To start, every airspeed indicator is off. That's why airplanes go from indicated to calibrated. It is only how much it is off.
Another factor is the difference between indicated and true. As density altitude increases, you go faster through the air than your indicated air speed reads. About 2% per 1000 feet. Less air molicules to create the pressure. So at 5000 feet density altitude you indicated would read 70 MPH but your true airspeed would be ( 2% times 5) 10 % higher or 77 MPH. Note your flight computer will give you 76 but pretty darn close. You stall at the same indicated airspeed at all altitudes.
Yes with the static port on most trikes in back of the dashboard/instrument, the static pressure lowers and the airspeed will read higher. To install a static port is not simple. It has to be put in the exact location or it can make things worse.
A simple calibration can be done with a GPS.
First determine a speed to calibrate at. Let's use 70 MPH indicated. Convert this to true airspeed at what ever altitude you want. At sea level standard conditions true and indicated should be the same. We will use 5000 density altitude so the true airspeed will be 77 MPH. Now since this is your true airspeed, that should match your ground speed in calm air. As simple as that. During your test do a circle at the same indicated airspeed to test for calm air. If your indicated stays the same and your ground stays the same, you have calm air. If there is any wind, you average your maximum and minimum speeds during your circle to get the ground speed number to calibrate to.
If the GPS ground speed is different than the true airspeed, you adjust/calibrate your indicated until your true and ground speed match. Again, at sea level standard conditions true and indicated should be the same.
I had to drop my indicated by 5% to get my true airspeed to match my GPS speed. On my Enigma, there is an indicated airspeed calibration in set up where you can do this so you are always reading an accurate indicated air speed. On the enigma it also has the calculated true airspeed so it is easy to look at the difference between true airspeed and GPS speed for accurate wind direction and speed while flying.
There is a simple and accurate way to calibrate your airspeed in trikes.
His flight route can be seen here
He is averaging 97 mph (hardly any headwind or tailwind according to him till right now) and is nearing Live Oak, FL (Peter Wallace) 24J.
You can see him on the SPOT here
I already fly with an electric heated jacket liner and gloves but before I spent the money on the heated boot liners, I decided to try blocking off the nose duct to see what would happen. Here is what I did.
1. I removed the CNC machined nose grill from my Revo with the intention of blocking the port. 5/32" Hex wrench and small adjustable wrench.
2. I had a used piece of neoprene from an old helmet visor that I cut just larger than the nose grill. If you don't have neoprene just go to your local Wally world or electronics store and buy a cheap rubber and cloth faced mouse pad for $1.99. Just make sure it is the thin type - about 1/8" thick max.
3. I attached it to the front of the grill with a few sqares of double sided foam tape. I then mounted the grill back into place.
This blocks the airflow through the nose and now my feet stay warm and comfortable. So far I've flown in temps down to 25*F and all is well.
In my opinion, this looks better than foam or duct tape and is easy to reverse when the weather warms.
Here are a few pictures that show the finished product.
If you remember back a year ago I wrote a blog about why I was getting a new trike and why I decided on the Revo. Here is that Blog written a year ago. After each reason I will provide the RESULTS after one year.
Blog from one year ago:
Background. I fly almost every day now professionally doing inrto flights and primary training. Awesome job loving it. Right now I am flying a stiff 14.5 square meter wing (very nice overall) with a 582 at density altitudes 5000 to 12,000 feet. Doing the math, the Rotax 65 HP goes to about 52 HP at 7000 foot density altitude and about 42 HP at 12,000. Barely enough to handle the 14.5 meter wing.
If I had a smaller wing, I could fly more hours and everyone would be happier. Bottom line, a smaller wing needs more horsepower . So after 3 years of flying full time I decided to sell my great Apollo Monsoon 582 and go to a 912S so I can get a smaller wing.
OK which trike? Here are the reasons why I choose a Revo, generally in the order of importance which helped my decision:
Almost everyone who calls and asks about buying a trike wants a Revo.
RESULTS a year later: Yes this still the case for new trikes. Some are interested in the lower cost Delta Jet 2 and super low cost ultralights, but the Revo is what everyone wants.
Topless small wings.
RESULTS a year later: Yes this fits into low hangers easily, takes up less space with a smaller wing span. Much easier overall. More on this later.
Easy to get in and out of loading and unloading people (similar to my Apollo Monsoon).
RESULTS a year later: Yes very easy to get in and out of especially loading many people for their first introductory flight.
Easy handling/response for ease of flying and safety/recovery in the bumps.
RESULTS a year later: This has turned out to be one of the biggest advantages with everything said and done. A large engine and a small wing would be an advantage with any brand of trike. Where this wing has really been awesome is recovery and more comfortable flying in the bumps. With the prevailing wind coming over the mountains here where I fly most, many times I fly in mountain lee side turbulence. The ability to blast up from 4700 to 10,000 MSL away from the mountains to minimize turbulence, crank on the speed to penetrate into the wind to get above the mountains/turbulence, and dive into the turbulence to get back down has increased my ability to fly safely and comfortably. This is amazing. With my larger 14.5 ProfiTL truck, I would limit the winds aloft to 20 to 25 MPH. Now I feel OK at 30 to 35 MPH winds aloft. Additionally, when you get thrown around, you can minimize roll and pitch attitudes for the comfort of the student. Now when I fly with the other CFI Bob Harington who is flying the larger ProfiTL wing, he feels/whines/complains about the bumps much more. His heavy turbulence feels like moderate turbulence to me now. WHAT A DIFFERENCE.
Super sexy looking.
RESULTS a year later: Beauty is in the eyes of the beholder so this is subjective but everyone really comments how nice the trike looks. Even airplane people.
Made in the USA with easy parts/great service.
