Texas Tragedy Info?

On Jun 20, 10:36*am, John Cochrane
wrote:
Ramy

Lark manual with scratched in hard to read W&B numbers for that particular ship:http://www.clubplaneadoresbari.com.a...ark_Manual.pdf

Seems to me that a tail dolly heavy enough to put it out of the aft limit would have to be very heavy.

The manual is interesting. P. 7 says the minimum front seat weight is
183 lbs. it also gives 22-47% mac range
The chart on the last page--an obvious reference if you're taking
light passengers in the front seat -- says 90 lbs in the front seat is
ok
The calculation on the second to last page says 183 in the front seat
is fine at 37%, and 121 in each seat is fine at 39%
Why is the placard 183 lbs then?
Somebody who knows how much a lark dolly weighs could certainly tell
us minimum front seat weight with dolly on given this chart
I surely hope we're not replaying this onehttp://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20001208X06614

John Cochrane

I hope not as well. Both cockpits are well ahead of the aerodynamic
center so I would expect the CG to be well forward with three souls on
board. I don't think the tail dolly had much effect in this accident
as long as it was not unusually heavy. In fact, it may have prevented
a forward-of-limit CG.

That said, the Twin Lark has some 'interesting' trim/pitch stability
behaviors. At higher speeds, even with negative flaps, the glider
becomes progressively nose heavy requiring significant aft stick
pressure to prevent a steeper dive. If re-trimmed for the higher
speed, slowing down causes increasing tail heaviness. This indicates
that pitch stability becomes divergent under normal flight conditions
which is not what I would expect from a standard category glider.

Bill D - former Lark owner.

http://www.memorialsolutions.com/sit...r=653176Blair#

At 17:15 20 June 2012, Bill D wrote:
On Jun 20, 10:36=A0am, John Cochrane
wrote:
Ramy

Lark manual with scratched in hard to read W&B numbers for that
particu=
lar
ship:http://www.clubplaneadoresbari.com.a...ark_Manual.pdf

Seems to me that a tail dolly heavy enough to put it out of the aft
lim=
it would have to be very heavy.

The manual is interesting. P. 7 says the minimum front seat weight is
183 lbs. it also gives 22-47% mac range
The chart on the last page--an obvious reference if you're taking
light passengers in the front seat -- says 90 lbs in the front seat is
ok
The calculation on the second to last page says 183 in the front seat
is fine at 37%, and 121 in each seat is fine at 39%
Why is the placard 183 lbs then?
Somebody who knows how much a lark dolly weighs could certainly tell
us minimum front seat weight with dolly on given this chart
I surely hope we're not replaying this
onehttp://www.ntsb.gov/aviationque=
ry/brief.aspx?ev_id=3D20001208X06614

John Cochrane

I hope not as well. Both cockpits are well ahead of the aerodynamic
center so I would expect the CG to be well forward with three souls on
board. I don't think the tail dolly had much effect in this accident
as long as it was not unusually heavy. In fact, it may have prevented
a forward-of-limit CG.

That said, the Twin Lark has some 'interesting' trim/pitch stability
behaviors. At higher speeds, even with negative flaps, the glider
becomes progressively nose heavy requiring significant aft stick
pressure to prevent a steeper dive. If re-trimmed for the higher
speed, slowing down causes increasing tail heaviness. This indicates
that pitch stability becomes divergent under normal flight conditions
which is not what I would expect from a standard category glider.

Bill D - former Lark owner.

Some of the gliders I fly will take a far greater weight of water in the
fin tank than even the heaviest dolly I have seen, getting airborne with
the tail dolly still attached is more embarassing than a danger.

Truly tragic. Condolences to the family and friends. Fred

On Monday, June 18, 2012 1:55:21 PM UTC-5, Ramy wrote:

If it is not the cause, must be to main contributing factor. I just find it hard to believe that it is unrelated.

