After training almost exclusively with a Cessna 172 Model N, I am now transitioning to a model Diamond DA-40. I have had the opportunity to fly 172 SPs. The 172 SP has basically the same engine as a DA-40 (Fuel Injected Lycoming 180 HP). So, there is some overlap on the procedures. However, the SP, M and N models have every similar flight characteristics. The Diamond is a bit different. This blog entry describes those differences that stood out for me.
As one would expect with a low wing, the landing roll is longer, as the plane enters and stays in ground effect longer. The wing span of the Diamond is greater than the Cessna 172. With lower wing loading, the take-off, climb an turning performance of the DA-40 is superior to the 172 SP. On the flip side, the 172 SP feels more stable in wind gusts. In the DA-40, I did feel more like a feather than within the 172.
The DA-40 has T tail. Flying with a T tail had only on significance to me in standard flying conditions. In a 172, the air movement from the prop wraps around the plan and interacts directly with the horizontal stabilizer. A drop in power results in a fairly pronounced drop in the nose. In the DA-40, I found this effect less pronounced. Please note that T tails have a disadvantage in slow turns, as disruptions from a stalled wind reduce the flow over the tail, deepening the stall.
I have heard that cross wind landings are more difficult in the DA-40, in part due to the low wing, reducing the amount of aileron that can be used in the flare and, more importantly, a small rudder. I am not convinced on the last part. For a test pilot, this may be true. For myself, I did not notice any less effectiveness in cross wind landings than the 172. Those wind conditions that test the plane's performance (about 15 its cross wind component) are outside the conditions I willing to try in either machine.
To get a sense of the transition to a DA-40, I am going to start at the ramp and walk through key parts of the check-list that are different and significant. I am picking only parts of the check-list thats meet this criteria.
On the ramp during the pre-walk around, I switched on the battery. I noticed that, given a few seconds, the engine instruments give me a more accurate reading from the digital display. I can get oil temperature and CHT. This is great in the winter to get an idea if preheating is necessary. The fuel indicators seem fairly accurate. It is a bit harder to judge the fuel visually since the tank filling ports are higher on the wing. After flying for over an hour, the gas will not be visible on a flat ramp. When lowering the flaps, I noticed they are tiny. There only two notches of flaps. I could not tell what the degrees are from the panel. My guess would be something like 10% and 30%. On inspection of the flaps, I though that the effect of the flaps on a T tail may be a different, with less disruption of air flow over the horizontal stabilizer. The battery is on, I noticed may of the instruments were working such as the attitude indicator. Why? Because the attitude and compass (HSI) are electrically powered. The 172 uses a vacuum pump powered from the engine.
The start up procedures are similar to the SP. The ammeter is not turned on until after engine start and engine instruments are in the green. It is best to pull the mixture a bit after start to prevent fowling of the plugs during taxi.
Taxiing the DA-40 is a more of a challenge than a 172 due to the free-castering nose wheel. Gentle tapping of breaks to handle direction changes is necessary for control in many situations.
At run up, the prop needs to checked. Pull the prop gently all the way back and then push it forward quickly. You do not need to wait for an oil pressure change. The change will show during the push forward to 2700 RPM. If it does't, try it a couple of more times to get the oil moving through the prop governor.
Before take-off, the fuel pump is turned on, on notch flap is added. Mixture and prop are full forward (low altitude). Take-off is easy and quick. If there is a bit of shake during the latter stages of the take-off roll, the nose wheel is has gaining too pressure so pull back (slightly). The Da-40 accelerates quickly. Watch the airspeed and hold the plan in a climb at around 80 kts. The DA-40 climbs very quickly. Once in a positive climb, bring up flaps, then adjusts prop to 2400 and, once safely above the 'deadly turn; height, shut off the fuel pump.
Watch the Engine temperate. At low altitudes, the DA-40 moves. I am always in the yellow arc when leveling off at low altitudes. So, it makes sense, at low altitudes, to adjust the manifold pressure to 24 inches.
Once in level flight, adjust the mixture. Switch the to EGT and pull back the mixture slowing until one of the CHTs flashes. Then notch forward on the mixture until the hottest cylinder is about 1400. I noticed in level flight, trimmed for cruise, the DA-40 has a nose-down attitude in comparison to the 172. I loved the visibility. Speaking of nose down attitude. Check out the two passenger weight balance for a DA-40 with full fuel. This places the plane near the forward CG line. This means there is less 'room' to pitch up before approaching the 16 degree angle of attack.
I practiced stalls in the DA-40. It feels just as stable as a 172 to me. Recovery is quick and easy. The DA-40 throttle and controls are extremely sensitive. I need a light touch to make adjustments. Trimming is a piece of cache with the trim control on the stick. I still like the trim wheel!
