25-01-2013, 09:35 AM
SYMMETRY CHECK OF PUSHPAK AIRCRAFT
SYMMETRY CHECK.docx (Size: 15.37 KB / Downloads: 21)
AIM
To check the symmetry of pushpak aircraft
OCCASION
On assemble/erection of new aircraft
Replacement/removal of major component
Heavy landing reports
Followed by flight through turbulence
Repeated smog on flight c.s
Any modifications on aircraft which affect its performance
As and when required by DGCA
PRECAUTIONS
Refer aircraft maintenance manual ensure the caution surroundings of aircraft
The jacking area should be free
Observe all safety precaution for leveling
Check the accuracy of spirit level
Always finish leveling procedure only by checking the longitudinal level
REQUIREMENT
Working hrs=3
Man power=3
Document= aircraft maintenance manual and rigging check up
TOOLS USED
Measuring tape
Spirit level
Plumb bob
Leveling board
Tripod jack
Support jack
PROCEDURE
METHOD:1
By means of direct measuring with tape
MEHTOD:2
By dropping plumb bob and marking and measuring method
METHOD:3
Place the aircraft in rigging position
Check the incident angle of wing
Check the dihedral angle of main plane
Check the sweep back angle
Check the dihedral angle of tail plane
Drop the plumb bob from spin centre and tail wheel centre and measure the length of aircraft
Drop the plumb bob from either wing tips and mark it on the ground
From fin top hinge or tail where centre drops the plumb bob and mark it
Measure the diagonal distance
Check the fin verticality
Measure the spin centre to each wing tip
Tabulate in the format given
RESULT
Above stated difference are measured and compared with the rigging chart and found with permissible limits