I consider myself a lucky pilot in that I get to fly just about every King Air type. I currently have a B100 and 300 under management and fly both more than 100 hours per year. I also regularly fly the King Air 90, 200 and 300/350 series either in training or ferry flights. Often, I am asked, “Which King Air is your favorite?” And every time, there is no doubt in my mind as to the answer – the King Air 300/350.
It’s powerful, hauls an impressive load, is a proven design, offers a high cabin max differential and boasts tremendous dispatch reliability. The 300/350 is the pinnacle of the King Air lineup and it’s hard to fathom anything improving upon the current design. But earlier this year, I received the nod to put Blackhawk’s latest XP67A engine upgrade to a flight test and I jumped at the opportunity.
Trip to Waco
The timing for this Blackhawk visit was perfect for many reasons, but the biggest one was that the owner of the King Air 300 that I manage is considering an upgrade to either a “stock” 350 or a 350 with the Blackhawk conversion. So, the King Air 300 owner (Ron), myself and two local pilots (Ben and Deanna) loaded up in Ron’s 300 at my home airport (KJSO) and flew the relatively short 100 nm flight to Waco Regional Airport (KACT). Waco Regional is an active airport with a good mix of airline and general aviation traffic and is the home to Blackhawk Aerospace (previously Blackhawk Modifications) – a recognized producer of performance improvements for turboprop aircraft.
Let me preface this by saying that the King Air 300 we fly is no slouch when it comes to performance. On this cloudy, nearly-ISA (but rainy) day, our King Air 300, powered by the PT6-60A engines, climbed out at 2,400 fpm up to our cruise altitude of 12,000 MSL. While that climb rate is impressive, I would later see an even better one.
The clouds did not break the entire way to Waco, and we needed the ILS approach to RWY 19 to get in. Upon arrival, we met Chris Dunkin, chief pilot for Blackhawk Aerospace, and soon saw our test airplane for the day – N188RU. The airplane is a gorgeous 2014 King Air 350 that was recently upgraded with Blackhawk’s XP67A (Pratt & Whitney Canada PT6A-67A) engines. Chris gave us a brief “differences” discussion and walk-around/preflight. Soon, I was stepping through the impressive interior to the cockpit.
Very little is different in the cockpit with the XP67A conversion, so I felt right at home in short order. The main dissimilarity was the time required to start the big engines. The Ng spools up slower and the ITT rises at a more leisurely fashion in the XP67A compared to a “stock 300/350,” therefore the start time takes a bit longer.
As we taxied out to the runway, we obtained an IFR clearance since the weather remained solid IFR. Not only did ATC give us the clearance, but they also gave us an unobstructed climb to FL330. They knew we were flying a “capabilities demonstration flight” and Chris was able to negotiate the nearly unheard of climb clearance all the way up to the flight levels. It was exactly what I wanted to give the XP67A upgrade a thorough checkout.
The takeoff roll and initial climb rate were similar to the stock King Air 300, but soon the power of the XP67A began to show itself. We climbed at 160 KIAS, with the climb rate soon increasing to 3,100 fpm passing through 10,000 ft MSL. The mighty Blackhawk 350 was then able to hold a 2,700 fpm climb rate through FL180, followed by 2,400 fpm through FL250, then slowly decreased to 1,400 fpm as we leveled off at FL330. For contrast, I regularly see 2,400 fpm at the lower single-digit altitudes in a stock 300, but it would normally climb at only 1,000 fpm just before level-off at FL280. The XP67A produces more power at a higher altitude than a stock King Air 300/350.
To contrast the performance more closely, the XP67A breathes better than the PT6-60A. The 60A “temped out” (became temperature limited) at 16,000 MSL on the flight home this day, while the XP67A “temped out” at FL240. This is the core reason the -67A achieves better performance; it simply breathes better at high altitude. At lower altitudes, the Blackhawk 350 out climbed the stock 300 by only 500-600 fpm, but once in the “20s,” the Blackhawk 350 out climbed the stock 300 by nearly 1,000 fpm. And at FL280, the Blackhawk 350 was climbing strong while the stock 300 was losing its “umpf” quickly. Down low, the Blackhawk conversion offers somewhat better performance, but up high, it’s a significant improvement.
