Eine Wasserung mit Flügelbruch

[cosy]

Eindrückliches Beispiel, was passieren kann, wenn man mit einem Segelflugzeug wassern muss:

beide Flügelholme brachen.

https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/105343/pdf

 

 

Cosy

[swissglobaltraveller]

Ein interessantes Bild. Das Docket offeriert noch ein paar zusätzliche Informationen; wobei ich den Pilot Report empfehle: https://data.ntsb.gov/Docket?ProjectID=105343

 

Zitat

The day of the incident was last practice day for the Truckee regional glider competition that started the next day. That morning's pilot's
meeting was called, a task for the day was given, and a forecast of a typical summer day in the area going south to Mono Lake and return.
For this area, a typical summer day meant 15k to 17k cloud bases, plenty of Cumulus cloud markers on course, and light winds. There
were to be about 15-20 gliders being launched that day t o go fly the task. A start time o f 12:30pm was set. The launch was slow due t o
only one tow plane available for the day, however I got off tow at 12:25 and found a decent climb to top of lift. I decided to start right away
and not look for an optimized start since everyone had already left the start gate. I headed south via the West side of Lake Tahoe and
had a very long slow, glide down to 1000 AGL to South Lake Tahoe Airport. I found a good climb there which allowed me to get out of the
Tahoe Lake Basin and continue south.
On my way south, cloud bases were as expected a t 15k MSL and they were raising to 17k as I flew South around Mono Lake. As I flew
South spending time between 12k MSL and 16k MSL, I started to become very cold around the time I got near Mono Lake. My air vent in
my cockpit does not close all the way and so outside air was being piped the entire flight. My OAT gauge showed 15 degrees Fahrenheit
at one point. Also as result of the cold air temperatures, my pee tube froze. I use a condom catheter to connect to the system, however
the pee tube does not drain fully after use. So I figured out m y pee tube froze as my condom catheter was filling up like a water balloon.
I spent approximately 45 mins flying North with myself exposed like this before getting low enough that pee tube unfroze and the water
balloon drained itself. I told people: before I landed in Lake Tahoe, my flight was the most miserable one I've ever had in a glider.
I returned North to around Topaz Lake and had to make a decision. Go to Freel Peak near Heavenly ski resort or go north off course t o
Mineral Peak on the Pine Nuts to find my last climb for final glide back to Truckee. There was a big cloud over Freel and Pine Nuts
looked like they were weak for the climb I was looking for. So I went to Freel Peak. I did find lift directly over Heavenly ski resort and was
climbing very slowly. During my time there, another glider joined my thermal. We weren't climbing very well and so the other glider left
the thermal. Considering that there was still good clouds showing on the east side of the lake and I was experiencing a west wind, those
factors lead me to think that I could "surf" ridge lift without losing too much altitude until I could find another, better climb.
I experienced nothing but sink until Marlette Lake where I found a decent climb, but not enough to give me plenty of margin to final glide t o
Truckee. I think I had enough altitude to go back south and find a lower spot on the ridge to dive into the Carson Valley to land at either
Minden o r Carson City if I couldn't find a climb in the valley or go for Brockway peak (lowest point on the ridge between me and Truckee).
I thought I could make Brockway and really wasn't sure of the Carson Valley plan, so | headed Northwest over Lake Tahoe. During this
glide, I experienced more sink. Fully committed to Truckee at this point, I looked for climb on the ridge that juts into the lake just west o f
Crystal Bay. I found a small, weak climb there but eventually leading to zero sink, and I was facing a headwind. With every turn not
gaining any altitude and getting pushed away from Truckee, I went for Brockway peak. About 1/2 mile away I felt that I would be really
endangering my life if I continued and always knew landing in the lake at minimum would keep me alive and unhurt. So I turned South
towards to a peak o f a small wooded hill. At this point I was 700 AGL over the lake, so I made 2 turns with no altitude gain.
At this time, I fully committed to the lake landing, looking for a place to land. I wanted to not swim and not hit anyone, and I was able t o
select a portion of the lake inside the boats moored in the water that was parallel to the wind. On downwind, I pulled my spoilers and put
down my landing gear. On final I noticed I was fast (50 kts) for a minimum energy landing, and began trying to slow the glider more. I hit
the water in a flat attitude, with the main landing gear hitting first, which assisted in pushing the nose into the water first. The glider
decelerated over the course of no longer than 2 secs. Water was entering into the cockpit via the nose vent and side vent in the canopy.
Already being cold from the flight, I wanted to get out the water as soon as possible. I opened m y canopy which caused water to rush in.
I unbuckled and easily got of the aircraft, and was able to walk onto the beach.
911 was called and I was taken to an ambulance, primarily to warm up and get wet clothes off. Around 7:00 pm, my trailer arrived with
other glider pilots to assist me in getting my glider out of the water and into the trailer where it was taken to Truckee.

 

Der Flug selber ist hier auf WeGlide dokumentiert: https://www.weglide.org/flight/952840

 

Die Offenheit ist zu begrüssen; so können wir alle etwas lernen aus dem Vorfall. Und das ist eigentlich eine Menge:

- Der Startort Truckee ist auf 1700m; das ist also ähnlich wie Samedan. Man muss sich von Beginn weg richtig anziehen für den Flug; damit man nicht kalt hat.

- Der Flug war fast 90 Minuten über 4000m (mit ein paar Minuten unterbruch); entsprechend ist seine Urin-Drainage eingefroren - offenbar schon auf dem Flug bis zum Wendepunkt (nach 2:20). Man „muss“ im Normalfall eigentlich nicht nach so kurzer Flugzeit; ausser man vergass vorher zu pinkeln oder man hat kalte Füsse. Oder beides. (Medizinische Gründe mal ausgeblendet; das könnte auch sein).

- Flugtaktik: Auf dem Rückweg war er die längste Zeit noch im Trichter von Minden-Tahoe und wohl auch Carson. Er hätte problemlos abgleiten können, statt in das schwierig landbare Becken vom Lake Tahoe reinzufliegen. 

- Wasserung: Die Optionen waren dann wirklich rar; das Gelände ist nicht sehr vorteilhaft. Allerdings geriet die Landung viel zu schnell; base-final mit über 100km/h; gemäss seinem Beschrieb 50kts (= ca 90km/h). Das ist viel zu schnell; Wasserlandungen sollten ohne Bremse bis an die Stall-Speed geflogen werden (eine LS-6: ca. 62km/h); um mit möglichst wenig Energie aufzusetzen. Dass einem dann die Flügel um die Ohren fliegen verwundert mich nicht. 

 

Eine Lehnstuhl-Analyse ist immer einfach; wir kennen die Tagesverhältnisse, Wolkenbild etc nicht - nur seinen Beschrieb und die Aufzeichnung. Abgesehen von einem geknacksten Flügel (und vielleicht auch Ego des Piloten..) ist aber zum Glück nichts passiert. Der Pilot fliegt wieder und wir alle durften von dem Vorfall was lernen. 

 

Nachtrag: Aus dem Beschrieb geht nicht hervor, ob der Pilot Sauerstoff zu sich genommen hat. Bei den Höhen über die lange Zeit (90min >4000m) eigentlich ein „must“. Ohne Sauerstoff würde ich eine verminderte Leistungsfähigkeit aufgrund Sauerstoffmangel der Liste hinzufügen.

 

Bearbeitet 3. Februar von swissglobaltraveller
Nachtrag Sauerstoff