Mod, SI ,STi & LTO

Question 1

A modification/mod refers to ________________ of the aircraft and/or associated airborne equipment, support and test equipment.

Answer 1

any changes/alterations made to the form, fit and function

Question 2

Modifications are carried out on aircraft and associated equipment to? (6)

Answer 2

Improve safety, performance, reliability, maintainability
Introduce new components
Ease production / facilitate servicing
Reduce operational cost
Meet new ops requirements
To align subsequent aircraft purchases to the RSAF aircraft-type baseline configuration

Question 3

Sources of Modification include? (2)

Answer 3

Foreign Sources - Aircraft & Equipment Manufacturers (OEM) & Other Operators
Local Sources - RSAF Units, MINDEF Approved Contractors (MAC) & DSTA

Question 4

Modifications are classified under? (2)

Answer 4

Major - Changes/alterations that have an appreciable impact on airworthiness or significantly affect the pilot’s handling of the aircraft
Minor - Changes/alterations that have no appreciable impact on airworthiness and do not significantly affect the pilot’s handling of the aircraft

Question 5

Major Modifications are approved by? (3)

Answer 5

DHAEL (AE) for ASMC [Aircraft Systems Modification Committee]
DD (O&S), DSTA for GEWMC [Ground Electronics and Weapons Modification Committee]
DHAEL (AE) for SMC [Software Modification Committee]

Question 6

[INFO]

Minor Modifications are endorsed by relevant Branch Heads via the staff channel and approved by Specialist Centre Head

Answer 6

Exceptions are sponsored by Structures Branch and Aerodynamics Branch, with approval authority being DHAEL (AE).

Question 7

Special Technical Instruction (STI) is Technical Instruction for?

Answer 7

one-time maintenance work

Question 8

Servicing Instruction (SI) is Technical Instruction for?

Answer 8

recurring maintenance work
eg.
Removed when: 
Incorporated into Scheduled Servicing
Made redundant by improvements

Question 9

Major STI/SI involve Safety, Hidden Safety or Operational concerns and require approval by?

Answer 9

DHAEL (AE) / DHAEL (SE).

Question 10

Minor STI/SI involve Economical, Non-hidden safety concerns and require approval by?

Answer 10

Relevant Centre Heads.

Question 11

A Local Technical Order (LTO) is raised to arrest an unsafe / potentially unsafe condition as well as?

Answer 11

a defect that has a significant adverse effect on mission / Ops Readiness.

Mandatory Compliance
To be done with 7 Days
Based on a specific condition, e.g. Prior to next flight, immediate, etc.
Approving Authorities: Comd AELG / CO 80X / CO 81X / CO 50X