In descents, a little more planning is required. Slowing down the DA-40 for the pattern takes a little more time. I keep the prop at 2400 RPM and ease back the manifold pressure to 18 inches. When in the pattern, I hold the plane at 100 kts until abeam of the numbers, then I apply one notch of flaps. Then, I pull back to about 15 inches and start my turning descent. On final, fuel pump is turned on, mixture full rich, prop full forward, and the landing light on. I adjust the manifold pressure to about 11 inches. Once landing is assured, I lower the flaps (second notch) and begin brining the power back. It is critical to keep the speed above 70 kts. The stall speed of the DA-40 is not as advertised. Once level with the runway in the flare, just pull back really slowly to slow down the plane. It settles nicely. Do NOT let the nose drop, as the nose wheel is not as forgiving as a 172. Aggressive pulling on the stick is not necessary. A slow steady pull keeping the nose slightly high is sufficient. Too much pull causes tail strike or, even worse, a premature stall above the runway, causing a bounce. If this happens, apply power, holding the stick steady. The plane will begin settle again.
Through out the process, I realized that the work load of the DA-40 is a bit more than the 172 models. That's fine by me. It moves me closer to the load of an RG and proficiency requirements for a commercial rating. In the end, the most important element is the ability to fly the plane. Of this, I have no doubts that I can handle the DA-40. Out of 5 landings so far, two were smooth and gentle. The other three were a little rough.
Showing posts with label aviation. Show all posts
Showing posts with label aviation. Show all posts
Saturday, January 14, 2012
Friday, January 23, 2009
Too sick to fly
The weather is frustrating enough. Having a fever for four days straight while the outside exhibits great flying weather is driving me insane. I will not have a chance to fly the next two weeks. This is close to a full month of no flying. Crap!
I try to be ambitious when I am at home sick. I try to read a good book, write some letters, whatever. This week, I made an effort to learn about weather, watching some training videos. I am not talking about the exciting stuff like reading METARs, TAFs, PIREPS, AIRMETs, etc. I am talking about the basic weather: fronts, adiabatic processes, lapse rate, fog, isobars, etc. With a fever, I think I got through 1/4 of the instructional video on every attempt before falling asleep. I just cannot get into it. I know that I need to understand weather to be a safe pilot. But, gosh, the subject can be soooo booorrring. It is more fun reading pilots arguments towards LOP/ROP. This is a fun heated debate. I personally have looked all the information, in there is a strong case for LOP in a small carburated engine. However, if you are renting, then just follow the POH recommendation unless the owner says otherwise!
Some good news came today. I have my medical certificate. Yahoo! It only took three months. I am sure CAMI is glad that it is done as well, because I called one a week for the last three months for a status check. The answer was usually the same, "it is being looked at now". Boy, the MD who looked at my medical information most have found it intoxicating to have spent three months looking at it "now".
Other good news, Obama's organization is halting the progress of last minute regulations. Perhaps this ADIZ will eventually go away. While they are at it, perhaps they should look at some restrictions on when TFRs are to be used. There seems to be an over zealous use of TFRs as of late. I am not saying we have reached a critical point yet, but the direction of TFR use is approaching ridiculous (weddings and such). I would even go so far as to say that some basic freedoms are being compromised.
Here are some thoughts running through my head tonight.
* Not keeping the tanks full in the winter can lead to a serious side effect. Consider condensation forming and then the water freezes in the line. It may be undetected if the fuel selector is on BOTH and one wing's line is frozen. Without proper consideration, the pilot could be running into a low fuel situation as one tank empties and an imbalance in the weight of each wing as the full wing tank just sits there, untapped.
* Low temperatures can result in an increase power output of the engine. Extended use of this new found power is not necessarily good for the engine.
* If the belt in the front of the plane breaks, will the engine still run? Heh, this is not a serpentine belt like on my GMC truck. If that breaks, the truck does not run. The belt on a plane breaks and the engine continues to run (magnetos!). So other than a hopefully detectable noise of a belt break, how does the pilot know the belt broke while in flight? The ammeter will show a loss of power. This can also occur if one of the two leads to the alternator break or come loose (like the ground). During flight, the belts primary function is to power the alternator. The pilot shutsdown the alternator switch and fly on batteries. Shutting down unnecessary lights and radios is good thing to do at this time. Also, consider not using flaps until landing is assurred, as flaps need those batteries as well.
* The engine of a single engine plane is not centered perfectly. It, and the prop, are at angle. This is difficult to see unless the cowling is pulled off. The reason is to deal with the P-factor (the downward rotation of the blade is at a higher angle of attack, this providing more thrust than the upward side).
