W DOC AIRBUS | AMM A320F

Aerodynamic Smoothness [IAE]

TASK 71-10-00-220-010-A
Aerodynamic Smoothness

1. Reason for the Job
This section covers the smoothness conditions for the parts of the nacelle that are in the air stream.
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
TASK 71-13-00-800-802-A
Adjustment of the Step between Fan Cowl Doors and Air Intake Cowl
F Aerodynamic Smoothness - Areas Definition
F Aerodynamic Smoothness - Mismatch Conditions
F Aerodynamic Smoothness - Mismatch Conditions
F Aerodynamic Smoothness - Mismatch Conditions
3. Job Set-up
Subtask 71-10-00-941-050-A ** ON A/C NOT FOR ALL
A. Not applicable
4. Procedure
Subtask 71-10-00-210-050-A ** ON A/C NOT FOR ALL
A. Smoothness is put in three groups:
Mismatch at joints
Waviness of skins
Height of flush-head fasteners
Subtask 71-10-00-210-051-A ** ON A/C NOT FOR ALL
B. The smoothness conditions for each group are divided as follows. This relates the aerodynamic importance of the area to other areas.
F Aerodynamic Smoothness - Areas Definition ** ON A/C NOT FOR ALL
Class 1:
- Inside and outside of the inlet cowl from the leading edge to a line 18.00 in. (457.2 mm) aft of and parallel to the inlet cowl leading edge.
- Common nozzle assembly internal surface.
Class 2:
- Inlet cowl aft from a line 18.00 in. (457.2 mm) aft and parallel to the inlet cowl leading edge up to the leading edge of the fan cowl.
- Fan Cowl
- Thrust Reverser outside and inside surfaces.
- Thrust Reverser pylon skirt
- Exhaust Cone and outside surfaces of Common Nozzle Assembly.
Subtask 71-10-00-220-050-A ** ON A/C NOT FOR ALL
C. Mismatch limits
F Aerodynamic Smoothness - Mismatch Conditions ** ON A/C NOT FOR ALL
F Aerodynamic Smoothness - Mismatch Conditions ** ON A/C NOT FOR ALL
F Aerodynamic Smoothness - Mismatch Conditions ** ON A/C NOT FOR ALL
   (1) Mismatch, or step, is the difference between the surface levels of two adjacent doors or panels where they come against each other.
   (2) The step is positive (+) when the surface of the panel that is aft of the point where the two panels come together is in the airflow. It is negative (-) when it is out of the airflow. (P) shows a step is parallel to the direction of airflow.
F Aerodynamic Smoothness - Mismatch Conditions ** ON A/C NOT FOR ALL
   (3) The gap is the linear difference between two adjacent doors or panels where they come against each other. (P) shows a gap is parallel to the direction of airflow.
   (4) The mismatch limits for the nacelle are as follows:
-------------------------------------------------------------------------------
! Inlet Cowl ! Nose Lip ! STEP !
!---------------!-----------------------------!-------------------------------!
! ! ! +0.000 in. (0.00 mm) max. !
! ! ! -0.020 in. (0.51 mm) max. !
! ! ! P0.030 in. (0.76 mm) !
! ! ! GAP !
! ! ! 0.000 in. (0.00 mm) to !
! ! ! 0.030 in. (0.76 mm) !
! ! ! P0.000 in. (0.00 mm) to !
! ! ! P0.040 in. (1.02 mm) !
!---------------!-----------------------------!-------------------------------!
! ! Outer Barrel Aft Edge ! STEP !
! ! to Fan Cowl Leading ! +0.030 in. (0.76 mm) max. !
! ! Edge ! (on 80% of edge length) !
! ! ! +0.065 in. (1.65 mm) max. !
! ! ! (on 20% of edge length) !
! ! ! -0.060 in. (1.52 mm) max. !
! ! ! GAP !
! ! ! 0.040 in. (1.02 mm) to !
! ! ! 0.130 in. (3.30 mm) !
!---------------!-----------------------------!-------------------------------!
! ! Outer Barrel Aft Edge to ! If the step value is more !
! ! Fan Cowl Leading Edge ! than 0.120 in. (3.05 mm), do !
! ! Upper Corner to a point ! a ground run at Min. Idle then!
