SETP San Diego

Hey Guys,

There is still time to reserve your spot at the SETP West Coast Symposia (link).

Justin Gillen and I will be speaking about the test work we did fir Aerochia on N62MH, N357AW and N23LF during the build up to Reno 2014.

Justin and I are extremely flattered to have been chosen to speak to this prestigious group and look forward to the opportunity to learn more about testing badass aircraft.

Go work on your airplane!
Elliot and Jenn

Title:  Wastegate Development For A Sport Class Pylon Race Aircraft.

Abstract:  During 2014 Aero Chia performance aircraft changed the pneumatic wastegate provided with their Super Lancair Legacy line of race aircraft.  The TSIO-550-C is rated to 300 horsepower, we believe the engine was making over 650 horsepower when the propeller failed in a heat race at Reno 2014.  The build up to that power setting took place over three airframes, and failed 4 turbos.  These are some of the lessons learned from that testing.

Sundays With Ralph Episode 5

Hey Guys,

Below is the report for FLT005 in the GT-400 "Snort".

It was a great flight.  Mojave Experimental Flyin is coming up and everybody is talking about records, so we used it as an excuse to get some performance data on Snort.  The result was 1.87 ft^2 effective flat plate area.

We also used this opportunity to further qualify an approach we use on Wasabi.  So by measuring manifold pressure (MAP) and the speed of the engine (RPM) we know the horsepower that a stock 520 would make in that configuration.  The issue is we don't know the efficiency of the propeller, and we don't know how strong the engine is.  The solution, as Andy would say is "more data!".

In order to get more data points to backup the assumption that Continental is accurate with their power estimates we use the dive method (see Hoot's report link).  If you know the weight of the airplane, you can derive the thrust given by a dive.  You already know how much power Continental thinks you should be making.  So by summing the two you know how much HP it took to go that fast.

Example:  The GT-400 weighed roughly 2400 pounds, so with a 500 FPM descent you are getting energy from gravity at a rate of 36 HP.  Add 36 HP to the 165 HP the engine was making and you get 201 HP.  Experimentally we found this correlated to a indicated airspeed of 250 MPH.  250 MPH correlates to a dynamic pressure of about 160 pounds per square foot.  206 HP at 250 MPH correlates to 302 lbs of thrust.  So 302 divided by 160 is 1.88 square feet of equivalent drag.

This is a little harder with Snort because the airplane is naturally aspirated and we try to keep the flights to about an hour.  Without automatic boost regulation the MAP (and therefore power) changes with altitude, and at -2000 feet per minute the altitude is changing pretty fast.  There are two options for this you can time your flying just right so that you pass through a particular altitude at the moment you are on condition.  Or you can take note of your altitude and MAP when you get stabilized and look up the HP for each pass individually.  We did the latter.

The plot below is the summary of the data.  The cluster is pretty tight, which almost makes me believe the data!!

Airplanes are cool,
Elliot

3 things worth noting:
1.  We made no attempt to compensate for the loss of thrust from the propeller.  Typically assumed to be 90% efficient, this makes our findings somewhat conservative.

2.  The reason this is a more difficult test with Wasabi is the Continental reference material does not typically go to the engine RPM that we are running, which requires making assumptions.

3.  Below is a picture of the panel on Snort.  Note on the Manifold pressure gauge (top right) that ~1/8" = 1 INHG.  This resolution is a little coarser than I would like for this kind of testing.

Sundays with Ralph episode 4

Hey Guys,

Ralph and I had a great time on Sunday, we are trying out different arrivals to the airport to get ready to land at a different airport for the first time.  We are also still investigating the "poor centering" experienced on flight two.  We have not been able to replicate it yet.

Check out this great GT-400 detail below.  This is the spring loaded gap seal on the bottom of the wing.  Such a cool airplane!!

Airplanes are cool,
Elliot

Spring loaded gap seal on the flap of the GT-400

Super Legacy Test Report

Hey Guys,

Over the last year Jenn, Justin and I have been very fortunate to help Andy Chiavetta of Aerochia Aircraft Performance and Racing with the testing on some of the Super Legacies.  We recently published the report on one of these aircraft, N357AW, on which we did the phase one test program during the summer of 2014.  That report is available here (link), there is a brief and inaccurate summary of my knowledge of Andy's career below.