Ramy, unless the glider was stalled and spun and couldn't recover, the tail dolly likely didn't have anything to do with it.

Aft CG makes a plane sensitive in pitch and possibly hard (or impossible) to recover from a stall/spin. But on tow you are way above stall speed.

Biggest problem with a tail dolly left on (on most gliders with a normal CG) is lack of directional control on takeoff or landing.

But again, this is all speculation.

Sad, whatever the cause. But Tom K may have to add number 45 to his list...

Kirk
66

On Jun 18, 12:35*pm, wrote:
On Monday, June 18, 2012 2:13:38 PM UTC-4, Ramy wrote:
On Monday, June 18, 2012 10:54:30 AM UTC-7, cuflyer wrote:
On Monday, June 18, 2012 9:37:03 AM UTC-4, Linwood wrote:
Anyone have any knowledge of the three fatality glider crash in Texas?
Glider type? Situation?

Linwood

Kid on his mother's lap - ? *Affecting control - ?
This is really ugly.

1FL

It was indeed the freaking tail dolly!!!
http://blog.chron.com/newswatch/2012...ash-under-inve...

Ramy

Nope- If the tail dolly was on, glider is still flyable. Most likely speculation on may part-#1 rule broken here which is FLY THE AIRPLANE.
I have seen a few tail dolly incidents or the years, and in every case, the pilot had to be told that the tail dolly was still on.
Other bad rule broken- NO unrestrained people in the glider- ever.
Terribly sad
UH

I remember my 3 year old would reach out and pull any yellow "toy" on
a string.

Nope- If the tail dolly was on, glider is still flyable. Most likely speculation on may part-#1 rule broken here which is FLY THE AIRPLANE.
I have seen a few tail dolly incidents or the years, and in every case, the pilot had to be told that the tail dolly was still on.
Other bad rule broken- NO unrestrained people in the glider- ever.
Terribly sad
UH

Photos do clearly show the tail dolly on. That can't help a cg, though
as Hank says unlikely to move it too far aft unless already at the
back limit. It does suggest things getting hurried in the preflight.

Photos also show both spoilers full open. That could happen in a crash
of course, but might also be indicative of things going wrong. There
was a spoler-open crash earlier this year where the pilots
interepreted the rudder waggle as a wing rock (NTSB). This is a very
dangerous combination. If you don't know the spoilers are open, you
won't know to use the much lower-nose pitch attitude that spoilers
require. You're at 200 feet, not aware your spoilers are open, and in
a pitch attitude that will lead quickly to loss of airspeed. I've been
having towplanes waggle rudders at BFR rides for a while, quite a few
of them release.

And I have to agree with Hank. They let you carry kids on airliners,
but this ain't an airliner -- there's no stick in seat 37E either.
Small children won't get that much out of a glider ride that can't
wait until they can sit alone. I don't let rides even bring video
cameras any more. They won't produce good footage, they'll just get
sick looking through the camera, and it can drop in uncomfortable
places.

John Cochrane

On Monday, June 18, 2012 12:04:38 PM UTC-7, John Cochrane wrote:

Nope- If the tail dolly was on, glider is still flyable. Most likely speculation on may part-#1 rule broken here which is FLY THE AIRPLANE.
I have seen a few tail dolly incidents or the years, and in every case, the pilot had to be told that the tail dolly was still on.
Other bad rule broken- NO unrestrained people in the glider- ever.
Terribly sad
UH

Photos do clearly show the tail dolly on. That can't help a cg, though
as Hank says unlikely to move it too far aft unless already at the
back limit. It does suggest things getting hurried in the preflight.

Photos also show both spoilers full open. That could happen in a crash
of course, but might also be indicative of things going wrong. There
was a spoler-open crash earlier this year where the pilots
interepreted the rudder waggle as a wing rock (NTSB). This is a very
dangerous combination. If you don't know the spoilers are open, you
won't know to use the much lower-nose pitch attitude that spoilers
require. You're at 200 feet, not aware your spoilers are open, and in
a pitch attitude that will lead quickly to loss of airspeed. I've been
having towplanes waggle rudders at BFR rides for a while, quite a few
of them release.

