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Business Aviation Industry Focus: DeHavilland 125

by Jeremy Cox 1. September 2008 00:00
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In 1958 the most successful designer and manufacturer of general aviation aircraft in Great Britain, Sir Geoffrey De Havilland - OBE/CBE (he was knighted in 1944 in reward for his services to the country) was struggling to bring his company back to profitability again after the tragic window design issues on his and the world's first jet airliner, the a DH 106 Comet had been fixed. The Mark IV Comet had just been returned to airline service (unfortunately too late) and even though he had officially retired in 1955 he continued to serve as the head of the company and he subsequently decided that it was time for his company to design a small business jet aircraft. His vision was of an aircraft that was sized between his extremely popular 1930's twin-engined-piston Gypsy Six powered DH 89 Dragon Rapide (also known as the Dominie within military service) and it's successor, the postwar twin-engined-piston Gypsy Queen powered DH 104 Dove. The Rapide seats eight passengers, four on either side of an aisle in a 'nearly' stand-up cabin, while the Dove seats eleven in a proper stand-up cabin. Sir Geoffrey, who was in his mid seventies by now, and his team, took the conceptual size of both the Rapides and Doves cabins and created the Jet Dragon, designated as the DH 125. The British post-war economy was booming in 1960; however the corporate treasury of DeHavilland had been depleted near to bankruptcy due to the Comet window design tragedies. Sir Geoffrey was grateful to be able to pass ownership of his company over to Hawker Siddeley Aviation. The DeHavilland name was kept until 1963.

The prototype DH125 Mark 1 first flew on August 13th, 1962 from Hatfield Aerodrome in Hertfordshire, about twenty miles north of central London. It was powered by two Armstrong Siddeley (later to be Bristol Siddeley, then Rolls Royce) Viper engines. These fine engines were a smaller derivative based upon the successful Armstrong Siddeley Sapphire turbojet that powered the Gloster Javelin and the Hawker Hunter of 1951. Eight Mark 1's were produced before the subsequent aircraft were fitted with up-rated Viper engines and designated Mark 1A (Viper 521) or Mark 1B (Viper 522.)

Shortly after the first flight of the DH 125 in 1962, Time Magazine wrote an article the same year that describes the DeHavilland aircraft as follows: "_the DH 125 was designed to operate on short runways and cruise with six passengers at 480 m.p.h., it is Britain's entry in the market for corporate jets. Price: $550,000_"

It is easy to confuse the 'A' and 'B' designations when they applied to the DH 125 and subsequent variants. The United Kingdom's Civil Aviation Authority (CAA) and our FAA, up until 1999, designated all of the aircraft that were approved and destined for the North American market as 'A' models (America); with the rest of the world designated as 'B' models (British.) The DH 125 Mark 1A was Type Certificate Approved by the FAA in the United States on September 23rd, 1964. The Mark 1A featured an unrestricted take-off and continuous engine thrust of 3,120 lbs that allowed 21,200 lbs MGTOW and accommodations for 8 passengers and 2 crew. The maximum rated altitude was 40,000 feet. The Mark 1B powered by the Viper 522 benefited by an additional 210 lbs of thrust for a 5 minute maximum continuous thrust of 3,330 lbs. Mmo (Maximum Mach Operating Speed) was also increased at altitude from 0.735 mach, to 0.75 mach. Nine months before the Mark 1B was approved by the FAA, Sir Geoffrey passed away after suffering a cerebral haermorrage at age 82.

The labour government of the then prime minister: James Callaghan, finished the work that had been started by his Labour colleague and former prime minister, Harold Wilson in the 1960's. Wilson had engineered the unification (and eventually nationalization) of the aviation industry. In April 1977 the forced merger of Hawker Siddeley with British Aircraft Corporation and Scottish Aviation was executed to create the government owned entity named British Aerospace (BAe.) If Sir Geoffrey had still been alive, he most likely would have fought this governmental merger plan with 'hair, blood, tooth and nail.'

The month following the forced nationalization of Hawker Siddeley into BAe, the engineers and executives celebrated the certification of their first Turbo-Fan powered version of the Jet Dragon; the HS125-700 Model fitted with two Garrett AiResearch TFE 731-3 engines. Prior to the introduction of the Model 700, the worldwide DH/HS 125 fleet amounted to over two hundred and fifty various Viper Turbo-Jet (now Rolls Royce) powered models, which included the Mark 1A; Mark B; Mark 2; Mark 3; Model 400 and Model 600 all for the civilian world, and the new Dominie model that was manufactured exclusively for the Military.

