All Activity

Differentials/derivatives tend to be noisier than the original signal, too, so it does get tricky. It does seem reasonable to expect to be able to augment the air data VSI with GPS and/or accelerometer data, though and decrease the delay.

So, you are correct. I usually think of averaging things over time and dividing by the number of samples, like the I term of a PID controller. But we are looking for the rate of change. So we have to look at the difference over a number of samples. It gets interesting trying to filter a differential signal.

You beat me to it! You would differentiate altitude to get VSI (time rate of change of altitude)

I land my J full flaps about 90% of the time. It lands better, and it’s easier on tires and brakes. I still practice other flap configurations, but “normal ops” is to land full flap. There’s not many good reasons not to, as skip pointed out.

I have a client looking for a low time 1986 or newer M20K with upgraded panel (not necessarily all glass). If your plane is NOT CURRENTLY LISTED please send me a private message. Thanks!!!

Sorry to ask but do you mean differentiate the altitude to get the rate of change of altitude or am I not understanding what you are after?

Why use flaps at all? What do flaps do? Flaps do three things: First, flaps add drag allowing for a steeper approach with power, and using power during an approach aids controllability by providing the ability to control airspeed and descent angle/rate independently. Second, flaps reduce the deck angle allowing better visibility over the nose. And, third (and most importantly) flaps reduce the stall speed allowing for slower and thus shorter landings. So, if flaps do all these good things, why not use all you can get? Are Mooneys easlier to land with partial flap settings? And, are Mooneys so difficult to land that we need to resort to lesser flap settings to make it easier? Judging by the fact that landing Mooneys seems to be a perennial topic of discussion, it appears that many have issues with landing these airplanes. Let's define a good landing as on centerline, with no sideways drift, on the main wheels first. We might further add touching down within say 100 feet of your aim point. Most every competent pilot can do that. But what I think everyone is really after is a soft touchdown which can be more difficult in a Mooney than lesser aircraft. Why? I think there are a number of reasons: 1. When you get a Mooney slowed down to 1.3Vso you are deeper in the region of reverse command (aka backside of the power curve) than many light aircraft and the airspeed is thus unstable in the sense that if it starts to get slow, it wants to get even slower. So, you have use the throttle and elevators more to keep it on profile. 2. Mooneys have a lot of gadgets in the elevator controls. M20Js and earlier have trim assist bungees and later models have a down spring interconnected with the trim and a bob weight. These gadgets add an unnatural control force at low speeds because the spring tension is constant where the elevator forces without the springs would decrease as the airplane slowed. 3. The laminar flow wing has the spar pretty far aft and so the landing gear, which is attached to the spar, is located farther aft of the CG than most other similar aircraft. This is why people sometimes call the airplane nose heavy. But this main gear position has an undesirable effect upon touchdown. At the instant the main wheels touch down, the pivot point shifts from the CG to the main wheels which shortens the moment arm to the tail. This produces a pitch down moment and the tendency to "bang" the nosewheel down harder than intended. 4. The rubber puck suspension system is pretty stiff and not very forgiving if you drop it in on landing even a little bit. Some of these negative aspects can be improved by landing with less flaps. The landing speed is higher so you will be less deep into the region of reverse command. The pitch angle is higher so the flare maneuver does not take as much rotation and is more tolerant of mistiming. But, wouldn't it be better to learn how to land the airplane correctly than to use the "crutch" of using less flaps just to make it easier? It's not that hard. The biggest mistakes I see (and make myself) are not looking far enough down the runway to properly judge height, flaring too high (risks running out of energy and dropping it in) or too low (scoots along in ground effect until it stalls and drops in) and not using a touch of power when it seems it is going to drop in. My best landings are with the power coming to idle just before touchdown and the elevators still coming back as it touches down.

Doolittle didn’t actually invent it but motivated Shell to produce it. Many people were responsible for its formulation but a few things, especially TEL made it possible. Sent from my iPhone using Tapatalk

No, the airplane I had at the time was a pre-G1000 M20M. On pre-G1000 M20M and M20R there was a circuit box in a box that was behind the LED indicator displays that had a 1/4 pico fuse that would go out. This fuse fix doesn't apply to newer models (G1000).