! ! measured 4 in. (101.6 mm) ! measure the step again before !
! ! down circumferentially ! cowl opening. If still out of !
! ! ! the limits, do a High Power !
! ! ! Assurance test (Ref. AMM TASK !
! ! ! 71-00-00-710-013) then measure!
! ! ! the step again before cowl !
! ! ! opening. !
! ! ! !
!---------------!-----------------------------!-------------------------------!
! ! Inlet Cowl to Pylon Visor ! STEP !
! ! ! +0.080 in. (2.03 mm) max. !
! ! ! -0.080 in. (2.03 mm) max. !
!---------------!-----------------------------!-------------------------------!
! ! Nominal Fan Case ! STEP !
! ! ! +0.020 in. (0.51 mm) max. !
! ! ! (on 70% of edge length) !
! ! ! +0.030 in. (0.76 mm) max. !
! ! ! (on 20% of edge length) !
! ! ! +0.035 in. (0.89 mm) max. !
! ! ! (on 10% of edge length) !
! ! ! -0.020 in. (0.51 mm) max. !
! ! ! (on 70% of edge length) !
! ! ! -0.030 in. (0.76 mm) max. !
! ! ! (on 20% of edge length) !
! ! ! -0.035 in. (0.89 mm) max. !
! ! ! (on 10% of edge length) !
! ! ! GAP !
! ! ! 0.002 in. (0.05 mm) to !
! ! ! 0.042 in. (1.07 mm) !
!---------------!-----------------------------!-------------------------------!
! ! TAI Access Doors ! STEP !
! ! ! +0.010 in. (0.25 mm) max. !
! ! ! -0.030 in. (0.76 mm) max. !
! ! ! P0.030 in. (0.76 mm) !
! ! ! GAP !
! ! ! 0.010 in. (0.25 mm) to !
! ! ! 0.060 in. (1.52 mm) !
! ! ! P0.010 in. (0.25 mm) to !
! ! ! P0.060 in. (1.52 mm) !
!---------------!-----------------------------!-------------------------------!
! ! Access Doors !STEP !
! ! ! +0.020 in. (0.51 mm) max. !
! ! ! -0.040 in. (1.02 mm) max. !
! ! ! P0.060 in. (1.52 mm) !
! ! ! GAP !
! ! ! 0.040 in. (1.02 mm) to !
! ! ! 0.110 in. (2.79 mm) !
! ! ! P0.040 in. (1.02 mm) to !
! ! ! P0.110 in. (2.79 mm) !
!---------------!----------------------------!--------------------------------!
! Fan cowl ! Between Fan Cowl Doors ! STEP !
! ! ! P0.060 in. (1.52 mm) max. !
! ! ! (on 80% of edge length) !
! ! ! P0.080 in. (2.03 mm) max. !
! ! ! (on 20% of edge length) !
! ! ! GAP !
! ! ! P0.100 in. (2.54 mm) to !
! ! ! P0.350 in. (8.89 mm) !
!---------------!----------------------------!--------------------------------!
! ! Fan Cowl to Pylon Skirt ! STEP !
! ! ! P0.120 in. (3.05 mm) max. !
! ! ! GAP !
! ! ! P0.43 in. (10.92 mm) to !
! ! ! P0.51 in. (12.95 mm) !
! ! ! (on 70% of edge length) !
! ! ! P0.43 in. (10.92 mm) to !
! ! ! P0.59 in. (14.99 mm) !
! ! ! (on 30% of edge length) !
!---------------!----------------------------!--------------------------------!
! ! Fan Cowl Aft Edge ! STEP !
! ! Translating Sleeve ! +0.040 in. (1.02 mm) max. !
! ! Leading Edge ! (80%) into wind !
! ! ! +0.065 in. (1.65 mm) max. !
! ! ! (20%) into wind !
! ! ! -0.100 in. (2.54 mm) max. !
! ! ! out of wind !
! ! ! GAP !
! ! ! 0.030 in. (0.76 mm) to !
! ! ! 0.250 in. (6.35 mm) !
! ! ! (on 80% of edge length) !
! ! ! 0.030 in. (0.76 mm) to !
! ! ! 0.310 in. (7.87 mm) !
! ! ! (on 20% of edge length) !
!---------------!----------------------------!--------------------------------!
! Thrust ! Between upper edge ! STEP !
! reverser ! ! +0.000 in. (0.00 mm) max. !
! ! ! -0.090 in. (2.29 mm) max. !
! ! ! GAP !
! ! ! P0.030 in. (0.76 mm) to !
! ! ! P0.190 in. (4.83 mm) !
! ! ! (on 80% of edge length) !
! ! ! P0.030 in. (0.76 mm) to !
! ! ! P0.250 in. (6.35 mm) !
! ! ! (on 20% of edge length) !
!---------------!----------------------------!--------------------------------!
! ! Between right and left ! STEP !
! ! thrust reverser doors ! P0.060 in. (1.52 mm) max. !
! ! ! (on 80% of edge length) !
! ! ! P0.080 in. (2.03 mm) max. !
! ! ! (on 20% of edge length) !
! ! ! GAP !