As a side note, the DH/HS 125 Dominie got its name from the military version of the DH 89 Rapide previously mentioned in this article. The Royal Air Force of Great Britain is the Dominie's primary customer, but it was, and in most cases, still is used by a multitude of military forces around the world. The Rolls Royce Viper 301 powered Dominie T1 has been in continuous service with the Royal Air Force (RAF) since 1965. According to the RAF, the Dominie today is used to train weapon systems officers and operators, air engineers and air loadmasters. With up to five students on board in the back, plus two crew up-front, a mixture of two-to-three hour sorties are flown, including both low and high-level flying, maritime operations, radar handling and target training.

Both the HS 125-600 and the HS/BAe 125-700 has the same fuel capacity of 1,419 U.S. Gallons, but the replacement of the Vipers with the Garrett Fans virtually doubled the range of the latter version; from approximately 1,100 NM to an impressive 2,100 NM. Static thrust of both the Viper and the Garrett were almost identical, with the Fan delivering 25 lbs additional thrust over the Turbo-Jet, in a 'stage-three' noise compliant package. Over the following decade, 100 various Viper powered aircraft were retrofitted with the Garrett Fan under after-market Supplemental Type Certificates (STCs) developed by AiResearch.

After Hawker Siddeley (HS) had completed its purchase of the De Havilland Aircraft Company, and also after the eight original DH 125 prototypes had been completed at the DH facility in Hatfield, HS moved all production of the 125 series 195 miles northwest to the DH facility that used to build the famous twine-engine DH 98 Mosquito attack/bomber, in the city of Chester, in Cheshire close to the border of Wales. It is here that production has remained ever since. It has even withstood the purchase of BAe's Business Jet Division by the North American behemoth, the Raytheon Company in 1993. Raytheon Aircraft Company (Beechcraft) moved completion and delivery of the BAe 125, which was now being produced as the model 800. Raytheon renamed the aircraft simply as 'Hawker.' After much upheaval of personnel Raytheon created an enclave of English men and women within the metropolitan areas of both Wichita and Little-Rock (BAe had built a delivery and sales centre for its U.S.A. Jetstream, 146 and ATP transport aircraft division in Little Rock, Arkansas prior to the Raytheon purchase; now a service and completion centre for the Hawker.) In 1996 some sub assembly manufacturing and all final assembly operations were moved to Wichita. Eight years prior to the purchase of the Hawker program in 1993, Raytheon Aircraft, nee Beechcraft, had started their jet aircraft product division in 1985 after purchasing the Diamond aircraft program from Mitsubishi in Japan and then renaming it the Beechjet. It seemed now that Raytheon were the new rulers of business and general aviation manufacture, as their product line encompassed the entire gamut of general aviation starting with their single-engine piston powered Beechcraft Bonanza, to the twin-engine piston powered Baron, the twin-engined PT6A turbo-prop powered King Air series of aircraft, the futuristic Starship, the Beechjet, the all-plastic Premier and the Hawker series. Additionally other divisions were building the Beech 1800/1900 airliners, and the license built Swiss military trainer from Pilatus that is called the Mark 2 T-6 Texan.

After growing this aircraft manufacturing company into what it is today, Raytheon sold it off to an investment consortium in 2007, which promptly renamed the entire operation 'Hawker Beechcraft' by combining two very illustrious and historic names.

Geoffrey DeHavilland's Jet Dragon has gradually evolved over the last 46 years starting from the Mark 1A, through the various models previously mentioned above, on to the model 1000, model 800XP, and now in its latest 2008 manifestation: the model 850XP, 900XP and the soon to fly, the model 750. Today a total of 1,657 Jet Dragon derivatives have been built and delivered around the world, since 1962; 1,457 of which are still operating. Everyone I believe can only take their hat off and doff it in respect to this impressive production history. Do you agree?

Okay so next month we shall focus on the Jet Commander as we further continue this look-back at the history of the various aircraft that have shaped modern business aviation. If you have a suggestion for me as to a specific business aircraft that one of these future Business Aviation focus articles should be dedicated to, please let me know your thoughts. Also remember that any input that you care to make will be of great interest to all of the readers here at Globalair.com. So don't be bashful. Go ahead and write your comments and suggestions here. Please don't forget that whatever you write here, can be seen publicly by everyone that visits this page, so please be funny, be inspired, but most importantly of all, please be nice.

