Different headwind T/O speeds.

[Lump Jockey]

Hi all.
Am I right in saying that, if you require a T/O speed of say 60kts, and you have a headwind of 10kts, then the groundspeed needed will be 50kts?
If true then what would the g/s need to be if you have a 60kt headwind? (See where I'm coming from?)
I only ask as it's bugged me for ages, plus I am not a pilot!
TIA!

[slim_slag]

Lump Jockey,

You would essentially be hovering over the same point on the ground. If you get something like a J3 Cub, which will fly at a ridiculously low airspeed if you hang the flaps out, it's quite possible. Seen it done in fact :)

Forgot to add. If the wind is blowing hard like that, getting to/from the runway in your J3 cub can be interesting. The wing has no idea of your groundspeed, so if a gust comes along it cause your wing to "fly", even though you are on the ground. I've seen that done too :o :o

[Flyin'Dutch']

HI LJ

With winds of 60 Kts you best keep a small bird in the hangar and have a beer instead.

However your basic assumption is correct. The stronger the headwind the lower the G/S. That and a few other issues are the reason that you normally take off and land into wind.

Slim-Slag:

IIRC a J3 has no flaps. :p

FD

[slim_slag]

Ooops Dutch.

I hang my head in shame :o

Still hungover, had super cub on mind.

Sorry about that :confused:

[Hairyplane]

Come on Lump Jockey - you surely knew the answers?!

I flew a Miles Messenger until recently - this stalls at an incredibly low 27mph at idle but a lot slower - 20mphish - with power.

Even in a moderate wind it is possible to land with negligable ground roll.

Many years ago I remember climbing to a few thousand feet on a fairly breezy summers day in a Turbulent (G-ASTA where are you now?) throttled back and flew 'backwards' across Maidstone.

Taxying a Cub in a strong wind is - I agree - definately not recommended. Only a few years ago at Enstone we were priveledged to see a very impressive STOL performance by a J3 owner. Trouble was, when he turned off the runway the aircraft was on its back before you could say 'what did you say your name was??'

Happy Landings.

HP

[Flyin'Dutch']

Hairyplane:

It is a bit of an art to know when to decide that while it is still OK to fly a tailwheeler it may be better to have a pint as conditions are not good for the taxying! :eek:

As to GASTA:

KIMBOLTON
HUNTINGDON


Is what G-Info gives as the address of the current owner.

FD

[wysiwyg]

12 years ago, when I was a full time gliding instructor, I remember on one windy day winch launching a two seater (did about 10 flights like this) up to 2000' slowing down to about 35-40 knots, drifting backwards until at a suitable point where we could lower the nose and land back on the airfield straight ahead. It was in effect a complete circuit without turning.

[FWA NATCA]

Lump,

I actually had a pilot in a C152 fly backward for several hundred feet over the runway in a strong head wind just to see if they could do it.

Mike

[poetpilot]

Wsywig, I did that too (as a staff cadet with an instructor in the back) at RAF Bovingdon around 1970..... ah, those were the days....). 1500 feet, then a gentle "downwind" backwards, then stuff the nose down to punch through the wind gradient and there we were, back at the launch point. It has to be a day where the wind is steady and strong rather than gusting, plus plenty of people around to hang on to the gliders....


Don't Try this at Home, kiddies....
:rolleyes: :rolleyes: :rolleyes:

Plus, a few years back (well in the 80s actually) we used to have a little tradition of trying to be first to fly on New Year's day at Barton. This entailed not getting bladdered the previous evening I might add, and an early turn in was recommended to be bright eyed and bushy tailed, so considerable sacrifice was called for.

One year, a certain young pilot woke up whilst the rest of the world was still sleeping, got down to Barton, pulled the old Jodel out of the hangar near the tower, noting that the wind was getting up. Luckily though, it was coming from the west, so he was sheltered in the lee of the hangar and tower. Being young & foolish, he was determined to win the honours that windy dawn, so (chocked and tied) he hand swung the aircraft, still in the lee of the hangar.

Gingerly taxying around to get onto the field, it became immediately apparent that this was indeed A Windy Morning, but being young and foolish, our hero managed to turn into wind without mishap. Some experimentation whilst stationary showed that he could raise the tail with only a dab of power. Bravado won out, and (not on the runway as such, but in line with it) he opened up and was promptly airborne. 10 feet ground roll at most. Just like a helicopter.

The problem now was to get safely down again.

He'd kept the nose low, going for as much airspeed as poss to get good control, but was still being bucked around like a bucking thing on national bucking day. She went up like a helicopter to about 1500 feet, where things smoothed out a little.

Our hero amused himself going backwards at this point, but then had to address the problem of saying hallo to Mother Earth once more. Knowing all about wind gradients, he stuffed the nose forward, hitting about 90 kts (usual approach was about 60) and stayed with the ride, though it was getting decidedly hairy. Somehow he managed to round out, with the speed bleeding off VERY rapidly, and he achieved a landing as close to the shelter of the buildings as he dared, dead into wind.

He then had to wait for 30 minutes, holding her into wind, with the engine running, effectively still flying her in order to not turn over, until more human life appeared to help him manhandle it back to the hangar.

[FlyingForFun]

Excellent story, poet - I'd love to have watched his face trying to "fly" the Jodel while stationary for 30 minutes!

Remember, the wind at 2000' is quite a bit stronger than the surface wind. So it's not at all uncommon to be able to take off perfectly safely with a ground-speed of, say 20 or 30 knots (depending on type as well as wind-speed), climb to altitude, and then slow down and fly backwards.

Tail-draggers are more fun in wind than tricycles, as others have said - firstly because they are more prone to weather-cocking in a cross-wind, and secondly because they sit at a very high angle of attack when on the ground - the angle of attack of a C152 would probably need a wind quite a bit higher than Vr to cause it to "fly", whereas this is not the case with a tail-dragger. In theory, of course, it would be possible to lift the tail off the ground, decrease the angle of attack, and effectively fast-taxy (although the use of the word "fast" may be correct in the dictionary-definition sense of the word!). Just be careful when turning - if you forget to pull the stick back again, the sudden change from headwind to tailwind would probably slam the tail onto the ground in a rather nasty way! Not something I've ever tried, nor something I'd suggest anyone else tries without some assistance from an expert!!!

FFF
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