! ! ! P0.010 in. (0.25 mm) to !
! ! ! P0.200 in. (5.08 mm) !
!---------------!----------------------------!--------------------------------!
! ! Between right and left ! STEP !
! ! thrust reverser doors ! (AROUND LATCHES) !
! ! adjacent to translating ! +0.060 in. (1.52 mm) max. !
! ! sleeve latches ! -0.060 in. (1.52 mm) max. !
! ! ! (BETWEEN DOORS) !
! ! ! P0.060 in. (1.52 mm) max. !
! ! ! (on 80% of edge length) !
! ! ! P0.080 in. (2.03 mm) max. !
! ! ! (on 20% of edge length) !
! ! ! GAP !
! ! ! (AROUND LATCHES) !
! ! ! 0.020 in. (0.51 mm) min. !
! ! ! P0.020 in. (0.51 mm) min. !
! ! ! (BETWEEN DOORS) !
! ! ! P0.010 in. (0.25 mm) to !
! ! ! P0.350 in. (8.89 mm) !
!---------------!----------------------------!--------------------------------!
! ! Pressure relief door ! STEP !
! ! (latch side of door) ! (Stream wise) !
! ! ! 0.070 in (1.78 mm) into wind !
! ! ! transverse !
! ! ! 0.070 in (1.78 mm) out of !
! ! ! wind !
! ! ! 0.100 in (2.54 mm) stream !
! ! ! wise !
! ! ! (Transverse) !
! ! ! 0.070 in (1.78 mm) into wind !
! ! ! 0.070 in (1.78 mm) out of !
! ! ! wind !
! ! ! !
! ! ! GAP !
! ! ! (Stream wise right) !
! ! ! 0.100 in (2.54 mm) !
! ! ! 0.160 in (4.06 mm) !
! ! ! !
! ! ! (Stream wise left) !
! ! ! 0.010 in (0.25 mm) !
! ! ! 0.225 in (5.715 mm) !
! ! ! !
! ! ! (Transverse) !
! ! ! 0.100 in (2.54 mm) !
! ! ! 0.160 in (4.06 mm) !
!---------------!----------------------------!--------------------------------!
! ! Thrust recovery nozzle ! STEP !
! ! (latch side of door) ! 0.070 in (1.78 mm) into wind !
! ! ! 0.070 in (1.78 mm) out of !
! ! ! wind !
! ! ! 0.100 in (2.54 mm) stream !
! ! ! wise !
! ! ! !
! ! ! GAP !
! ! ! 0.100 in (2.54 mm) !
! ! ! 0.160 in (4.06 mm) !
!---------------!----------------------------!--------------------------------!
! Common Nozzle ! CNA Outer Barrel to ! STEP !
! Assembly (CNA)! Translating Sleeve aft ! (HOT) !
! ! Edge Outer Surfaces ! +0.030 in. (0.76 mm) max. !
! ! ! -0.060 in. (1.52 mm) max. !
! ! ! (COLD) !
! ! ! -0.055 in. (1.40 mm) min. !
! ! ! -0.175 in. (4.45 mm) max. !
! ! ! (60% of edge length) !
! ! ! +0.000 in. (0.00 mm) max. !
! ! ! -0.235 in. (5.97 mm) max. !
! ! ! (40% of edge lenght) !
! ! ! (OUT OF WIND. FOR TOP !
! ! ! CORNERS ONLY AND ON WING !
! ! ! ONLY) !
! ! ! +0.000 in. (0.00 mm) max. !
! ! ! -0.256 in. (6.50 mm) max. !
! ! ! GAP !
! ! ! (HOT) !
! ! ! 1.90 in. (48.26 mm) max. !
! ! ! (COLD) !
! ! ! 1.06 in. (26.92 mm) to !
! ! ! 1.58 in. (40.13 mm) !
!---------------!----------------------------!--------------------------------!
! ! CNA Outer Barrel to ! STEP !
! ! Translating Sleeve aft ! (HOT) !
! ! Edge Inner Surface ! +0.045 in. (1.14 mm) max. !
! ! ! -0.175 in. (4.45 mm) max. !
! ! ! (COLD) !
! ! ! +0.120 in. (3.05 mm) max. !
! ! ! -0.015 in. (0.38 mm) max. !
! ! ! GAP !
! ! ! (HOT) !
! ! ! 1.500 in. (38.10 mm) max. !
! ! ! (COLD) !
! ! ! 1.170 in. (29.72 mm) max. !
!---------------!----------------------------!--------------------------------!
! ! CNA Inner Barrel to ! STEP !
! ! Thrust Reverser ! (HOT) !
! ! Trailing Edge Inner ! +0.045 in. (1.14 mm) max. !
! ! Barrel ! -0.175 in. (4.45 mm) max. !
! ! ! (COLD) !
! ! ! -0.035 in. (0.89 mm) min. !
! ! ! -0.245 in. (6.22 mm) max. !
! ! ! (80% of edge length) !
! ! ! -0.015 in. (0.38 mm) min. !
! ! ! -0.265 in. (6.73 mm) max. !
! ! ! (20% of edge length) !
! ! ! GAP !
! ! ! (HOT) !
! ! ! 0.500 in. (12.70 mm) to !
! ! ! 0.700 in. (17.78 mm) !
! ! ! (COLD) !
! ! ! 0.100 in. (2.54 mm) to !
! ! ! 0.373 in. (9.47 mm) !
-------------------------------------------------------------------------------