I try to be ambitious when I am at home sick. I try to read a good book, write some letters, whatever. This week, I made an effort to learn about weather, watching some training videos. I am not talking about the exciting stuff like reading METARs, TAFs, PIREPS, AIRMETs, etc. I am talking about the basic weather: fronts, adiabatic processes, lapse rate, fog, isobars, etc. With a fever, I think I got through 1/4 of the instructional video on every attempt before falling asleep. I just cannot get into it. I know that I need to understand weather to be a safe pilot. But, gosh, the subject can be soooo booorrring. It is more fun reading pilots arguments towards LOP/ROP. This is a fun heated debate. I personally have looked all the information, in there is a strong case for LOP in a small carburated engine. However, if you are renting, then just follow the POH recommendation unless the owner says otherwise!
Some good news came today. I have my medical certificate. Yahoo! It only took three months. I am sure CAMI is glad that it is done as well, because I called one a week for the last three months for a status check. The answer was usually the same, "it is being looked at now". Boy, the MD who looked at my medical information most have found it intoxicating to have spent three months looking at it "now".
Other good news, Obama's organization is halting the progress of last minute regulations. Perhaps this ADIZ will eventually go away. While they are at it, perhaps they should look at some restrictions on when TFRs are to be used. There seems to be an over zealous use of TFRs as of late. I am not saying we have reached a critical point yet, but the direction of TFR use is approaching ridiculous (weddings and such). I would even go so far as to say that some basic freedoms are being compromised.
Here are some thoughts running through my head tonight.
* Not keeping the tanks full in the winter can lead to a serious side effect. Consider condensation forming and then the water freezes in the line. It may be undetected if the fuel selector is on BOTH and one wing's line is frozen. Without proper consideration, the pilot could be running into a low fuel situation as one tank empties and an imbalance in the weight of each wing as the full wing tank just sits there, untapped.
* Low temperatures can result in an increase power output of the engine. Extended use of this new found power is not necessarily good for the engine.
* If the belt in the front of the plane breaks, will the engine still run? Heh, this is not a serpentine belt like on my GMC truck. If that breaks, the truck does not run. The belt on a plane breaks and the engine continues to run (magnetos!). So other than a hopefully detectable noise of a belt break, how does the pilot know the belt broke while in flight? The ammeter will show a loss of power. This can also occur if one of the two leads to the alternator break or come loose (like the ground). During flight, the belts primary function is to power the alternator. The pilot shutsdown the alternator switch and fly on batteries. Shutting down unnecessary lights and radios is good thing to do at this time. Also, consider not using flaps until landing is assurred, as flaps need those batteries as well.
* The engine of a single engine plane is not centered perfectly. It, and the prop, are at angle. This is difficult to see unless the cowling is pulled off. The reason is to deal with the P-factor (the downward rotation of the blade is at a higher angle of attack, this providing more thrust than the upward side).
Wednesday, December 3, 2008
picking a school
I am getting asked quite a bit on why I picked Rising Pheonix Aviation at Manassas for my school. Picking a school is not always easy. The cost of flying is high AND a student wants to get the best education for the price. With the rich set of material out there (DVDs, On-line testing and knowledge programs, books, audio tapes and CDs, etc.) the knowledge portion of flying is generally going to be the same regardless of the school. It really comes down to the student/instructor relationship and the scheduling options. My choice is based on the fact the Rising Pheonix Aviation instructors have become my friends through shared interests. I enjoy hanging out with them. Their knowledge and instruction skills are exceptional, backed by MANY years of experience. I get quality education and I enjoy the process of learning.
There are schools that specialize in pilot training (e.g. Aviation Adventures). These schools often have more flexible scheduling options and more CFIs to work with. These schools are optimized for quality and fast training. For most people, this is the best option. There are caveats though. Fast is determined by preparedness of the student and consistent scheduling. With consistent scheduling, it may not always be possible to work with the same instructor. For some students, this can be an issue. Dedicated schools provide the option for faster and more flexible training. The burden of learning still falls on the student to be prepared, consistent and on time for each lesson. Very few, if any, school is going to hurt their reputation by letting a student do a solo or check ride without being competent in the required skills.
In the end, the only advice I can give is to visit several different schools before choosing. The time spent up front investigating the best school for each individual is valuable, considering the cost of training. Meet the instructors, see the planes, look over the knowledge materials, look at payment options and look at scheduling options.
There are schools that specialize in pilot training (e.g. Aviation Adventures). These schools often have more flexible scheduling options and more CFIs to work with. These schools are optimized for quality and fast training. For most people, this is the best option. There are caveats though. Fast is determined by preparedness of the student and consistent scheduling. With consistent scheduling, it may not always be possible to work with the same instructor. For some students, this can be an issue. Dedicated schools provide the option for faster and more flexible training. The burden of learning still falls on the student to be prepared, consistent and on time for each lesson. Very few, if any, school is going to hurt their reputation by letting a student do a solo or check ride without being competent in the required skills.
In the end, the only advice I can give is to visit several different schools before choosing. The time spent up front investigating the best school for each individual is valuable, considering the cost of training. Meet the instructors, see the planes, look over the knowledge materials, look at payment options and look at scheduling options.
Subscribe to:
Posts (Atom)
