of drive brakes is most missed as you are being sucked into
the clouds when flying at high speed under a cloud-street. Normally,
you would speed up (rough air speed limit considered) to dive away
and just pull open the dive brakes without concern if you needed the
extra sink-- but I really hesitate to drop my flaps at higher speeds.
My beleif is that Vfe is far below Vne. (Perhaps some other HP
owners can state thier Vfe; I belive mine is 90 mph and I further
reduce it from there before going beyond 30 degrees to further
reduce stress. I like to hold mine under 75 mph at 90 degrees.) So
you have to slow down (resulting in more altitude gain) when you
would normally be speeding up and making time in the strong lift.
Things to watch out for:
1) Flap mechanism. There are several ways that were used to
operate the HP flaps. In my opinion, the *mechanical crank* is
the only way to go. The *slide-handle* seems to lack leverage and
the ability to quickly retract the last 30 degrees (initial lock-down
position) of flaps if you start coming in short. The *hydraulic pump*
is prone to leaks and also is fairly slow to change settings.
2) Counter ballances. The HP’s original wing tip is quite ugly
(unique?) with its external aileron counter balances. Some builders
left them off. They are REQUIRED to prevent flutter. My HP
came without them-- flutter is not my idea of fun! It was significant
work to get them added.
3) Control slop. The HP has a very short control horn for attaching
the aileron pushrod to the aileron. This makes the controls prone
to aileron control slop and is probably part of the slow roll-rate
problem. Find an HP with tight controls. All of my pin/bushing
joints have been replace by bearing joints to reduce slop.
4) Drag spar slop. 14’s are prone to drag-spar slop. Find one
where the wing-tip doesn’t move fore and aft at the tip.
5) Wheel brake. The standard drum brake is weak-- at least mine
is. Some have disk brakes. I need to upgrade my wheel brake.
6) Most HP’s are dry, and from what I can see it would be very
difficult to put water in one after it was built. If you have dreams
of being wet, better that you start off that way.
About filled wings: Some people filled the airfoil imperfections
on their wings (depressions between the ribs) with Bondo or
some similar substance. This adds wing-loading (which is good
out West) and increases performance. The down side is that the
filler tends to crack over time.
In summary, the HP-14 is a good, solid ship that performs
exceptionally well in weak conditions. It is also a good cross-
country ship, very capable of Diamond Distance, and can land
in very short fields; but it only runs about as well as a dry Libelle
201. Its light wing-loading and stiff wings make it uncomfortable
to fly faster than 90mph in rough air. I’ve flown mine as fast as
140mph in smooth air. It is worth paying extra for one that has
most of the common problems resolved.
John deJong
>After reading this article I think I like the design and am giving
>serious thought to buying an HP-14.
>http://www.iac.net/~feguy/soaring_symposia/70-synop.html
>So what should I be aware of? When I see some ads they specify that the
>wings are filled. Is that a departure from the original design? How
>does the epoxy hold up over the years?
>I would like any first hand info or where to find it.
>Looking forward to finding more GREEN AIR.
I just bough an HP-14 this spring with a partner, and there are just a few
things that you might want to watch for that we have found on ours.
1) Filled wings are desirable, as long as they were done properly. On
ours, it appears that a poor job was done in places, and when water gets under
the filler when winter comes it cracks the filler off in pieces. The places
we found it the worst was on the underside of the flaps, on the outermost
section which gets hit a lot by grass etc. in landings. If done poorly, you
night have a fair bit of work ahead of you to clean things up/smooth them.
2) Check the landing gear strut, ours was totally flat and required
rebuilding. This is not difficult, it only takes a couple of hours, ~$2 worth
of O-rings (2), some hydraulic oil (or motorcycle shock oil), and a brake
cylinder hone to clean up the cylinders if they are a bit rusty/pitted. We
did ours this spring, and have yet to need to do anything more with it.
If you have any more questions, let me know.
John
------------------------------------------------------------------------------
jde...@mgl.ca
HP-14 Sailplane A4000/40 2M chip/15M fast Pheonix A1000 2M chip/2M fast
16.4m 2 X 2091 Comspec Scsi controller
CF-WHZ Seagate 120M, Syquest 44M, CDROM, WRENIII 150M, Quantum52M
S/N 12 Quantum 40, 2X CDROM CSA MMR 68030/25Mhz
1942 Moniter 1080 Moniter, Digiview (A1000)
A1010
Chuck Smith
Clarence A. Hurd wrote:
>
> After reading this article I think I like the design and am giving
> serious thought to buying an HP-14.
