sensors Mode-S transponder

A91DBA

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N687FE · AIRBUS A-300-600 · operated by FEDERAL EXPRESS CORP

Hex
A91DBA
Octal
52216672
Decimal
11,083,194
Country
US
Tail
N687FE
Type
A306
Photo of N687FE
No current signal · last broadcast 16h ago
Flights observed
2
Distinct callsigns
2
Country
US
Last broadcast
16h ago

Last known position

Most recent position reported by Mode-S A91DBA.

Country allocation

The ICAO 24-bit address A91DBA falls within the block assigned to United States (US) by ICAO Annex 10, Volume III. Every aircraft registered in United States receives a permanent address from this block at the time of registration; the address stays with the airframe even if the aircraft is re-registered to a different operator within the country.

Callsign history 2 distinct

Callsign Airline Flights Last seen
FDX1479 - 1 2026-04-14
FDX1364 FedEx Express 1 2026-04-14

Recent flights last 2

DateFlightRouteTakeoffLandingDuration
2026-04-14 FDX1479 - Apr 14, 09:40 UTCApr 14, 10:25 UTC45m
2026-04-14 FDX1364 BNA → MEM Apr 14, 05:15 UTCApr 14, 05:50 UTC35m

About Mode-S

A Mode-S transponder code (also called an "ICAO 24-bit address" or "hex code") is a 6-character hexadecimal identifier permanently assigned to an aircraft when it's first registered. Unlike callsigns (which change with each flight) or registrations (which can change if an aircraft is sold internationally), the Mode-S address stays with the airframe for the life of the aircraft in that country.

Every ADS-B transmission from an aircraft includes its Mode-S address, making it the most reliable way to identify a specific airframe. Flight-tracking services like Apparatus use the Mode-S address as the primary key for tying position broadcasts, callsigns, and ownership records together.

Prefer a tail-number view? See the N687FE page for operator, model, and routing details .

Mode-S A91DBA frequently asked

What is Mode-S code A91DBA?
A91DBA is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N687FE.
Where is Mode-S A91DBA registered?
Mode-S code A91DBA is allocated to United States (US). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is A91DBA broadcasting right now?
No active broadcast right now. Last signal was 16h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A91DBA, octal 52216672, decimal 11,083,194.
What flights does A91DBA operate?
Mode-S A91DBA has broadcast 2 distinct callsigns, including FDX1479, FDX1364.