We ask ourselves, “How can we add value?”


When was the last time you had to do something over, because it was more important in the urgent moment, to have the appearance of being “done,” of “having arrived?” And how often it is that we believe that success, or at least this appearance of success, is what draws others toward us — as people, as businesses, as communities?

But is this true? Yes, our track records do matter. But what is a track record made of except the real value that we add to our endeavors? At Streamline Designs, instead of striving for a certain appearance, we simply consider adding value: adding value to our engagements, adding value to our families, adding value to our industry. We believe that adding real value changes not just the way things look, but the way they actually are.

Our goal is to meet you right where you are, to learn about who you are and where you have come from, to get an idea of where you think you are going, and to help you get there.

If certification issues have your attention, we want to add value in that spot. If information management has “got your goat,” then let’s get things unstuck and resolved together. Or maybe a ninth customer just called with that same field issue, and you don’t have enough engineering help on site. We would love to hear from you. Enabling solutions for difficult problems are our specialty, it is just where we love to add value.

From the archives: Propeller Inertia and Why It Matters

With our website refreshment in-process, we decided to go back through the archives and select some of the most popular articles for re-posting. Enjoy this “classic” on prop inertia from the Fall of 2009.
In recent years, there has been substantial confusion in the light aircraft and ultralight industry regarding propeller inertia.

Rotax specifies the following propeller mass moment of inertia limits for their various gearboxes in order to “not overstrain the propeller shaft and gearbox and to avoid problems with the shock absorber installed in the gearbox”:

  • Model “A” or “B” gearbox–less than or equal to 3000 kg cm^2
  • Model “C” gearbox–less than or equal to 6000 kg cm^2

So what exactly is “mass moment of inertia”, and what does it mean?

In a nutshell, inertia is defined as the amount of resistance to a change in motion. The more resistant an object is to changes in motion (whether that is slowing down or speeding up), the greater its inertia. One example is that a heavy book is harder to get sliding than a lightweight book (ignoring friction effects). The heavy book has more resistance to changes in motion, so it has more inertia.

The definition of inertia is based on Newton’s First Law: objects in motion tend to stay in motion and objects at rest tend to stay at rest. Imagine a book sitting on a table. The book will not slide across the table unless something pushes it. Another example is the feeling of being pushed back into your seat when your car accelerates. Your body tends to stay at rest and the car moves forward. The difference you feel is the seat pressing into your back.

Specifically, engine manufacturers are concerned with the rotational mass moment of inertia of the propeller. Rotational mass moment of inertia is defined as the sum of the product of mass times radius squared, where the radius is the distance of the mass from the axis of rotation.

Rotational Mass Moment of Inertia = mass * radius^2

For a propeller, the mass in this definition includes the mass of the propeller hub and the propeller blades. Notice that the units on Rotax’s limits match the definition [kg (mass) * cm^2 (radius, or distance, squared)]. Rotational mass moment of inertia can be thought of as the amount of resistance to changes in rotational speed. Here are a few everyday examples of rotational mass moment of inertia:

  • It is easier to get a merry-go-round turning when children are at the platform’s edges than when the same merry-go-round has adults at its edges. The one with the adults on it has the higher rotational mass moment of inertia because it has greater mass.
  • A person sitting in an office desk chair is easier to spin with her arms tucked in than when she has her arms extended. Because the distance of mass (her arms) from the axis of rotation is greater with her arms extended, she is more resistant to being spun or stopped, and she has more rotational inertia in this position.

Notice that rotational inertia is not only determined by mass, but also the distance of the mass from the axis of rotation (also called the moment).

Every object has a unique equation for calculating mass moments of inertia. The more complex the geometry, the more complex the equation gets. Just like the merry-go-round and office chair, the rotational mass moment of inertia of a propeller is directly related to its geometry, the amount of mass and its distance from the axis of rotation. Every time a cylinder fires in your engine, it exerts a rotational force on the shaft and accelerates the propeller. The rotational inertia of the propeller causes it to resist the acceleration, putting torsional loads on the gears and shafting. The higher the mass moment of inertia, the higher the loads. These loads are transmitted through the gearbox, engine, and airframe thousands of times per minute in a typical light aircraft setup. Unless the loads are reduced or dissipated, the associated vibration can cause instrument failure, engine and airframe damage.