At level-off, that incredible climb rate was converted to forward airspeed. We saw 328 KTAS at FL330, which is best described as “jet-like.” There were five of us onboard, so there was plenty of room for everyone in the back of the King Air, and they were able to hold headset-free conversations in the super quiet cabin, courtesy of the five-blade props.
The descent back to Waco Regional was typical of any King Air, meaning we were able to pull back the power and descend rapidly. Easily holding 4,000 fpm for much of the descent, we were soon vectored for the ILS to RWY 19. Landing the XP67A-powered 350 was routine, and soon I was pulling back up to the hangar at Blackhawk Aerospace.
Just when I thought the fun was over, Chris notified me that there was another flight potential; Blackhawk also had an early model King Air 300 with the XP67A conversion. I was eager to see how much the XP67A would enhance the performance of the 300. This particular airplane was still being used for testing and was super light. All of the interior amenities (including the seats) were removed and specialized equipment was added for monitoring performance. So, with only two people onboard, a greatly reduced empty weight, and the biggest engines ever mounted on a King Air, we were going to fly a true rocket ship.
Following a similar template of our first flight, we received another unobstructed climb to FL330. I rotated off the runway, pitched up to 20 degrees nose-high and let the horses run. It took us a grand total of 15 minutes to reach FL330 in the Blackhawk 300. That’s an incredible rate of climb. And for all of the naysayers, I get it – performance like this cannot be expected on a King Air that is properly appointed with an executive interior, full fuel and full seats. But, it does show what a true hotrod the King Air is if operated lightly. Of course, all of the excess rate of climb is turned directly into true airspeed once the level-off occurs, and we saw 338 KTAS as our top speed this day. Again, we descended quickly and soon I flew the ILS 19 again. The total trip up to cruising flight at FL330 and back was a mere 35 minutes.
Weighing the Options
So, is a Blackhawk conversion right for you? Simply put, if you want the best climb and fastest speed, you will want the Blackhawk XP67A. Or if you want to fly in the RVSM altitudes in your King Air 300/350, you’ll also want the Blackhawk upgrade. At $1.7+ million, the conversion is not cheap. But, speed is never cheap. From a pilot’s perspective, there is not a better performing King Air to fly than a Blackhawk 350. From a passenger’s perspective, the converted 350 is quieter and faster. Block-to-block speeds are certainly quicker, not only due to the higher cruise speeds but also because the airplane climbs to faster cruise speeds.
A note for those interested in flying in RVSM airspace: The rules recently changed in January, 2019 which make ownership of a properly equipped ADS-B RVSM airplane easier and cheaper. The Blackhawk XP67A is ideal for use at RVSM airspace, making the King Air 350 even more attractive for the buyer who has a long way to go and wants the lowest fuel burn. The choice between a Blackhawk 350 or a comparable jet might seem difficult at first, but I think it’s an easy one once the glamor of a jet is removed from consideration. In most cases, the King Air will show up a few minutes later than a similarly equipped jet, but the King Air has bigger cabin, carries more, lands on shorter fields, requires only one pilot and costs a lot less to operate. Add in the Blackhawk XP67A upgrade, and the King Air 350 is comparative to just about any jet and not only a stock 350.
My suspicion, based on our flights and visit with Blackhawk, is that many King Air 300 and 350 owners will opt for the XP67A upgrade. In the world of aviation, power and speed are seductive. And Ron, the King Air 300 owner who accompanied me to Waco, is now weighing his options and considering upgrading the King Air 300 he presently owns. As the pilot, I hope he does. A King Air 300 with the Blackhawk XP67A engine upgrade would be a perfect addition to the hangar.