And I have to agree with Hank. They let you carry kids on airliners,
but this ain't an airliner -- there's no stick in seat 37E either.
Small children won't get that much out of a glider ride that can't
wait until they can sit alone. I don't let rides even bring video
cameras any more. They won't produce good footage, they'll just get
sick looking through the camera, and it can drop in uncomfortable
places.

John Cochrane

While may not related to this accident, I understand there was another rudder waggle accident recently??
Just to show how confusing it is, I specifically asked in my last BFR to get a rudder waggle (I know, it is not as effective when you ask for it) - the instructor or tow pilot misunderstood and gave me a wing rock instead. It was still effective, since my decision is to always check my rudder first before releasing no matter what the tow plane is doing. If we always trained that way, we could eliminate this deadly but common mistake.

Ramy

Can you elaborate on what you mean by "since my decision is to always check my rudder first before releasing no matter what the tow plane is doing. If we always trained that way, we could eliminate this deadly but common mistake. "

My control (including rudder check) is before hookup. If I understand what you're saying, you work the rudder before release.
1) how does that eliminate this deadly mistake?
2)What do you do if you discover it to be jammed at that time? Tow back to a landing? That's hardly the best time to discover that, I would think. {that may sound a little snarky, but I don't mean it that way - just a genuine inquiry}


On Monday, June 18, 2012 12:46:53 PM UTC-7, Ramy wrote:
On Monday, June 18, 2012 12:04:38 PM UTC-7, John Cochrane wrote:

Nope- If the tail dolly was on, glider is still flyable. Most likely speculation on may part-#1 rule broken here which is FLY THE AIRPLANE.
I have seen a few tail dolly incidents or the years, and in every case, the pilot had to be told that the tail dolly was still on.
Other bad rule broken- NO unrestrained people in the glider- ever.
Terribly sad
UH

Photos do clearly show the tail dolly on. That can't help a cg, though
as Hank says unlikely to move it too far aft unless already at the
back limit. It does suggest things getting hurried in the preflight.

Photos also show both spoilers full open. That could happen in a crash
of course, but might also be indicative of things going wrong. There
was a spoler-open crash earlier this year where the pilots
interepreted the rudder waggle as a wing rock (NTSB). This is a very
dangerous combination. If you don't know the spoilers are open, you
won't know to use the much lower-nose pitch attitude that spoilers
require. You're at 200 feet, not aware your spoilers are open, and in
a pitch attitude that will lead quickly to loss of airspeed. I've been
having towplanes waggle rudders at BFR rides for a while, quite a few
of them release.

And I have to agree with Hank. They let you carry kids on airliners,
but this ain't an airliner -- there's no stick in seat 37E either.
Small children won't get that much out of a glider ride that can't
wait until they can sit alone. I don't let rides even bring video
cameras any more. They won't produce good footage, they'll just get
sick looking through the camera, and it can drop in uncomfortable
places.

John Cochrane

While may not related to this accident, I understand there was another rudder waggle accident recently??
Just to show how confusing it is, I specifically asked in my last BFR to get a rudder waggle (I know, it is not as effective when you ask for it) - the instructor or tow pilot misunderstood and gave me a wing rock instead. It was still effective, since my decision is to always check my rudder first before releasing no matter what the tow plane is doing. If we always trained that way, we could eliminate this deadly but common mistake.