Engines and gearboxes are designed to carry specific loads. Engine and gearbox manufacturers specify mass moment of inertia limits so these design loads are not exceeded. Exceeding the mass moment of inertia limit can put your powerplant and airframe at risk for rapid or excessive wear or even failure.

It’s easy to go to AirVenture and pick up a snazzy new composite prop or to want to get that same 3-bladed big prop your buddy raves about. But whenever purchasing a new propeller, it is always a good idea to contact the manufacturer to be sure the prop does not exceed the mass moment of inertia limitations of your engine and gearbox combination. You could be saving yourself a lot of headaches or even avoiding a premature engine failure.

If this article was helpful to you or for more information on this or other topics, please contact us.

The Backpack

So Adam just ordered this new backpack.


We hope it arrives in time for our AirVenture departure. He travels quite a bit, and has traversed the globe through airports and public transportation, preferring to do so hands free. His previous pack, also by Wenger, lasted about 8 years. It was a workhorse. We love(d) it. Perfect pocket placement, understated styling, and enough structure to stand upright. Obviously Swiss Gear (Wenger) has achieved some brand loyalty with the engineers. The only complaint he had is that 90% of the old pack is still completely useable. The interface between the strap and the top of the pack goes through several layers of various materials, including some plastic piping. Had the manufacturer left a larger seam allowance, the pack would likely have lasted many more years, I believe. Design for failure? Have I mentioned my theory on consumer product design for failure? Oh well, I will cannibalize the hardware off of it and Adam will (hopefully) enjoy his new pack.

See you at AirVenture!

See Adam’s new laptop backpack here:


ASTM International Awards 2012

In the fall of 2012 Adam Morrison and Severin Kempf of Streamline Designs, LLC were recognized for their service to the light aircraft community.In September, Adam was presented with a Service Award for his performance on the Committee on Technical Committee Operations (COTCO) for 2010-2012. As stated in the committee’s scope, “COTCO develops and maintains the Regulations Governing ASTM Technical Committees and acts upon recommended changes.” Kenneth F. Yarosh, the 2012 Chairman of the Board for ASTM International, recognizes members of COTCO for their contribution to the “legislative arm” of standards development for ASTM.In October at the 10th Anniversary Meeting of ASTM International Technical Committee F37 in Atlanta, GA, both men were recognized for their contributions and service to the committee.

Severin was presented with a Standards Excellence Award 2012. This award was presented for effective leadership of the task group which developed the first audit program standard specifically for Light Sport Aircraft.* Severin said about receiving this award, “It is always great to see work turn into something useful for the industry and I am humbled by the award from the committee regarding this work.”

Adam was recognized with the first annual Daniel A. Schultz Award. This award, named in honor of Daniel Schultz and his contributions to ASTM, is given in recognition of his leadership on committees and contributions to standards development, and is awarded for significant and outstanding contributions to global standardization by the Light Sport Aircraft community. This highest- recognized F37 Committee Award was presented to Adam for his long time devotion to standards development in support of light sport aircraft.

Adam responded to the recognition by saying it was an honor to be recognized by the Light Sport Aircraft committee on it’s 10th Anniversary during Streamline Design’s own 10th Anniversary year.

Technical Committee F37 addresses issues related to design, performance, quality acceptance tests and safety monitoring for light sport aircraft (LSA). While in Atlanta the committee also passed F2972, a new standard for light sport quality assurance. www.astm.org/standardization-news(external link)

Streamline Designs at AirVenture

Oshkosh, Wis.-During the week of July 23-29, Adam Morrison and Severin Kempf of Streamline Designs led multiple committees and task groups at EAA AirVenture in Oshkosh, Wisconsin. Severin, as Task Group Chairman, had the difficult job of leading the group working to redefine the minimum useful load of Light Sport Aircraft while Adam led the discussion and writing of new quality assurance standard for all LSA to consolidate and harmonize five of the current standards.