Reduced price ($900) OBO. Shop said yellow tag is still valid and in use for overhaul.

Any news on the gears?

I have an Ovation 3 GX (G1000) and my flap indicator on the G1000 is acting up. When you say the fuse works on later Ovation models, did you mean the GX models? And where is the fuse located? I am only aware of the circuit breaker panel. Thank you.

I used to practice this in a PC 12. 800 feet was the altitude needed to successfully complete. Practiced in the sim multiple times prior to field. Actually worked well with room to spare. However, as stated above many variables to take into consideration.

This is good to practicen the sight picture and perceived speed/descent rate can be very different.. Another consideration is that if one has had ice on the airframe, flaps are limited to T/O in the long body (and maybe mid body) Mooney’s. The tail is a much more efficient ice collector than is the wing, full flaps blank the tail from some of the airflow past the wing, and a tail stall on short final is likely to be a non-survivable lawn-dart terminal event. -dan

You can say that again. I have to drive this same section of highway to get home after working the accidents. I have made it 4 times so far this weekend. Continue pray for me.

Thanks for sharing. Did not know that Jimmy invented 100LL. One learns every day.

Thrilled to let everyone know that we found ( well, really, my mechanic- but give me credit for taking off the cowl..) one of the two wires to the transducer was broken - hidden inside the plastic cover. all fixed! Rob

I have one

One key takeaway for me is a Vy climb an altitude that makes the turn a possibility; I've been transitioning to a cruise climb prior to that. I'm very impressed by her flying skills and she makes great video. It's really nice to have see/get data from a Mooney. King used a J model to demonstrate the power off 180.

Does anyone have an extra PC disconnect switch? I have the vacuum type and the disconnect is a cylindrical valve button with two O-rings. I dropped mine while working on the airplane and after searching for hours I’ve given up hope of ever finding it.

A question on sequencing on a Go Around (for a manual C model sorry I am the wrong forum). So doing some instrument training an instructor found it odd that I would raise the gear first before applying power (Throttle). The flaps I never extend flaps just place the flap diverter valve lever to down (Manual flaps 100MPH limit). Is this bad habit on my part? or? Thanks bring this topic up, James 67C

To get you into the mindset, for every takeoff it helps if you train yourself to expect an engine failure just before applying full power. Most important to know your minimum altitude before attempting the return. If fields are available ahead then that would be my first choice.

All you need to get a VSI is the altitude. All you have to do is integrate the altitude signal over time. It kind of depends on the update rate of the A/D converter. The shortest time you can integrate is two samples at the ADCs sample rate. That would almost certainly be very noisy. So you need to integrate over a longer time to get a stable reading. This can make the indication lag. So you have to pick a time span that is a good compromise between noise and lag. You could sum it with the output of the vertical component of the accelerometer to speed it up some. Everything is a compromise. You just have to come up with a solution that meets the requirements. Whatever they come up with, it will be better than a mechanical VSI.

@OGBPilot That's a great looking Mooney! Who did the paint job?

I was reading the history of Avgas 100 Octane (UL thread is somehow depressing to read), it's interesting that Spitefire engine could even run on 87 Octane? they were later switched to run on 100 Octane, this increased speed by 30mph and gave an edge versus ME109 ! https://www.warbirdforum.com/octane.htm A nice history find is that the man who made 100 Octane at Shell in 1930's was the same guy who made flight instruments for flying without visibility in 1930's, he was also a famous racer. Doolittle set the world's high-speed record for land planes in 1932 using Shell avgas https://www.shell.com/business-customers/aviation/100years/more-uptime/high-octane.html https://irontontribune.com/2021/01/16/jimmy-doolittle-pilot-racer-and-inventor-of-100-octane-gasoline/ A bit later, he was more famous with "Toolittle Raid".