A Tale of Two Takeoffs

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.

There was a bit of a tailwind (under 5 kts.). But the biggest contributor was a slightly heavy right wing caused by the water not being evenly distributed. I had checked it on the grid but I noticed the girl who (very competently) balanced the wings while the glider launched ahead of me held the right wingtip a bit higher than normal. Just before takeoff, though, she passed it to a young man who actually ran it. In the hurried exchange, it’s possible he leveled the wings, thereby allowing the water to shift in that direction. With partial tanks, any imbalance is quickly magnified although I’ve only touched a wingtip once before in 25 years of flying the ‘24.

Speaking of which, now for my “secret.� Almost exactly a year ago at last year’s Nephi nationals, I had full ballast, a 10 kts.. tailwind, high density altitude, and (I’m told) a very young, inexperienced wing runner. My impression was that the tow pilot stood on the brakes as he ran the engine up, then released them. The rope stretched and we popped off the line impressively, then seemed to sag as the stretch came out of the rope before accelerating again, in somewhat more leisurely fashion.

The initial surge surprised the young wing runner and he held onto the tip briefly, swinging me to the right, before dropping it. The tip hit the ground almost immediately as we gathered speed. I was near the front and knew there was a lot of emphasis on keeping the launch going. This was the first contest day and launching 55 gliders had taken too much time on the practice days. So I felt (self-imposed) pressure to stay on tow. And I felt (again, self-imposed) pressure to recover from what I judged was my mistake.

The wide runway and gravel/grass on the right looked completely clear: I didn’t see spectators, vehicles, aircraft, or other obstructions. So I broke my rule of almost 40 years and held on. I remember thinking “I can do this!� As we accelerated, the glider continued straight at an angle to the runway centerline, drawing closer to the edge. My ship has a CG hitch so with the right wing still down, there was nothing to help straighten us out. With full left aileron and rudder, the right wing refused to come up. I knew the gravel on the edge of the runway and the scrubby grass beyond were smooth. So I held on as we rolled off onto the gravel.

By that time we were traveling fast enough that I really didn't want to release. And I could sense that the wing was just about to pop up. It did. I steered back onto the runway, put the dive brakes in (which I use on takeoff roll to improve aileron response), then lifted off, sliding back into position behind the towplane. My heartrate was a little higher but to be honest, I didn’t think it was that dramatic.

I flew the difficult task and landed back late that afternoon. As I rolled to a stop at the end of the runway, I was startled to see the operations director leap out of his car with a grim look on his face and start snapping photos of my right wing. Turns out I had hit a landing light on takeoff, slightly damaging the leading edge about 2/3 of the way out and punching a small hole in the underside of the aileron. I never heard or felt it! Thanks to the heroic efforts of York Zentner--and with assists from my brother, Mark, and poor weather the next day--I was back in the air in time not to miss any action.

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.

I could have blamed the tailwind and young wing runner, as another ground crew member did a few days later as we chatted on the line. His inexperience almost certainly triggered the incident. 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�

Great write-up. I've also learned the importance of a well briefed experienced wing runner, and letting it sit wings level "until the sloshing noise stops" before takeoff. I do have one question, however. How does extended spoilers improve aileron response? They're inboard of the ailerons on a standard class glider, and therefore should have zero aerodynamic effect on ailerons, except for contributing to total drag and reducing acceleration...(probably an impercievable amount at low speeds, since weight and stationary inetia is the larger factor to overcome, not parasitic drag). I've seen many people use this technique in contest flying, and I never understood it. The only argument that I could maybe see is giving some drag stability, much like hanging out the landing gear does to a large aircraft. And even then, it just adds complexity to an already high workload segment of the flight.

Again, I think your post is both informative and a great pointer for anyone staring to carry water ballast or inexperienced in flying a CG hook. I'm mainly just curious as to why people use the spoiler on takeoff technique.

Jordan

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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Jordan, I have heard several "reasons" for using spoilers on standard class gliders. First of which is that the spoilers "board" the air out ward and increase flow over the ailerons. Second that "spoiling" the lift on the raising wing will let it come back down. I tend to think the first is closer to the truth. But from personal experience in an ASW-19, it works. I didn't really believe it until I tried an experiment. When landing, I put the spoilers away on the last half of the rollout not using the brake untill one of the wings started to drop and I had full aileron deflection in and it continued to drop. At this point I was traveling at around 10-15 mph, when I then opened the spoilers the wing imediately came back up and stayed there until I was down to less than a couple of mph. All I really know is that it works.