As Vice Chairman of ASTM Committee F37 on Light Sport Aircraft, Adam played an integral role in organizing several task groups and committee meetings that met during the week. These meetings were all attended by representatives of the FAA and covered a variety of topics including: electric propulsion and their incorporation into LSA, equipment standards on avionics and the systems avionics interact with, a discussion on airframe emergency parachute systems and the definition of make and model of LSA. The last was of particular interest to manufacturers and the FAA as the FAA begins to audit manufacturers when they release new models.

In addition to committee meetings Adam and Severin were able to meet with Quicksilver Aeronautics LLC to discuss the ratings assessment Streamline Designs had done for Quicksilver regarding their viability of moving into LSA. For the complete article go to Quicksilver at AirVenture(external link).

Severin and Adam were able to spend Tuesday touring the various booths in the Exhibit Hangers. There they had the chance to talk with suppliers, software and avionics companies about the latest innovations and technologies available. Severin especially appreciated the opportunity to talk with other engineers and professionals who understand the challenges faced by those working in the light aircraft industry.

Image AirVenture is a family affair for Streamline Designs and both families look forward to Thursday when everyone comes out and enjoys KidVenture. As Severin puts it, “It is refreshing to be in a family friendly business involved in a family friendly industry. It is great to give the kids a glimpse of what I do and the kind of people I work with.” Building balsa gliders and flying gas-powered control line models were particular favorites with the kids.

Adam summed up the week by saying, “It is always good to visit a familiar place and connect with people from the industry. To see that Streamline Designs plays a significant role in the light aircraft industry and for the kids to have a family friendly environment where they can see what we do as a company.”

Streamline Designs heavily involved with LSA meetings and activities prior to the 2010 U.S. Sport Aviation Expo in Sebring, Florida.

Sebring, FL Just prior to the 2010 LSA Expo in Sebring, Florida, Adam Morrison and Severin Kempf of Streamline Designs led ASTM meetings related to Light Sport Aircraft standards. Adam serves as Chairman of the fixed-wing subcommittee as well as overall committee Vice-Chairman and Severin serves as Task Group Technical Contact for the development of a new audit standard for LSA. The meetings covered subject matter such as Electric Propulsion Units (EPU), IFR/IMC operations, audits, integrity of engine installations, and improved internationalization of the standards.

Just prior to the 2010 LSA Expo in Sebring, Florida, Adam Morrison and Severin Kempf of Streamline Designs led ASTM meetings related to Light Sport Aircraft standards. Adam serves as Chairman of the fixed-wing subcommittee as well as overall committee Vice-Chairman and Severin serves as Task Group Technical Contact for the development of a new audit standard for LSA. The meetings covered subject matter such as Electric Propulsion Units (EPU), IFR/IMC operations, audits, integrity of engine installations, and improved internationalization of the standards.

Severin had the following to say after these meetings, “Although there are many interests represented on the ASTM LSA standards committee, the ASTM process has proven to be very robust. At the end of the day, there was consensus to do the right things. I was also pleased to see that there is general agreement within the community as it relates to the developing audit standard for LSA.”

Adam noted following the Sebring meetings, “There are some very exciting things happening within the LSA industry. Aircraft designs and manufacturers are maturing and the industry is beginning to appreciate the value of high-quality consensus standards. We are on the forefront of electric propulsion and are actively developing standards to help assure that these systems can be safely operated. Developments are happening quickly, and the consensus standards process is proving well-suited to support the safety of significant innovations. Streamline Designs is ready, as always, to continue supporting this growing industry.”

Streamline Designs has been involved with the LSA industry since its inception and provides affordable, high-quality engineering services ranging from detailed design and analysis to setup of manufacturing quality systems to management and execution of complete compliance programs for LSA. For more information on these and other services, please contact us.

