Landing into strong head winds...

[Guest Pabloako]

I feel that one of the best things about flying is that every flight is different and even on those regular local flights, no flight is the same. Time to leave the problems of the world behind and concentrate on just flying and enjoying the view. (Almost priceless in my opinion!)

 

Here is my experience from today’s little trip in rather strong winds and I hope someone can help me with some of the questions I have left unanswered…

 

Today’s weather was rather average, with cloud around 2500 feet, showers in the local area and a rather strong wind, which according to the windsock at the airfield was approximately 130 degrees and around 20 knots. (Not quite horizontal, but almost). It was rather steady too and not gusting too much.

 

Due to the strength of the wind, I decided a flapless take off was the order of the day, lined up on runway 12 and gave it full throttle into the headwind. I was airborne a little earlier than normal (normal as in light winds) and started a nice gentle climb. Due to the lack of flaps I gave a quick glance at the airspeed as I started the climb and I was around 65 knots. At about 200 feet I felt a bit of lift and all of a sudden I had an airspeed indicator was showing 90 knots, which I put down to wind gradient. I left the circuit as normal and had a glorious scenic flight to the west, dodging a few rain showers and flying towards clearer skies maintaining VMC all the way. On my way west I calculated my ground speed to be around 130knots, so that made around a 30 knots tail wind, which was a bit stronger than what the area forecast was saying. I got to where I wanted to look at, flew around for a bit and then turned back to the east and back home. Again on my way back I calculated my ground speed to be around 70knots, so as before the wind was around 30 knots but this time a head wind. The same as before I had a glorious scenic flight back, once again dodging showers and maintaining VMC all the way, but a lot slower than I did when I was heading west!

 

I got back to the airport with about 15 minutes of my hire time left, so I thought I would do some circuits to play in the strong wind. I joined the circuit for runway 12, did the downwind leg in record time, did all of the usual procedures and turned base early (almost level with the threshold) and consequently got blown halfway to Alice Springs on the base leg due to the cross wind. I kept the circuit tight and turned final for a flapless landing straight into the strong headwind. So far so good and exactly how I had planned, however I was slightly higher than normal, but all good, until strange things happened!

 

On short final, I was still at 500 feet and 60 knots (ish). Getting towards the threshold I was still around 450 feet and my ground speed felt ridiculously slow, so I had a quick glance at the ASI and it was now reading 85kts. Over the threshold I was still around 400 feet, so I decided I would go around, feeling rather confused.

 

As I was turning crosswind a Pioneer aircraft behind me had turned final and then announced a go-around too. As I turned downwind, I saw him about 500 feet above the runway doing a go-around, exactly the same as I did.

 

Once again, I did the downwind leg in record timing, turned base the same as before, turned final, got to approximately 500 feet and the same thing happened... She wasn't going down! However as I had my final leg a bit longer this time I managed to get to 300 feet and a quick glance at my ASI and it was reading 85knots again. At 100 (ish) feet I got a bit of mechanical turbulence and then my airspeed and ground speed felt normal again and it was a normal landing.

 

My questions are… What caused us both to have to go around and not to be able to descend below 400-500 feet by the time we got to the threshold?

 

Was the strange (well it felt strange anyway) increase in air speed as a result of wind gradient or me subconsciously “pushing forward” to try and make the aircraft descend?

 

If I had been controlling my airspeed and been my usual 55 knots on final, I have a feeling it would have been rather nasty if I had got to 100 feet and the 35 knot head wind had almost disappeared after the small bit of turbulence. Was I doing the right thing?

 

Any help will be much appreciated!

 

 

 

[facthunter]

You probably felt that your groundspeed felt too slow. At some point the wind will drop off a bit' It always does at some point and you should allowfor it. Being a bit fast is not a problem relating to runway available but you will still have trouble putting it "on the deck" at high airspeeds. You will be nose low and have weight on the nosewheel. If you pull back on the stick you will balloon rapidly. Don't know why you got it high but you do have to make a good approach angle to an aim point as you normally do.. Nev

 

 

[Guest Maj Millard]

Yes sounds a bit interesting. It does sound like there was a steep wing gradient or layer, as you found on take off. This sort of thing can happen when the wind is strong.