>
> http://www.iac.net/~feguy/soaring_symposia/70-synop.html
>
> So what should I be aware of? When I see some ads they specify that the
> wings are filled. Is that a departure from the original design? How
> does the epoxy hold up over the years?
>
> I would like any first hand info or where to find it.
>
> Looking forward to finding more GREEN AIR.
HP's are good gliders. The performance per $$$ is probably about the
best
around.
The only thing you'll hear is flaps instead of spoilers.
And the people who have never flown flaps will tell you
not to buy it. As far as I'm concerned, its the only
way to go.
Anybody with a flapped ship I know has wondered why all
gliders aren't equipped with them. The HP is great with flaps
because the best L/D speed is virtually the same as your
"std." approach speed. At 55 MPH you can have 90 degrees
of flap, be coming down faster than any glider you've ever seen,
and then dump them and be flying almost 40:1 That's versatility!
Another nice thing is that every HP I've ever seen is nicely
equipped for cross country flying. The only drawback is it
takes about 50 feet of tape every time you rig on putting
on the fairings.
Now, mind you, I'm a little biased.
Chuck
HP11T N821Z
"Tango Charlie"
Hernan C. Mapua
I understand that HP 14s are homebuilts. If there are plans available, I
would like to purchase a set. HP 18s also.
****************************************************
Hernan C. Mapua madh...@skyinet.net
16 Antares St.
Bel-Air Vill. 4
Makati City
Philippines 1209
****************************************************
Bruce Hoult
Chuck Smith <csm...@vivanet.com> writes:
> Anybody with a flapped ship I know has wondered why all
> gliders aren't equipped with them. The HP is great with flaps
> because the best L/D speed is virtually the same as your
> "std." approach speed. At 55 MPH you can have 90 degrees
> of flap, be coming down faster than any glider you've ever seen,
> and then dump them and be flying almost 40:1 That's versatility!
How does this differ from ships like the Club Libelle and Hornet
that have trailing edge airbrakes? In the Club Libelle I can descend
as close to vertical as I like, and never go over 85 knots. And
naturally, being airbrakes, you can close them any time you want.
-- Bruce
Raul Blacksten
Libelles and a few other gliders have what are called
"terminal" dive brakes which act like 90 degree flaps at
limiting the airspeed in a dive to the "terminal" airspeed.
This is not to say that this is the speed where you die, it
just means that the glider will not go any faster.
--
***************************************************************
RAUL BLACKSTEN Wishing you green air!
Vintage Sailplane Association Archivist
ra...@earthlink.net
<http://www.earthlink.net/~raulb>
"It may not be smart or correct, but it's one of the things
which make us what we are" --Red Green, The New Red Green Show
Chuck Smith
The flaps move the CP and increase stability on the approach.
They also lower the stall speed. With the flaps down the angle
of incidence is increased and you fly a more nose down attitude.
The view in an HP with 90 degrees down is, shall we say, spectacular.
As far as closing the flaps, there is no law against raising
them to increase L/D BUT AIRSPEED MUST BE SUFFICIENT TO AVOID
A STALL. I've played with this at altitude and discovered the first
20 degrees come and go pretty easy. I like to drop about 20 degrees on
downwind since it lowers the L/D pretty good and allows me to fly
a tighter pattern.
I've never flown a TE airbrake setup, but with no net increase
in circulation the open brake's effect on the flowfield ahead would
likely lower the lift coefficient for a given angle of attack,
especially given that at the low Mach numbers (order 0.1!)we fly
gliders at, the flow is virtually incompressible.
What that means is you are raising the stall speed AND increasing
drag. That makes me a little uncomfortable. Seems like if your going
to put a drag device on the back of the wing you should get both
benefits.
But hey, I'm weird. I'd REALLY like to fly an ASW12. I guess a
17m Kestrel with the tail 'chute would be the ultimate ride.
Chuck
I've never flown a ship with TE airbrakes, but they seem to
be effective.
