Grob ASTIR CS 77 Technical specifications

GROB
ASTIR CS 77
Flight and Maintainance Manual
For the ASTIR CS 77 glider
Registration: 0-7634 Work No: 1705
Re-registered as: British Gliding Association No: 4401
Manufacturer:
Original Owner:
Current Owner:
B. GROBFLUGZEUGBAU
8939 Mattsies
Flugplatz Mindelheim-Mattsies
Telefon O 82 68 I 4 11
Luftsportgemeinschaft, Wolfsburg
Amselweg
51 , 3180 Wolfsburg 1
Northumbria Gliding Club Ltd.,
Currock Hill,
Chopwell
LBA recognized edition February 1977
This manual must be carried in the aircraft (German requirement).
1

FLIGHT MANUAL ASTIR CS 3
1. Addenda
Current Page Reference I Date Signature
number
Addenda for ASTIR CS
1 3,4,5, changed 22. 5. 76
7,8
2 3,4,5,6 Ichanged 3. ·1 77
14.16,17 I
I
3
25a
I 1. 6.
77
new page
4
20 new page
26 . ·7 79
5 3,28 changed 4. 5
81
6 2,3,29 changed
and new page
30 . 9. 81
7 3,26a
Inspection of the 25.3.85
a:irbrake lockinq lever
Addenda for ASTIR CS n and ASTIR CS Jeans
1 4,5,7,8, Remarks for retractable 1. 6. 77
9,11 , 12
gear and waterballast
13,19,26 deleted for
ASTIR CS Jeans
2 25a, new page 1. 6. 77
3
25
changed 1. 8 77
4
20
new page
26. 7. 79
5 3,28 ·changed 4.
5. 81
.
6 2,3,29 changed an new page 30. 9. 81
7 3,26a
Inspection of the
25.3.85
airlrake lockinq lever
25.03.1985 (TM 306-26)

Disclaimer
This English version of the manuals has been translated with reasonable care by
John
R. Greenwell and is accurate to the best of his knowledge. However in all offical
matters the original German text is the authoritative and definite document.
Modifications to Manual:
Issue Pages Description Date Signature
No
Valid for ASTIR CS
1a 3,4,5,7,8 Exchanged
in the flight manual 22/5/76
1b 3,4,4a,4b Insert photo-copies
in the flight manual 22/5/76
,5
2 3,4,5,6,1 Exchange (valid from Serial No 1438) 3/1/77
4,16,17
3 25a Insert (sketch of wing quick-lock 1/6/77
mechanism)
4
20
Insert (information on hinge moments) 2617179
5 3,28 Exchange (maintenance of Hotellier 4/5/81
connectors)
6 2,3,29 Exchange/new (increase in operating 30/9/81
time)
Valid for ASTIR CS 77 and ASTIR CS Jeans
1 26 Exchange (horizontal tail unit assembly 515177
2 4,5,7,8,9, References to water ballast operation 1/6/77
11 ,12,13, and colour coding (valid for ASTIR CS
19,26 Jeans)
3 20 Insert (information on hinge moments) 20/2/78
4 3,28 Exchange (maintenance
of Hotellier 4/5/81
connectors)
5 2,3,29 Exchange/new (increase
in operating 30/9/81
time)
I
Note: the page numbers refer to the original German documentation, the pagination in
this translation is different.
2

OPERATING LIMITS
Airspeed Limits (/AS)
Maximum permitted speed
Maximum manoeuvring speed
Maximum speed on winch/auto launch
Maximum speed on aerotow
Airspeed indicator markings:
60 -170 km/h
170 -245 km/h
245 km/h
Weights:
(32 -92kt)
(92 -132kt)
(132kt)
Empty weight approx.
245 km/h
170 km/h
120 km/h
170 km/h
green sector
yellow sector
radial red line
(132kt)
(92kt)
(65kt)
(92kt)
Maximum weight without water ballast
270kg (5951b)
380kg (8381b)
450kg (9921b)
240kg (5291b)
with water ballast
Maximum weight of non-lifting parts
Weak Link in launching cable: 500 ± 30kg (1102 ± 661b)
Cloud flying and simple aerobatics:
Permitted without water ballast, see pages 11 and 13.
LFS Airworthiness Group:
Normal glider (N)
Centre of Gravity Position in Flight:
Aircraft Attitude: Slope 1000:40 tail down from horizontal measured
on the upper
surface
of the fuselage 300mm forward of fin
Datum: Wing leading edge at root rib
Forward Limit:
31 Omm aft of datum
Rearward Limit: 480mm aft
of datum
3
-2.2906 degrees
-2d 17m 26.196s

