Thread: Short field landings

Having just started flying my new CTLS, and because I operate out of a rather short runway (1000ft) and would like to take it to even shorter runways, I decided to explore it's slow flying capabilities before trying to land real short. I had been following FD recommendations of coming in at 55kn, and found that this led to uncomfortably lengthy landings. 50kn recommended by some on the forums as a minimum low speed was ok, but still can produce a (relatively) lengthy landing. I went up with a very experienced ex Israeli airforce pilot who is also a certified instructor for ultralight aircraft and began to explore at altitude the slow flying envelope of the aircraft. I could not believe it: we were flying with a little power at 25kn and under- without loosing altitude at all (make sure you fly level and high before you try this). Power off stalls at full flap and at 30 degrees were observed at the lower 30knt and at even slower (all this assuming, of course, that we are getting correct speed readings). Following this we decided to try out some much slower landings- 45Kn. At that speed we could really stop the plane very short. The plane felt completely under control at that speed, and since it seemed that the stall speed was well below the FD published numbers, my pilot friend thought that there was no problem coming in at those speeds and even slower. I must say that I was a little surprised by the disparity between the published stall Figures given by FD and what we were observing. I did have my speed calibration checked a few weeks ago - and it all seemed fine.
I would be glad to hear your thoughts and experience on the matter.

unless pitched up high the ct will mush stall. the stall can be very hard to detect at altitude.

the same mush stall close to the ground is a different matter, the sink rate can be dangerously high.

if you approach slower then 1.3 VSo (52kt) then you increase your risk. you become more dependant on the engine and cooperative winds.

the published stall speeds are correct. the ct runs out of energy very quickly.

in short fields full flaps will help

Richard,
I picked up my CT2K a couple of months ago in England and had read a lot of differing opinions regarding short field/slow speed landings, which are an absolute must here in Ireland. Anyway, the guy that I was buying it from was a tug pilot who regularly towed up to 20 gliders a day in his Piper Pawnee and he gave me a quick demonstration flight in the CT before I headed back to Ireland with it. I asked him for the approach speed and was amazed when he said 45 knots with full 40 degrees. Sure enough with a stiff wind straight down the runway he brought her in at what seemed like a walking pace and in the length of a car park. Everything seemed under control and when you consider that Vs 40 degrees on the CT2K is 34 knots X 1.3 = 45 knots it seems to make sense. I never had the need or the nerve to try that since but can get her in to 300 mtrs with 30 degrees at 50 knots approach. So they are short field enough for me and for the patchwork fields of Ireland.

Mac

Richard,

I wouldn't go below 45 knots. You are asking to for problems. If anything changes during the landing you may become a crash statistic. I'm happy at 50 with 30 or 40 flaps, but know I can do 45 if need be. Anything below that is living on borrowed time. There are just too many factors out of your control that can cause you grief.

Just remember that if you're flying into a headwind, you could loose some or all of it in the last 100ft due to gradient. If you're at 45kt and the wind goes from 15 to 5 kt, you're suddenly right at or below stall speed. I like 50kt with 15 or 30 flaps (I never use 40) since this gives a little extra energy and the CT bleeds it off quickly with flaps, particularly at 30 flaps.

I'd hate to try flying a 600kg CTSW into and out of a 1000ft strip here in TX, where our density altitudes are high. For example, DA here at KDAL right now (not yet in the highest part of the day) is 3300ft; 4000ft isn't uncommon in the summer. Maybe in the winter when we get DAs around 0'.

A 450kg CT2K with less weight and the longer wings would be a better short field airplane than the 600kg CTSW that we have here in the states.

Doug

Note that the operators manual for the CTSW lists 45 knots for a final approach speed after an engine failure. That being said, I almost never approach at less than 50 knots and seldom have trouble not turning off at 300 meters - even if I float the first 100 meters.

Originally Posted by Doug

...I'd hate to try flying a 600kg CTSW into and out of a 1000ft strip here in TX, where our density altitudes are high. For example, DA here at KDAL right now (not yet in the highest part of the day) is 3300ft; 4000ft isn't uncommon in the summer. Maybe in the winter when we get DAs around 0'...Doug

hey doug,

our summer da's run 9,000' to 11,000' and short field ops still work well. if i routinely used a 1,000' strip i might go for the matco brakes.

In very slow flight at altitude, you will see shockingly low indicated air speed. I have always believed this is in part due to an extremely nose high attitude causing the pitot tube also to be pointed up and reading low. Thus, do not be fooled into thinking you can do those speeds while landing.
Wind can do funny changes right at ground level. Since the air speed indicator is registering "what was", if I see the airspeed slip to 50, most likely it is already several knots below that and I would add immediate power if not already in the landing flare. Any slight tail gust will drop you, and if one wing stalls first, you may not be aligned with the runway.
Tundra tires with matco brakes make a huge difference in shortening the landing distance. (I have had both small tires & original brakes to compare)
I do not believe you can safely drop in at 45 knots "repeatedly". It would just be a matter of time until something went just enough wrong and you landed too hard.

i agree john,

one added thought, not only is your pitot tube pointed up due to a high pitch attitude but the relative wind in a mush stall is coming from below making the angle even greater, and the error.

1.3 Vso applies to most all fixed wing aircraft, it was learned over decades at the cost of many pilot's lives. it is no joke and it isn't a wild ass guess, it is the correct approach speed that is unless it is too slow due to gusty conditions.

Originally Posted by CharlieTango

hey doug,

our summer da's run 9,000' to 11,000' and short field ops still work well. if i routinely used a 1,000' strip i might go for the matco brakes.

No thanks; you are a braver man than I. No way I would fly a loaded CT into and out of a 1000' strip with 9000' density altitude. I wouldn't even do it at 4,000' DA.

The current POH lists a distance of 760ft for takeoff over 50ft at SL/ISA and 600kg; this assumes a fresh airplane and perfect piloting. Using a Koch Chart, you need to add 50% to the ISA/SL takeoff distance at 4000' DA, so call it 1250ft. At 8000' DA, you need to add 140% to the ISA/SL value, so it becomes 1,825ft.

I've comfortably done T&Gs at a 2500ft long field at MGTW and 4000' DA with no wind; you can always go around or taxi back and use the whole length if you land a little long. There's also plenty of room to take off with 0 flaps.

I'd hate to work out of a field half that length with the kind of DAs we get here; too much to go wrong and no room for error. YMMV.

Doug