Ramy

On Monday, June 18, 2012 3:13:11 PM UTC-5, Bill Palmer wrote:
Can you elaborate on what you mean by "since my decision is to always check my rudder first before releasing no matter what the tow plane is doing. If we always trained that way, we could eliminate this deadly but common mistake. "

My control (including rudder check) is before hookup. If I understand what you're saying, you work the rudder before release.
1) how does that eliminate this deadly mistake?
2)What do you do if you discover it to be jammed at that time? Tow back to a landing? That's hardly the best time to discover that, I would think. {that may sound a little snarky, but I don't mean it that way - just a genuine inquiry}


On Monday, June 18, 2012 12:46:53 PM UTC-7, Ramy wrote:
On Monday, June 18, 2012 12:04:38 PM UTC-7, John Cochrane wrote:

Nope- If the tail dolly was on, glider is still flyable. Most likely speculation on may part-#1 rule broken here which is FLY THE AIRPLANE.
I have seen a few tail dolly incidents or the years, and in every case, the pilot had to be told that the tail dolly was still on.
Other bad rule broken- NO unrestrained people in the glider- ever.
Terribly sad
UH

Photos do clearly show the tail dolly on. That can't help a cg, though
as Hank says unlikely to move it too far aft unless already at the
back limit. It does suggest things getting hurried in the preflight.

Photos also show both spoilers full open. That could happen in a crash
of course, but might also be indicative of things going wrong. There
was a spoler-open crash earlier this year where the pilots
interepreted the rudder waggle as a wing rock (NTSB). This is a very
dangerous combination. If you don't know the spoilers are open, you
won't know to use the much lower-nose pitch attitude that spoilers
require. You're at 200 feet, not aware your spoilers are open, and in
a pitch attitude that will lead quickly to loss of airspeed. I've been
having towplanes waggle rudders at BFR rides for a while, quite a few
of them release.

And I have to agree with Hank. They let you carry kids on airliners,
but this ain't an airliner -- there's no stick in seat 37E either.
Small children won't get that much out of a glider ride that can't
wait until they can sit alone. I don't let rides even bring video
cameras any more. They won't produce good footage, they'll just get
sick looking through the camera, and it can drop in uncomfortable
places.

John Cochrane

While may not related to this accident, I understand there was another rudder waggle accident recently??
Just to show how confusing it is, I specifically asked in my last BFR to get a rudder waggle (I know, it is not as effective when you ask for it) - the instructor or tow pilot misunderstood and gave me a wing rock instead.. It was still effective, since my decision is to always check my rudder first before releasing no matter what the tow plane is doing. If we always trained that way, we could eliminate this deadly but common mistake.

Ramy

Friends ..
Being so crushed and speechless sitting "mind empty" at my desk .. not be able to gather thoughts, I decided to share with you something I am gathering keen observation on , which may or may not played a rule here but it may be equally important preventing another tragic accident.
I have been flying glass ships for a while, and kind of the ship I fly requires solid 60-65 knots on the tow. This is what makes me comfortable and provides me full control over her..
I have been flying in different places, and I noticed NOT A ONE TIME when tow pilot slowed down so dramatically in a deep turn (intentionally or not) ... that my stick become very.. very.. mushy (and some oscillation my shows up when getting in-and-out of the wake.
To cut some comments right away .. YES - I always ask for 65kts - 60kts min .. on the radio before a take off as a part of my pre-takeoff routine ..
Nerveless, things happen as I learned to live with unexpected ... My method is stay close to the wake (and hide there at the earliest speed drop) especially during early part of the takeoff and watching my release handle just-in-case .. before my wings drop beyond recovery ..
Believe me when I say then one tow pilot had a ASI in miles .. and did not translated my "knoted" requests to proper speed...
And sometimes tow pilots wants to pull me up as quickly as they possibly could ... since the weather is so nice ..and the WAITING LINE is long.

HEAVY TAIL (with a dolly -- but STILL FLYABLE) ... suddenly reduced speed on tow in a first turn ... maybe not much but enough to stall "out of balance" glider ... and pitching may be just a desperate case to wrestling last bits of control from stalling glider ... until the rope broke ..

Respectfully Yours - KiloCharlie