USDA FOREST SERVICE FEPP, CALIFORNIA DEPT OF FORESTRY AND FIRE P· ICAO24 a54aee· last seen Feb 2026

N440DF is a Marsh Aviation S-2T Turbo Tracker, a twin-engine turboprop operated by USDA FOREST SERVICE FEPP, CALIFORNIA DEPT OF FORESTRY AND FIRE P. SkyMeter has tracked 134 flights totalling 104 hours of airtime via ADS-B. The most frequent segment is KMCC to KMCC. Service window in our records spans 254 days. Of those flights, 22 (16.4%) carry at least one detected incident: a go-around, unstable approach, stall warning, or runway excursion. The Marsh Aviation S-2T Turbo Tracker has a maximum takeoff weight of 28,500 lb, medium wake category.

About the Marsh Aviation S-2T Turbo Tracker

The S-2T Turbo Tracker is a turboprop conversion of the Cold War-era Grumman S-2 Tracker anti-submarine aircraft, transformed into one of the most capable single-engine-out airtankers in the aerial firefighting fleet. Marsh Aviation of Mesa, Arizona developed the conversion in the 1980s, replacing the original piston radials with twin Garrett TPE331-14GR turboprops and adding a 1,200-gallon retardant tank system. The result is an aircraft that combines the rugged carrier-capable airframe of a 1950s naval design with modern turbine reliability and the ability to operate from short, high-altitude airstrips near active wildfires.

The S-2T's low-and-slow delivery profile (it can drop retardant at speeds around 130 knots just above treetop level) makes it particularly effective for initial attack on fast-moving fires in mountainous terrain. Its twin-engine configuration provides crucial safety margins when operating in the hot, high, and heavy conditions typical of Western U.S. fire seasons, and the type's excellent single-engine performance has made it a mainstay of state and federal firefighting agencies.

The California Department of Forestry and Fire Protection operates the largest fleet, with aircraft often seen working the steep canyons of the Sierra Nevada and coastal ranges. SkyMeter has tracked flights across airframes and operators, with the largest observed operator.

FLIGHTS
134
all time
FLOWN HOURS
104
tracked time
📍
AIRPORTS VISITED
19
unique
📡
CALLSIGNS
1
30 routes
📅
SERVICE PERIOD
05/30/2025 → 02/09/2026
first → last
INCIDENT RATE
16.4%
22 flagged

Top routes

By flight count

10
9
6
5
3
2
2
2
1
1
1

Flight numbers

Most-flown by this airframe

1

Aircraft specifications

Marsh Aviation S-2T Turbo Tracker

Engines
Twin Turboprop
Vref (approach)
95 kt
MTOW
28,500 lb
Wake category
M

Recent flights

Newest 50 operations of N440DF

50
02/09/2026
1h 1m
No alerts
02/04/2026
44m
No alerts
02/04/2026
1h 6m
No alerts
02/03/2026
1h 4m
△ Low approach-stability score
02/03/2026
58m
No alerts
01/28/2026
24m
No alerts
01/28/2026
34m
No alerts
01/28/2026
48m
No alerts
01/27/2026
47m
△ Low approach-stability score
01/27/2026
58m
No alerts
01/08/2026
1h 1m
No alerts
12/03/2025
42m
△ Low approach-stability score
12/02/2025
18m
No alerts
11/19/2025
31m
△ Low approach-stability score
11/13/2025
2h 26m
No alerts
11/11/2025
31m
No alerts
11/10/2025
22m
No alerts
11/02/2025
41m
No alerts
10/29/2025
43m
No alerts
10/22/2025
35m
No alerts
10/19/2025
25m
No alerts
10/15/2025
1h 3m
No alerts
09/05/2025
48m
No alerts
09/03/2025
5h 29m
△ Low approach-stability score
09/03/2025
1h 7m
△ Low approach-stability score
09/03/2025
33m
△ Low approach-stability score
09/02/2025
1h 55m
No alerts
08/29/2025
21m
No alerts
08/27/2025
9m
No alerts
08/27/2025
6m
No alerts
08/27/2025
10m
No alerts
08/27/2025
1h 29m
No alerts
08/26/2025
7m
No alerts
08/26/2025
2h 4m
No alerts
08/11/2025
8m
No alerts
08/11/2025
13m
No alerts
08/10/2025
17m
No alerts
08/01/2025
1h 22m
No alerts
07/05/2025
15m
No alerts
07/04/2025
20m
No alerts
07/04/2025
28m
No alerts
07/04/2025
17m
No alerts
07/04/2025
19m
No alerts
07/03/2025
6m
No alerts
07/03/2025
16m
No alerts
07/03/2025
6m
No alerts
07/03/2025
10m
No alerts
07/03/2025
55m
No alerts
07/03/2025
4h 4m
No alerts
07/03/2025
17m
No alerts
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