Experimentals Have Come a Long Way

    Nowadays, it’s more common to ask the
    builder to add an old style tach or oil
    pressure gauge to his glass cockpit digital
    display. Even though you can download
    data after every flight, it’s not as easy to
    spot trends and problems at a glance
    during initial test flights.

    Another trend is to put everything but the kitchen sink into the
    cockpit. On most first flights I’ll have several circuit breakers
    pulled to make sure I don’t get all kinds of bells and whistles
    that distract me from just flying the plane.

    Needless to say, its been an interesting and ever changing
    business. One project that really stands out from all the rest, is
    the Star Kraft. Not so much for the finished aircraft, as all flying
    aircraft are cool,but in their approach and execution of
    building this very large and complex aircraft. The Star Kraft is
    a carbon fiber/all composite, eight passenger twin engine
    aircraft with an extremely large cabin and the added safety of
    center line thrust.

    I became involved in the project in 1994 when the structural
    analysis was done by Martin Hollman of Aircraft Design Inc.
    Martin recommended me as a test pilot and human factors
    designer to help with the placement of controls and systems
    during the assembly of the aircraft. This plane was not your
    typical prototype. The founders and primary investors of Star
    Kraft are both pilots and successful businessmen who have
    flown both certified and experimental aircraft for the past
    twenty years. They firmly believed there was a need for a new
    generation of corporate aircraft, one that would outperform
    turbo props and some jets. Roger and his dad Harold had
    their first introduction to homebuilts when they built a Lancair
    360 to use for company travel. This worked out so well that
    they decided to build a larger airplane using the best
    technology had to offer. The design work was done with state-
    of-the-art CAD equipment. The stability and control profiles
    were calculated by renowned aeronautical engineer, Jim
    Phillips. With solid research data,they felt comfortable building
    the plug and making the first plane from production molds.
    Their plan was to sell kits to help subsidize the expense of
    developing the Star Kraft. As with most projects of this
    magnitude, it took on a life of its own. Roger researched the
    issues of building an aircraft this size as a kit. The FAA was
    threatening to crack down on professionally built airplanes.
    Eventually plans for kit production were abandoned but work
    on a production version moved forward.


    Whenever possible, Star Kraft used the latest technologies
    such as the TKS leading edge anti-ice system. This is the
    system where the leading edge of the wing has thousands of
    microscopic holes and alcohol is weeped through to prevent
    icing. They incorporated lightning protection mesh into the
    molded composite parts to ensure IFR certification. My
    personal favorite is the drive shaft. The Star Kraft uses a six
    foot drive shaft to power the rear engine. Just before the first
    flights,we did a vibration survey and had a real problem with
    the frequency matching of the metal prop, engine and drive
    shaft. Alignment was also critical and we needed to find a
    good solution. We tried an MT composite prop and had great
    results with the natural damping of the light weight composite
    prop. We still had a few frequencys that coupled between the
    drive shaft and the engine. After much research, we located a
    drive shaft from a California manufacturer of carbon drive
    shafts for NASCAR race cars. Its made of carbon fiber and
    weighs only 8 lbs versus 40 or so for the steel shaft. We had
    no more vibration problems and one big safety benefit. If the
    steel shaft ever broke or the coupling at one end failed, I felt
    that the tail of the aircraft could be knocked off from the
    slinging 40 lb shaft. If the carbon shaft fails, it shatters and
    turns to dust leaving the structure intact.


    Star Kraft's commitment to this project was really tested when I
    recommended that they move the project 100 miles to a bigger
    airport for test flights. This meant all the final assembly would
    be in a rented hangar 100 miles from home. At this point there
    were four people helping on the assembly and they all moved
    from beautiful Fort Scott,Kansas to the Motel Six in Topeka for
    a month.


    My experience with pushers is they overheat and on the first
    flight that was true. With some tuft testing and help from Dan
    Bond, one of the key players in the Nemesis Formula One
    team, we got it all sorted out. We did have some trouble with
    oil temps on the TSIO 550 ‘s but I think that was due to the
    small oil coolers that RAM uses on the 414 conversions that
    they do and that we copied.


    So how does it fly. Actually much like a 414. Because there
    aren’t any engines on the wings, the roll inertia is less and the
    pitch and yaw inertia is greater. This is a very big airplane and
    it takes awhile to get it going but it’s also a very clean airplane.
    When you fail an engine not only is there no yaw but it takes
    awhile before the air speed even starts to decay. I found that
    the rear engine single engine performance was just slightly
    better than the front and that with the front engine you had to
    hold right rudder during climb versus no rudder change for
    climb on just the rear engine. Definitely user friendly with the
    exception that you really had to think to figure out which
    engine quit and be careful to shut down the correct one.


    Up to this point, Roger had kept a rather low profile and
    concentrated on building and running his other business. To
    continue with the certification process required more
    investment. To attract investors,we decided to start showing
    the aircraft’s potential and flew the plane to the NBAA show in
    Las Vegas in September, 1995. After the reception we got
    there, we decided to move ahead and set some point to point
    speed records .

    I brought the plane to my home base in San Carlos to prepare
    for the record flights. As the weather window we were looking
    for approached,we moved the plane to Hayward for the full
    gross weight take off. The 2600’ runway at San Carlos was
    just a little short at max weight. On the way to Hayward we had
    one of those beautiful days in California with unlimited visibility
    and smooth air. We took advantage of those conditions to
    capture several beautiful pictures of the Star Kraft .


    Being economically challenged, we wanted to get the most for
    our money and decided to set two records on one flight. The
    hardest thing about setting records is notifying all the parties
    involved and coordinating with all the ATC centers that you fly
    through. This needs to be done just before you launch
    because if you arrange for LAX center to record your time
    over a fix on Monday and then cancel and try again on
    Tuesday, the new controller will just say he’s never heard of
    you squawk whatever and go away. If that happens at the start
    of a record it’s no big deal but at the end of a really good
    flight, it could really bum you out.Anyway, ATC was very
    helpful and all went smoothly. The center in ABQ even went so
    far as to fax me the schedule of the military operations for that
    week in their airspace so I could pick the best times to transit
    and get the best direct routing. The only trouble I had on the
    whole record flight was each new controller said “Starship
    700SK” then I’d correct them to Star Kraft which always
    followed with “what's a StarKraft” then I’d give them a little
    soliloquy on the Star Kraft. This was fun the first twenty or so
    times but did get a little old after awhile.

    My route was depart Hayward and climb VFR to 17,500’. At
    Bakersfield, Id pick up an IFR clearance and climb to FL250.
    The first record would be from Palm Springs to Phoenix, then
    on to El Paso, TX for as econd record. The first leg we had a
    little cross wind and were still pretty heavy but 312.87 mph on
    36 gph is not bad. The second leg was more aligned with the
    wind and we really got on the step for a speed of 346.47 mph
    After several more months of flight testing, Star Kraft will install
    Orenda “600” engines which should increase speeds by 100
    mph.

    And this is what the experimental movement is all about. To
    push new technologies into the real flight world and learn by
    doing. Then do what no certified plane can; 8-place
    pressurized comfort Phoenix to El Paso, at 346.47 mph in just
    59 min. 30 sec, on 36 gallons of av gas.
    FMI:  Starkraft 316.223.1900 PO Box 190 Fort Scott, Kansas
Testing