I flew hundreds of hours in a CG hook Pegasus and never used spoilers during a takeoff. No problems.

gkemp

I don't recall using spoilers or not with my ASW-19b (CG hook), but I
always used spoilers and negative flaps with my LS-6a also a CG hook)
and found that to be an improvement. I continued using negative flaps,
but no spoilers, in my LAK-17a (CG hook), and had no problems there, either.

In Chip's case, I agree with his assessment that the main cause of
trouble was the partial ballast load shifting outboard on one side
(inboard on the other).

On 6/17/2017 6:22 AM, gkemp wrote:
I flew hundreds of hours in a CG hook Pegasus and never used spoilers during a takeoff. No problems.

gkemp

--
Dan, 5J

Spoilers open on takeoff works. Until you're trying to take off high altitude, hot, cross-downwind, full of water, you won't notice the need. Then you will. You get a crucial second or two of better aileron control.

Thanks much Chip for the good post. Wing running is a constant problem at contests. I've had several incidents where despite my careful briefings, contest wing runners just can't get it right. The wings must be balanced, level, sloshed through the baffles, but if there is a significant cross wind (mifflin), the upwind wing cannot be high. You must run. This is not a 2-33. Runway lights make it a higher priority.

It's hard to whine. The wing runners are volunteers, and spending a long hot day running wings for cranky pilots cannot be fun. Still, along with slow tows, this is a constant problem at contests, and perhaps more regular emphasis by contest management would help.

(Why must every contest start with a litany of "towplane alpha bravo, more speed please." "towplane alpha bravo, more speed please.".... )

John Cochrane

Yup John you are whining 😀. If you need and desire the best for you, wing runners and tow pilots, you can bring them along or better yet be a wing runner for a contest. All are volunteers and they do the best they can and contest management do the best with the resources available.

Ron:

Thanks, and I really did hesitate to say anything, as I hesitate and hesitate again to complain at contests. On the other hand, we do have a problem of wing drop after wing drop, sometimes causing damage, once causing damage to a spectator, and the problem is not hard to fix. We also have a constant problem of too slow tows with ballasted gliders. Everyone gets used to flying without ballast over the winter I guess.

Perhaps you can help with social suggestions. While showing my deep appreciation for the volunteers and towpilots, who give up their free time and suffer in the sun all on my behalf, how can I get the message across -- wings must be balanced, slosh ballast through baffles in tanks if need be, they should be darn close to level -- which is hard to see given winglets, and a contest glider wing at familiar shoulder height is way too high -- and if there is a crosswind, it is imperative to have the upwind wing at least level if not a foot low at the moment of release. Plus, run. How do I say that really politely, and show the deep appreciation that I really do feel?

It is frustrating to be sitting on the side of the runway, in the dust, bottom of the wing all scratched up, on account of an easily preventable error..

John Cochrane

On Saturday, June 17, 2017 at 11:40:18 AM UTC-4, John Cochrane wrote:
Spoilers open on takeoff works. Until you're trying to take off high altitude, hot, cross-downwind, full of water, you won't notice the need. Then you will. You get a crucial second or two of better aileron control.

Thanks much Chip for the good post. Wing running is a constant problem at contests. I've had several incidents where despite my careful briefings, contest wing runners just can't get it right. The wings must be balanced, level, sloshed through the baffles, but if there is a significant cross wind (mifflin), the upwind wing cannot be high. You must run. This is not a 2-33.. Runway lights make it a higher priority.

It's hard to whine. The wing runners are volunteers, and spending a long hot day running wings for cranky pilots cannot be fun. Still, along with slow tows, this is a constant problem at contests, and perhaps more regular emphasis by contest management would help.

(Why must every contest start with a litany of "towplane alpha bravo, more speed please." "towplane alpha bravo, more speed please.".... )

John Cochrane

I don't fault the wing runner.
It was Chip's responsibility to have the glider with acceptable wing balance.
Possibly a very experienced wing runner might have stopped this event, but most don't have the experience or judgement.
This is the second case of serious wing drop due to balance at contest I have flown at this year. The other resulted in a glider not flyable.
The lessons I see he
1-The pilot must be careful to ensure balanced loading.
2-Line crews need to be trained to recognize imbalance and be prepared to stop the launch to correct. The line boss needs to be ready to confirm the problem or declare good to go.
3- We all need to ready and more incline to end a bad start.

FWIW
UH