Bob Astle
King Air E90 Owner/Pilot
After 300 hours of usage on your Ram Air Recovery System and Aerodynamic Speed Stacks, I feel obliged and competent to comment on the performance increases I am seeing.
As you know, Trend Monitoring was in place prior to your modifications and is still being used.
When I took delivery of N341MH, after your modifications, for a moment, I thought I had walked to the wrong aircraft! It looked so different, a totally smoother, and more attractive machine.
Like most, just after we purchased our new/used E-90, I took numerous photos, from various angles of the new arrival. It was only after comparing the photos of pre-mod. and post-mod. that I fully realized and appreciated the esthetic change. Not only the nacelles, but the entire aircraft looks considerably longer, more streamlined, and flowing. I am still amazed, 300 hours later, at the number of pilots and people on the ramp that stop, look, and ask questions.
Our torque readings at any altitude have increased by an average of 150 pounds and we are never "temp" limited. Our oil temps, at lower altitudes, are lower by 3 to 4 degrees and the oil pressure increased about 3 to 4 pounds per side at all altitudes. True air speeds at 15,000 feet now average 264 knots. I have yet to be corrected that, "N341MH is the fastest -28 powered E-90 in the world." And since your modifications, fuel burns are slightly less.
Even after 300 hours, no loose screws, nuts, or fasteners. No missing rivets, no loose bonding or fillers, and no visible cracks or flaws - the installation was superb.
Feel free to use this letter as necessary and I will be happy to confirm or show proof of any of the statements herein mentioned.
Bob Astle, King Air E90 Owner/Pilot
Back to Top
Larry Clement
King Air C90 Owner/Pilot
As I write this letter, I am cruising at 25,000 feet in the 1975 King Air N660GW.
I must say that as much as your Ram Air Recovery Systems and Speed Stacks improves the Cheyenne, it helps the King Air even more. I have enclosed the climb and cruise performance on our trip home from Coeur d'Alene to Fort Dodge. The improvement is unbelievable!
The airplane is much faster with the ice vanes deployed than it was before without the vanes deployed. By being able to cruise at a much higher altitude, the fuel burn is much lower and the range is significantly extended.
The money spent for your system will be the best investment a King Air owner ever makes. It also improves the appearance of the aircraft.
We landed with approximately 1300 lbs. of fuel after the 1010 nm trip with average tailwind of 55 knots. We could have flown the trip with a 50 knot headwind and still landed with reserves.
The figures were used from the pilot's airspeed indicator, which reads 2-3 knots slower than the co-pilot.
Larry Clement, King Air C90 Owner/Pilot
Pilot/Owner Larry Clement's Notes for N660GW
Equipped with Ram Air Recovery System, Speed Stacks, and FAA Approved cruise ITT of 695°C
9200 lb, full fuel, 3 passengers, and luggage.
| Torque (ea.) | ITT (ea.) | RPM (ea.) | %Ng (L/R) | Fuel Flow | Altitude | True OAT | IAS | TAS |
| 1250 | 680 | 1900 | 101.2/100.2 | 265/265 | 19,000 | -24°C | 187 | 252 |
| 1200 | 660 | 1900 | 100/100 | 255/255 | 19,000 | -24°C | 185 | 248 |
| 1010 | 680 | 1900 | 101.2/99.6 | 220/220 | 25,000 | -36°C | 168 | 250 |
| 960 | 665 | 1900 | 99/99 | 210/210 | 25,000 | -36°C | 165 | 246 |
| 900 | 635 | 1900 | 97/97 | 190/190 | 25,000 | -36°C | 162 | 240 |
Climb to FL190: 11.5 minutes, 1452 fpm, 1100 torque, 660° ITT, 135 KIAS
Tom Coble
King Air E90 Owner/Pilot
Thanks again for installing the Ram Air and Speed Stacks on my E-90. Your shop did a beautiful job with the installation.
As promised, I am reporting back to you with the performance changes I am seeing. I can tell you the rate of climb is now dramatically better, probably because I have about 100 lbs. more torque available from each engine from the mid-teens up to altitude.
My cruising speed is now averaging nineteen to twenty knots faster and the fuel flow is the same or sometimes ten pounds more fuel per hour per engine. I think my actual fuel consumption for each trip is probably down a little now that I tend to fly at higher altitudes and go faster with the same fuel burn.
Please give my complements to your design team as well. The airplane now has a much more modern appearance. It even looks 20 knots faster.
Tom Coble, King Air E90 Owner/Pilot
Back to Top
Stan Slaton
King Air C90 Owner/Pilot
I wanted to take this time to let you know how pleased I am with the results of the performance enhancements recently installed on my King Air C-90-21 (N717JG). It has been about a month since the installation of the Ram Air Recovery and Speed Stacks and I can now give you my opinion based upon 10 flights in the past 30 days.
As you are aware, most of my flights occur between Minden, Nevada (4700 foot altitude) and Camarillo, California (sea level). This route takes me directly over the Sierras, normally between 16,000 feet and 21,000 feet, depending on winds aloft. There have been a number of days in Minden in which the temperatures at the field have been close to 100°F. I have taken off with 7 passengers, lots of luggage and about 1700 pounds of fuel, utilizing only 3,000 feet of runway and a climb rate of about 1800 feet per minute. I am truly amazed at the increased performance on these hot days at altitude. My previous average for my flight between CMA and Minden (no wind condition) has been between 1.5 and 1.6 hours, normally attaining average true airspeeds of 220 knots. I can attest that I am now making the same flight in 1.3 to 1.4 hours, attaining average speeds of 238 - 240 knots. In addition, I can now climb to higher altitudes with increased torque since the improvements were installed.
Although your STC does not include increased loading, I am confident that we have achieved the ability to carry more weight, with better climb rates and 18 - 20 knots increased true airspeeds.
Based upon the number of hours that I fly N717JG, I estimate that I will be able to pay for the improvements in about three years through fuel and maintenance savings. As a side note, I have gotten a lot of feedback on how great the Speed Stacks look. I was at Raytheon in Van Nuys for a maintenance check, and their head technician commented on the intakes and stacks, saying that is was a "very professional installation and looked very aerodynamic."
As you can tell, I am very pleased and would be happy to recommend American Aviation to all King Air owners.
Stan Slayton, King Air C90 Owner/Pilot
Back to Top