RESULTS a year later: This has been incredibly helpful. The best way to find out how quick and easy parts are to come by, teach students landings. Parts are usually shipped the next day and overnight if needed. Larry answers the phone or returns calls almost immediately.
Some other RESULTS a year later that are noteworthy.
Almost all the upgrades are retrofitable. Wing upgrades for the Rival S, roll trim, instrument panels, tires, engine covers etc...
No question about it, Revo's are expensive but after one year of full time use and servicing my customers/buyers it is worth it. I justified the cost initially for my Revo trike by saying "I cannot afford not to buy one". This has been the case for sure.
It should be known that I can pretty much get most brands if any of you want any brand here in the Western US. I have a Northwing and a Delta Jet 2 coming in very soon. But buying a Revo was my choice for the reasons listed above which have worked out as anticipated. Looking forward to 2015. Come take a test flight in a Revo and I will almost always have one in stock for you to fly home or order a custom one just for you.
After waiting to see if Rotax settles on its quest to make 912iS stable, it seems like they have setlled on 912iS Sport configuration now for some time to come.
We are beggining to take orders and starting second quarter deliver Rotax 912iS powered trikes to provide potential customers wanting fuel injection and better fuel economy this choice. We will do the same with our gyroplane as well.
There is a substantial premium to pay for 912iS engine but the choice is the customer's. Please free to contact us for further details at email@example.com
Yesterday was one of those days flying that the wind gradient amazed me. Report was 30 knots winds aloft at 9000 Feet MSL and the surface forecast was light and variable all day. Beautiful at the airport. The wind reading on top of Slide Mountain almost 10,000 feet was 30 gusting to 43. HUH. Pretty high gust factor and winds overall. More than I like but we would go up and see what happens. Predictions and observations spelled out what was to come.
Takeoff at 4700 feet MSL and climb out was glass calm until about 6500. Little wind and bumpy until we got to 9000, than started getting pretty bumpy. Additionally being on the lee side of mountain peaks does not help. Reading my ground and true airspeed it was hard to tell exactly where the wind was coming from. Very inconsistent direction. This was the first clue to an unusual situation. The peaks where I fly typically are at 9,000 to 10,000 so I had to get to 10,000 or 11,000 to have a safe margin of altitude above the mountain mechanical turbulence. Typically after I get 1000 to 2000 feet above the peaks it smoothes out because you are above the mechanical turbulence. I informed the intro student, who was an airplane pilot who flew some knarley air, that it typically would smooth out about 10,000.
Not today. The higher we climbed above the mountain peaks the worse it got. In this type of air, typically students chicken out and want to go back down. Not experienced Alaska bush pilot Frank. Did not bother him. Handling the turbulence was my problem so we continued to climb to get over the ridge hoping it would get better. NO GO. the higher the worse. Finally at 10,500 I knew it was not going to get any better. Now fighting a 40 MPH NW quartering headwind we have a safe glide so we headed out to Washoe Lake.
At this point in the flight you have to decide to head out high to avoid the mountain turbulence or descend to get lower to where it is calmer. Typically if there are big mountain rotors, more than 15 knots coming over the peaks, you stay high to get away from the mountain peaks to minimize turbulence. Here I split the difference. Moderate descent to get away from the mountain turbulence but get down to the calmer air. We descended and it got nicer as we descended. We got down to about 6500 and it was glass calm.
So what happened which are lessons learned applicable to trike pilots:
Winds aloft and TAF predictions and observations are pretty darn accurate. Use them. Winds aloft are important. It was pretty much what the weather said.
Evaluate all the information and make the best decision of Weather to Fly. We have great tools for weather predictions. Fly within your pilot and aircraft limitations. Especially newer pilots, use the Weather to Fly system, you will get smarter each time you fly.
This was pretty much what I expected except the turbulence ABOVE the mountain peaks. One of the reasons I chose the Revo trike is the small wing, high power and easy handling. All this makes flying in these conditions more practical and has extended my flying envelope.
We had three new Revos arrive about a year ago. One for me, one for Raj/John and another fully loaded fuel injectedI I had in stock which went to a happy owner. We have a new batch, a wide variety of new trikes ariving early this coming year. In January, a Delta Jet 2 and a Northwing soaring trike with 17M wing. Both to students who are training with me. Additionally, I will have a new fully loaded fuel injected Revo in March which I will have in stock ready for you to fly away. I will be also selling my 912S used Revo so you will have two Revos to choose from.
2014 was awesome and I feel a great 2015 is ahead.
Hopefully you will get some new trike or trike accessory you want for this holiday season or in 2015.
Happy new year to all.
Winter is here and I have been really bothered by water/moisture in my oil system. When I check my oil water drops on the oil cap or a milky substance indicates unwanted moisture in the oil system. Rotax recommends that the oil temperature should get to 212F/100C sometime during the flight to evaporate this moisture. I was only getting to 180 max when it was 40F or so OAT so I blocked off the cooling air inlet with some aluminum tape and now I get to 212 and the moisture is not there anymore.
I have seen others cover the oil cooler surface directly to achieve this.
Other thoughts on this subject. Boiling point of water where water will vaporize goes down by about 2 degrees per 1000 feet in altitude so water would boil at 202 degrees at 5000 feet. Additionally, oil temperature is read after it goes through the oil cooler and cooled to the engine so the temperature of the oil leaving the engine going to the oil canister will be higher than that read from the oil temperature gage. Under this scenario perhaps I could boil off my water at 5000 foot altitude with the oil temperature reading 192F or so. Any experience or observations from other pilots?
Finally getting a handle on fine tuning the oil temperature, heating it in low temperatures in the winter, and cooling it in high temperatures during the summer.