King Air 350 XP67A Milestone Update | March 2017

Blackhawk Modifications King Air 350 XP67A with MT 5-Blade Composite PropellerMarch with be a busy month for the XP67A Engine+ Upgrade program. Below are some newsworthy accomplishments and items we will be working on this month with our FAA certification efforts:

  1. A major milestone was reached last week. We successfully obtained FAA conformity on the PT6A-67A new engine upgrade on our King Air 350 test aircraft. This means that all the parts that have been used up to this point have been replaced with production parts that conform to FAA-approved manufacturing drawings. Our test configuration now represents what each and every customer will be getting once we begin shipping the XP67A Engine+ Upgrade kits.
  2. Instrumentation has been installed and tests are underway for the MT propeller vibration surveys.
  3. Our flight testing will ramp up this month with the goal of 2 flights per day.
  4. STC completion date is June 2017.
  5. Demo flights will be offered from May 15th through June 17th. Please contact our Marketing Coordinator, Lindsay Allmon, and we will try to schedule a location near you. Lindsay can be reached via email at, or by phone at +1 (254) 755-6711.

Stay tuned for more news and updates on the XP67A Engine+ Upgrade program for the King Air 350!

Safe flying,

The Blackhawk Team


  1. Mike Fleming on March 23, 2017 at 8:54 AM

    I would like a price

    Mike Fleming

    • Donnie Holder on March 23, 2017 at 9:28 AM

      Thank you for your interest in the Blackhawk XP67A Engine+ Upgrade. One of our Engine+ Upgrade experts will get back to you shortly.

  2. Stan on April 22, 2017 at 9:13 AM

    Is the MT prop the only prop that will be allowed/included by STC ?

    • Donnie Holder on April 25, 2017 at 7:41 AM

      Hi Stan,

      Currently, the only propeller we are seeking approval with in conjunction with our PT6A-67A engine upgrade is the MT 5-Blade 102” natural composite propeller. MT removes the minimum prop RPM limit as well as the ground idle solenoid. We have been very pleased with the results with the MT propeller. Having said that, we are working with Hartzell to provide an alternative 5-Blade composite propeller and with Raisbeck for their 4-Blade aluminum propeller, but major alterations will be required. As an example, the PT6A-67A engine has a 12-bolt mounting flange compared to the 8-bolt mounting flange on PT6A-60A engine so new hubs are required. Adding a different propeller after we receive the initial STC will require a new certification test plan that could take nearly a year if the performance, vibration, noise level and weight requirement testing succeeds to schedule.

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