AIRCRAFT COMPARATIVE ANALYSIS - GULFSTREAM GII
Category: Corporate Aircraft – Comparative Analysis
Author: Mike Chase
Aircraft Comparative Analysis - Gulfstream GII
A little obsolete, or still a competitive player?
In this month’s Aircraft Comparative Analysis, we’ll provide information on a selection of pre-owned business jets for the purpose of valuing the pre-owned Gulfstream GII. We will consider the productivity parameters - payload/range, speed and cabin size - and cover current and future market values. The field in this study includes the Dassault Falcon 900 (1980s), Bombardier Challenger 601-3R (1990s), and the follow-on Gulfstream III (1980s) model.
The Gulfstream GII (factory model G-1159) was the first of the Gulfstream (formerly Grumman) jet line. Derived from the GI turboprop, the GII is today regarded as a bit obsolete - but is still attractive as an inexpensive long-range luxury business jet; especially the improved GIIB model. These aircraft were manufactured between 1967 to 1979.
The GIIB is a GII modified with a GIII wing, adding greater speed and range. Other variations include the GIITT - a GII modified with wing tip tanks for greater range - an unofficial model designation, and the GIISP given to a GII, GIIB or GIITT modified with the $475k Aviation Partners Blended Winglet modification. The Blended Winglet modification provides greater speed, ceiling altitude, range and climb performance. Naturally, the tip tanks are removed on any GIITT for this particular modification.
GII aircraft can be RVSM certified when Aircraft Service Change ASC499 or ASC498 is complied with. Currently there are 256 Gulfstream GII/IIB aircraft built with 205 (164 GII and 41 GIIB) currently in service.
With the GII traditionally being a Stage-2 aircraft, it had faced the threat of limits on places it could operate into and out of due to noise pollution regulations. However, Hushkit technology is becoming available - including QS3 Hushkits - that upgrade the aircraft to meet Stage 3 noise requirements (more information below).
PAYLOAD AND RANGE
The data displayed in Table A (top left) was published in the B&CA, May 2009 issue, but is also sourced from Conklin & de Decker.
As we mentioned in past articles, a potential operator should focus on payload capability as a key factor. The Gulfstream GII ‘Available payload with Maximum Fuel’ at 2,190 pounds is greater than the CL601-3R and Falcon 900 aircraft.
According to Conklin & de Decker, the cabin volume of the GII at 1,269 cubic feet is 23% larger than the Challenger 601-3R aircraft at 1,035 cubic feet (Chart A, left), and is virtually the same in volume as the Falcon 900 at 1,264 cubic feet.
The GII and GIII aircraft are powered by a pair of Rolls-Royce Spey 511-8 engines, each offering 11,400 lbst, while the Falcon 900 aircraft has three Honeywell TFE 731-5AR/BR engines with thrust at 4,500 pounds each. The Challenger CL601-3R has two General Electric CF34-3A1 engines each with thrust ratings at 8,729 pounds.
Using data published in the May 2009 B&CA Planning and Purchasing Handbook and the August 2009 B&CA Operations Planning Guide we will compare the operational costs of our aircraft.
Jet A fuel cost used from our source publications was $4.25 per gallon at press time for the August 2009 edition, so for the sake of comparison we’ll chart the numbers as published.
Note: The fuel price used from this source does not represent an average fuel price for the year.
COST PER MILE COMPARISONS
Chart B (left), details ‘Cost per Mile’, and compares the GII to its competition factoring direct costs and with all aircraft flying a 1,000nm mission with a 1,600 pound (eight passengers) payload.
The GII at $10.84 cost per mile has a significantly higher cost to operate compared to the rest of the field.
TOTAL VARIABLE COST COMPARISONS
The “Total Variable Cost”, illustrated in Chart C (right), is defined as the cost of Fuel Expense, Maintenance Labor Expense, Scheduled Parts Expense, and Miscellaneous trip expense. The total variable cost for the GII at $3,990 is significantly more expensive to operate compared to the CL601-3R and the Falcon 900 aircraft - but a little less than the GIII.
The points in Chart D (center right) center on the same group of aircraft. Pricing used in the vertical axis is as published in the B&CA 2009 Purchase Planning Handbook and Vref. The productivity index requires further discussion in that the factors used can be somewhat arbitrary.
Productivity can be defined (and it is here) as the multiple of three factors.
1. Range with full payload and available fuel;
2. The long range cruise speed flown to achieve that range;
3. The cabin volume available for passengers and amenities.
The result is a very large number so for the purpose of charting, each result is divided by one billion. The examples plotted are confined to the aircraft in this study. A computed curve fit on this plot would not be very tight, but when all business jet aircraft are considered the “r” squared factor would equal a number above 0.9. Others may choose different parameters, but serious business aircraft buyers are usually impressed with Price, Range, Speed and Cabin Size.