Peter Deane
I owned a HP'14 for 3 years. I never had any problems with the flaps but
you need to modify you pattern approach. You must NEVER get low and slow
with a large amount of flap so that to make the threshold you have to put
the flaps away quickly. You will fall out of the sky and die if youre
close to the ground. The same is true of any ship with significant flaps
for approach control.
The procedure I used was always to come in on the high side and add flap
appropriately. The flaps are SO powerful that at 45MPH you can point the
glider in a 45 degree dive and you wont speed up. DONT fly too fast with
full flap, as on the flare you will float forever along the runway with
the nose pointing down. Not cool at all. My 17m HP14 stalled at 32mph
with full flap so with 45mph you have plenty of margin. When landing
with full flap at first, be careful of the roundout: some people find
judging the roundout from a steep approach quite difficult.
You can land on a dime, the glide performance is outstanding for a metal
ship and theyre great value for money. I did my diamond goal in mine.
The V tail means that turn coordination is slightly different but the
difference is not great. Crosswind landings need care, more speed and
less flap to allow greater rudder authority (low tail area) Theyre
very strong designs. Check out the history and build quality of any 14
you look at. Workmanship varies. Mine was built by an AandP and was
made so well that no paint or filler was necessary, just polish the
aluminum.
Regards
Peter deane (ASW20 2T)
The usual disclaimers apply.
Bruce Hoult
Actually, full airbrake on the Club Libelle I mentioned drops the stall
speed from 39 to 34 knots. That's pretty handy for making short
landings, if you're happy to commit to leaving the brakes on full
from the flare onwards -- just don't close them if you're below 40
knots!
-- Bruce
Jonathan Gere
> Raul Blacksten <ra...@earthlink.net> wrote:
> Vintage Sailplane Association Archives
> Libelles and a few other gliders have what are called
> "terminal" dive brakes which act like 90 degree flaps at
> limiting the airspeed in a dive to the "terminal" airspeed.
> This is not to say that this is the speed where you die, it
> just means that the glider will not go any faster.
Terminal velocity dive brakes in a Libelle??? No way! Double check
before adding that to the archives.
Jonathan
Peter Cassidy
Jonathan Gere wrote:
> Terminal velocity dive brakes in a Libelle??? No way! Double check
> before adding that to the archives.
That was my first thought too. But I think he means a Club libelle
not a Std libelle. Club libelles have Hornet-style flapbrakes(?).
Peter
Raul Blacksten
OK, you got me.
But it is not as if the Libelle is important like a wooden
BG-12 or a steel tube TG-2 glider is. It is just tupperware
and thus insignificant.
In truth, I was keying off what the previous post said which
sounded like terminal dive brakes. I got my keyboard into gear
before my mind was--I am certainly good at that as there ain't
much mind to get in gear. I have never denied being an idiot.
Victor Grubbs
organization: University of Georgia, Athens GA
newsgroups: rec.aviation.soaring
>
>> Raul Blacksten <ra...@earthlink.net> wrote:
>
>> Vintage Sailplane Association Archives
>> Libelles and a few other gliders have what are called
>> "terminal" dive brakes which act like 90 degree flaps at
>> limiting the airspeed in a dive to the "terminal" airspeed.
>> This is not to say that this is the speed where you die, it
>> just means that the glider will not go any faster.
>
>Terminal velocity dive brakes in a Libelle??? No way! Double check
>before adding that to the archives.
>
>Jonathan
>>
History lesson time:
Back in the '60's the Standard Class rules required "terminal
velocity" dive brakes that would limit speed in a _vertical_
dive to redline and ships such as the Ka6 had them. With
the advent of the first generation of fiberglass Std. class ships
(Std. Libelle, LS-1, Std. Cirrus and ASW-15) the manufacturers
decided to ignore the "terminal velocity" rule and produced the
above list of ships. (My guess is that installing terminal velocity
dive brakes would have incurred more performance penalty than the
designers were willing to accept.) By the early '70's, rather than
declare the current crop of ships to be ineligible for the Std.
Class, the "powers that be" changed the rule to read that the
dive brakes should limit the terminal velocity in a 45 degree
dive instead of the older 90 degree spec.
Ironicly, when Schweitzer designed their 1-34, they took great
pains to make sure that their new ship's dive brakes would limit
speed in a vertical dive to below the redline, thus making the
1-34 the only "real" Std. Class ship of that generation.
cheers,
victor
Victor Grubbs, KV
vic...@groucho.dev.uga.edu