Flaps and V-Tails of Death

Hi all,

I'm here to report that I cheated death and survived a flight in a
glider with the dreaded "Landing Flaps and V-Tails of Death". Jim Harper
graciously allowed me to fly his beautiful HP-16. What's an HP-16 you
say? Well, looks to be just like the HP-18 (or I should say the HP-18 is
just like the -16) except that the -16 has a large and comfortable all
metal cockpit instead of the narrow composite cockpit of the -18.

Jim's -16 is equipped with winglets and, as far as I know, the ailerons
are standard (not with the J.D. Colling mod, correct me if I'm wrong
Jim). Center stick. Tow was behind our 180hp Cessna 175 on a 275 foot
long rope. Started out in -2 flap position, went to + 5 at 40 knots. Had
no trouble keeping the wings level. The bird lifted off level and was
easy to fly on tow. Released and tried slow flight (no stalls), flight
up to 90 knots. Steep turns, etc. Well sealed and quiet. Good rudder
response and easy to coordinate compared to my 301 Libelle. More stable
in a thermal than my Libelle. Aileron response was a little slower than
my Libelle at thermaling speeds, but was positive and more than adequate
for centering thermals. Climbed a few hundred feet in a very week
thermal. Very nice thermalling glider.

Landing was the best part. I stayed high and close in the pattern. I
rolled on some flap on downwind, maybe 30 degrees or so. I was way high
on final so I started rolling in more flaps. I never quite got to the
full 90 degrees mark as I had the nose down at a truly obscene angle
just to maintain 50 knots. Steeper than my 301 with the tailchute and
full divebrakes. Steeper than a Mosquito with everything hanging out.
This was more like parachuting than flying. Nothing but dirt out the
front of the canopy. The horizon was visible more towards the top of the
canopy. I aimed at a target and just kept the nose pointed there. I
pulled back on the stick when I ran out of nerve. The bird settled on
with a slight bump of the tailwheel and a little bounce as the main
dropped on (I flared just a bit too much). I have no doubt that I could
easily put this bird in a tiny field much easier than I could my Libelle
(and that is not difficult at all).

So, I'd have to say that all the bad things I've been told about landing
flaps on gliders and V-tails are definitely untrue with respect to the
HP-16. It is a comfortable and easy to fly glider and compares very well
to my Libelle and also to other glass birds, including my favorites for
handling, the Mosquito and LS-4.

Wallace Berry wrote:

So, I'd have to say that all the bad things I've been told about landing
flaps on gliders and V-tails are definitely untrue with respect to the
HP-16.

If you believe that, perhaps you haven't been told "all the bad things".
For example, I've had HP pilots tell me getting sucked up into a cloud
can be "awkward" to deal with when all you've got is flaps.

My first and only flight in an HP went like Mr. Berry's; even so, I hope
anyone beginning to fly a flaps only glider gets thorough checkout,
because there are ways to go wrong.

--
-----
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Eric Greenwell
Washington State
USA

"Eric Greenwell" wrote in message
Wallace Berry wrote:

So, I'd have to say that all the bad things I've been told about landing
flaps on gliders and V-tails are definitely untrue with respect to the
HP-16.

If you believe that, perhaps you haven't been told "all the bad things".
For example, I've had HP pilots tell me getting sucked up into a cloud
can be "awkward" to deal with when all you've got is flaps.

My first and only flight in an HP went like Mr. Berry's; even so, I hope
anyone beginning to fly a flaps only glider gets thorough checkout,
because there are ways to go wrong.

No offense, Eric, but speaking from the vantage point of one with all his
1-26 glide-ratio time in flaps-only ships (C-70, HP-14, Zuni), the more
powerful the flaps, the _less_ 'exciting' it need be if you allow yourself
to get sucked into a cloud. (For those unfamiliar with lift in the western
U.S., streets miles long and wide containing lift exceeding 10 knots are not
uncommon, and 'getting sucked into a cloud' _can_ happen, even if relatively
savvy and switched on...scale effects, new experience learning curves, etc.)

Can we take as a given that what's 'thrilling' about IFR flight with a VFR
panel is the very real possibility of pulling wings off in the ensuing
spiral dive? If that's true, then the more drag you have available...and
flapped HP's tend to have a LOT of disposable drag [a great thing as Wallace
B. better understands now, :-)]...the less thrilling blind flight. My HP-14
wouldn't exceed 55 knots (as I recall) with full flaps when left to its own
(hands-off) devices for minutes on-end. Sure, it took on some interesting
attitudes as it alternately nosed up, stalled, fell off on a wing, regained
speed, nosed up...etc., but there was no way it was ever going to come close
to maneuvering speed. To avoid the repeated stalling, all one needed to do
was hold 40 knots with full flaps (required forward stick). You'd
eventually end up in a steep spiral, but, so what?

