Grumman Gulfstream II
Encyclopedia
Design
The Gulfstream II is a twin-jet swept wing corporate transport designed to provide high speed and long range capability without sacrificing the airport performance, reliability, and other operational advantages of its predecessor, the turboprop Gulfstream I. Preliminary design of the wing was influenced by both cruise and low speed considerations. The aft-mounted engine location was selected after extensive analysis and design iterations considering aerodynamic, structural, and ground clearance requirements. Airfoil geometry was developed to maximum sweep benefit from the selected planform. The interference problem at the wing-body juncture was treated by modification of the airfoil shape and thickness over the inner third of the wing span. The basic airfoils for the main area of the wing are similar to those of the Grumman A-6 Intruder aircraft and utilize NASA 6-series thickness distributions combined with an in-house mean line. A buffet boundary commensurate with the M=.85 speed capability was attained by incorporating a row of co-rotating vortex generators on the outer wing panel. In developing the wing contours, attention was paid to the aircraft's low speed requirements by tailoring the leading edge radius to preclude leading edge separation. The high lift configuration, consists of a one piece, single-slotted Fowler flap of 30% chord. Stall initiation on the basic wing was found to occur at midspan but spread rapidly to the tip, particularly at large flap deflections. The addition of an upper surface fence at about midspan provided a strong pitch down at the stall, without sacrificing maximum lift, and also afforded an adequate margin between initial and tip stall.The high angle of attack investigations on the Gulfstream II indicated that stable trim conditions existed up to 45 degrees angle of attack. The elevator deflection required to trim to the primary stall at most forward center of gravity was sufficient to trim a deep stall at the aft center of gravity, but recovery from deep stall was immediate upon forward stick motion, and more than adequate nose-down elevator control was available. The acceptability of the Gulfstream II high angle of attack characteristics and the absence of a deep stall influence on configuration sizing and arrangement was attributed to the mitigating influence of the nacelle-wing overlap on nacelle contribution. Configuration buildup studies revealed the adverse nacelle influence on tail pitching moment contribution above 30 degrees angle of attack was not unduly severe and no appreciable effect on elevator or stabilizer effectiveness was found.
It was found in flight testing that the stall characteristics were satisfactory but did not preclude stall penetrations to the point of secondary stall pitchup. Rather than pursue a lengthy flight test research effort, and in view of the excellent primary stall behavior, it was decided to mechanically limit the extent of stall penetration with a stick shaker
Stick shaker
A stick shaker is a mechanical device to rapidly and noisily vibrate the control yoke of an aircraft to warn the pilot of an imminent stall...
and stick pusher
Stick pusher
A stick pusher is a device installed in some fixed-wing aircraft to prevent the aircraft from entering an aerodynamic stall. Some large fixed-wing aircraft display poor post-stall handling characteristics or are vulnerable to deep stall...
.
During installation of the Aviation Partners Inc.
Aviation Partners Inc.
Aviation Partners Inc. or API is a Seattle-based private corporation, which specializes in the production of performance enhancing winglet systems...
winglets (as the G-IISP), the vortex generators and midspan fence were removed and replaced with six leading edge vortilons similar to those found on the Gulfstream IV
Gulfstream IV
The Gulfstream IV and derivatives are a family of twin-jet aircraft, mainly for private or business use. The aircraft was designed and built by Gulfstream Aerospace, a General Dynamics company based in Savannah, Georgia, United States from 1985 until 2003.-Design and development:Gulfstream, in...
.
Variants
Gulfstream II- Twin-engined executive, corporate transport aircraft, with accommodation for up to 14 passengers, powered by two Rolls-Royce Spey RB.168 Mk 511-8 turbofan engines. Received FAA Type Certificate A12EA on October 19, 1967.
Gulfstream II TT
- Modified version with tip tanks. FAA certified May 13, 1977.
Gulfstream IIB
- Modified version, the wingleted wings of the Gulfstream III were fitted to the body of the Gulfstream II. FAA certified on September 17, 1981.
Gulfstream II SP
- Aircraft modified by the addition of Aviation Partners winglets. FAA certified under STC ST00080SE on April 22, 1994.
VC-11A
- VIP transport version for the US Coast Guard. One built.
Special Mission Variants
Gulfstream IIs have been popular as special mission aircraft, particularly when used aircraft became available for less than $1 million.A modified version of the G-II, called the Shuttle Training Aircraft
Shuttle Training Aircraft
The Shuttle Training Aircraft is a NASA training vehicle that duplicates the Space Shuttle's approach profile and handling qualities, allowing Space Shuttle pilots to simulate Shuttle landings under controlled conditions before attempting the task on board the orbiter.-Development:The aircraft's...
(STA), mimics the cockpit configuration and flight characteristics of the Space Shuttle
Space Shuttle
The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...
and is used by NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
as a training airplane for practice shuttle approaches (referred to as "dives"). Four G-IIs were used for this purpose N944NA, cn 144; N945NA, cn 118; N946NA, cn 146 and N947NA, cn 147.
NASA contracted Lockheed-Georgia to modify one G-II as the Propfan Test Assessment aircraft (N650PF, cn 118). The aircraft had a nacelle added to the left wing, containing an 6000 hp Allison 570 turboprop engine (derived from the XT701 turboshaft developed for the Boeing Vertol XCH-62
Boeing Vertol XCH-62
|-See also:-References:* Wilson, Michael. "". Flight International, 13 July 1972, pp. 44c–47.-External links:* * * at Friends of The Helicopter Museum...
program), powering a 9-foot diameter Hamilton Standard SR-7 propfan
Propfan
A propfan was first defined as a small diameter, highly loaded multiple bladed variable pitch propulsor having swept blades with thin advanced airfoil sections, integrated with a nacelle contoured to retard the airflow through the blades thereby reducing compressibility losses and designed to...
