19
9) Stall
Certain behaviour or weather conditions can cause a full stall. This is
a serious deviation from normal flight and can be difficult to manage. If a stall
occurs at less than 100 m above the ground, throw your reserve parachute.
Main Causes of a Full Stall:
Poorly timed or excessive use of the brakes when the air speed of the
wing is reduced (e. g. when coming out of a spiral or after a B-line stall).
A soaked or heavily drenched leading edge (from rain or a cloud) can
result in a stall due to uneven airflow over the leading edge. Reported
cases of this phenomenon are linked to high levels of porosity
in the glider‘s fabric.
Whatever the cause, a full stall can be either symmetrical or asymmetric
(a spin). In both cases the pilot has two possible courses of action:
If the full stall happens above 100 m AGL it is strongly recommended
to initiate standard stall recovery assuming the pilot is familiar with it
(i.e. a complete execution of the full stall, stabilization of the wing and
progressive lifting of the hands to resume normal flight).
If the full stall happens below 100 m or if the pilot is unfamiliar with stall
recovery the reserve parachute should be deployed immediately.
10) Flying Without Brakes
If a brake line or pulley breaks it is possible to fly the Bi 4 2 using the
D risers (rear risers). Inputs should be finely controlled as the deformation
of the wing when using D risers is greater than when using the brakes.
The Bi 4 2 is an intermediate paraglider approved in Class B. It is therefore
intended for pilots who have completed a tandem training course with
an approved school where practical experience of using D-riser steering has
been gained.
Tip:
Practice this method of steering to be prepared before a real brake
failure!
11) Comments on testing Procedures
All manoeuvres were carried out over water in a stable air mass with standard
temperature, humidity and pressure. They were carried out by professional
pilots trained to react to each manoeuvre in the correct manner.
Test reports are available on the website:
www.sky-cz.com
.
12) harness adjustment
For test flights the pilots used ABS harnesses with the following set-up:
We recommend the use of a harness with adjustments as close as possible
to those used during the certification flights.
Excessive cross-bracing (chest strap very tight) increases the risk of risers
twisting during certain manoeuvres. A looser setting may result in a tendency
to fall towards the collapsed side.
Size
Distance from seat board
at the base of the hooks
Distance between centres
of karabiners
Bi 4 2
55 cm
55 cm
19
