G-IV picture
Gulfstream IV-SP (AKA Gonzo)

The Gulfstream IV-SP (GIV) is a high altitude jet that can fly up to 45,000 feet. The GIV is used to fly around hurricanes and gather data about the hurricane environment using dropwindsondes. This data is sent to the National Hurricane Center to assist them in forecasting the hurricane path and intensity.

The GIV is regularly used in the Winter Storm Reconnaissance program, which is run by the National Centers for Environmental Protection (NCEP). The goal of the Winter Storm Reconnaissance Program is to better predict the location and intensity of high winds, surf conditions, and severe weather caused by winter storms using dropwindsondes. The GIV also occasionally takes air chemistry observations of the upper troposphere in the jet stream area above the winter storm.


Two Fuselage Mounted Rolls Royce Tay 611-8 twin spool turbofan jet engines


(Hurricane and Winter Storm Missions):
2 pilots
1 flight engineer/mechanic
1 flight meteorologist (flight director)
1 ASPEN Dropwindsonde Processing System
3 Engineering Technicians/Dropwindesonde (Sonde) system operators


45,000 feet

Rate of Climb (approximate - fully loaded):

3000 fpm (first 25000 ft.)
1500 fpm (through 33000 ft.)
1000 fpm (to 41,000 ft. – max wt. ceiling)

Operational Airspeeds:

41,000 – 45,000 ft. True Airspeeds (Mach .77-.80, 440-460 kts.)


Two engine driven alternators (36KVA, 115 volt, unregulated 3 phase)
One Auxiliary Power Unit (APU) (36KVA, 115 volt, 400Hz, 3 phase)
Two Converters (converts and regulates engine alternator power)
Each provides: 23KVA, 400Hz, 3 phase AC power
250 amps, 28 volts DC power

Scientific Power:

SED has an Uninterruptable Power Source (UPS) for scientific gear

Max. Gross Weight:

Ramp 75,000 pounds
Takeoff 74,600 pounds
Landing 66,000 pounds

Empty Weight:

43,700 pounds
(operational configuration)

Useful Load:

31,300 pounds
(operational configuration)

Fuel Load:

29,500 pounds

Type Fuel:

Jet A, JP4, JP5, JP8

Standard Fuel Burn:

(fully loaded) = 5000 pounds/hr for first hour and 3000 pounds/hr for every hour after that

Maximum Range:

3800 nm. (with a 1 hour fuel reserve)

Maximum Duration:

8 hrs. 45 minutes (with 1 hour fuel reserve)

External Dimensions:

Radome to trailing edge of horizontal stabilizer = 87.58 ft.
Radome to aft end of fuselage = 78.83 ft.
Wing Span = 77.83 ft.
Horizontal Tail Span = 32 ft.
Vertical Tail Height = 24.4 ft

Internal Dimensions:

Head Room = 6ft.
Bulkhead to Bulkhead = 8 ft.
Cabin Length (Cockpit to Baggage Comp.) = 33 ft.

Useable Volume:

Usable Length = 33 ft.
Usable Width = 6 ft.
Usable Height = 4 ft.
Usable Volume = 792 cubic ft.

Additional Standard Equipment


2 High Frequency (HF) Radios
2 VHF Radios
Honeywell SATCOM Phone
GPS and Inertial Reference Systems (IRS) for navigation
1 UHF Radio
Honeywell TCAS II System (with FAA Change 7)
EROS Quick Donning Oxygen System
Collins WXR-700C (C-band weather radar)


Dropwindesonde Tube with 8-channel tracking capability
Satellite Communication System with voice/data transmission capability
Numerous Computer Systems


Nose art from the GIV-SP, N49RF

© The Jim Henson Company