Grob TWIN-ASTIR User manual

GROB
GROB-FLUGZEUGBAU
8939 Mattsfes
Flugplatz Mlndelhelm-Mattsies
Telefon
08268/411
FLIGHT HANDBOOK
-,- ""-' I IV - 1-~J:::':I} • , I
11?
This handbook must be carried on board at atl times.
Jt refers to the TWIN ASTIR Sailplane
Registration: Factory Serial Number:
Owner:
German edition
of operating instructions are approved under § 12/2.
of LuftGerPO.
Published
Approval of translation has been done by beat knowledge and judgement -In any case the
original text In German language Is authoritative.
N8485W
3250
Utah Soaring Association

· GROB
GRO~-FLUGZEUGBAU
8939 Matts!es
FJugplatz Mindelheim-Mattsies
Terefon 08268/411
FLI"GHT HANDBOOK
-.--~I I'J -I I .!*S·
TRAINER • I
.......... <~1
ThJs handbook must be carried on board at all times.
lt refers to the TWIN-ASTIR TRAINER Sailplane
Registration:
Factory Serial Number:
Owner:
German edition of operating instructions are approved under § 12/2.
of LuftGerPO.
Pub fished
Approval of translation has been done by beat knowledge and judgement -In any caea the
original text
In German languag& Is authoritative.

FLIGHT HANDBOOK TW~N ASTIR 1
Updates
Current Page Reference Date
Signature
LBA-
number
Approval
1 Sa TWIN ASTIRTRAINER 1.4.78·
2 17 New Control Levers 1.10.78
\
3 18 New Control Levers 1.10.78
4 25 Check of wing 1.10.78
5 25a Fittings 1.10.78
6 1, 28 Service Butletin 28.09.92
315-50
7
1,25,25a
TM 315-58 04.11.96
8 1,
7, 1"1
As ·a315-64 30.06.2003
Envelope Limitations
-
MSB 315-64/3
~ /
t(_~
1
2. DKr. 2aa~
9 1, 7,
11
Revised Limits of
14.09.2004
f2\
Operation
/.~~ _..
~ t- ..- ·
~
14 September 2004

FLIGHT HANDBOOK TWIN ASTIR 2
Contents
I. General
I. 1 Updates 1
I. 2 Contents 2
1 •. 3 Photograph 4
I. 4 Drawing 5
I. 5 Description 6
11. Operating limits
ll. 1 Airworthiness Group 6
11. 2 Permitted operating conditions 6
11. 3 Minimum equipment 6
11.
4 Maximum Speeds 7
11. 5 Flight envelope 7
11.
6 Weight limits 8
11.
7 Centre of gravity position 8
11. 8 Load scheme 8
11.
9 Tow hooks 10
11. 10
Weak link strength 10
11. 11
Tire pressure 10
11. 12
Cros:swlnds 10
11.
13 Required placards
11
11. 14
Symbols 13
Ill. Emergency procedures
Ill. 1 Exit from a spin
15
Ill. 2 Emergency canopy jettisoning and exit 15
Ill. 3 Landing with a retracted undercarriage 15
Ill. 4 Others (Rain, ice, stall, groundloops} 15
Ill. 5 Instruments specifications 16

FLIGHT HANDBOOK TWIN ASTIR 3
IV . Normal operation
IV.
1 Cockpit and controls (Picture) 17
IV.
2 Daily preflight inspection 19
IV· 3 Control checks before
take off 21
IV.
4 Take off
21
IV. 5 Free Flight
22
IV. 6 Slow flying and stalls 22
IV. 7 High speed flight 22
IV .. 8 Cloud flying 22
IV.
9 Simpre Aerobatics
23
IV. 10 Approach and landing
24
IV. 11 Flying with waterballast
24
V. Rigging and derigging
V. 1 Rigging, derigging
25
V.
2 Storage 26
V. 3 Transport
27
V. 4 · Ma intenance of the glider
27
VI. Appendices
VI. 1 Flight performance
29
VI. 2 Service and Maintenance instructions 30
VI. 3 ·_ Reference to repairs
31
Vl. 4 - Reference
to release hooks 31
VI. 5 Determination
of the center of gravity
31

FLIGHT HANDBOOK TWIN ASTIR 5
I
'

