A Tale of Two Takeoffs

On 6/16/2017 5:55 PM, wrote:
I have a secret.

Well, like secrets in a Congressional Intelligence subcommittee, this one
is probably known by several hundred people. But I haven’t written about
it. Until now.
Lucid write-up of two wing-drop-included takeoff runs snipped

But I was humbled. How could I have messed up so badly? One respected
colleague offered that I had failed to have a contingency plan. But that’s
not true. I had a plan; I just ignored it.ng runner, as another ground
crew member did a few days later as we chatted on the line. His
inexperience almost certainly triggered the i



I could have blamed the tailwind and young wincident. But the fault for the
damage was all mine. I could have prevented it by pulling the release. Why
didn’t I?

I think it came down to ego. I remembered thinking I had made a mistake in
dropping the wing, a mistake I wanted to--and was convinced I
could--correct. And I was sure, until I landed that night and even for a
few hours afterward, that I had acted reasonably, that the landing light
hidden in the high grass was just one of those things that can’t be
controlled and that my decision to try to recover from a takeoff gone bad
was justifiable. After all, I would have gotten away with it except for the
light.

I was wrong. The correct decision was to pull the release immediately, the
way I had several times in earlier years and the way I did two days ago.
Some decisions are easy: we make them before we fly and all we have to do
is execute. Are there times when we should modify our contingency plans due
to circumstances? Sure, but we need a better reason than trying not to look
stupid or saving a few minutes on the launch grid.

Chip Bearden “JB�

Thanks for sharing your experience (and experiences), Chip. I completely agree.

Sharing and discussing these sorts of things is - IMHO - the *other*
fundamental raison d'etre of RAS...as methinks is well-demonstrated by Jordan
Pollock's question (i.e. "How does extended spoilers improve aileron
response?") elsewhere in the thread. It's a question I think I first
encountered in print several decades ago in "Soaring" magazine, and which I'll
toss out for discussion my 2-cent's-worth response. Undoubtedly others will
contribute/elaborate/disagree...all good stuff in principle.

The way I think about raised spoilers enhancing roll response during takeoff
is this: by reducing the amount of total lift the wing is producing, the
"aerodynamic roll stiffness" is reduced, hence any aileron input will have
less roll inertia to overcome. Viola! Improved roll response. (Imagine a wing
infinitely stiff-in-roll at all speeds - there'll be zero aileron effect.)
Others have (and likely will) posit at least one (other/secondary?) effect
related to the changed spanwise flow-field over the wing positively
assisting/improving the ailerons' flow fields (hence improving their actual
"power"). If this is so, I'd expect short-spanned gliders to (painting with a
broad brush, here) to be more likely to benefit from use of the open-spoiler
technique than long-winged birds, because of short-spanners' lower,
mass-related, roll inertia.

FWIW, the same thinking "works" for camber-changing-flap-equipped birds, and
at least for the one in which I have all of my experience, it can be shown to
"work" in reality, as well. Next time you're ground-bound on a day with a more
or less steady 10-15-knot breeze, face your ship into the wind, snag a
wing-tip buddy for a few minutes of experimentation and fun. Have your buddy
level the wing and let go on your command while you attempt to keep wings
level. Odds are you'll find it's easier to do so with
spoilers-open/flaps-negative than not.

Bob W.

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That's pretty interesting. Seems incredibly minute, but if it gets results there's not much to argue with. My only point against teaching it is the complexity it adds to a launch, when there's already a lot going on and plenty to be aware of. I can see it needs to be muscle memory. Thanks for the explanation.

Jordan

Actually, I consider this incorrect.

When trained for any job, there is a lot to learn. Things like:
Glass ship, dive brakes open, pilot typically HAS to be holding them open. No comment pre launch
Metal ship, dive brakes open, may be by mistake, say something.
Check for tail dolly
Point out other traffic
Etc.

Nut behind the stick is final say.

Example, annual Snowbird contest in Elmira, people talk about practice for the event (look it up for rules and goal). In reality, it is to reinforce energy management for potential off airport landings and proper landing placement. People that have to practice means they are not ready when it happens in the future, but if properly reinforced all flying season you should do well when needed.

Running a wing should be the same every flying day, contest should only get a minor tweak due to a slightly faster than normal launch and potentially higher glider density. Judgement on go/no go by the runner may be hard, but all the other basics should be covered.

Posted by someone that used to work contests (as ground crew, runner, retrieve, etc.) since the mid '70's and contest flying later on. I also do ground duties even now when at the airport.

The old adage of, practice for the worst, hope for the best, comes to mind. If you don't do it all the time, a contest can be a bad place to learn.

Chip, thanks for the thread. It takes some guts to post this in front of some of the RAS crowd. I have had some of my own nail biters in the past, so I understand.

I agree, Hank; ballasting was my responsibility. On the grid at Cordele, I removed the wing wheel and double checked, taking time to make sure the water had stabilized and the wings were level. Obviously I misjudged it standing at the right wing because later, after the line crew removed my wing wheel, from the cockpit it seemed like the girl at the right wingtip was holding it a little high (indicating it was heavy). I called out to her over the tow plane noise not once but twice with "Are they balanced?" She nodded the first time. The second time she took her hand off the wingtip to show me ("why doesn't that man believe me?" haha). Since she had the wings balanced, I didn't even think about declining the launch; the line crew had it under control.