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Jeremy Cox

Identification of a Congested Area Under FAR Sect. 91.119

by Greg Reigel 1. September 2008 00:00
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The primary issue in a recent NTSB decision, Administrator v. Folk, was whether the airmen's low-level flights occurred over a "congested area" as referenced in FAR § 91.119. Although this case arose in the context of an aerial applicator operation, it is instructive for FAR Part 91 general aviation operations as well.

The Regulation

As you may recall, FAR § 91.119 delineates the minimum safe altitudes for operations under FAR Part 91: Over a "congested area" of a city, town, or settlement, an aircraft must operate 1,000 feet above the highest obstacle within a horizontal radius of 2,000 feet of the aircraft (§ 91.119(b)); and over other than congested areas, an aircraft must operate 500 feet above the surface, unless it is over open water or sparsely populated areas, in which case the aircraft must stay at least 500 feet away from any person, vessel, vehicle, or structure (§ 91.119(c)).

This regulation first appeared in the Air Commerce Regulations of 1926. The purpose of the rule is to provide minimum safe altitudes for flight and to provide adequate protection to persons on the ground. Unfortunately, neither the FAA nor the NTSB has ever provided airmen with a precise definition of what constitutes a "congested area." Rather, a "congested area" is determined on a case-by-case basis. According to the Board, "the determination must take into consideration all circumstances, not only the size of an area and the number of homes or structures, but, for example, whether the buildings are occupied or people are otherwise present, such as on roads."

Multiple legal interpretations issued by the FAA's Office of the Chief Counsel have also addressed this issue and reiterated the "case-by-case" analysis used to determine whether an area is congested. Size of the area is not controlling, and violations of the rule have been sustained for operation of aircraft: (i) over a small congested area consisting of approximately 10 houses and a school; (ii) over the campus of a university; (iii) over a beach area along a highway; and (iv) over a boy's camp where there were numerous people on the docks and children at play on shore. The legal interpretations have noted that the presence of people is important to the determination of whether a particular area is "congested." Thus, large, heavily congested residential areas of a city, town, or settlement would be considered "congested areas."

The Case

In the Folk case, the FAA alleged that the airmen had both engaged in agricultural aircraft operations in violation of 14 C.F.R. §§ 137.51(b)(1) through (3)2 ( ); 91.119 (minimum safe altitudes); and 91.13(a) (careless and reckless). One of the main disputes in the case was whether the area over which the airmen had flown was a "congested area." At the hearing, the FAA argued that its case-by-case analysis of the facts and circumstances supported the conclusion that the area was indeed a "congested area." One of the airmen's arguments in response to the FAA's position was that the logical extension of the FAA's position that congested area determinations are made on a case-by-case basis is that nobody can know whether or not an area is congested until after their case has been decided.

During the hearing, the FAA inspector who investigated the allegations regarding the airmen testified that "if an operator conducts an application in an area the FAA might later determine to be a congested area, the operator ignores that potentiality at his or her peril." The inspector went on to say that he had warned the airmen that the area around their farm could be considered a congested area. When the airmen requested a definition of "congested area," the inspector told them there was no definition, and referred the airmen to FAA guidance, including an inspectors' handbook. After studying the regulations and, apparently, finding no examples in the handbook that applied to their operations, the airmen then decided the area around their farm was not congested.

Unfortunately for the airmen, the Administrative Law Judge (ALJ) agreed with the FAA. He concluded that the area over which the airmen had flown contained upwards of 30 homes, buildings, and structures and, as a result, was a "congested area." The ALJ also rejected a number of other defenses raised by the airmen and held that the airmen violated the regulations as alleged.

On appeal, the airmen renewed their argument that the area over which they had flown was not a "congested area." Initially, the Board observed that the FAA "has not pronounced a precise definition that includes the factors of the density of the population in an area; whether there is surface traffic in the vicinity; or the numbers and proximity of residences, buildings, or structures." It went on to note that "it is clear that the intent of the regulations is to protect persons and property on the ground and to fairly apply the rules to operators of aircraft, and, in the case of Part 137, to operators of agricultural aircraft." The Board then affirmed the ALJ's determination that the area over which the airmen had operated was a "congested area."

