11 July 72 AC 20- 78 Appendix 2 Хсто Xcw 69.5 OR ₩ 239.8
467.0 FRONT SPAR (FUSELAGE STATION
463.0 SPOILERS 663.0)
CENTER SPAR X1$ 508.9 FUSELAGE STATION
781.7) *78 519.0
REAR SPAR Xrs589.0 355.3) FUSELAGE STATION
INNER AILERON P$ 624.0 X*- 3.1 iNNER FLAP X18693.0 × 37.9
442.9 X 129.3 X+s 237.7 x 437. TRIM × ,238.8 „761.7 554.5 TAB FLAP EXHAUST GATE X, 303.7 X,697.8 X₩564.0 × 408.0- LX,$ 358.0
OUTER AILERON - OUTER FLAP
- Х р8763.0 -Х,$428.0
WING STATIONS Fig 3. Wing Station Charts Page 3
AC 20- 78 11 July 72 appendix 2
ENGINE AFT MOUNT
56.2 141.4 216.9 NACELLE 100.0 178.0 ORIGIN (YNO)
• EJECTOR STROKE = 72.0 FIREWALL 118.7 186.0 258.0
FIRESE AL
ENGINE FORWARD MOUNT
INBOARD PYLON AND NACELLE → _ 266.7 NACELLE ORIGIN 255.2 (YNO)
OUTBOARD PYLON AND NACELLE (SAME AS INBOARD EXCEPT AS NOTED) Fig 4. Pylon/Nacelle Station Charts Page 4
11 July 72 AC 20- 78 Appendix 2
FUSELAGE X£28.8 XE 77.0
FRONT SPAR
ACTUATING POINT × E 149:0
REAR SPAR XE221.0- HINGE POINT XE 272.0 XET103.2 XET 1852 XE721.5 Xg312.5 X4285.9 HORIZONTAL STABILIZER STATIONS
HORIZONTAL STABILIZER ORIGIN (FUSELAGE STATION 1541.4) THIS POINT DESIGNATED XpSO
PIVOT AXIS (FRONT SPAR STATION O) (FUSELAGE STATION 1665) FRONT SPAR PLANE (22. 7%) 25% PLANE THIS POINT DESIGNATED XEO (ELEVATOR STATION O)
REAR SPAR PLANE (44.7%) THIS POINT DESIGNATES
TAB ORIGIN LINE *×E *XET TAB HINGE (93.7%) ELEVATOR HINGE (75.0%) X 2839 ELEVATOR LEADING EDGE (66.2%)
METHOD OF DESIGNATING HORIZONTAL
STABILIZER STATIONS Fig 5. Horizontal Stabilizer Station Charts Page 5
AC 20-78 11 July 72 Appendix 2 FRONT SPAR - Ip 329.2 ZA 283,0
CENTER SPAR- Zp 219:0 REAR SPAR ZR 161.O ZRT 132.7 ZR 103.0 ZRT 56.6 ZA 54.5
VERTICAL STABILIZER STATIONS Zv
307.2 REAR SPAR PLANE (51.0%) CENTER SPAR PLANE (35.5%) - FRONT SPAR PLANE (20.0%) RUDDER LEADING EDGE 25% (52,0%) + Zv CHORD
FUSELAGE RUDDER HINGE STATION 1464.2 Zv 103.0 35 ° (65.0%) TAB HINGE (92.9%) VERTICAL STABILIZER +ZAS + ZCS +ZAS+ZR RUDDER TAB ORIGIN ORIGIN -Yv + YV YR FYFS +YCS +YRT
50.1
89.0 FUSELAGE 127.8 130.5 RUDDER ORIGIN REFERERENCE 162.9 PLANE 235.7
• 250.7
METHOD OF DESIGNATION
VERTICAL STABILIZER STATIONS Fig. 6. Vertical Stabilizer Station Charts Page 6
11 July 72 AC 20- 78 Appendix 3
STRUCTURAL ITEMS 1° DESCRIPTION. Five significant structural items are discussed in this appendix. If in a high time DC-8 aircraft a crack occurs in one of the continued airworthiness of the aircraft may be adversely affected
a. Fuselage Aft Pressure Bulkhead
(1) Location. Aft flat pressure bulkhead vertical angles. (See Figure 8, Appendix 3).
