soft field/ short field landing advice
- Thread starter Ngrossman
- Start date
bdhill1979
Gone West
Opening the window will have no effect on the instrument unless the alternate static is opened, the primary static port is outside the cabin.i know a few instructors who have opened windows on short final just because it was too hot and to see if their student could correct for it so if she wont let me do it i know a couple that could be possibly convinced
i know a few instructors who have opened windows on short final just because it was too hot and to see if their student could correct for it so if she wont let me do it i know a couple that could be possibly convinced
It is a good way to demonstrate rudder authority, but a poor way to demonstrate anything with regards to airspeed for reasons bd gave.
Careful with any statements after the word "but" when you go for your check ride. All that does is open you up to questions you are likely not prepared to answer or dig yourself a hole. In this case, CAoA has little relation to lift coefficient. Energy management also isn't the driving force behind the discussion of CL and AoA but instead is related to lift.
I just wanted to put this out there, since the "tell to much" was a big problem for me on checkrides.
bdhill1979
Gone West
I call it handing the examiner a shovel
I made it easier for them, I gave them a drink and a lawn chair while I dug the hole for them.
Yes, momentum is a function of speed and weight. Slowing speed reduces momentum.
One older method, not commonly used as it is simply stupidly unsafe, was to bring the aircraft in just above stall speed so you eliminated all float. Read the book stick and rudder sometime, a great old book with wonderful ideas for visual flying. I caution though that he rambles a lot, but he can't hold a candle to me!!!
If you have a good memory a library card is fine, but it is a cheap book maybe 10 bucks. Emergency Maneuver Training is another great book for aerodynamic information.
tgrayson
New Member
Not according to the flight test books or any aerodynamics book that discusses it. The pitot tube is supposedly highly accurate across a wide range of AoAs, well beyond the stall.
Here's a quote from Aerodynamics for Naval Aviators, which I quote only because you can find it online:
(2) The calibrated airspeed (CAS) is the result of correcting IAS for errors of the instrument and errors due to position or location of the installation. The instrument error must be small by design of the equipment and is usually negligible in equipment which is properly maintained and cared for. The position error of the installation must be small in the range of airspeeds involving critical performance conditions. Position errors are most usually confined to the static source in that the actual static pressure sensed at the static port may be different from the free airstream static pressure.
As for "why", I don't know. I speculate that since what the pitot tube measures is stagnation pressure, it's pretty easy to create a stagnation point around an opening that is more or less facing the relative wind. The real trouble is not creating one, because that's what screws up the static port.
I don't think I am following you here. What does a stagnation point around the pitot tube have to do with effective pressure by the static port mounted on the fuselage. Unless you are speaking of pitot tubes combined with static ports found on pipers?
I should have ignored the power settings and what I said earlier might make a little more sense. At faster airspeeds, airflow over the static port will create a suction on the static port, much like that of airflow over an aircrafts doors, acting to suck air out of the static port and reduce the pressure inside.
Now if they calculate (when installing the instrument) for this at normal cruise speeds than as you slow down the flow reduces and the pressure increases. That increase in pressure from slowing down would cause a lower reading in the airspeed indicator than the actual speed. Like you I am just speculating, but what do you think about that.
Obviously we won't come to a final answer, but as I am sure you noticed I have to know the why and how behind everything. It has been like that since I was 5 pulling apart random electronics in the house. Unfortunately I rarely discovered how to put it back together, probably why I am a pilot and not a remote control technician.
PS That is really interesting about the pitot tube, I would have never guessed that, I guess coanda works a little.
tgrayson
New Member
I don't follow what you don't follow.
But taking a stab at it, a sideslip can direct the relative wind into the static port, adding some stagnation pressure to the static pressure being sensed. (This isn't the source of error in non-slipping flight.)
ppragman
FLIPY FLAPS!
Why? It just takes more skill to do, that does not necessarily mean unsafe. If you want to stop an airplane quickly, bring it in with power just above stall speed, with a nose high attitude (this means you usually can't see out of the front, so you'll have to look out the side). Instead of flaring cross the threshold, and simultaneously reduce power and increase pitch. You won't float, and you'll hit at the lowest possible speed.
If you're really good, you can come in high and fast it so you can deadstick it in from about 100AGL and keep enough airspeed so that you can flare to a full stall at exactly the threshold and exactly 6" or so, that's a little harder if the runway is short and its really gusty, or if you're not really comfortable in the airplane, but it works well too.
Of the two techniques, I think the power on technique is a little better in gettting in short, but offers you less in the way of visibility on final (which may be critical, idk).
Just above stall meaning maybe a knot. A true "mushing" it in landing as the author of stick and rudder puts it. If one of your students brought the aircraft to 35 knots or below on short final I would be surprised if you didn't have an unexpected boule movement. Less than 5 knots above stall speed isn't necessary for 99.9999999% of runways and one slip up, one gust of wind, one sudden updraft, could quickly stall your aircraft.
I do agree it requires more skill though and if you want to do it solo that is fine by me. If you did it with me in the plane I would hit you upside the head so hard you wouldn't consider that again with me in the plane, but that is just me.
ppragman
FLIPY FLAPS!
Where you're at maybe, however if you're going into a 2000' gravel strip (or less) covered in glare ice, I'd recommend being as slow as possible. 5kts above stall is typically what I used in the 207, these Cherokees are a little bit different, but the principle is mostly the same, that being said, around these parts, everything is pretty long and nothing really presents a serious shortfield problem. Bottom line is, nothing will get you in shorter than a full stall landing right at your point.
On a different note, if you even thought about touching me when I was going into one of these strips because you didn't like my "technique." Something I have significantly more experience in than you, I'd probably clean your clock, and fly you back to home base, where, you could pay for the charter. Touching the pilot at a critical moment can be hazardous to your health.