If you are like me, you are wondering "how am I supposed to know what constitutes a "congested area" if the FAA won't tell me?" Interestingly, Board member Hersman's dissent, although not determinative in the case, addresses this question and provides some pointed commentary on how the FAA could have avoided this dispute and how it could avoid such disputes in the future. She states that "this controversy could have been resolved (eliminating the many hours of work by all parties in appellate process) had the operators received from FAA more directive instructions about what the regulatory agency expected." She goes on to observe that "what constitutes congestion is dynamic and highly subjective" and "[i]f the FAA believes an area is congested, thus generating certain expectations of agricultural air operators operating there, the agency should make those expectations clearly known from the beginning and avoid a legal dispute that leads to license suspension followed by a lengthy and expensive appeals process."


So what does this mean to an FAR Part 91 operator? For most airmen, this regulation raises little concern. They take off, climb to their enroute altitude and later descend and land at their destination. However, airmen who enjoy flying "low and slow" or who want to "get a closer look" need to keep this regulation in mind during those operations.

Fortunately, the ball isn't completely hidden by the FAA's and NTSB's lack of a specific definition for "congested area." We do have previously decided cases in which this issue has been determined that provide some guidance. At the end of the day, how low you can go will depend upon the type of area over which you are flying. Hopefully your analysis of the area over which you fly will correspond with the 20/20 hindsight exercised by the FAA and NTSB.

This is a case of FAA not giving airman enough information. Tell us what some of your experiences have been.

*Remember this is the Internet, using your nickname is the best policy.

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Greg Reigel

Budgeting and Reducing Costs

by David Wyndham 1. September 2008 00:00
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Most of us are back from summer vacations, the kids are heading back to school, and 2008 is two-thirds finished. Now is a good time to take a look at your aircraft expenses and start planning for next year. Costs are going up, inflation might be 3.5% - more than in past years, and our economy isn't exactly firing on all cylinders. Managing and reducing costs are likely at the forefront of the budget process. Here are a few ideas the help you reduce your costs as you budget for 2009.

As discussed before, you can't control what you can't measure. How do you track your costs? We've worked with operators who only have a few categories of costs. They typically find it hard to manage their costs effectively with a few large-dollar categories. Those we've helped set up with more detailed accounts find it easier to manage and control their costs as they have the detail needed to understand their costs. Once you know where your dollars are flowing, then you can begin to examine ways to reduce those costs.

How much will you fly next year? Ask those who your aircraft for inputs. Remember, changes in your utilization will impact your variable costs, but your fixed costs will remain essentially unchanged. If prices remain unchanged, a 5% reduction in flying hours will mean maybe a 2.5% reduction in your total budget as the fixed costs (hangar, training, salaries, etc) won't change.

Next, is to have a feel what some of your cost drivers will be for next year. Fuel is a big one. Fuel cost amounts to somewhere around half of your variable operating cost. Don't plan on fuel prices dropping. We'll be fortunate if they stabilize. If there are no changes in your utilization, figure on fuel increasing maybe 5% to 10% next year and hope to get lucky.

If you've read the GAN newsletters, you know about different ways to save on fuel. Continue to work with your FBO's to arrange for fuel discounts. If you don't ask for a discount, you won't get one! Shop around for prices and take advantage of fuel discount programs when they make sense for your operation. Even five cents per gallon savings will add up. Tanker fuel when it makes sense, and evaluate the total cost of a stop - fuel plus all services needed.

Reduce the amount of deadhead, or unoccupied trips. Combine trips when able. This may mean opening up the business aircraft to more than just the top executives. If it doesn't affect your mission, the savings can be significant.

You know your aircraft's maintenance requirements and planned utilization. So now you need to budget for the next year's maintenance events. You need to research those costs. Review past costs. If you are facing a major cost event, consider soliciting bids from two or more well qualified shops. Both cost and schedule need to be considered. If your aircraft is under warranty, make sure the shops you use are equipped to handle any warranty claims, something the manufacturer's facility should do well.

Evaluate the costs of exchanges versus overhauling your own. Using loaner parts while yours are repaired may be less costly than exchanging for new. But with your own part, you'll know the history of that part. Your maintenance folks will have the knowledge in this area.

Don't overlook warranty. On a new aircraft, we all keep very careful track of what repairs are in warranty. But even older aircraft have many new parts installed. Those parts typically carry some sort of warranty. Tracking that warranty might save money when they need replacement.

The use of a spreadsheet or life cycle costing tool can be valuable in making the budgeting process go smoothly. Ask for help. We all can't specialize in all areas of aviation. Lastly, start the process early. Budgeting is not something done well at the last minute.

If you have some tips I can pass along to folks, click reply and let me know.


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