(2) Applicable Airworthiness Directive. None
(3) Other Reference Documents.
(a) Service Bulletin 53-46.
(4) Recommendations
(a) Accomplish Service Bulletin 53-46.
(b) Perform subsequent periodic inspections starting at a later date to insure continued structural integrity.
b. Freon Compressor Exhaust Door Opening.
(I) Location. Below forward passenger door at longeron 29 (See Figure 9, Appendix 3).
(2) Applicable Airworthiness Directive. None
(3) Other Reference Data. None
(4) Probable Consequences. Extensive cracking around the freon compressor exhaust door opening may lead to more serious structural damage.
(5) Recommendations. Periodically inspect to assure continued structural integrity.
c. Forward Passenger Door Area.
(1) Location. Forward fuselage, left hand side (See Figure 10, Appendix 3).
(2) Applicable Airworthiness Directive. None.
(3) Other Reference Data. None Par 1 Page 1
(1) FUSELAGE AFT PRESSURE
BULKHEAD
(4) AFT PASSENGER DOOR AREA Fig. 7 DC-8 Structural Inspection Locations STA. 857 STA. 1566
(2) FREON COMPRESSOR EXHAUST
DOOR OPENING WING REAR SPAR - (5) AFT LOWER WING SKIN
AT CENTERLINE SPLICE
(3) FORWARD PASSENGER
DOOR AREA DC-8 FUSELAGE/EMPENNAGE/WING STRUCTURAL
INSPECTION LOCATIONS
11 July 72 Fig. 8 Fuselage Aft Pressure Bulkhead VIEW B (PAPICAL) AT STATION 1566 AFT PRESSURE BULKHEAD VIEW A-A cce OF AIRCRAFT CENTERLINE BULKHEAD PRESSURE AFT VERTICAL ANGLE BULKHEAD PRESSURE INSPECT Appendix 3 AC 20-78 Page 3
Page 4 Appendix 3 AC 20-78 Fig. 9 Freon Compressor Exhaust Door Opening VIEW A TYP. SKIN CRACK LOCATIONS 11 July 72
11 July 72 AC 20- 78 Appendix 3
INSPECT ALL CORNERS FOR SKIN
AND DOUBLER CRACKING
TYPICAL DOUCLER
CRACK LOCATION
TYPICAL SKIN CRACK LOCATION VIEW A Fig. 10 Forward Passenger Door Areas Page 5
AC 20-78 11 July 72 Appendix 3
(4) Probable Consequences. Extensive fuselage cracks in this area may lead to more serious structural damage.
(5) Recommendations. Periodically inspect to assure continued structural integrity.
d. Aft Passenger Door Area.
(1) Location. Aft fuselage, left hand side(see Figure 1l, Appendix 3)
(2) Applicable Airworthiness Directive. None
(3) Other Reference Data. None
(4) Pro 20 Come serious damage. Extensive fuselage cracks in this
(5) Recommendation. Periodically inspect fuselage skin around door cutout to assure continued structural integrity.
e. Aft Lower Wing Skin at Centerline Splice.
(1) Location. Aft lower wing skin at the centerline splice plate attach to the rear sper cap. (See Figure 12, Appendix 3)
(2) Applicable Airworthiness Directive. None
(3) Other Reference Documents. None
(4) Probable Consequences. Crack extension in other area can significantly reduce the structural integrity of the wing.
(5) Recommendation.
(a) Periodically inspect to assure continued structural integrity.
(b) Perform preventive rework in this area equivalent to Service Bulletin 57-70 at an appropriate later date depending on the airplane model.
Page 6 Par 1
11 July 72
CRACKING FOR SKIN AND DOUBLER INSPECT ALL CORNERS Fig. ll Aft Passenger Door Area VIEW A
TYPICAL CRACK LOCATION Appendix 3 AC 20-78 Page 7
11 July 72 AC 20-78 Appendix 3
WING LOWER REAR
SPAR CAP
STGR STGR #52 #51 LOWER
WING SKIN SKIN CRACKS (TYPICAL)
KEEL (REF) AIRPLANE = 0 AFT
EXTERNAL
SPLICE PLATE VIEW A
LOOKING UP Fig. 12. Aft Lower Skin at Centerline Splice Page 8