After consideration of the Price, Range, Speed and Cabin Size (and factoring purchase price), we can conclude that the GII is highly productive compared with the other aircraft shown. Note how the Gulfstream GIII continued to improve the Gulfstream product line. Further, this month, we have included the CL601-1A and 3A to show how the earlier Challenger models have changed with each new version.
In a direct comparison to the field in this study, the GII: has the second largest cabin volume; costs significantly more to operate per mile and has the second highest variable cost of the competitors in this field; offers the second fastest speed (TAS) at 475 kts; boasts the second longest range with maximum payload; and is offered at a significantly lower price.
Table B (right) contains the relative retail prices from B&CA magazine and from Vref for each aircraft with the price shown for the last year of manufacture. The number of aircraft in-operation, percentage “For Sale”, and the number “Sold” over the past 12 months are from JETNET. As shown in the table, 51 GII/IIB aircraft have sold in the past 12 months - an average of over four per month.
LOCATION BY COUNTRY
According to JETNET’s Evolution and STAR Reporting systems, a majority 163 (80%) of the GII/IIB fleet resides in the United States, followed by Mexico with 15 (7%), and South Africa with 8 (4%).
Within the preceding paragraphs we have touched upon several of the attributes that business aircraft operators value. There are other qualities such as airport performance, terminal area performance, time to climb performance, and maximum transition altitude levels that might factor in a buying decision, too, however.
The Gulfstream GII aircraft fares well against its competition, so those operators in the market should find the preceding comparison of value. Our expectations are that the GII aircraft will continue to do very well in the pre-owned market as an inexpensive longrange luxury business jet.
For more information: Michael Chase is president of Chase & Associates, and can be contacted at 1628 Snowmass Place, Lewisville, TX75077; Tel: 214-226-9882; Web: www.mdchase.aero
THERE’S A NEW KIT IN THE NEIGHBORHOOD!
Hubbard Aviation Technologies’ QS3 is the new Hushkit system in the neighborhood, and is available for installation on the Gulfstream GII, GIISP, GIIB and GIII aircraft reviewed above. Company founder Stanley S. Hubbard of Hubbard Broadcasting in Minneapolis, Minnesota himself owns a GII with the QS3 Hushkit. He has previously owned a GV, GIVSP and GIII - but the GII and GIII serve his corporate needs at a significantly reduced overall cost.
It is true that the GIV and G450 are more fuel efficient as well as in terms of maintenance/ cost per hour to fly, but if you consider the full cost of these aircraft, including purchase value and insurance, you could find it significantly more economical for your own business needs to own and operate a GII or GIII (see comparisons table below).
The time to keep these airplanes flying as Stage 3-compliant is now: A growing number of airports are imposing curfews – and in some cases outright bans on Stage 2 aircraft, and Federal legislation outlawing Stage 2 aircraft may soon be enacted. The installation of a QS3 Hushkit will upgrade your aircraft to meet Stage 3 requirements without operational restrictions, meaning owners can takeoff at gross weight, with no adjustments to flap settings, and no reduction of EPR.
Gulfstream has always backed its aircraft, and has pledged to support Stage 2 and Stage 3 airplanes far into the future. Indeed, it has developed a program to extend the life of an airframe from 20,000 hrs to 30,000 hrs. With that support, and the installation of a Hushkit conversion system, GIIs and GIIIs should be flying for years to come without restriction.
THE QS3 HUSHKIT
There are three components of the QS3 Hushkit, including: An alternating-lobe exhaust nozzle; a fuselage-mounted acoustically lined and fixed titanium-core ejector; and a cascade-style thrust reverser (TR).
The new, state-of-the-art cascade-style TRs dramatically reduce the amount of engine power needed to provide the same reverse thrust, and as a result, the operator benefits from reductions in:
• Reverse-thrust noise - both in-cabin and external - to meet the Stage 3 requirements;
• Temperatures, stresses and vibration loads on the engine;
• Empennage vibrations and associated fatigue-inducing stresses.
In fact the cascade TR is so efficient that N1 is reduced from 94% to 82% on landing. Of further benefit, each combined thrust reverser and mixer nozzle assembly weighs 106 lbs less than the OEM unit it replaces, and is designed for high reliability and low maintenance.
From August 2010, delivery of the kits will be one per-month. Installation takes four weeks (or less) and includes:
• Structural reinforcements to the aft fuselage;
• Installation of pylon-mounted ejectors;
• New cascade-style thrust reversers;
• Complete systems verification and maintenance check flight.
BRIEF QS3 HUSHKIT HISTORY
• December 17, 2003: STC issued by the Los Angeles Aircraft Certification Office (ACO) for the Stage 3 Noise Suppression Huskit.
• May 16, 2005: STC amended to include new Thrust Reversers.
• September 22, 2009: STC transferred to STC Acquisition LLC, dba Hubbard Aviation Technologies, LLC.
More information from Hubbard Aviation Technologies: www.hubavtech.com