Author Archives: Darren Tilman

EASA approvals for Power Flow STCs now available

Updated: 03/01/2018

Power Flow Tuned Exhaust Systems – Now Sporting a Certain “European Flair”!

Up until December 2017, European fixed-wing pilots have not been able to easily install Power Flow exhaust systems onto their EASA registered aircraft.  Unless Power Flow already held EASA validation on the STC’d kit specific to their aircraft, the governing agency would not approve the installation.   The company had attempted a couple of EASA validations on their STCs at a cost of several thousand dollars but encountered a variety of obstacles which prevented full validation.

Now, thanks to a recent policy change, EASA registered aircraft may apply for a specific single airframe serial number approval from EASA for a one time application fee of 200 Euros.  EASA says that provided that the STC meets seven specific criteria (all of which are met by all of the company’s Tuned Exhausts), they will issue the approval.  EASA further guarantees that they will either issue an approval specific to that aircraft or they will refund the Customer’s application fee.    

Working through their Authorized Dealer in the U.K., Airspeed Aviation, LTD in Derby, the company has successfully received approval for two Cessna 177RG aircraft. They have also received approval for a Mooney M20J that had been trying for over five years to navigate the difficulties of obtaining EASA approval for the installation as well as a Diamond DA40.

The EASA approval process generally takes less than 30 days and requires that Power Flow provide a letter of authorization specific to a particular aircraft.  Power Flow provides this letter at no cost.  For UK customers, we direct all inquiries through our exclusive UK Authorized Dealer, Airspeed Aviation.

“We are thrilled that EASA has created a pathway through the regulations to allow EASA aircraft owners to benefit from the terrific safety and performance improvements that a Power Flow exhaust adds to their aircraft.” stated Darren Tilman, General Manager of Power Flow Systems.

For more details on the EASA rule change, go to:

https://www.easa.europa.eu/the-agency/faqs/general-aviation#category-validation-of-faa-stcs-classified-as-basic-and-limited-to-one-serial-number

Change for Cessna Short Stack Installations

November 10, 2017 – After feedback from installations in the field and our own experiences in-house, we have implemented a change in our installation that affects C172, C175, and C177 fixed gear aircraft with short stacks.  Over the years we received a few reports that the installation of the Power Flow exhaust short stack could result in the exhaust stack not being centered when coming out of the existing cowling hole.  When this occurred, it was typically displaced to the outboard side.

Typical Stock Exhaust:

C172_Stock_Exhaust_Exit

The Power Flow as originally installed, pre-modification:

C172_ShortStack_Exit_Before_Change

To address this, beginning with kits that were shipped in October, we have added an additional step to trim the 4 to 1 (the part that the short stack slides onto on the main heater section) slightly to allow for a more centered placement of the short stack.

C172_ShortStack_Exit_After_Change

This change also affects aircraft with the classic installation, however the tube coming out of the cowling on the classic installation is a 2.0 inch diameter instead of a 3.0 inch diameter, so displacement was not noticeable and had not been reported.

This will result in a nicer looking final product, easier installation and improved clearance for exhaust fairings.

We are always striving to make all our products, both future and existing, the very best we can produce. We always appreciate feedback from our customers, as it helps us to achieve this goal.

Changes to 1967/68 C177 with Lycoming O-320 and/or Original First Year Cowlings

November 10, 2017 – One of the many things that are unique to the first year of C177 aircraft is the cowling. The lower cowling has an integral airbox built-into the cowling, as shown in the image below.

1968-c177-O320OriginalCowli

The cabin heat source is an oval shape designed for a 3.0 inch diameter SCAT tube.

CabinHeatSource

On the original Cessna exhaust system, there is sufficient clearance for the SCAT tube to work its way over to the original exhaust’s cabin heat source.

1968-c177-stock-exhaust-airbox-clearance

The Power Flow second generation shroud was designed to fit all models of the C177 aircraft from 1967-1977.  Unfortunately, we weren’t aware of the difficult job of routing the 3.0 inch SCAT hose through what turns out to be a 2.5 inch space.

SCATHoseRouting

Installers in the field would have to squash the SCAT hose to get into the tight clearance and then rapidly turn the tube up at a 90 degree angle to go into our shroud.

IMG_5529

Clearly this is not ideal and can result the SCAT tube rubbing against the aluminum airbox.  We are sorry to say that we weren’t aware of the magnitude of the problem until recently. So in our relentless pursuit of perfection, we have implemented a number of changes in a complete redesign of the shroud exclusive to the first year Fixed Gear Cardinal.

– The cabin heater input is now an oval tube that comes out of our shroud at a right angle and extends over the shroud.

13704-Rev-IR-shroud-view-2

Here is the view as installed and seen from the left side:

13704-rev-ir-shroud-w-oval-LeftViewClearance

Here is a view of the new clearance to the airbox:

13704-Oval-heater-input-to-airboxclearance

– Originally, the carburetor heat came out at an angle that was awkward for the 1968 cowling, resulting in a lot of carb heat SCAT tube twisting as depicted below.  Note how close the output is to the input.   

13704-Output-Input-Labelled

Here is the new carburetor heat output – it allows for a shorter length of tubing that doesn’t have to twist or turn nearly as much:

1968-c177-new-shroud-and-ca13704-rev-ir-shroud-carb-he

– The original 1968 C177 uses a very long throttle arm – too long in fact to allow full travel in some instance as pictured below.

1968-c177-original-throttle

The solution?   Trim the throttle arm to remove the furthest hole and move the throttle cable to the middle arm.  Problem solved.  This step will be incorporated into our installation instructions.  See the below picture for the final results.

1968-c177-shroud-throttle-a

One more change on the way:

We are going to change the cabin heat output to angle down and outboard so that the 3.0 SCAT hose can work its way around the mess of fuel hoses and header tubes and enter the shroud on the lower left hand corner.

Customer shipments for 1968 Cardinals starting in January 2018 will have the new shroud design.  Any existing C177 can replace with the latest shroud starting then as well.

We hope you like the changes! We are always striving to make all our products, both future and existing, the very best we can produce. We always appreciate feedback from our customers, as it helps us to achieve this goal.

Thank you!