Loading limitations of the ASTIR CS 77
For the empty weight, all up weight and cockpit load limitations of this particular aircraft
refer to the C of A document or the cockpit Loading Placard.
Minimum cockpit load 70kg (1541b)
The permitted maximum all up weight may not be exceeded:
Without water ballast 380kg
(8381b)
With water ballast 450kg (9921b)
For the additional loading limitations with water ballast as a function of the cockpit load
(pilot with parachute and luggage), see the Figure
on the next page.
Pilots below the minimum cockpit weight limit must use ballast in the seat to adjust the
loading to be within the placarded limits.
The moment arm of the pilot with parachute is 485mm forward of datum.
Centre of Gravity Position in Flight:
Forward Limit:
Rearward Limit:
31 Omm aft of datum
480mm aft of datum
4

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- 551 175
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220 ________________________ __
485 60 70 80 90 100 110 120 [ kp]
132 154 176 198 220 242 264 [lbs]
Zuladurtg im Rumpf
Cockpit load
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5

DATA AND PLACARDS IN THE COCKPIT:
Maximum flying weight
Without water ballast 380kg
With water ballast 450kg
Maximum Permitted Speed
Absolute never exceed 245 km/h
Rough Air 245 km/h
Aerotow 170 km/h
Winch
or Autotow Launch 120 km/h
Airbrakes Open 245 km/h
Maximum manoeuvring speed 170 km/h
Cockpit Load (pilot andparachute)
The maximum weight may not be exceeded.
Minimum cockpit load: 70kg (1541b)
(8381b)
(9921b)
(132kt)
(132kt)
(92kt)
(65kt)
(132kt)
(92kt)
Missing weight is to be supplemented by ballast in the seat.
Placard at the main wheel door:
WHEEL 2.5 atmospheres (2.53 Bar , 37 psi)
Weak Link Maximum 500kg (1102lb)
6

-
Cockpit Labelling of Controls
<~~
~~>
<~~>
/~~
~ ' ~~ ~ /
<~~>
Pedal adjustment
BLACK plastic grip
Top right of
instrument panel
Ventilation
BLACK button
Top left of
instrument panel
Undercarriage
BLACK handle
seat pan right
Trim
GREEN lever
seat pan left
Airbrakes
BLUE handle
seat pan left
Water Ballast
WHITE lever
seat pan right
Canopy
RED knobs on the canopy frame
left button: open
left and right button:
Emergency jettison
Cable release
YELLOW grip
Bottom left of
instrument panel
7

Relationship between indicated and calibrated air speed
From this diagram the airspeed error can be obtained. This is due to the positioning of
the static vents.
Pitot Pressure Input: Pitot tube near the top of the vertical fin
Static Pressure Input: Fuselage side in front of the wing root
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50
100
150
200
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250
Berichtigte Geschwindigkeit VcAS [km'h1
:1:> :o m 140
Calibrated Airspeed VCAS [ktsJ
8

NORMAL FLYING OPERATION PROCEDURES
Winch Launch
Maximum speed: 120 km/h (65kt).
The glider has a cable release
in the landing gear well in front of the landing wheel.
Winch launches can be accomplished at all permitted centre of gravity positions and
flying weights without difficulty. The glider has
no tendency to pitch up or veer
sideways. With powerful winches, or during rapid acceleration, the glider rate of climb
should
be limited until a height of 1 OOm (330ft) is reached.
Aerotow Launch
Maximum speed: 170 km/h (92kt).
The towrope can
be attached at either the nose hook, or the release hook in the
landing gear bay.
On the ground run the glider can be controlled with rudder and aileron deflection (up to
maximum deflection if necessary). There
is little tendency to veer even in strong cross
winds. At
an airspeed of approx. 65 km/h (35kt) the glider can be taken off. At an
airspeed of 70 -75 km/h (38 -40kt) the glider will take off itself if the control stick is
held in a neutral position.
If the nose hook is used, after a safe height is achieved, the wheel can be retracted
during the launch.
The yellow release knob is located at the bottom left of the instrument panel and must
be pulled fully out to release the cable.
To adjust the rudder control pedals
To adjust the pedals, release and hold the pedal locking pin clear, by pulling the pedal
lock handle
at the top right of the instrument panel, while at the same time pressing the
pedals forward with your heels. The pedals can then slid back under spring tension, or
can
be pushed forward with your heels. After adjusting the pedals, check that the pedal
locking
pin has engaged in the new position by releasing the pedal lock handle and
pressing firmly forward
on the rudder pedals with your heels.
Canopy
The one-piece Plexiglas canopy with emergency 0-V panel and ventilation flap is
hinged on the right side of the glider. The handle to open the canopy is on the left side
of the canopy frame. The handle for jettisoning the canopy
is on the right fuselage
side.
Retractable landing gear
The operating handle for the undercarriage is on the right side of the seat pan. The
undercarriage must
be locked in either the extended or retracted position.
Airbrakes
The operating handle for the airbrakes is on the left side of the seat pan . Check the
brakes are locked before launching. Because of the high rate of descent the brakes
should not be further extended when rounding out during a landing.
9

