Accident in Namibia, SH Ventus 2cxm

The news of the crash in Namibia on the 11th January 2016 was published yesterday.
http://www.republikein.com.na/ongelu...r-lodge.262951

Summary in English:
A French couple bailed out of a Nimbus 4DM (German registered D-KCTI) near the Bitterwasser Lodge, on the 11th January 2016 at 15:40 UTC (16:40 local).

According to the report the left wing dropped while thermalling and recovery was not possible. My assumption is that this was another Nimbus 4 in flight break up during spin recovery.

The 65 year old male sustained minor injuries while the 60 year old woman suffered no injuries. They managed to bail out at about 700 meters AGL.

"My assumption is that this was another Nimbus 4 in flight break up during spin recovery."

How many of these have there been?

Boggs

Le vendredi 15 janvier 2016 16:12:36 UTC+1, Waveguru a écrit*:
"My assumption is that this was another Nimbus 4 in flight break up during spin recovery."

How many of these have there been?

Boggs

Some. Spiral dives and spins with 25m+ gliders go with a huge chance of not being able to recover inside the flight enveloppe. The moment of inertia of these gliders are massively higher than with a 15m/18m glider. They take longer time to stop the rotation, while airspeed increases very rapidly.

Bert
Ventus cM ZW

How can they get certification if they come apart recovering from a spin?

Boggs

Le vendredi 15 janvier 2016 17:44:12 UTC+1, Waveguru a écrit*:
How can they get certification if they come apart recovering from a spin?

Boggs

You can recover from a spin, but you'd need to be sharp. You miss a beat, you'll loose a wing.
Not sure whether a glider 25 m is required to undergo spin testing for certification.

Actually my Nimbus 4 was an honest spinner. Once while thermaling in a valley very close to the moutons a gust tried to get a spin developed, normal recovery. Prior to this I had done a number to spin entries followed by normal recovery. I never let a spin develop as i would not in normal flying either. There is a wait time while you wait for a control surface to dig in, but all in all I thought it was honest a normal. I also have several hundred hours in a Nimbus 4D. I found the 4D flew considerabily different than the single seat Nimbus 4.

The rigging is very important on a Nimbus and when I first got mine is was rigged horribly and flew horribly. Fixed the rigging and it was a beauty to fly.

On Friday, January 15, 2016 at 9:01:21 AM UTC-8, Tango Whisky wrote:
Le vendredi 15 janvier 2016 17:44:12 UTC+1, Waveguru a écrit*:
How can they get certification if they come apart recovering from a spin?

Boggs

You can recover from a spin, but you'd need to be sharp. You miss a beat, you'll loose a wing.
Not sure whether a glider 25 m is required to undergo spin testing for certification.

Le vendredi 15 janvier 2016 22:07:57 UTC+1, Jonathan St. Cloud a écrit :
The rigging is very important on a Nimbus and when I first got mine is was rigged horribly and flew horribly. Fixed the rigging and it was a beauty to fly.


Hi Jonathan,
Very interesting. I have a N4DM since 17 years and 2.500 hours and see no possibility at all to change any setting during rigging. I can't understand how I may "rig horribly"... Thanks for explaining to me and others.
Instead, I can change the setting of the flap angle and the force of airbrake locking by changing the extension of the controls between the fuselage and the inner wing, but this is something that takes time and attention, not simply a rigging. BTW, I actually change the airbrake locking force twice a year, for cold flights in Patagonia and warm ones in Europe. See my book "Dancing with the Wind" page 194 and following (on sale at Cumulus Soaring)..
All the best
jm

On Tuesday, February 2, 2016 at 11:58:17 AM UTC+3, wrote:
Le vendredi 15 janvier 2016 22:07:57 UTC+1, Jonathan St. Cloud a écrit :
The rigging is very important on a Nimbus and when I first got mine is was rigged horribly and flew horribly. Fixed the rigging and it was a beauty to fly.


Hi Jonathan,
Very interesting. I have a N4DM since 17 years and 2.500 hours and see no possibility at all to change any setting during rigging. I can't understand how I may "rig horribly"... Thanks for explaining to me and others.
Instead, I can change the setting of the flap angle and the force of airbrake locking by changing the extension of the controls between the fuselage and the inner wing, but this is something that takes time and attention, not simply a rigging. BTW, I actually change the airbrake locking force twice a year, for cold flights in Patagonia and warm ones in Europe. See my book "Dancing with the Wind" page 194 and following (on sale at Cumulus Soaring).

"Rigging" is a set of devices for adjusting positions, angles, tensions etc of aerodynamic surfaces -- or as a verb the use of such adjustments. Originally from sailing ships but later applied to aircraft (which were initially made in very similar ways. The "rigging angle", for example, refers to the angle between the chord of the wing and the fuselage.

What we refer to as "rigging" of gliders is merely the use of precision quick-release mechanisms that are expressly designed to not alter the settings!

Ailerons, flaps and mixing was rigged wrong. Once that was corrected she was a beauty. Recovered from spin entry within quarter turn of control inputs, dry. Single place Nimbus 4. I still miss that bird!

On Tuesday, February 2, 2016 at 12:58:17 AM UTC-8, wrote:
Le vendredi 15 janvier 2016 22:07:57 UTC+1, Jonathan St. Cloud a écrit :
The rigging is very important on a Nimbus and when I first got mine is was rigged horribly and flew horribly. Fixed the rigging and it was a beauty to fly.


Hi Jonathan,
Very interesting. I have a N4DM since 17 years and 2.500 hours and see no possibility at all to change any setting during rigging. I can't understand how I may "rig horribly"... Thanks for explaining to me and others.
Instead, I can change the setting of the flap angle and the force of airbrake locking by changing the extension of the controls between the fuselage and the inner wing, but this is something that takes time and attention, not simply a rigging. BTW, I actually change the airbrake locking force twice a year, for cold flights in Patagonia and warm ones in Europe. See my book "Dancing with the Wind" page 194 and following (on sale at Cumulus Soaring).
All the best
jm

On Sunday, January 3, 2016 at 3:39:58 PM UTC-5, smfidler wrote:
http://www.az.com.na/unf-lle/schweiz...ngl-ckt.428806

25 m certification; I would chance a guess that the spin recovery
test is done by a very experienced (possibly test) pilot.

John F

An old, no longer bold pilot.