6.3 Special Service Requests & Minimum Connection Times

6.3 Special Service Requests & Minimum Connection Times

Quick Answer: Special Service Requests (SSR) use standardized 4-letter IATA codes (e.g., WCHR for wheelchair, VGML for vegan meal, UMNR for unaccompanied minor) to transmit operational demands directly to airline flight crews and ground staff. Separately, Minimum Connection Times (MCT) represent legally mandated transit thresholds established by airport authorities and IATA. Connecting itineraries that fall below published MCT limits are flagged as illegal by the GDS and cannot be ticketed.

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1. Special Service Requests (SSR) vs. Other Service Information (OSI)

When servicing passengers with specific operational, medical, or dietary requirements, travel agents transmit supplemental data to operating airlines via the GDS. IATA standardizes this communication under two distinct message formats:

Special Service Request (SSR)

• Format: Standardized 4-letter IATA designators transmitted via AIRIMP (the ATA/IATA Reservations Interline Message Procedures - Passenger manual, which standardises reservation messages between carriers).
• Operational Impact: Requires specific operational action, confirmation status, or resource allocation from airline ground handlers, catering teams, or cabin crew.
• Confirmation Loop: Transmitted with action code NN; airline returns status HK (confirmed) or NO (unable/declined).
• Amadeus Entry Example: SR VGML (Request Vegan Meal) or SR WCHR (Request Wheelchair to Ramp)

Other Service Information (OSI)

• Format: Free-text informational remarks.
• Operational Impact: Informational only; does not require system confirmation, seat allocation, or catering changes.
• Common Uses: Advising airlines of VIP status, commercial company affiliation, spoken language preferences, or senior citizen traveler details.
• Amadeus Entry Example: OS BA PASSENGER IS A CELEBRITY VIP or OS AA SPEAKS SPANISH ONLY

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2. Standardized IATA 4-Letter SSR Code Categories

A. Mobility & Disability Assistance Codes

IATA defines three distinct wheelchair assistance codes based on the passenger's exact degree of mobility. Misapplying these codes creates severe airport operational bottlenecks:

• WCHR (Wheelchair Ramp): Passenger can ascend/descend aircraft steps and walk inside the cabin to their seat, but requires a wheelchair for long distances across the terminal ramp/concourse.
• WCHS (Wheelchair Steps): Passenger cannot ascend or descend aircraft steps, but can walk slowly inside the cabin to their seat. Requires wheelchair transport and ramp elevator/lift to aircraft door.
• WCHC (Wheelchair Cabin Carry): Passenger is completely immobile. Requires wheelchair to aircraft door, specialized narrow aisle-chair inside the cabin, and physical lift/carry into the aircraft seat.
• BLND: Blind or visually impaired passenger (specify if traveling with guide dog GDOG).
• DEAF: Deaf or hearing impaired passenger.
• DPNA: Passenger with intellectual, developmental, or cognitive disability requiring airport assistance.

B. Unaccompanied Minors & Special Passengers

• UMNR (Unaccompanied Minor): Children traveling without an adult parent or guardian (typically ages 5 to 11 mandatory, ages 12 to 15 optional depending on carrier policy). The SSR entry must specify the child's exact age, as well as the name, address, and contact phone numbers of both the dropping-off parent at origin and the picking-up adult at destination.
• MAAS (Meet and Assist): Ground staff assistance for elderly or first-time passengers who do not require a wheelchair.
• MEDA (Medical Clearance): Case requiring prior approval from airline medical department (e.g., recent surgery, unstable cardiac condition).
• STCR (Stretcher Passenger): Immobile medical patient requiring a cabin stretcher (occupies 6 to 9 economy seats).

C. Dietary Special Meal (SPML) Codes

Special meal requests must be submitted into the GDS at least 24 to 48 hours prior to departure to ensure catering uplifting:

D. Equipment & Baggage SSR Codes

• BIKE: Bicycle in protective case.
• GOLF: Golf equipment bag.
• PETC: Pet in cabin (small dog/cat in approved under-seat carrier).
• AVIH: Animal in hold (pet transported in climate-controlled cargo hold).

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3. Minimum Connection Times (MCT)

A Minimum Connection Time (MCT) is the shortest officially permitted time interval required for a passenger and their checked baggage to transfer between two connecting flights at a specific transit airport hub.

MCT standards are determined by airport operating authorities and published globally via the Official Airline Guide (OAG) and IATA GDS databases.

The Four Core MCT Routing Combinations

MCT values at any given airport depend directly on the flight routing categories:

1. Domestic to Domestic (D-D): Passenger stays within domestic terminal concourse; no border control. Shortest MCT (e.g., 30–45 minutes).
2. Domestic to International (D-I): Requires document/passport check at departure gate (e.g., 45–60 minutes).
3. International to International (I-I): Passenger remains in international transit lounge; requires security re-screening (e.g., 60–90 minutes).
4. International to Domestic (I-D): Passenger must clear inbound passport border control, collect checked baggage from customs carousel, clear customs inspection, re-check baggage at transfer desk, and pass security screening. Longest MCT (e.g., 90–150+ minutes at gateways like JFK, LHR, or LAX).

                  TRANSFER COMBINATION MCT SEVERITY
                  
  D-D  [Shortest: 30-45 mins]   --> No border control / Same terminal
  D-I  [Moderate: 45-60 mins]   --> Exit passport verification
  I-I  [Substantial: 60-90 mins]--> Transit security re-screening
  I-D  [LONGEST: 90-150+ mins]  --> Immigration + Baggage Claim + Customs

Key Factors Inflating Standard MCTs

• Terminal Transfer: Changing terminals (e.g., London Heathrow Terminal 3 to Terminal 5 via inter-terminal shuttle adds 30–45 minutes to standard MCT).
• Interline Transfer: Connecting between two different airlines vs. an online connection (same airline).
• Aircraft Size: Connects involving super-jumbo aircraft (e.g., Airbus A380) carry higher buffer requirements.

System Validation & Legal Connections

When an agent books a connecting itinerary, the GDS automatically compares the elapsed time between the arrival of Segment 1 and departure of Segment 2 against the database MCT table:

• Legal Connection: Elapsed transit time >= Published MCT. GDS allows ticket issuance.
• Illegal Connection: Elapsed transit time < Published MCT. GDS issues warning prompt: BELOW MINIMUM CONNECTION TIME.

Critical Exam Rule: If an agent overrides a GDS warning to force-book or ticket an illegal connection, the operating airlines bear NO legal liability to provide free hotel accommodation, meal vouchers, or priority rebooking if the passenger misses the connecting flight.