I see that the air speeds of the Turbo III is at 175kts. I am guessing this is @ high teen altitudes. Also, is that seen by many pilots for real? Does the turbo have any advantages in speed at say FL40 to 100
I realize the turbo is for getting over those pesky mountains but I live in flat lands and looking truly for long distance speed not high FL.
Thanks,
Scott
Scott,
I have a 1981 Turbo Arrow IV and live in Florida. Most of the time we fly up at 10,000 to 12,000 feet. This is mostly to get above bumps and into cooler temps. I see about 160 knots at 12K running 2450 RPM and 32 inches of maifold pressure with a fuel flow of about 13 GPH. The turbo has not been a big maintanence item, although we do have the intercooler installed so the CHTs and TITs are typically low. We also try to change the oil every 25 hours, it is the life of the turbocharger. Oxygen is needed at those altitudes, you will get a headache and lightheaded if you stay at 12,000 feet too long. I would not go back to a normally aspirated aircraft, the turbo gives you speed at altitude and gets you up into better weather. It is the same speed as a non-turbo below 5,000 feet.
I own a 78 TA III without an intercooler but I do have a Merlyn wastegate. I typically fly in the low to mid teens. I must admit that I'm spoiled by the turbocharged aircraft and I don't think I could ever own a normally aspirated airplane. The Turbo Arrow climbs and cruises very comfortable in the low to mid teens. Maintenance has not been a costly issue with oil changes at 25 hr intervals. My engine has 1100 hours and I haven't had to replace any cylinders due to the heating issues associated with turbocharged aircraft. I usually turn about 158 kts at 13,000 running at 65% (30 inches) and 2400 RPM on the prop. Fuel flows typically are around 13 GPH. I obtained my instrument rating in a RA Arrow and I can definitely say there is no advantage between the two under 6,000 feet as far as speed. In fact, the Turbo Arrow has a disadvantage at the LOWER altitudes due to the higher fuel flow required to maintain appropriate CHT's without an increase in TAS compared to the regular aspirated Arrow. Generally, a turbo arrow's operating costs will run more than a RA Arrow due to those heating issues inherent in turbocharged aircraft.
Steve,
I have a built-in oxygen system, but the portables from Aerox and Mountain High are very good. The cannulas that you can adjust and that have a flow meter will save the oxygen and give you the correct dose at altitude.
The oxygen altitudes are not just those mandated by the FAA, if you are getting a headache or lightheaded at 8,000 or 10,000 feet, oxygen will help. If you are flying IFR and need to be sharp at the end, the oxygen will help. The higher altitudes are usually smoother and cooler, but in our little aircraft we rarely will ever "get above" the bad weather.
I have Aerox portable oxygen in my TA and utilize nasal cannula's. Another indication for oxygen is to improve night vision at altitudes above 7000 feet. I had the opportunity to experience the changes in night vision with & without oxygen in an unpressurized environment at 25,000 feet in a USAF altitude chamber.
My 200 Arrow is not turbocharged but I fly normally at 12,000 and above where my TAS is 140 kts at 8.2 gph (I live in Colorado and travel mostly in the mountain states). For my mission a 50% fuel savings (8.2 gph vs 13 gph) is a "no-brainer" even if my TAS is a bit slower than a T.A. Further, I strongly recommend against blind adherence to altitude level determining the use of O2. My house sits at 6500 feet and I certainly don't use O2 in my living room at night! But I do strongly advise using a "Pulse/Oximeter" for determing when and how much O2 to use when flying. For folks who live at low altitides this is very important if you fly at the high altitudes. I find that my O2 saturation level here at home is 98% or better and when I fly high (> 12.5) I start to use O2 when my sat level approaches 90%. You can save LOTS of O2 ($$) by using a O2 sat measuring device rather than the flow gauge on the typical O2 bottle. Just keep your saturation level > 90% and you should not experience any adverse effects.