My Zuni is less forgiving (considerably weaker flaps...i.e. less drag than
the HP-14) in this regard, and will pretty soon exceed 75 knots
hands-off-the-stick in the zoom, stall, fall off sequence, but like the HP
is utterly innocuous if trimmed aft w. full flaps and held at 40 (or 45 or
whatever one is comfortable with). Again, you're likely to eventually end
up in a tight spiral if using this technique, but you're not going to pull
the wings off.

IMHO, playing imaginary mind games (and backed up by considerable
experimentation over the years), my personal adrenaline level will be a lot
lower in a flaps-only ship having 'adequate drag' (and I know of no 15-meter
flap-only ships that do not) than in a spoilers-only ship if I envision
being in a big, turbulent cloud with a VFR panel. For the record, I'm aware
of the 'benign spiral mode.'

Actually, I suspect 'flapped cloud safety' comes not so much the flaps
as-such, but from their high level of drag. Imagine a tail-chute-only of
'ridiculously large diameter' to see what I mean...likewise, 'ridiculously
large spoilers'. For non-U.S. pilots, the most powerful spoiler-only
gliders I know of are the Schweizer 1-34 and 2-32, both of which have
terminal-velocity-limiting dive brakes. Personally, I'd much rather come
out the bottom of a cloud doing 40 knots in a spiral than at Vne more or
less vertically. Adrenaline may have its place in the human condition, but
I prefer to keep mine out of the cockpit!

Regards,
Bob - you can't have too much disposable drag - Whelan


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Bob Whelan wrote:
"Eric Greenwell" wrote in message

Wallace Berry wrote:


So, I'd have to say that all the bad things I've been told about landing
flaps on gliders and V-tails are definitely untrue with respect to the
HP-16.

If you believe that, perhaps you haven't been told "all the bad things".
For example, I've had HP pilots tell me getting sucked up into a cloud
can be "awkward" to deal with when all you've got is flaps.

My first and only flight in an HP went like Mr. Berry's; even so, I hope
anyone beginning to fly a flaps only glider gets thorough checkout,
because there are ways to go wrong.


No offense, Eric, but speaking from the vantage point of one with all his

1-26 glide-ratio time in flaps-only ships (C-70, HP-14, Zuni), the more
powerful the flaps, the _less_ 'exciting' it need be if you allow yourself
to get sucked into a cloud.

The situations described to me were the difficulty of avoiding the cloud
entry in the first place. A pilot can open his spoilers at 90 knots and
begin descending immediately, but deploying the flaps at 90 knots first
increases your altitude, making it much harder to stay out of the cloud.
If you do lose control in a cloud, lots of drag is an advantage.

The main point I hoped to make is landings aren't the only way spoilers
and glide path flap operation differs, and one good landing isn't enough
to know the pitfalls, even for landings. I think everyone agrees the HP
series is a great ship to make off-field landings in the hands of a good
pilot.
--
-----
Replace "SPAM" with "charter" to email me directly

Eric Greenwell
Washington State
USA

Eric Greenwell originally replied...
If you believe that, perhaps you haven't been told "all the bad things".
For example, I've had HP pilots tell me getting sucked up into a cloud
can be "awkward" to deal with when all you've got is flaps.

My first and only flight in an HP went like Mr. Berry's; even so, I hope
anyone beginning to fly a flaps only glider gets thorough checkout,
because there are ways to go wrong.

Bob Whelan followed with...

No offense, Eric, but speaking from the vantage point of one with all
his
(greater-than)
1-26 glide-ratio time in flaps-only ships (C-70, HP-14, Zuni), the more
powerful the flaps, the _less_ 'exciting' it need be if you allow
yourself
to get sucked into a cloud.


Eric G. further replied...
The situations described to me were the difficulty of avoiding the cloud
entry in the first place. A pilot can open his spoilers at 90 knots and
begin descending immediately, but deploying the flaps at 90 knots first
increases your altitude, making it much harder to stay out of the cloud.
If you do lose control in a cloud, lots of drag is an advantage.

The main point I hoped to make is landings aren't the only way spoilers
and glide path flap operation differs, and one good landing isn't enough
to know the pitfalls, even for landings. I think everyone agrees the HP
series is a great ship to make off-field landings in the hands of a good
pilot.

I figured there was some nuance I was missing. No harm no foul. I agree
with all your points. For my part I just wanted to throw out for general
consideration that though flaps ARE different than spoilers, 'different'
doesn't necessarily strongly equate with 'bad.' Nor does 'different'
necessarily strongly equate with 'large cojones.'