. The aircraft, so configured, first flew in March 1987. After an extensive test program, the modifications were removed from the aircraft and the aircraft became a Shuttle Training Aircraft (STA).
One G-II (N82CR, cn 80)was modified for use by Northrop Grumman
Northrop Grumman
Northrop Grumman Corporation is an American global aerospace and defense technology company formed by the 1994 purchase of Grumman by Northrop. The company was the fourth-largest defense contractor in the world as of 2010, and the largest builder of naval vessels. Northrop Grumman employs over...
as a demonstrator for the Broad Area Maritime Surveillance
Broad Area Maritime Surveillance
Broad Area Maritime Surveillance is a UAV system, which will provide continuous maritime surveillance for the US Navy and complement the 737 based Multimission Maritime Aircraft , the P-8A Poseidon....
(BAMS) contract.
One G-IIB (N74A, cn 36) was modified for use as the HALO I aircraft for the US Missile Defense Agency
Missile Defense Agency
The Missile Defense Agency is the section of the United States government's Department of Defense responsible for developing a layered defense against ballistic missiles. The agency has its origins in the Strategic Defense Initiative, which was established in 1983 and was headed by Lt...
.
A second G-IIB (N178B, cn 125) was modified by the addition of a large dorsal fairing as the HALO II aircraft for the Missile Defense Agency.
A G-IISP (N950NA, cn 185) was modified by the addition of a wing tip pod and a ventral radome as the HALO III aircraft for the Missile Defense Agency. This aircraft serves as a target for the Boeing YAL-1
Boeing YAL-1
The Boeing YAL-1 Airborne Laser Testbed, weapons system is a megawatt-class chemical oxygen iodine laser mounted inside a modified Boeing 747-400F. It is primarily designed as a missile defense system to destroy tactical ballistic missiles , while in boost phase. The aircraft was designated...
Airborne Laser Testbed.
A G-II (N10123, cn 107) had tip tanks added containing ground mapping radar, along with fairings on the wing undersurface and a centerline pod. This aircraft operated as the Calgis Geosar and is now owned by Earthdata Aviation.
A G-II (N105TB, cn 31) had underwing pylons and various fuselage appendages added to enable it to operate as a sensor testbed for MIT Lincoln Labs.
A G-II TT (N81RR, cn 246) is being modified for NASA, by the addition of fuselage appendages and underwing pylons, to serve as the High Ice Water Content (HIWC) sampling aircraft.
A G-II (JA8431, cn 141) is operated by Diamond Air Service in various configurations to support missions involving environmental measurements. In one configuration, it can carry two 3D X/L band PI SAR (Parametric Interpherometric Synthetic Aperture Radar) pods under the forward fuselage.
A G-IISP (N510AG, cn 159) is operated by the Orion Air Group in support Northrop Grumman’s development of the multi-role, tactical-command data link (MR-TCDL). The aircraft was modified with 19-inch and nine-inch, satcom dish-antennas, as well as additional radomes on the top and bottom.
A G-IIB (N186PA, cn 317) has been modified by the addition of a Raytheon SeaVueTM coastal and sea surveillance radar in a belly radome and is operated by the Phoenix Air Group in support of Raytheon Ktech. The aircraft provides airborne maritime range surveillance for the Missile Defense Agency (MDA) and other Department of Defense range facilities.
Military operators
- Libyan Air ForceLibyan Air ForceThe Libyan Air Force is the branch of the Libyan Armed Forces responsible for aerial warfare. In 2010, before the 2011 Libyan civil war, the Libyan Air Force personnel strength was estimated at 18,000, with an inventory of 374 combat capable aircraft operating from 13 military airbases in...
- Royal Moroccan Air ForceRoyal Moroccan Air ForceThe Royal Moroccan Air Force is the air force branch of the Moroccan Armed Forces.-History:...
- Nigerian Air ForceNigerian Air ForceThe Nigerian Air Force is the air arm of the Nigerian Armed Forces.It is one of the largest in West Africa, consisting of about 15,000 personnel and aircraft including 15 Chengdu F-7s, and 24 Dassault-Dornier Alpha Jets, armed helicopters, and military transport aircraft. However in recent years...
- NASANASAThe National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
- United States ArmyUnited States ArmyThe United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...
- United States Coast GuardUnited States Coast GuardThe United States Coast Guard is a branch of the United States Armed Forces and one of the seven U.S. uniformed services. The Coast Guard is a maritime, military, multi-mission service unique among the military branches for having a maritime law enforcement mission and a federal regulatory agency...
Civil Operators
The aircraft is operated by private individuals, companies, non-government organizations and executive charter operators. A number of companies also use the aircraft as part of fractional ownershipFractional Ownership
In business, fractional ownership is a percentage share of an expensive asset. Shares are sold to individual owners. A fractional owner enjoys priorities and privileges, such as reduced rates, priority access on holidays and income sharing. Typically, a company manages the asset on behalf of the...
programs.
Accidents and incidents
- May 3, 1982 - A Gulfstream II from the Algerian government was shot down by a fighter jet in the border area of Iraq, Iran and Turkey. All 15 people on board, including the Algerian foreign minister Mohammed Seddik Ben YahiaMohammed Seddik Ben YahiaMohammed Seddik Benyahia was an Algerian politician. Militant nationalist during the war in Algeria. After the independence he became the Minister of Information , Higher Education , Finance , and of Foreign Affairs .-Early life: He was born on January 30, 1932 in Jijel...
were killed.