Whee/brake
The wheelbrake lever is on the control stick.
Trim
The trim control is on the left front edge of the seat pan . At mid -point cockpit loading it
is possible to trim for airspeeds of approximately 60 -180 km/h (32 -97kt).
Flight with water ballast
Flying at maximum cockpit load with full water ballast, the glider has a gross weight
nearthat of the normal two-seater glider.
The slow-speed flight and take-off behaviour of the glider fully loaded therefore differs
somewhat from the behaviour of the glider flown without water ballast. The take-off
speed rises to approximately
70 km/h (38kt). For correction of the flight attitude larger
control deflections are necessary. The loaded wing will tend to drop a tip near the
ground, but with rapid application of normal control movement this can
be corrected.
Slow-speed flight, and stalling with full additional load, should be practised by the pilot
at a safe height.
The water tanks are
in the wing leading edge, extending from the root rib and contain
approximately
50 litre/wing (11 gallons/wing).
Filling the containers
is done through the covers on the upper side of wing. The covers
can
be lifted out with a pin .
During flight with partly filled tanks
no noticeable water movement arises because of
the inserted bulkheads.
The desired quantity of water ballast must
be distributed evenly between both wing
tanks,
so that the lateral stability is not affected.
Discharging takes place via
an opening in the lower fuselage side behind the
undercarriage bay.
To open the drain valves on the tanks the white lever on the right
side of the seat pan must
be pushed to the rear. Draining the tanks takes about three
minutes.
The draining of the water ballast tanks takes place via
an overflow pipe, which ends in
the fuselage fairing under the root rib . This pipe must not be masked with tape. During
a flight with water ballast, the wing-fuselage junctions on the lower surface under the
overflow pipe should not
be masked with tape; this will avoid the leakage of water into
the fuselage.
With long flights
in air temperatures around 0°C (32°F) the water must be completely
discharged because of the danger offreezing.
Before 'off-field' landings the water ballast should
be completely discharged.
When 'parking
up ' the glider, the water tanks should be emptied in principle, in order to
prevent freezing.
When derigging the glider the tanks empty themselves automatically through the tube
end
in the root rib .
With long tow-outs
on uneven ground the tanks should be emptied to reduce the wing
bending loads.
10

Stalling behaviour
The stall warning occurs at 60-70 km/h (32-38kt), depending upon wing loading, and is
indicated by strong vibration of the horizontal tail unit.
When the control stick
is pulled hard back the glider settles into a controllable flight
attitude in which, with aileron and rudder,turns of up to 20 ° bank can be flown.
When the control stick is released, the glider immediately returns to the normal flight
attitude. When the stick is pushed forward, the glider tips nose down, and the bank
can
be controlled with the aileron.
Flight at high speeds
The glider does not have a tendency to flutter in the permitted speed range. Starting
from 170 km/h (92kt), maximum permitted deflections of
all flying controls are reduced
gradual to be 1/3 of full deflection at maximum permitted speed.
In a 45 ° dive at maximum flying weight, with fully open airbrakes, the maximum never
exceed speed (VNE)
is not exceeded.
Approach and landing
The approach can be flown at 90km/h (50kt) normally.
The airbrakes are sufficiently powerful for steep approaches to be made.
The airbrakes give some nose-down trim,
so the glider will automatically maintain the
pre-set trimmed speed when the brakes are opened.
Sideslip
The sideslip is easily controllable and can be used as an additional landing aid.
However,
it is effective only with a large sideslip angle and should be terminated at
sufficient height.
Note: Landing preparation: - at the correct position, at a height of approx. 150 m
(500ft), airspeed of 90 km/h (50kt), undercarriage down and locked.
Flight in rain
Past experience with wet or slightly frozen wing surfaces indicates that there is no
noticeable degradation of the flight characteristics. With a thick layer on the wing
surface the stalling speed increases
by approximately 5 km/h (3kt) and the stalling and
landing behaviour remain unchanged. Increase the approach speed by approx. 10
km/h (Skt) .
Aerobatics
Certified figures and entry velocities:
Loops Forbidden
Turn
Lazy Eight
Chandelle
Spin:
180 km/h (97kt)
120 km/h (64kt)
150 km/h (81 kt)
After a slow complete stall, cross the rudder and aileron controls to full deflection and
keep the elevator pulled back. Centralising or releasing the controls stops the spin. The
11