   (5) For adjustment of the step between the fan cowl doors and air intake cowl (Ref. AMM TASK 71-13-00-800-802).
Subtask 71-10-00-220-051-A ** ON A/C NOT FOR ALL
D. Waviness of Skin Limits
F Aerodynamic Smoothness - Mismatch Conditions ** ON A/C NOT FOR ALL
   (1) Waviness of skin is a smooth variation in the flat or curved surface of a part.
     (a) One wavelength (L) is the distance between adjacent high points.
     (b) Slope is a measure of the incline of the wave at any given point.
     (c) Amplitude (H) is the vertical height from the top of a high point to the bottom of the next low point.
   (2) These are the maximum waviness values for the four areas:
-------------------------------------------------------------------------------
! ! Max ! Max ! Max !
! ! Amplitude (H) ! Ratio H/L ! Slope !
!---------------!-------------------!-------------------!---------------------!
! Class 1 ! 0.064 in. ! 0.003 ! 0.012 inch per inch !
! ! (1.6 mm) ! ! !
!---------------!-------------------!-------------------!---------------------!
! Class 2 ! 0.090 in. ! 0.006 ! 0.024 inch per inch !
! ! (2.29 mm) ! ! !
-------------------------------------------------------------------------------

Subtask 71-10-00-220-052-A ** ON A/C NOT FOR ALL
E. Height of Flush-Head Fasteners
   (1) The fastener step is positive (+) when it is in the airflow (above the surface of the panel). It is negative (-) when it is out of the airflow (below the surface of the panel).
   (2) Fasteners other than latches are to be flush within +/- 0.003 in (+/- 0.076 mm) for 90 percent of the fasteners. 10 percent may be flush within +0.003 to -0.005 in (+0.076 mm to -0.127 mm).
   (3) Max local dishing at rivets or other fasteners may be added to the nacelle waviness data with a depth of 0.010 in. (0.254 mm) over a max diameter of 1 in. (25.4 mm).
   (4) Solid flush-head rivet height limits:
Class 1 +0.003 in. (+0.076 mm)
-0.001 in. (-0.025 mm)
None to exceed +0.006 in. (+0.152 mm)
Class 2 +0.004 in. (+0.102 mm)
-0.001 in. (-0.025 mm)
None to exceed +0.006 in. (+0.152 mm)

   (5) Solid flush-head rivet height limits:
Class 1 +0.030 in. (+0.76 mm)
-0.030 in. (-0.76 mm)
Class 2 +0.040 in. (+1.02 mm)
-0.050 in. (-1.27 mm)

[Rev.10 from 2021] 2026.04.01 12:56:17 UTC
"Aviabrain" 2025