Gulfstream IV-SP (G-IV) is a high altitude, high speed,
twin turbofan jet aircraft acquired by AOC in 1996.
The G-IV is currently configured for operational support
of the National Hurricane Center synoptic surveillance
mission and is expected to provide support for NOAA
programs for many years to come. This mission is designed
to collect, process and transmit vertical atmospheric
soundings in the environment of the hurricane. The principle
tool used for this task is the GPS dropwindsonde.
The dropsonde is released from the G-IV measuring and
transmitting back to the aircraft the pressure, temperature,
humidity, and GPS Doppler frequency shifts as it descends
to earth. The Doppler shifts are used to compute the
horizontal and vertical wind components. After analysis
and processing of the dropsonde data the information
is formatted into a TEMP-DROP message using the standard
WMO format. The TEMP-DROP message is then transmitted
to the National Centers for Environmental Prediction
and the National Hurricane Center for inclusion into
the global and hurricane model runs. The TEMP-DROP message
is also provided to the hurricane forecaster providing
real-time observations depicting the synoptic patterns
surrounding the hurricane.
G-IV SP (Special Performance)
G-IV SP Transformation Article
Fuselage Mounted Rolls Royce Tay 611-8 twin spool
turbofan jet engines
and Winter Storm Missions):
1 flight engineer/mechanic
1 flight meteorologist (flight director)
1 High Altitude Profiling System (HAPS) system operator
(can be automated)
3 Engineering Technicians/Dropwindesonde (Sonde)
of Climb (approximate - fully loaded):
fpm (first 25000 ft.)
1500 fpm (through 33000 ft.)
1000 fpm (to 41,000 ft. – max wt. ceiling)
– 45,000 ft. True Airspeeds (Mach .77-.80,
engine driven alternators (36KVA, 115 volt, unregulated
One Auxiliary Power Unit (APU) (36KVA, 115 volt,
400Hz, 3 phase)
Two Converters (converts and regulates engine alternator
Each provides: 23KVA, 400Hz, 3 phase AC power
250 amps, 28 volts DC power
has an Uninterruptable Power Source (UPS) for scientific
Takeoff 74,600 pounds
Landing 66,000 pounds
A, JP4, JP5, JP8
loaded) = 5000 pounds/hr for first hour and 3000
pounds/hr for every hour after that
nm. (with a 1 hour fuel reserve)
hrs. 45 minutes (with 1 hour fuel reserve)
to trailing edge of horizontal stabilizer = 87.58
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
Room = 6ft.
Bulkhead to Bulkhead = 8 ft.
Cabin Length (Cockpit to Baggage Comp.) = 33 ft.
Length = 33 ft.
Usable Width = 6 ft.
Usable Height = 4 ft.
Usable Volume = 792 cubic ft.
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)
Tube with 8-channel tracking capability
Satellite Communication System with voice/data transmission
Numerous Computer Systems
specific equipment and systems onboard the G-IV for
the hurricane surveillance mission are the:
Aircraft Data System
- Two Data System Modules for instrument interface
and data collection
- Four Networked Sun Sparc5 Workstations
- Extensive atmospheric instrumentation
Airborne Vertical Atmospheric Profiling System
- Dropsonde Data System for drop execution, data collection
- Dropsonde Launch Chute
- GPS dropwindsonde
Analysis and Processing System
- Workstation accomplishes data analysis, processing,
and message formatting
- VHF, UHF, ADF, Flight Phone, SATCOM and Passenger
Collins WXR-700C C-Band Weather Radar w/ 30-inch antenna
G-IV aircraft is on standby or deployed 180 days for
hurricane surveillance, another 30-60 days are required
for instrumentation and calibration, and 30 days for
maintenance and training while anticipating between
200 to 300 hours of flying every year.
G-IV Winter Storms Reconnaissance
February 28, 2012 - NOAA's Gulfstream IV-SP will operate out of Anchorage, Alaska during the next few weeks in support of the agency's Winter Storms Reconnaissance (WSR) program. The specialized aircraft will gather data as needed over the Pacific Ocean in an effort to enhance winter storm forecasts for the entire North American continent.
During the WSR missions, the aircraft will deploy special sensors over the ocean to collect information where the jet stream and moisture from the ocean interact and breed potentially powerful winter storms that impact North America several days later.
Data on wind speed and direction, pressure, temperature and humidity from the sensors will be monitored and quality checked by meteorologists aboard the aircraft. NFOAA then will use the information to predict the location and intensity of high winds, destructive surf conditions, severe weather and flooding rainfall caused by winter storms.
"These atmospheric observations, combined with satellite and other data, have proven to significantly enhance 4-7 day winter weather forecasts," said CAPT Barry Choy, NOAA, Chief Science Officer for the National Centers for Environmental Prediction (NCEP), part of NOAA's National Weather Service. "Improved forecasts mean longer warning lead times for the public, emergency managers, air carriers, utility companies and others to prepare for significant winter storms, protect lives and property and minimize economic impacts."
"Together, these flights will help forecasters paint a detailed three-dimensional picture of weather systems over Pacific regions where more accurate information is needed for computer weather forecast models," said Jack R. Parrish, Flight Director and Meteorologist with NOAA's Office of Marine and Aviation Operations (OMAO), Aircraft Operations Center (AOC)..
Prior to repositioning to Anchorage, the aircraft supported the WSR program out of its temporary base at U.S. Coast Guard Air Station Barbers Point in Honolulu HI. NOAA aircraft have supported the WSR program since 1998, when the program was established by NCEP.
Based at the NOAA Aircraft Operations Center, located at MacDill Air Force Base in Tampa, FL, the Gulfstream IV is part of the NOAA fleet of aircraft and ships operated, managed and maintained by the NOAA OMAO. The aircraft, which typically operates at an altitude of 40,000-45,000 feet, is also known for its role in Atlantic hurricane surveillance.
For more information on the Winter Storms project visit