Distracted Pre-Flight Preparation and Checks.

Distracted Pre-Flight Preparation and Checks.

In early May an intermediate rated mini wing pilot hiked the POM North Side to the lower launch by the windsock.  Winds were strong.  The pilot put the wing in a rosette intending to walk down from the saddle to a lower section of the side-hill. The wind inflated the glider ripping it from his hands.   As the glider inflated the pilot noticed that his risers were twisted.  Due to a lot of practice ground handling the pilot was able to untwist the risers just before he was plucked from the ground.  

In this case the pilot’s preflight was distracted/interrupted by the strong wind conditions.  Obviously, anything including strong winds that interrupt your preflight checks increases your risk. 

Regardless the size of glider, launching in strong winds is an advanced skill that even advanced pilots avoid when possible.  In this case the pilot was intermediate and accepted risks avoided by some advanced pilots. 

Flight Outside of Conservative Weather Parameters. Flight Outside of Conservative Equipment Choice Parameters.

Flight Outside of Conservative Weather Parameters

Flight Outside of Conservative Equipment Choice Parameters

In early May a speed wing pilot impacted the ground at the top of the back upper bench of the North Side.  Conditions were strong with winds gusting to approximately 25 mph.  The pilot was reported to have been doing spirals and barrel rolls too close to the ground for the pilot’s level of experience.  The pilot was also flying a mini wing he was not experienced with.  The pilot was able to relaunch and continue his flight to the LZ.

Lessons to be learned here involve the pilot flying in extreme conditions and on wing he was not experienced with.  Witness reports indicate that the pilot was flying maneuvers beyond his level of experience and ability.  

From the Book of Risk:

With the aid of counseling, mindfulness meditation, religion or whatever means of your choice, understand your ego.

Flight outside of conservative weather conditions

Flight outside of conservative weather conditions

In early May an advanced rated pilot was flying a C rated glider for the first time in strong wind conditions at the North Side POM.  The pilot reported using the speed bar frequently during the flight presumably to keep the glider from being blown over the back of the upper ridge.  After more than an hour of flying, in which the pilot said he felt comfortable with the conditions, the pilot found himself descending in the compression zone behind the upper ridge unable to penetrate to the front of the ridge.  Use of bar at that point just increased the rate of decent.  Fearing descent into the mechanical rotor behind the ridge the pilot turned south, flew to the south behind and away from the ridge and landed in strong surface winds on a small hill near a housing development.

In this case the pilot seems to have turned directly downwind from the point he determined he could not penetrated the headwind head on.  Another strategy is to first crab to the west.  Crabbing is flying crosswind so you are not trying to penetrate the full strength of the wind.  Moving west in this fashion can also increase your ground clearance because the ground’s elevation is dropping away.  If you still cannot penetrate forward of the ridge you will have more clearance fly over the back nearer or over the South Side.  Don’t try to land at the south side, rather land as far south as you possibly can.  Mechanical turbulence can propagate as far as 10 times as far behind the ridge as the ridge is high.   

From the Book of Risk:

As you fly continually assess the wind strength and cloud development.

Know how to get down quickly.  If you see a weather risk you do not wish to accept fly out away from terrain.  Find the greenest most obstruction free landing area you can and land as far away from even the smallest obstacles as possible. 

From the UHGPGA website safety briefings for the North Side:

1. While benching up at the north side fly to the front occasionally to check penetration.
2. If you are above the back ridge and cannot penetrate forward get as high as possible and fly to the west end.  Fly over the south side and land in the fields well south of the south side.

 

Flying in strong winds always increases pilot risk.  The stronger the wind the higher the risk.  There are strategies to mitigate those risks.  At the North Side, those would include staying well out in front of the back ridge.  All of the wind piling up from the bottom of the ridge to the top must combine to make it over the top.  As a result the winds will always be considerably stronger over the top of the ridge.  The depth of this compression zone changes with wind conditions.  

With stronger wind comes stronger turbulence everywhere those stronger winds exist.  

Always weigh your risks against your rewards.  Is moving slowly, or sitting parked in high winds at the edge of being blown back over the back ridge worth the added risk?

Flight (kiting) in known/knowable turbulence.

Flight (kiting) in known/knowable turbulence.

Mid Spring, a pilot was kiting on the Grass at the North Side LZ in strong, gusty, turbulent conditions. Pilot was kiting in the mid-section of the LZ nearer the sidewalk than the launch area. A strong gust picked up the pilot off the ground pushing him backward toward the parking lot. Pilot struck a parked vehicle in the parking lot, but never stopped flying the wing. He was able to safely bring the wing back down and disable the wing in the middle of the parking lot. No known injuries to the pilot, but damage to the struck vehicle did occur.