FLIGHT HANDBOOK TWIN ASTIR
5a
The sailplane TWIN-ASTIR TRAINER is derived from the TWIN-ASTIR.
The differences are fixed sprung undercarriage with disc brake, and
the deletion of the wing ballast tanks.
Therefore, the remarks In the flight handbook and the maintenance
handbook concerning retractable undercarriage and water tanks do
not apply to the TWIN-ASTIR TRAINER.
The wheel brake of the TWIN-ASTIR TRAINER is a disc brake. The
brake cylinder with the storage tank for brake fluid Is mounted on the
undercarriage box.
The marks for minimum and maximum reserve must be observed.
For refilling use brake fluid DOT 3 (amber).
1. 10.78

FLIGHT HANDBOOK TWIN ASTIR
6
I. 5 Description
The TWIN ASTIR Is a high performance two seater sailplane with a
T-tail, fitted with a retractable undercarriage, upper surface airbrakes
and water ballast tanks in the wings.
This sailplane is manufactured using the latest techniques in industrial
Glass fibre construction.
it is designed for training, high performance and simple aerobatic
flying.
Technical Data:
Span 17.5 m (57.4ft.)
Length 8.1 m (26.6 ft.)
Height 1.6 m (5 .2 ft .)
Aspect
Ratio 17.1
11. Operating Limits
11. 1 Airworthiness Group
(U, Utility, LFSM}
Wing Area 17.8 m•
(191.6ft.2}
Maximum Flying Weight 650 kg
(14351bs)
Maximum Wing Loading 36.5 kg/m1
(7.841bs/ft.2)
The LFSM (Lufttuchtigkeitsforderung fUr Segelflugzeuge und Motor-
segler) published 23. 10.
1975 are the basic rules and requirements for
the licensing of a new type of glider or motorglider in Germany.
11. 2 Permitted operating conditions.
The plane is licensed for:
1· Flight in VMC
2. Simple Aerobatics (Loops, Stall turns, Lazy eight, Chandelle and
SpiA).
3. Cloud flying {When fitted with suitable Instrumentation as defined
in section
11. 3) .
11. 3 Minimum equipment
1. 2 Air speed Indicators reading to 300 km/hr (162 kts, 187 mph)
2. 2 Altimeters.
3. Full Harness Straps in front and back cockpit.
4. Parachute
or back cushion at least 7 cm (3 inch) thick.
5. Loading limit plaque in front and back cockpit.
6. Flight Limits plaque.
7. Flight Handbook.

FLIGHT HANDBOOK TW-IN ASTIR
Cloud Flying.
For cloud flying the additional instruments listed below must be
installed. ·
1. Variometer.
2. Electric turn and slip indicator.
3. Magnetic Compass (Compensated inside
the glider).
11. 4 Maximum -Speeds
Maximum permitted
speed in calm air • ·
Maximum permitted
speed in rough air
Maximum Manoeuvring speed
Maximum winch launch speed
Maximum Aerotow speed
VNE = 250 km/h ( 135kts, 155 mph} I
Vs = 170 km/h ( 92-kts, 105 mph)
VM = 170 km/h ( 92 kts, 1-05 mph)
Vw = 120 km/h ( 65 kts, 74 mph)
VT = 170 km/h ( 92 kts, _105 mph)
Conditions· in rough air are similar to those encountered in rotors,
cJouds, whirlwinds and when overflying mountain ranges.
Manoeuvring speed is the maximum·speed at whi ch full control deflec-
tions may be used. At maximum speed (VNE) the control deflections
should be restricted
to 1/3 of the full range.
Air speed indicator markings
51-105 mph = 44- 92 kts = 82-170 km/h -Green arc
105-155 mph == 92-135 kts = 170 ----- 250km /h -Yellow arc I
at 155 mph = 135 kts = 250 km/h (MSB315-64/3}-- Red line
at 65 m ph = 55 kts = 102 km /h - Yellow triangle
(recommended minimum appr. speed}
Position Errors
The airspeed indicator must be connected to the foUowing sources:
Pitot head in the tail fin. static vents side of the fuselage between the
two seats.
Using a cal - ibrated ASI the posaion error is not greater than ± 2 km/h
or 1 kt or 1.2 mph. A calibration curve is therefore not necessary.
If . 5 Flight envelope.
The sailplane design limit load factors are as follows:
At manoeuvring speed + 5.3 - 2.65
At VNE + 4.0 - 1.5
(Brakes closed and calm air}
14. September2004
7