Airplanes are cool,
Elliot

Andy Chiavetta has built more than 20 airplanes, 8 of which are the Super Legacies that he is most known for, he has also built several hundred skim boards, is part owner in a skim board company (Exile), and has appeared in several skim movies (Exile Bearded).  To me Andy is first a master of composite manufacturing, who's technical skill has consistently put him around some of the smartest people in the business.  The result is that Andy's depth of knowledge, especially with airplanes, extends far beyond the physical building of things with composites.

Andy and Darryl in Race 33, Photo Andy Chiavetta

Andy learned composites building sailboat masts in the LA area.  But the experience that makes me particularly jealous is the work he did with skim boards in the early 90's.  As an engineer in aerospace I spend a lot of time designing and building aircraft structures but little time structurally failing them.  If an engineer is lucky the part that is being designed will be taken to failure once before it is installed on the airplane.  By comparison, when Andy was designing and building skim boards with his friend Aaron Peluso they built and broke hundreds of boards.  The idea of laying up a board, and riding it to failure the next day, seems at once perfectly foreign, perfectly educational, and freaking awesome!  I believe this is a fundamental series of experiences for Andy, and has led to his supreme understanding for composites and how they fail.

Andy Skimming, Photo Matt Adams

With his composite experience and his background in ultralights it was probably only a matter of time before Andy started building composite airplanes especially with the boom in composite kitplanes that was happening in the 90's.  The result, Andy built several kitplanes with customers, which prepared him for the second experience that makes me so jealous of Andy, the moment he met Darryl Greenamyer.  Andy was at a place in his career where he was seeing at once a change in the market, he had been building Wheeler Express' and they were beginning to lose favor, and a plateau in his experience.  He had gotten pretty good at what he was doing and not one to let himself get bored he was looking for the next challenge.  Meanwhile the long awaited Sport Class of Reno Championship Pylon Racing had just gotten on it's feet and Darryl Greenamyer was interested in getting in on the action.  Darryl was asking around to find someone to help him assemble an airplane (Race 33), a perfect combination was born, and four consecutive championships were the result.

Darryl and Andy with Race 33, Photo Andy Chiavetta

The trick in racing is to find a way to sell the technology that you are proving on the race course, making it slightly more financially practical.  Andy was able to turn the modified version of the Lancair Legacy into its own new type of sport aircraft with it's own following, the Super Legacy became the work that kept Andy busy the rest of the year.  Through selling the parts to modify your stock Legacy or doing the actual work of modifying the airplane Andy supplemented the air racing habit that had firmly taken hold.  Eight of these Super Legacies have been built.

Andy and 3 of the Super Legacies, Photo Andy Chiavetta

Lastly Andy's enthusiasm and willingness to push through the problem to a solution with shear will has made him the guy to go to for so many different types of airplane problems.  As a result Andy has worked with and is well respected by the best in the business.  It is fantastic to see good things happen to good natured and hard working people and Andy is one of those.

Andy performs a hasty mid week repair to Strega, Reno 2013

Connor Madison's Radio Spot

Hey Guys,

We did this radio spot with Connor a month or so ago.  Connor was putting it together for his advanced radio production class at the University of Wisconsin Oshkosh.  Andrew Findley talks about racing in the Sport Class and Elliot had the chance to talk a bit about Wasabi.

Go work on your airplane.

Elliot and Jenn

Race 44 test hop for Lynn

There are good days and there are really good days.

Twice during race week we were asked to fly test sorties for Andy and Lynn.  I had been doing the break-in and power testing on the airplane in Mojave but it is a different thing to test over Stead, to some a holy thing.

Turning the power up while in a leisurely left hand turn in a truly hot airplane while the sun sets over that valley of speed is something air race freaks dream about. I remember checking and rechecking my data, I wanted to be damn sure I wasn't blowing this awesome opportunity.

After landing I taxied up to the team; Andy, Lynn, Jenn, Donald, Terry, and even Klaus and Jenny. The looks on their faces told me the airplane had sounded good. The look on Andy's face said "give me the data".

Thank you Andy and Lynn, for a truly awesome Reno experience.  I can't wait until we get this thing hooked up.

Nice Shirt Andy!