I have assumed--but don't know--that when she handed the wingtip to the actual wing runner, that balance was lost. If it looked high to me, it probably did to him. Maybe the slight tailwind contributed. Maybe I just did a bad job on takeoff. Most important, unlike at Nephi, this time I made the right decision and pulled the release. No harm done.

[I'm thinking of using a bubble level or other visual indicator so I can ensure the wings are level when I'm solo. I've seldom launched with full tanks and dumped down; even at max gross the water still sloshes around and the takeoff performance is reduced.]

Agreed, wing runners don't have to be experts but they must know the basics.. And that includes balancing the wings. Even when my tanks are absolutely even, the wing runner still has to make sure one tip isn't lower/heavier than the other. There are no baffles; just two compartments per bag that allow water to flow easily back and forth. It's as important as not letting go of the tip after two steps and not holding back when they can't keep up.

Contest line crews are heavily populated with local kids, many of whom don't have much experience. They're enthusiastic and athletic and they learn quickly. But they have to be trained and supervised. Perhaps we need to add a session for them in the pre-contest briefing where pilots can express their concerns and even demonstrate what works and doesn't work for their gliders.

Some years ago, the young, inexperienced wing runner at a Hobbs multi-class nationals was holding back, steering pilots off course. The problem was the advice he was getting to grasp the wing by both the leading and trailing edges. I didn't want to argue technique on the line so I immediately drafted my daughter, who had never run a wing before. I briefed her for a few minutes, calmed her nervousness, and reassured her she would do great. A 16-year-old high school track star, she ran it perfectly...and was promptly approached by half a dozen pilots to run their wings. The operations director watched what was going on, then quickly recruited her for the line crew. She ended up running wings for nearly all of the crewless pilots at the contest.

This made the contest a lot more fun for Tina, she took home a few bucks from the "pass the hat" line crew fund, and she wrote her college common app essay on the experience, which apparently impressed admissions directors. Soaring is a great sport!

Don't just gripe; speak up...constructively. The Cordele line crew did a fine job the past two weeks. But when I observed one of the younger ones struggling to balance a ballasted wing during the pre-contest weighing, I approached the operations director there and politely advised him that many of us would be launching with partial ballast and it was critical to balance, not necessarily level the wings before launch. He graciously acknowledged my concern and said he would make sure the crew were properly instructed. I believe they were.

John is correct. It's hardly whining to suggest there are problems at many contests involving the launch sequence. I've thrashed the wing runner issue to death. Sometimes tow pilots show up who haven't towed a lot of ballasted gliders, or towed at that airport, or whose aircraft have ASIs that aren't spot on. I have to call for "[towplane ID], 5 knots more airspeed, please" at least once a contest.

The next tow I got at Nephi after my incident last year was from the same tow pilot. And, again, he seemed to stand on the brakes while powering up, then release them with a predictable slingshot effect on the tow rope. I sought out the chief tow pilot, asked him about the practice, and diplomatically offered my assessment. He listened thoughtfully and promised to talk to the tow pilot. Whatever was said, if anything, it didn't happen again.

He didn't suggest that I bring my own tow pilot if I didn't like the ones he managed.

We pilots should be proactive in helping organizers address staffing issues.. Pilots certainly make mistakes; organizers do, too. The smart ones accept our criticism and suggestions graciously, decide which ones make sense, and take appropriate action.

Just my opinion.

Chip Bearden
"JB"

That's pretty interesting. Seems incredibly minute, but if it [using
spoilers early in the takeoff roll] gets results there's not much to argue
with.

The effect may indeed be minute, and it almost certainly will vary from ship
to ship for a host of subtle, perhaps forever-mysterious, reasons but, "If it
happens, it must be possible!" That noted, "safe soaring" is all about risk
management, and risk management is all about maximizing one's margins in any
given situation. By single-main-wheel definition, takeoff in a sailplane is a
low-margin situation (hence the near-universal need for a wing runner), and
anything Joe Pilot reasonably can do to minimize his time at risk is arguably
worthwhile doing.

My only point against teaching it is the complexity it adds to a launch,
when there's already a lot going on and plenty to be aware of. I can see
it needs to be muscle memory.

Ah, yes, a sixty four dollar question: "Where and by whom shall the technique
be taught and practiced?" Beaucoup soaring skills are self-learned/self-taught
(one of the attractive charms of the activity in my view). Arguably a quick
way to kill the sport dead would be to mandate from the top down a list of
things that *must* be taught over and above those things presently mandated,
on the grounds of soaring presently having insufficient safety. That's not
meant to suggest I completely agree with the level of federal mandation
presently existing (I am not an an instructor nor have I ever played one on
TV), just that "the safety card" over-enthusiastically applied can squash just
about any human activity unto death. (How ironic.) A life reality is there's
no practical way to avoid having to "self-certify" by innumerable daily
decisions/judgements/practices, if we're to remain alive so we can continue to
enjoy what life has to offer. Soaring isn't immune from the
"self-certification need."