From the Book of Risk:

Don’t fly (kite) closer than 500 feet to the ground (thinks you don't want to hit), except at take off and landing, anywhere that turbulence might be present. 

This type of kiting is valuable to improving a pilots handling skills for in the air or on the ground.  The lesson is obviously to do it with a safe margin. 

Flight outside of conservative weather parameters.

Flight outside of conservative weather parameters.

In late winter, a speed wing pilot crash landed on the North Side of the Point of the Mountain.  By his own report the winds were switching at the time of launch and landing.  The pilot forward launched in a Southwest wind running down the road at the top of the back ridge.  The pilot soon encountered significant lift that did not make sense in his mind so he turned to the west to leave the lift.  At this time the lower wind sock was showing wind from the north northeast. Setting up for landing the pilot noticed his ground speed was excessive.  And he planed to skid the fast landing out on his butt.  At 20 feet AGL the pilot felt himself drop suddenly to the ground causing some injury.  

The pilots description of switching light winds combined with thermic winds indicates complicated wind gradients.  When a glider transitions from one air parcel to parcel moving slower or in a significantly different direction the glider’s air speed can be affected.  If the glider’s air speed is lowered it will immediately dive to regain its airspeed.  When this happens close to ground it feels as though you drop to the ground like a rock.   Lesson learned here is that even with light winds, switching conditions close to the ground increases your risk level.

Changing weather conditions increase our risk because it is possible that conditions can switch form safe to unsafe or the transition can be momentarily unsafe.  XC flying by its nature is flying in changing conditions.  When we are high this is less of a problem than when we are low.  Speed flying and ridge soaring cause us to spend a much greater amount of time close to the ground and therefore it is wise to be even more conservative in the weather we choose to fly in.  Just waiting for conditions to stabilize after a change can decrease our risk.

From the Book of Risk:

Begin your day early studying weather forecasts.  Learn to read them and what they mean.  Watch the wind, clouds and birds as you travel to and set up on launch.  As you fly continually assess the wind strength and cloud development.  

We had an accident today at the Y.  No reports have been filed and we don't know much.  What we do know is that the winds aloft forecast for the area was 21mph at 12k ft.  Measured winds at Baldy (11k ft) between 7AM and 5PM were consistently between 22mph and 29mph with gusts in the low to mid 30s.  By 6PM winds were 38mph gusting 54mph.

From the Book of Risk:

Mechanical turbulence and rotor downwind of obstacles start with winds at about 9 miles per hour.  At 12 miles per hour that turbulence has the strength to collapse a paraglider.  At 15 miles per hour the collapses become difficult to block.  At 18 miles per hour even the very best among us will begin to lose their wing. 

Conservative winds aloft numbers for intermediate pilots for the the Wasatch are 

12 mph at 12K ft.
  9 mph at 9K ft
  6 mph at 6k ft

Flight in known/knowable turbulence

On February 5, 2020 an intermediate pilot landed downwind through a switching wind directions and hit the ground hard enough to cause serious bruising.

The pilot hiked to the top of the North Side and noticed the wind at the top had switched from 4mph out of the northwest to 3mph out of the Southwest.  After kiting along the road at the top the pilot launched downwind.  Soon after launching the pilot encountered leeside thermic lift.  Not expecting lift the pilot turned west.  The lower wind sock was showing light northeast wind.  Despite the lower wind sock direction the pilot noticed his approach landing speed was above 30mph.  Suddenly the pilot's glide angle dropped more quickly the last 20 feet and unable to complete a flare he hit the ground hard.

Switching base wind with leeside thermals pulling localized wind toward the thermal core made a complex mix of convoluted air for the pilot to fly through.  From his description it is likely that he was flying in zero to light downwind air into stronger down wind air with the transition causing the sudden drop similar to flying through a wind gradient.

Strong thermals will always mess up what we believe the local wind direction to be.  Nonetheless, the safest conditions are with base winds consistent in both strength and direction or no wind at all.  The highest risks come with high winds followed closely by switching winds.

From the book of risk:

Turbulence can be knowable with some education in weather and wind effects.  Study the weather a lot, read a lot of books about weather especially that related to paragliding and hang gliding:

Understanding the Sky by Dennis Pagen

Thermal Flying by Burkhard Martens

Mastering Thermaling by Kelly Farina

Weather for Dummies