height loss is about ?Om (230ft) per revolution. The recovery speed about 160km/h
(86kt).
The execution of aerobatics and flight conditions, which would give negative loading,
are not permitted.
Advanced aerobatic manoeuvres are likewise illegal.
Spinning
With the centre of gravity between 415 and 480mm aft of datum, the glider can be held
in a spin. The control stick must be held fully back, and the rudder and aileron controls
crossed to full deflection. The glider spins in the direction of the rudder deflection and
with rearward centre of gravity positions will settle into a constant rate spin with a slow
rotation speed and a flat fuselage attitude.
Recovery from the spin does not require critical control movement.
It is sufficient to
release the backpressure on the stick and at nearly all centre of gravity positions and
wing loading the glider will return to normal flight.
A more rapid recovery (without further turning of the glider)
is achieved if all controls
are returned to the central position. The height loss
up to the recovery from the spin is
approximately 70 meters (230ft) per revolution.
The glider can be held within the flight envelope at all certified positions of the centre of
gravity and flying weights. With full
up elevator, crossed aileron and rudder control, at
rearward positions of the centre of gravity; the glider will enter a spin. This can
be
terminated quickly by centralising all controls.
Immediate recovery is achieved by the "standard recovery method":
1. Apply opposite rudder against the direction of the spin
2. Pause
3. Ease the control column forward until the rotation ceases and the airflow is
restored.
4. Centralise the rudder and pull gently out ofthe resulting dive.
During the high-speed recovery, pay attention to keeping the airspeed within the
permitted range.
Avoid large control deflections at high speeds.
12

EMERGENCY PROCEDURES
Emergency exit
The freedom of movement in the roomy cockpit ensures an unhindered emergency
exit. The following sequence
is to be observed:
a) Grasp the red knobs on the left and right sides
of the canopy frame and
simultaneously pull both rearwards. With the left hand force the canopy upwards.
b) Loosen the seat harness belts.
c) Stand up and depending upon flight attitude step out
to the right or left.
d) With a manually operated parachute, grasp the release, and after 1 - 3 seconds
pull the release.
Cloud Flying
Minimum equipment for cloud flying:
Airspeed indicator, altimeter, rate of climb indicator, compass, turn and slip indicator,
spirit level, radio.
(Past experience indicates that the pitot -static system
is insensitive to freezing up)
To avoid high airspeeds (over approx. 170km/h (92kt}}, the airbrakes should be opened
promptly.
Note: Aerobatics and cloud flying are to be performed only by pilots who have the
appropriate authorisation. The legal regulations still apply!
Minimum equipment
1. Airspeed Indicator to 300 km/h (162kt)
2. Altimeter
3. Four point seat harness
4. Packing cushions, at least 7 cm thick under load, or parachute
5. Weight I loading placard
6. Flight limitations placard
7. Flight and maintenance manual
,
13

WEIGHTS AND THE CENTRE OF GRAVITY POSITION
When additional equipment is fitted, or after repairs, or a new gel/paint finish or any
other weight change of the glider, the empty weight and centre of gravity position
is to
be determined.
If the ranges of the empty weight, and the centre of gravity position (table below), and
the cockpit loading limits, are satisfied, the flying weight limitations will
be in the
permitted range.
Unloaded weight (kg) CG range (mm aft)
245 697 -756
250
690- 750
255 683 -745
260 675 -740
265 654- 735
270
633- 730
275 612 -726
280 593- 721
285 574 -717
CONTROL DEFLECTIONS -RIGGING ANGLES
Glider wings level, with fuselage upper surface at a slope of 1000 : 40 tail down from
the horizontal, measured 300mm forward of fin.
Elevator Up 60
±6mm
Down
54 ± 6mm
Rudder Left 190 ± 10mm
Right 190 ± 10mm
Aileron Up
93±10mm
Down 48 ± 5mm
Rigging Angle wing chord to fuselage longitudinal axis 2 degrees
Tail chord to fuselage longitudinal axis 0 degrees
14