Self-Regulation of the Light Sport Aircraft Industry: The Role of Third-Party Independent Audits

A Google search for the term “industry self-regulation” quickly turns up over 87,000 hits, with much of it being bad news: from papers on how self-regulation fails to keep dangerous internet advertising from children, to articles on salmonella in peanut butter. In a culture of instant news and visual media, whole companies and even the livelihood of entire towns (e.g. Peanut City, Georgia or Toy Paint City, China) wax and wane based on two things: industry sustainability, and the media. Today most of the general public hasn’t heard about LSA or Sport Pilot, despite the fact that our own spouses suffer from information overload on the topic. And while the goal is to revitalize and provide new cost-effective entryways to aviation, the idea is to do it without having LSA show up on the 11 o’clock news.
After working with regulating and advocacy organizations for at least a decade, the LSA industry in its pre-adolescent state has gotten the car keys from mom and dad. The question is, will we chin up to responsibility, get legitimate, and enjoy our newfound flexibility — or will we wreck with the freedom we have received?

According to Harvard Business author Michael Toffel “there are four angles [to industry self-regulation]: how the rules are designed, who adopts them, whether and how compliance is monitored, and whether these rules actually achieve what they purport to achieve.”1 How has the LSA industry stepped up in these four areas? First, the ASTM standards process has received accolades and has moved the standards development process at a lightning-quick pace, enabling the industry to even exist. 2Next, the “who” of adaptation includes over 60 manufacturers of thousands of registered LSA at the time of authoring this paper. The third area — compliance monitoring — is where we will linger for the rest of this white paper.

Imagine you are getting ready to engage in combat. Your product and savvy are your offensive weapons and your compliance to regulatory expectations, as legal protection, is your defense. Historically, the ASTM consensus standard approach provides very good protection, if the product and manufacturer are truly compliant. Despite the popular notion that auditors are “the bad guy,” auditors and their audits provide needed testing and proving for sustained industry legitimacy and public confidence. Just as a team’s defense or soldier’s defense is tested either with “drills” or with real games and combat, audits test a company’s defense and adds confidence that under fire, a manufacturer’s statement of compliance will hold. According to ASTM legal counsel, in cases where independent, third-party verification of compliance was completed, this protection resulted in some cases never even making it to court.3

So what are the characteristics of a sound, third-party audit program that will gain the respect of both legislative and judicial branches of the government? In other industries dealing with public safety such as food or amusement rides, water-tightness is not necessarily the expectation. Humans are clearly imperfect and the industries we create and sustain are done so imperfectly. One characteristic of effective compliance monitoring is that problems are identified and corrective action is taken. Another is that a healthy pattern with response to change in the industry and standards is established. Finally, a third characteristic of a successful oversight program is the fostering of a general attitude of responsibility and due diligence which is publicly exhibited.

The state of the LSA industry will clearly impact the way a penetrating audit program is designed. Today’s oversight has different needs and requirements than the oversight for more established industries, or for what the LSA industry will need ten years from now. The idea is to show that we can be responsible: that we are trustworthy to declare compliance, willing to be examined, and willing to correct any shortcomings.

The LAMA audit program, an effort recognized by the FAA, has been designed with these requirements in mind. The approach itself is two-pronged, consisting of a Compliance Check and an On-Site Check. The Compliance Check is typically the initial focus, involving a comprehensive check of verifiable compliance materials. An On-Site Check follows, which involves a spot-check of the facilities, including compliance to quality systems requirements and continued airworthiness standards.

Upon signing up for a LAMA audit, a manufacturer is asked to provide verifiable evidence for each and every requirement of the standards against which the audit is being conducted. This doesn’t mean that a long-time employee says to the auditor, “we have a fleet of 100 planes and haven’t seen a problem yet,” or “that landing gear member is so thick, there is no way it will bend.” It means that each requirement is addressed objectively. And the flexibility of the standards today makes this possible and affordable. Passing the LAMA audit not only puts the manufacturer in an improved legal position, but is just another pixel in the collective picture of good standing in the eyes of the consumer and our governing agencies.

