Menu Sign In Contact FAQ
Banner
Welcome to our forums

Airspeed check against groundspeed (and stabilised approaches)

Administrator
Shoreham EGKA, United Kingdom

If there is a strong wind I often compare IAS and GS during the downwind leg. On final I concentrate on the approach itself. Aerodynamically the GS is irrelevant until touchdown, isn’t it?

Low-hours pilot
EDVM Hildesheim, Germany

Aerodynamically the GS is irrelevant until touchdown, isn’t it?

Yes; correct.

Administrator
Shoreham EGKA, United Kingdom

MedEwok wrote:

If there is a strong wind I often compare IAS and GS during the downwind leg. On final I concentrate on the approach itself.

Bear in mind while doing your approach, and before touchdown, that your glide angle at a given power setting is steeper with a strong headwind.

Thoughts on landing somewhere without radio?

Anyone experienced a faulty ASI or suspecting a faulty ASI?

Anyone experienced a faulty ASI or suspecting a faulty ASI?

Only as part of the training (my own one and what I do with students). Fly your power setting as usual, fly your pitch attitudes as usual, configure your airplane as usual and everything will be fine. An ASI failure would be the least scary instrument failure for me.

EDDS - Stuttgart

I usually check ASI against GS when doing a CDFA (constant descent final approach). Rate of descent checked against GS will give a better profile than ASI if there is strong wind. Especially if there is a strong gradient.

I do it in CBIR training to calculate the necessary descend rate to stay on the glide slope.

Safe landings !
EDLN, Germany

Sure on an LNAV (or NDB) Approach i use GS x 5 for the descent rate … but they are getting rare, LNAV/VNAV and LPV everywhere in Germany and France.

what_next wrote:

An ASI failure would be the least scary instrument failure for me.

Me to. Not worried about that aspect. I was more interested in partial failures where the ASI is over or under reading.

In another arena I am conscious of automatically comparing the G/S with the IS without a second thought but realised it is something I rarely do when flying other than in the cruise and event then without doing any mental calculation that the IAS and G/S make sense. (I appreciate that they will almost without exception).

In fact there is a wealth of information where the electronics constantly give you wind direction, velocity and G/S all based essentially on GPS and seperately you have IAS. It seems to me there is a lot of information there during the descent and approach and, to a lesser extent, in the cruise. Uses could include cross check of accuracy, monitoring the wind during an approach and approaches into unmanned strips, where once I will freely admit I managed to land with a tail wind because I had managed to “confuse” the correct runway on which to land.

Sign in to add your message

Back to Top