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FLYING PERFORMANCE -GLIDE POLAR CURVE
FLIGHT
PERFORMANCES
BEST LIFT/DRAG RATIO
MINIMUM SINK (mis)
THERMALLING SPEED
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16

WEIGHING SHEET
a
Bezugsebene
Datum li
ne
Xs
G,
Incidence boord
Ke iI 1000 : 40
b-- --- -
Datum Line: Wing leading edge at the root rib
Glider Attitude: Fuselage upper surface at a tail down slope of 1000:40 measured
300mm forward ofthe fin.
Weight at the landing wheel G1=
Weight at the tailskid G2=
Empty weight GL= G1+ G2=
Datum to landing wheel
Datum to tailskid
Centre of gravity of Empty Glider
X = (G2x b I GL) +a=
a=
b=
kg
kg
kg
mm
mm
mm Aft of Datum
The determination
of the empty weight and the centre of gravity are always determined
without water ballast.
17

MASS AND RESIDUAL MOMENT LIMITS OF THE CONTROL SURFACES
After repainting or a repair the hinge moments and weights may not exceed the
following values:
ASTIR CS (S/N 1002 -1536)
Elevator:
Rudder:
10.0 to 15.0kgcm
13.65kgcm ± 10%
Aileron: 16.0kgcm ± 12%
ASTIR CS 77 (S/N 1601 -1698)
ASTIR CS JEANS (S/N 2001 -2092)
Elevator:
Rudder:
10.0 to 15.0kgcm
16.5kgcm ±10%
Aileron: 16.0kgcm ± 12%
ASTIR CS 77 (starting from S/N 1699)
ASTIR CS JEANS (starting from S/N 2093)
Elevator
Rudder
Aileron
10.0 to 15.0kgcm
Oto 5kgcm
Oto 1kgcm
2.40 to 3.25kg
3,2kg ± 10%
4,1kg ± 12%
2.40 to 3.25kg
4,5kg ± 10%
4,1kg ± 12%
2.40 to 3.25kg
max.6.0kg
max. 6.0kg
For the measurement of the hinge moments the controls must be removed from the
glider. For the determination of the hinge moment (M =P. r) the control hinge should be
as friction free as possible. The force P can be measured with a spring balance. If the
values are exceeded, then the balance weight should be increased. Before a repair of
the control surfaces and/or a replacement of the balance weight, the manufacturer is to
be contacted.
p
----r
18

-
RIGGING THE GLIDER
Rigging the glider can be accomplished by three persons.
1. Wing
Open the four spigot lock rings in the fuselage, and unlock the airbrakes in the wing
and at the brake control lever. Insert the right wing into the fuselage. Rotate the two
right wing lock rings so that the guide pins are located
in the guide slots.
Gently move the wing until there
is an audible click as the lock rings engage.
Next insert the left wing into the fuselage and,
by appropriate movement of the wing
tips; engage the two spar end spigots
in the bearings in the wing root ribs. Rotate the
two left wing lock rings to locate the guide pins and engage the lock
by back and
forward movements of the wingtip. To safety lock the wing to fuselage connection
rotate the lock rings until they are firmly held
by the guide pins.
Wing socket lock rings
3 2
4
2. Controls
A.OPENED 1. Lock ring
2. Guide oin 3. Guide Slot
B.CLOSED
C. SECURITY LOCKED Note the Smm
spacing of the guide pin in the guide slot.
The push connector sleeves must cover the
red rings on the control rods.
The connections for ailerons and airbrakes lie behind the main spar.
The short connecting rods
in the fuselage are fitted with quick-locking mechanisms,
which must
be coupled to the ball connections on the wing control push rods.
To ensure the security of the connection the following check must
be carried out.
When the connecting rods are assembled, visually check that the locking wedges are
sufficiently engaged
so that they stand out some millimetres from the catches. Then, by
slight rotation and pushing and pulling, try to pull the connecting rods from the ball
connections. If the connections remain fixed under a load of approximately Skg the
controls are correctly attached.
19