Free information is always worth every cent paid for it, but (in my
flap-biased view) there seems to be more misleading/'flaps are bad'
information floating around about flaps than there is of the sort to be
found in this particular thread...which thus far contains accurate - if
necessarily incomplete - information in every post.

Just to provide a counterpoint to your scenario of avoiding the cloud in the
first place (always a good idea, if not always achieved), it's worth
pondering how ANYone comes to the decision s/he may require imminent cloud
avoidance techniques. Consider the particular case of a powerful western
U.S. cloud street. Odds are J. Pilot will be cruising along at 80+ mph and
suddenly have a "HolyCOW!' moment upon realizing cloud avoidance is
necessary. Options likely to spring to the surprised mind?: 1) course
change; 2) nosing over/adding energy; 3) adding gear drag; 4) adding
flap/spoiler drag. All will be exciting in a suddenly more thrill-filled
cockpit.

I've spoken to 2 pilots (years apart) soon after each first intentionally
opened spoilers at above-pattern speeds, one in a St'd Cirrus near 120 knots
trying to get below a finish gate in a regionals, and the other in an
Astir-CS trying to avoid being sucked into a big, wide, western cloudstreet
who had options 1, 2, & 3 prove insufficient. We laughed about things
because we were on the ground, but they were both wide-eyed recollecting the
BIG negative G event occasioned by opening spoilers at
higher-than-pattern-speeds, even though both had time to realize prior to
pulling the spoiler handle they were treading in new (for them, at the
times) territory. Playing Joe Test Pilot is always best done (IMHO) under
more controlled conditions than 'needing' to play JTP.

FWIW, I thought the St'd Cirrus pilot did by far the more foolish
thing...because he took an avoidable risk, whereas the Astir CS pilot felt
he had no other choice. Both whanged their heads on the canopy. The Astir
pilot wound up in a high-speed, gear-down, spoilers-out slip trying
desperately to stay out of the cloud street. About the time he could see he
was going to be successful avoiding the cloud, he heard a radio call to the
effect, "Glider at XXX over YYY, this is Cessna ZZZ. Are you OK?" Being at
XXX over YYY, he declined to answer (would've required a 3rd hand w/o a boom
mic), though afterwards he could appreciate a certain irony in the
situation!

Regards,
Bob W.



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From: Eric Greenwell

If you believe that, perhaps you haven't been told "all the bad things".
For example, I've had HP pilots tell me getting sucked up into a cloud
can be "awkward" to deal with when all you've got is flaps.

"all the bad things"? Do go on, Eric.

I fly an RS-15 and I don't worry about spoiler(s) not being connected or
accidentally opening. There are some very positive things about the HPs.
Also, when landing flaps are deployed the ship becomes incredibly stable and
the stall speed decreases. That's a nice feeling when down low.


My first and only flight in an HP went like Mr. Berry's; even so, I hope
anyone beginning to fly a flaps only glider gets thorough checkout,
because there are ways to go wrong.

As with any ship that is "new in type" to the pilot. But good advice.

Regards,

-Doug

Here are some pictures of Jim Harper's HP-16:
http://www.soaridaho.com/Schreder/HP...rst_Flight.htm

Wayne
http://www.soaridaho.com/


"Wallace Berry" wrote in message
...
Hi all,

I'm here to report that I cheated death and survived a flight in a
glider with the dreaded "Landing Flaps and V-Tails of Death". Jim Harper
graciously allowed me to fly his beautiful HP-16. What's an HP-16 you
say? Well, looks to be just like the HP-18 (or I should say the HP-18 is
just like the -16) except that the -16 has a large and comfortable all
metal cockpit instead of the narrow composite cockpit of the -18.

Jim's -16 is equipped with winglets and, as far as I know, the ailerons
are standard (not with the J.D. Colling mod, correct me if I'm wrong
Jim). Center stick. Tow was behind our 180hp Cessna 175 on a 275 foot
long rope. Started out in -2 flap position, went to + 5 at 40 knots. Had
no trouble keeping the wings level. The bird lifted off level and was
easy to fly on tow. Released and tried slow flight (no stalls), flight
up to 90 knots. Steep turns, etc. Well sealed and quiet. Good rudder
response and easy to coordinate compared to my 301 Libelle. More stable
in a thermal than my Libelle. Aileron response was a little slower than
my Libelle at thermaling speeds, but was positive and more than adequate
for centering thermals. Climbed a few hundred feet in a very week
thermal. Very nice thermalling glider.