Sensible ways for Joe Soaring Pilot to "post-licensing self-certify" would
seem to be much more widely known in general than are (f'r'example) certain
areas of need (e.g. how to enhance aileron power at low speeds). But that'd be
another thread...!

Thanks for the explanation.
You're welcome. This aspect of soaring eventually became a subtlety left for
Joe Soaring Pilot to discover, contemplatitively explore, and learn how to (if
deemed desirable) mitigate "on his own"...and evidently, still is. An easy way
to "avoid the need" for this particular bit of self-teaching is to avoid
flying those higher-aspect ratio glass gliders none of us would ever willingly
give up! Interested readers will find references to the technique beginning to
appear in "Soaring" mag way back in the 1980s.

Bob W.

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Many a tow pilot has wondered, "why are they all whining about 60 knot tows, when that's well above their stall speed, even ballasted?" The answer is that gliders following the towplane are in the downwash of the wing -- not the propwash, the downwash -- but the wingtips are not. So, the wingtips are operating at a larger angle of attack than the main wings. They will now stall first.
Even if the wingtip doesn't stall, the aileron does -- you get the aileron response of ragged edge of stall though the main wing is flying. That's why gliders get wallowy and hard to control on tow behind slow towplanes. This has caused crashes. That's also why it's especially a problem when the towplane takes off, gets up to speed, and then heads for the sky, losing speed, as quite a few tow pilots seem to do. Now the glider is slow, stuck in ground effect, well below the towplane, and deep in the downwash. Yes, airspeed indicators are off, but it's not that hard to be aware of the issue, and ask the first few pilots for a calibration. I think the larger problem is we all get used to towing dry, and the higher speeds just don't feel right.. It's a worse problem for standard class, since they're stall speed challenged to start with and many flaps typically allow a little more twist.

10.6.2.9 ...Towplanes will tow at 80 miles per hour (unless otherwise requested) in a pre- selected pattern to an altitude of 2000 feet AGL (or as specified by the CD).

What John said, even though he had to go and mention "whining" again.

For more discussion (any takers?), see "Glider Handling on Tow" on RAS a few years ago: https://groups.google.com/forum/#!searchin/rec.aviation.soaring/%22glider$20handling$20on$20tow%22/rec.aviation.soaring/rxCTVDJnKVc/Qn6gkHnP7EgJ

My number is 60 kts. dry and 70 kts. fully ballasted in a Standard Class glider. Below those numbers, I am VERY uncomfortable and less maneuverable. So add 5 kts. to allow for tow pilots who ease back on the stick after they've climbed up a few hundred feet.

Flapped 15M gliders have a bit more margin. Big ships seem to have still more but I can't speak from experience.

Chip Bearden
"JB"

I must admit the downwash discussion is one I'm not fluent on. I've been around a while, but it's certainly an interesting concept I don't know much about. Makes you wonder how high a position you'd have to be for it not to matter...especially when you consider actual climb gradient, compared to AoA and angular fluid dynamics from the tug wing back to a glider 200' back. I haven't seen it in any book, but the books have been updated a few times and it doesn't mean it doesn't exist.

On Saturday, June 17, 2017 at 4:25:51 PM UTC-4, Echo wrote:
My only point against teaching it is the complexity it adds to a launch, when there's already a lot going on and plenty to be aware of. I can see it needs to be muscle memory. Thanks for the explanation.

I don't know of anyone who teaches it. I watched other pilots do it and spoke with them, then tried it myself. It works on my ASW 24.

BTW, I cycle the dive brakes open and closed (without locking them) as the slack comes out of the rope to let the wing runner know I haven't simply forgotten to lock them. Once I have aileron authority, I close and lock them and then focus on lifting off smoothly. Yes, it's one more motion. But I flew a flapped ship for a long time and lowering the flaps to lift off is a little bit analogous, although the lever moves in the opposite direction.

Gary, it's possible you didn't find it necessary because the Pegasus wing may have had a lower angle of incidence than some other Standard Class gliders. I seem to recall reading or hearing that although I can't find any references.

Chip Bearden
"JB"

On Friday, June 16, 2017 at 7:55:55 PM UTC-4, wrote:
I have a secret.

Well, like secrets in a Congressional Intelligence subcommittee, this one is probably known by several hundred people. But I haven’t written about it. Until now.

But first, the lead in. A few days ago on the last day at the Cordele nationals, I dropped a wing on takeoff. The ballast tanks were half full so although the tip didn’t go down hard, the water sloshed in that direction and the wing stayed down. My ASW 24 started to swing off to the right. I wasted no time in pulling the tow release. The glider continued to swing and I braked as I rolled off the asphalt runway into the grass and stopped..

No big deal. I’ve had a rule for many years that if the wing goes down early with ballast, I release. It's almost impossible to get the tip up again (more later). I’ve done it twice before--both times on grass--and it’s slightly embarrassing but uneventful except for blocking the launch. This time I actually rolled out of the way. Not much more than five minutes later, I had been retrieved with a golf cart, put back on the launch line, and was away without ever having to climb out of the cockpit.