 

I recall during my time as a skydiver landing on square chutes, that on some occasions it wasn't unusual to descend through more than a couple of different layers of air from 1000' to the ground. On a chute you could really feel the transition from one to the other, and the strength and direction would change also. I have had these 'transitions occur 100' above the ground.

 

No doubt as you found today, a good wing with a lot of air going past doesn't want to go down. No doubt if you dropped flaps and slowed down it would be a different story. But I'm with you, in big winds it pays to keep the flaps stowed and the speed up !.................Maj

 

 

[Ballpoint 246niner]

Paul, when I flew just after with a student the conditions had stabilised a little but still similiar- I would suggest that given your interpreted lack of groundspeed you kept pushing fwd( an easy thing to do) and not in itself unsafe when flapless. This truly gave you the 85kts airspeed you noticed when looking at your SECONDARY reference( the ASI), can you recall what attitude you were holding?, or were you focused on your coverage to the aiming point and secondarily the ASI?

 

Strong conditions often cause us to amplify our inputs, there was a strong gradient today but wind gradient, (the decreasing windspeed with reducing height due to mechanical turbulence), tends to rob the aircraft of energy, and result in excessive sink low to the ground. Rememer the rule- add 1/3 the windspeed to your approach speed and elect no flaps in the Tecnam if this calculated speed is greater than 60kts VFE.

 

Your efforts today were to be commended and simply build on your experience- don't ever feel their is hocus pocus at work! It generally can all be explained and has been experienced by others but never take conditions for granted.

 

 

[.Evan.]

On the days where I've flown in strong winds, I've had to 'drive it in' with plenty of throttle - sometimes even up to 2200 RPM on the worst days! I've not so far experienced what you've described, however some days when there is strong thermals on mid/late finals I have had to really work to get the plane to sink.

 

 

[Guest davidh10]

As others have said, you sometimes encounter multiple layers of air travelling at different speeds and directions, even between circuit height and the ground.

 

If you back off the power a bit, you will sink at some point without having to point the nose down. Having said that, speed is your friend in gusty or turbulent conditions. You may have to adjust power several times to maintain your glide slope as the conditions change.

 

Today, it was quite turbulent here in the early afternoon. A dust devil went through the AD both during take off and landing. During final, with only about a 10kn head wind, I encountered thee separate cycles of sink and lift, each adding or subtracting about 500'/min to my descent rate. The final bit of sink hit when about 20' above the runway and the added power to counteract it made me balloon a little, now at about 8'. I was prepared to go around if needed, but was able to just keep flying at 8', re-stabilise, and then reduce power a little to complete the landing.

 

As you say, every landing is different.

 

 

[pilotdave69]

I remember a flight recently in the J160 where I had 40 knots tail wind, GS was 133 knots, quite suprised at 5000 ft. Heading back to aerodrome, took forever to get home , as it was now a headwind. I was the same, i had to power it in at 2200 revs as GS was 55 knots. I landed like i was floating, thankfully winds were on the nose for the main runway.. Phew.

 

 

[facthunter]

If you are going to have the runway aspect the same (with a strong headwind), as it is normally, you will need extra power because you are (in the parcel of air you are IN) actually descending at a much shallower angle than normal. IF you make a shallower angle your descent rate will be less. That might be a bit hard to understand. Look at it another way, then . At 600 feet on final you are the normal distance away for your height, but since the headwind is so strong it will take you longer to get to the runway. (Your groundspeed is less). You descend the same amount but it takes longer so your descent rate is less than normal. Any time you reduce your descent speed for the same airspeed to be maintained, you need more power. Nev