Boeing 737-400
Narrow-body jet
- Passengers flown a year
- 241.9K
- 44th-most common US type
- Airframes in US fleets
- 21
- US operators
- 4
- Airports served
- 8
- Countries
- 3
- Load factor
- 29.2%
Where the Boeing 737-400 flies
Filed traffic dataThe operators table below counts the registered Boeing 737-400 airframes each airline owns (US DOT Form 41). These figures are how much the type actually flew — departures, seats, and passengers filed with US DOT T-100 over the trailing 12 months, not fleet size.
Departures flown
6,407
July 2026
Seats flown
876,638
Passengers
241,928
Load factor
29.2%
RPM ÷ ASM
Block hours
10,046
Busiest Boeing 737-400 routes
The Boeing 737-400's busiest US routes over the trailing 12 months, by departures.
Havana – Miami (HAV–MIA)
2,018 departures · 61,393 passengers · 235 mi
19.5%
Load
Miami – Santa Clara (MIA–SNU)
1,197 departures · 53,031 passengers · 228 mi
28.4%
Load
Camaguey – Miami (CMW–MIA)
441 departures · 23,163 passengers · 339 mi
33.8%
Load
Holguin – Miami (HOG–MIA)
439 departures · 25,232 passengers · 427 mi
36.8%
Load
Cap Haitien – Miami (CAP–MIA)
241 departures · 20,087 passengers · 664 mi
53.1%
Load
Miami – Santiago (MIA–SCU)
226 departures · 9,416 passengers · 491 mi
26.8%
Load
Havana – Fort Myers (HAV–RSW)
204 departures · 10,120 passengers · 248 mi
32.0%
Load
Richmond – YIP (RIC–YIP)
99 departures · 52 passengers · 463 mi
32.5%
Load
Austin – Cincinnati / Covington (AUS–CVG)
87 departures · 0 passengers · 958 mi
—
Load
Cedar Rapids – Cincinnati / Covington (CID–CVG)
83 departures · 0 passengers · 419 mi
—
Load
Cincinnati / Covington – Philadelphia (CVG–PHL)
81 departures · 40 passengers · 507 mi
26.7%
Load
Cedar Rapids – Kansas City (CID–MCI)
81 departures · 0 passengers · 238 mi
—
Load
Cincinnati / Covington – St Louis (CVG–STL)
62 departures · 0 passengers · 308 mi
—
Load
Fort Myers – Santa Clara (RSW–SNU)
58 departures · 2,750 passengers · 301 mi
30.1%
Load
42 departures · 0 passengers · 426 mi
—
Load
The longest and shortest Boeing 737-400 flights
The two ends of the type's working envelope, from the routes it actually flew — not what the airframe is certified to do.
Longest route flown
664 mi
Cap Haitien – Miami (CAP–MIA)
2h 10m block · 241 departures · 53% load
Flown by Eastern Air Express.
Shortest route flown
228 mi
Miami – Santa Clara (MIA–SNU)
1h 14m block · 1,197 departures · 28% load
Flown by Eastern Air Express. Also one of the type's busiest routes anywhere in the US — a short hop worked like a bus line.
Source: US DOT Bureau of Transportation Statistics, T-100 Segment. Data through July 2026.
Airports the Boeing 737-400 serves
The Boeing 737-400 serves 8 US airports across 3 countries. The busiest, by departures:
- MIA
2,283 departures · 6 routes · 1 operator
47.9%
Share
- HAV
Havana
1,108 departures · 2 routes · 1 operator
23.2%
Share
- SNU
Santa Clara
599 departures · 1 route · 1 operator
12.6%
Share
- CMW
Camaguey
221 departures · 1 route · 1 operator
4.6%
Share
- HOG
Holguin
219 departures · 1 route · 1 operator
4.6%
Share
- CAP
Cap Haitien
120 departures · 1 route · 1 operator
2.5%
Share
- SCU
Santiago
113 departures · 1 route · 1 operator
2.4%
Share
- RSW
103 departures · 1 route · 1 operator
2.2%
Share
Who flies the Boeing 737-400
Two questions in one table. Airframes is what each carrier reported owning in its US DOT fleet filing; seats flown is how much of the type it actually operated. They can rank differently, and the gap is the interesting part.
| Operator | ||||
|---|---|---|---|---|
| Eastern Air Express37Q | 8 | 876.6K | 100.0% | 23.9 yr |
| Kalitta Charters IIKLQ | 7 | 0 | 0.0% | 9.1 yr |
| Northern Air CargoNC | 5 | — | — | 11.7 yr |
| Aloha Air CargoKH | 1 | — | — | 1.1 yr |
Airframes are the latest Form 41 filing; seats flown and share are US DOT T-100 for the type's most-flown operators — a dash means a carrier isn't among them (a freighter operator, or one that flies fewer).
How old is the US Boeing 737-400 fleet?
Age is measured from each airframe's delivery date — the FAA airworthiness date where available, otherwise the manufacturer's. Bars share a fixed scale across every fleet page, so two carriers can be compared directly.
Monthly Boeing 737-400 capacity
How common is the Boeing 737-400?
The Boeing 737-400 makes up 0.2% of all tracked US airline aircraft — the 44th-most common type in service.
Share of all tracked US airline aircraft · top 12 types shown · 118 others hold the remaining 37.4% · Boeing 737-400 is the ringed slice at 0.2%
- 1
872 aircraft
10.0%
Share
- 2
708 aircraft
8.1%
Share
- 3
526 aircraft
6.1%
Share
- 4
481 aircraft
5.5%
Share
- 5
470 aircraft
5.4%
Share
- +38 more types
- 44
Boeing 737-400#44 · this type
21 aircraft
0.2%
Share
Frequently asked
How many Boeing 737-400 are in US airline fleets?
US carriers operate about 21 Boeing 737-400 aircraft across 4 airlines, 20 of them in service.
Which airline operates the most Boeing 737-400?
Eastern Air Express operates the largest US Boeing 737-400 fleet, with about 8 aircraft.
What is the busiest Boeing 737-400 route?
The busiest US route flown by the Boeing 737-400 is HAV–MIA, with about 2,018 departures over the trailing 12 months.
Which airline flies the Boeing 737-400 the most?
Eastern Air Express flies the most Boeing 737-400 capacity in US service, with about 876.6K seats flown over the trailing 12 months.
How many passengers does the Boeing 737-400 carry?
The Boeing 737-400 carried about 241.9K passengers on US routes over the trailing 12 months.
What is the longest Boeing 737-400 flight?
The longest US route flown by the Boeing 737-400 is CAP–MIA, about 664 miles, flown by Eastern Air Express.
How many airports does the Boeing 737-400 serve?
The Boeing 737-400 serves about 8 US airports across 3 countries, led by Miami (MIA).
How old is the average Boeing 737-400?
The US Boeing 737-400 fleet averages about 14.9 yr.
How common is the Boeing 737-400 in US fleets?
The Boeing 737-400 is the 44th-most common aircraft type in tracked US airline fleets, by number of aircraft.