AC 20-78 11 July 72 Appendix l
(3) Xp This designation represents stations in inches, located perpendicular to the wing flap hinge line.
(4) Xes This designation is both a wing and a horizontal stabilizer station numbering subsystem, representing stations in inches located perpendicular to their front spars. In the wing, the point of C• Horizontal Stabilizer Subsystem Designations.
(1) Xe This designation refers to stations in inches, located perpendicular to the elevator hinge line.
(2) Xet This subsystem designation represents stations in inches, located perpendicular to the elevator tab hinge line.
(3) XIS This designation represents stations in inches, located perpendicular to the front spar. The point of origin is the centerline of the fuselage.
(4) X1 This subsystem designation represents the stations in the horizontal stabilizer system. The subsystem's point of origin is at the fuselage centerline.
d. Vertical Stabilizer Subsystem Designations.
(1) Zoy This subsystem designation denotes the stations in the vertical stabilizer system. Its origin is located 47 inches above the FRP at fuselage station 1464.2. The stations in this subsystem are segments divided into inches, parallel to the FRP.
(2) Zes This designation represents stations in inches along the center spar of the vertical stabilizer.
The stations are located perpendicular to the center spar and originate at Zy.
(3) Lfs This subsystem designation represents the front spar system of the vertical stabilizer. It consists of stations divided into inches, located perpendicular to the front spar and originating
(4) ZIe This subsystem designation represents stations in inches, along and parallel to the leading edge of the vertical stabilizer, originating at Zy, Page 2 Par 1
11 July 72 AC 20-78 Appendix 1
(5) Ly This subsystem designation refers to the rudder system of the vertical stabilizer. It consists of stations divided into inches, located perpendicular to the rudder hinge line and originating at Zy.
(6) Irs This subsystem designation refers to the rear spar system of the vertical stabilizer. It consists of stations divided into inches, located perpendicular to the rear spar and originating at Zy.
(7) Zat This designation represents the rudder tab hinge system of the vertical stabilizer. It consists of stations divided into inches, located perpendicular to the hinge line of the rudder tab, and originating at Zy.
Par 1 Page 3
11 July 72 AC 20- 78 Appendix 2 142'4"
FUSELAGE REFERENCE PLANE 12'3" 10° 30° 2'6".
20'10"
PIVOT AXIS x = 125.0 STATIC GROUND PLANE Y = 921.0 Z =-41.1 150'8" RUDDER →6'3" RIGHT 32 1/2° LEFT 32 1/2° 29'10" 42'4" 137 4'5" 1Ґ з" 415"11" 57'6"
PIVOT AXIS Х =Ô FUSELAGE REFERENCE PLANE Y=240.0 Z=-50.I STATIC GROUND PLANE
HORIZONTAL GROUND REFERENCE PLANE Fig. l Basic Dimensions Page 1
AC 20-78 11 July 72 Appendix 2 265 1517 1400 123 718 798 0000 1 1661 40 285 LOWER FUSELAGE CONSTANT 1420| 1601 1795 360 SECTION 1180 1490 1310 360
CABIN CONSTANT SECTION oooo oo..aoo.....a. • 0 1220 1100 855.5 683.0 540 374.6 1355 (CENT ERWING (CENTERWING 412.7
REAR SPAR) FRONT SPAR)
781.7 ( CENTERWING
CENTER SPAR) Fig. 2. Fuselage Station Charts Page 2
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