Stall speed of a wet wing

[Guest Crezzi]

Pretty much what i do bar No4 & 5 sometimes and I also dont land in real short paddocks, probably 300meters would be the shortest, I know a bloke who used to fly landed in a real short paddock with his mate cause they needed a leak and couldn't get back out, had to de-rig the trike and trailer it out, he only done it once, his ambitions exceeded his and his trikes ability.But he made a good decision that day.

Alf

Good call by your man - its not easy to admit to yourself that you made a mistake

I should really have included "If in doubt - DON'T" as step 1 above :-)

 

Trikes at least have the advantage of being rather less hassle to trailer home than most other types.

 

Cheers

 

John

 

 

[Guest Crezzi]

How do you recognize min safe flying speed?

You are absolutely right about not watching the ASI - far too much else going on. In a trike there is quite a lot of feedback about your airspeed - I try to use that to judge the correct point to rotate.

 

In a previous post you mentioned avoiding the problems associated with the bar out technique. Could you explain what those problems are?

The point of the technique is to lift off at minimum airspeed so your vulnerability to sudden changes in wind is increased. If there is any cross-wind component it will affect you more (since your airspeed is less). If either, or both, of these factors occur you have reduced control effectiveness (again due to the reduced airspeed).

For sure trikes generally accelerate quite quickly wheels off and clearly a lot of people do regularly use this technique with anything nasty happening. It might only be a 1 in 10000 chance of getting caught out but, to my mind, its better to minimise your exposure to the risk by not lifting off at min airspeed unless there is a good reason to do so.

 

At least as important is the fact that taking off with the bar held forward doesn't involve the pilot in the process - he's just sat there waiting for something to happen. Taking off with the bar neutral the pilot has to make decision when to rotate factoring in the wind conditions, take-off weight etc. Of course these should be considered before you start rolling but the implementation is still a real-time pilot input. It provides pilot feedback (why didn't it lift off immediately when I eased the bar forward - fat pax, hot day, tailwind ?) and what you can learn improves your capabilities as a pilot for such things as the short field take-off above. In some ways this is my main objection to "lazy" take-offs - I don't like to see passive pilots :-)

 

Hope that helps

 

John

 

 

[Guest davidh10]

You are absolutely right about not watching the ASI - far too much else going on. In a trike there is quite a lot of feedback about your airspeed - I try to use that to judge the correct point to rotate

I don't seem to have any problem having time to check the ASI for rotate speed, even in a formation takeoff, although if number two, it is only one criteria for rotation.

 

 

[allowera]

I was taught that (with my particular aircraft), I should always 'short field take-off'.

 

Particular attention being paid to air conditions ( wind speed, direction, turbulence, moisture e.t.c.), surface condition (resistance) and Bar position (centred and full-out). As soon as separation between front wheel and terrain occurs to 'nose down' and increase safety speed.

 

My teacher was aware that I would be almost exclusively using grass strips and warned me heavily about the dangers of moisture. He was aware of a fatality that occured due to the friction between 3 wheels, wet grass and a fence. I am unsure if there was a damp wing involved.

 

I intend to continue this practice as I am still here, but would love to hear any comments.

 

 

[Camel]

The short field technique to get off the ground is fine but what follows is the most important ( as you have said) because you need airspeed to create more lift without that speed you will have a problem.

 

 

[Bluey]

With the trike, airspeed usually builds very quickly because of the high power to weight ratios we have at our disposal. Anyhow, I'm not sure how people are getting airborne at the stall speed as I generally can't get either the streak or the SST off the ground slower than about 45kts. The stall speed of both wings is 35kts at MTOW and around 32kts solo with a full tank. With the streak, holding the bar out will get it airborne above 40kts. I have even tried pushing the bar out to nudge it at about 35kts and it won't fly until it gets above 40 at least.

 

Bluey.

 

 

[Guest davidh10]

Keep in mind that although we often quote "stall speed", that is under very specific circumstances. It is angle of attack with respect to the effective airflow, not speed that causes a stall. The effective direction of airflow is perturbed by gusts, wind, turbulence, thus if you are flying in ground effect, picking up speed to climb, there is increased risk of a stall being caused by a gust.

 

 

[Guest Crezzi]

I don't seem to have any problem having time to check the ASI for rotate speed, even in a formation takeoff, although if number two, it is only one criteria for rotation.

Indeed but you are an experienced pilot - "clock watching" is not something that should really be recommended on a public forum IMO

 

Cheers

 

John

 

 

[Guest davidh10]

Indeed but you are an experienced pilot - "clock watching" is not something that should really be recommended on a public forum IMOCheers

 

John

I think you have misinterpreted my comment as being a recommendation for some unstated procedure (clock watching), which is not described.

As I'm not an instructor, I never recommend flying techniques. Anyone wanting "how to..." information about flying should consult their instructor. I am however, happy to discuss flying and my thoughts and experiences, but again, I do not describe flying procedures or recommend techniques.

 

 

[Guest Crezzi]

I think you have misinterpreted my comment as being a recommendation for some unstated procedure (clock watching), which is not described.

Not at all David - I was simply explaining why I agreed with skeptic's comment about not judging rotation airspeed by the ASI

 

Cheers

 

John