Landing was the best part. I stayed high and close in the pattern. I
rolled on some flap on downwind, maybe 30 degrees or so. I was way high
on final so I started rolling in more flaps. I never quite got to the
full 90 degrees mark as I had the nose down at a truly obscene angle
just to maintain 50 knots. Steeper than my 301 with the tailchute and
full divebrakes. Steeper than a Mosquito with everything hanging out.
This was more like parachuting than flying. Nothing but dirt out the
front of the canopy. The horizon was visible more towards the top of the
canopy. I aimed at a target and just kept the nose pointed there. I
pulled back on the stick when I ran out of nerve. The bird settled on
with a slight bump of the tailwheel and a little bounce as the main
dropped on (I flared just a bit too much). I have no doubt that I could
easily put this bird in a tiny field much easier than I could my Libelle
(and that is not difficult at all).

So, I'd have to say that all the bad things I've been told about landing
flaps on gliders and V-tails are definitely untrue with respect to the
HP-16. It is a comfortable and easy to fly glider and compares very well
to my Libelle and also to other glass birds, including my favorites for
handling, the Mosquito and LS-4.

The situations described to me were the difficulty of avoiding the cloud
entry in the first place. A pilot can open his spoilers at 90 knots and
begin descending immediately, but deploying the flaps at 90 knots first
increases your altitude, making it much harder to stay out of the cloud.
If you do lose control in a cloud, lots of drag is an advantage.

The main point I hoped to make is landings aren't the only way spoilers
and glide path flap operation differs, and one good landing isn't enough
to know the pitfalls, even for landings. I think everyone agrees the HP
series is a great ship to make off-field landings in the hands of a good
pilot.
--
-----
Replace "SPAM" with "charter" to email me directly

Eric Greenwell
Washington State
USA


Eric.
Good points.... But flap deployment at speed needn't cause an altitude
change.
Roll 40 or so your favorite direction, g up and put them out. Minimal
altitude gain if any.

Scott.

Scott remember Eric speaks for the little old lady division of the SSA.

Winter is here let the fun begin.

Al


"Scott Correa" wrote in message
...

The situations described to me were the difficulty of avoiding the cloud
entry in the first place. A pilot can open his spoilers at 90 knots and
begin descending immediately, but deploying the flaps at 90 knots first
increases your altitude, making it much harder to stay out of the cloud.
If you do lose control in a cloud, lots of drag is an advantage.

The main point I hoped to make is landings aren't the only way spoilers
and glide path flap operation differs, and one good landing isn't enough
to know the pitfalls, even for landings. I think everyone agrees the HP
series is a great ship to make off-field landings in the hands of a good
pilot.
--
-----
Replace "SPAM" with "charter" to email me directly

Eric Greenwell
Washington State
USA


Eric.
Good points.... But flap deployment at speed needn't cause an altitude
change.
Roll 40 or so your favorite direction, g up and put them out. Minimal
altitude gain if any.

Scott.

In article ,
Eric Greenwell wrote:

Wallace Berry wrote:

So, I'd have to say that all the bad things I've been told about landing
flaps on gliders and V-tails are definitely untrue with respect to the
HP-16.

If you believe that, perhaps you haven't been told "all the bad things".
For example, I've had HP pilots tell me getting sucked up into a cloud
can be "awkward" to deal with when all you've got is flaps.

My first and only flight in an HP went like Mr. Berry's; even so, I hope
anyone beginning to fly a flaps only glider gets thorough checkout,
because there are ways to go wrong.

No doubt there are ways to go wrong, but every design has it's quirks. I
would sooner turn a low time pilot loose in that HP-16 than my 301
Libelle.

For sure my one experience in a landing flapped equipped bird is far too
little experience to generalize. That's why I limited my comments to the
HP-16. However, I have been told horror stories about V-tails and
landing flaps. You know the stories. I was told the V-tail HP's were
hard to fly and dangerous for any but the most experienced fliers. I'm
no ace but I thought the thing was very easy to fly. Maybe the other
HP's are different. The main myth is that you can't modulate the flaps
to control glide path. In the HP-16, I rolled the flaps on and off
within a fairly wide range and the glider behaved very much like a
glider with very effective divebrakes. I would be very comfortable
landing Jim's HP-16 in any reasonably landable field.

Deploying flaps at high speeds can be problematic in a number of ships.
I have heard that at least one 301 Libelle structural failure was due to
flap deployment at a speed significantly above Vne. However, a number of
ships which have flaps that deploy with the divebrakes have maximum
deployment speed limitations too. And, not to forget, deployment of just
divebrakes at high speeds can be dangerous. I think a couple of open
class ships have lost their wings when the divebrakes were deployed well
over Vne.

As for getting sucked into a cloud, I would have an easier time keeping
that HP-16 out of the cloud than my Libelle with it's relatively
ineffective divebrakes. I have been in the gear down, full divebrakes
and full slip configuration diving for the edge of the cloud at high
speed to keep from getting sucked in.


Fly safe,

Wallace