In the case that major findings are determined during an audit, LAMA has structured tools and programs in place to help solve manufacturers’ compliance issues. Whether that means coaching the writing of a missing report or conducting additional testing or analysis, the audit team has cost effective resources at its fingertips. The aim of the LAMA audit program is to develop a healthy pattern of problem identification and cost-effective and efficient correction.

Recertification audits are completed periodically and cover areas of question, or of change to either the product or the standards. A focused, third party organization like LAMA can keep up with a dynamic and rapidly developing industry, helping manufacturers keep verifiable evidence for their compliance current. Just as a flight review completed every other year by pilots can help sharpen skills, develop new ones, or awaken a pilot to unknown dullness, these recertification audits add confidence to manufacturers who have already passed the initial two-part LAMA audit.

So we arrive at the fourth aspect of LSA self-regulation: is the industry achieving what the rules and rule-makers purport to achieve? Long, long ago in a land not too far from where you are now, many men and women started the work of dreaming and incubating the idea of an affordable way to fly simple aircraft. The LSA industry self-regulation journey walks a fine line between industry legitimacy, public reputation, and the flexibility, affordability, and accessibility of the aircraft. The answer to whether LSA will successfully and sustainably achieve this high calling is up to you. If you are an aircraft manufacturer or importer, will you advance public and governmental confidence by engaging the LAMA audit program?

If this article was helpful to you or for more information on this or other topics, please contact us.

3. ASTM International Legal Counsel, “Standards and Liability” presented in Miami, FL on 2 October 2008 by Tom O’Brien.

Streamline Designs POH Design Receives Accolades

Indianapolis, IN In early 2008, Streamline Designs finished the complete rewrite and redesign of the Jabiru J250-SP Pilot’s Operating Handbook in accordance with the current requirements of ASTM F2245. The newly refreshed handbook was featured among others in EAA’s Sport Pilot and Light Sport Aircraft. The comments in the magazine were very complimentary of the POH.

Streamline Designs offers technical communications solutions at any level of involvement needed. We have worked with clients to audit existing technical manuals, redesign existing manuals to meet the international standards requirements, manage tracking databases for fielded manuals, refresh graphics and manual content, and more. Cost for these services varies depending on the nature of the project, but our rates are extremely competitive.

So whether your manuals need to be refreshed or if they don’t even exist yet, we have the skills and expertise necessary to capture your vision and we would love to see your technical manual featured here in the future.
POH Weight and Balance

To see the full article which includes the redesigned J250-SP Pilot’s Operating Handbook, click here:

Adam Morrison of Streamline Designs featured on the award-winning UltraFlight Radio Show

NewsIndianapolis, IN Streamline Designs’ Adam Morrison was a featured guest on the UltraFlight Radio Show on 11 March 2008. Adam talked with host Roy Beisswenger about Streamline Designs’ involvement with light aircraft manufacturers, aircraft design, and the ASTM standards for Light Sport Aircraft. Adam currently serves as chairman of the ASTM subcommittee responsible for fixed-wing LSA consensus standards.

Click on the UltraFlight Radio link below to listen to the 20-minute interview (MP3 format). Note that there may be a delay after clicking the link while the file downloads.

Adam Morrison of Streamline Designs named as chairman of ASTM Light Sport Aircraft Fixed-Wing Subcommittee

Toronto, Canada Adam Morrison took over as chairman of the ASTM subcommittee F37.20 for fixed wing aircraft during the May 2006 LSA consensus standards meetings in Toronto, Canada. Adam has been actively involved with the ASTM consensus standard process for LSA since its formation in 2002. Going forward, Adam will be responsible for leading the subcommittee in the refinement of existing standards for design and performance, quality systems, and continued airworthiness for Light Sport Aircraft. In addition, Adam will lead any new activity related to standards for fixed-wing aircraft.

Upon taking this position, Adam said the following: “This position is extremely important as this industry is still in its infancy and is working through many growing pains. I look forward to leading the consensus standard effort for fixed wing aircraft to help insure that the integrity of the Light Sport Aircraft industry is maintained.”

The same expertise that Adam brings to the ASTM committee is available from Streamline Designs. Please contact us for help with any of your light aircraft technical needs.