Sling 4 TSi
Section 7
Pilot Operating Handbook
Supplementary
Information
Document Number: DC-POH-001-X-F-3.0
Page | 9-13
Revision: 3.0
Date: 2021/07/14
9.5.1.2
Specifications
Specifications
Tow hook weight
1 kg
Tug and towing operating speeds
50-90 KIAS, as required
Max. tugged glider weight
700 kg
Max. permissible cable load
10.7 kN (1090 kg)
Max. permissible release lever force 140 N (14 kg)
Max. release lever restoring force
50 N (5 kg)
9.5.1.3
Flight Performance
There is no noticeable change in flight performance between an
aircraft fitted with the tow hook mechanism and without. The change
in overall mass is considered insignificant and the change in
dimensions in the aircraft has no noticeable effect on performance. A
Sling 4 TSi aircraft fitted with a glider tow mechanism can accordingly
be safely flown by a pilot without a tow rating or experience, provided
that it is not used for any tug or towing activities.
9.5.1.4
Installation of Hook and Release Mechanism
The glider tow hook is fitted to an aluminium structure attached to the
lower rear fuselage. Since the rearward extent of the hook attachment
mechanism is forward of the rearmost extent of the rudder, there is
no change in overall aircraft length. The installation does, however,
extend closer to the ground than fuselage without the mechanism, and
the tie down point is accordingly marginally extended with fitment of
the tow hook, so that in the event of a tail strike the tie down point
strikes the ground before the tow hook mechanism itself. This is to
protect the tow hook mechanism in the case of a tail-strike. A tail-
strike with tow mechanism installed will accordingly occur at a slightly
lower angle than without the mechanism. This is not, however,
considered to be of any significance. The tow hook installation design
