Calculating Approach speed --additions
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Calculating Approach speed --additions
Aside from 1.3Vs (computed to the landing configuration) what other additions do you make and why?
I've read about a number of different additions including half max gust strength (is that the whole gust strength or just the additional"gust" above the steady wind ?). Alternatively steady state wind plus "Gust Factor". Are the winds those reported or their resolved components ie those (hopefully) headwind components only?
This is particularly in relation to light aircraft.
Thanks TIM
I've read about a number of different additions including half max gust strength (is that the whole gust strength or just the additional"gust" above the steady wind ?). Alternatively steady state wind plus "Gust Factor". Are the winds those reported or their resolved components ie those (hopefully) headwind components only?
This is particularly in relation to light aircraft.
Thanks TIM
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In a light aircraft the 1.3Vs is all that is required, far too much is made of approach speed by those who want to make themselfs feel important by turning flying into a black art.
Far too many short runways have holes in hedges at the ends made by people who have added a few Knots for this and a few knots for that to the approach speed resulting in an approach speed that looks like the Vref for an airliner.
Next time someone starts this adding speed to what is in the flight manual tell him he is being TFC and remind them that the extra speed blows holes in the flight manual landing distance.
Far too many short runways have holes in hedges at the ends made by people who have added a few Knots for this and a few knots for that to the approach speed resulting in an approach speed that looks like the Vref for an airliner.
Next time someone starts this adding speed to what is in the flight manual tell him he is being TFC and remind them that the extra speed blows holes in the flight manual landing distance.
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It also blows holes in the flight manual performance to stall into the near hedge, makes a complete mockery of the ldr, reduces it something chronic.
Half the gust factor added to 1.3 vs, perfectly acceptable practice.
Half the gust factor added to 1.3 vs, perfectly acceptable practice.
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In a light aircraft the 1.3Vs is all that is required, far too much is made of approach speed by those who want to make themselfs feel important by turning flying into a black art.
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It will sound like a harsh rebuke of the question, which I don't intend, but;
Where the choice is being made to fly an actual airplane, as opposed to a numbers based simulator, enjoy flying the plane, and practicing with greater precision and skill each time! Feel the plane. It will tell you what the optimum speed will be on final based upon the conditions. Not to suggest that there are not occasions where a slight increase in approach speed might be warranted, but generally, it should not be needed. Aircraft have lots of control.
Adding speed will just mean that you will be displacing your touchdown point further down the runway. If you have the space, or that is what you intend, great. If you are planning to touch down in the touch down area of the runway, then approach at the approach speed published by the aircraft manufacturer, or 1.3Vs1.
If the conditions are so gusty that this speed leaves you feeling not confident, then increasing your speed will probably just take you to a place to feel less confident, a little further away! If things are that bad, perhaps landing somewhere else is a better idea.
Under suitably skilled supervision, fly a few circuits with no airspeed information presented to you (pretend a failed ASI) You'll find that once you learn to feel the plane, you'll actually fly your approaches a little slower than the book speed, and feel quite fine about it.
Where the choice is being made to fly an actual airplane, as opposed to a numbers based simulator, enjoy flying the plane, and practicing with greater precision and skill each time! Feel the plane. It will tell you what the optimum speed will be on final based upon the conditions. Not to suggest that there are not occasions where a slight increase in approach speed might be warranted, but generally, it should not be needed. Aircraft have lots of control.
Adding speed will just mean that you will be displacing your touchdown point further down the runway. If you have the space, or that is what you intend, great. If you are planning to touch down in the touch down area of the runway, then approach at the approach speed published by the aircraft manufacturer, or 1.3Vs1.
If the conditions are so gusty that this speed leaves you feeling not confident, then increasing your speed will probably just take you to a place to feel less confident, a little further away! If things are that bad, perhaps landing somewhere else is a better idea.
Under suitably skilled supervision, fly a few circuits with no airspeed information presented to you (pretend a failed ASI) You'll find that once you learn to feel the plane, you'll actually fly your approaches a little slower than the book speed, and feel quite fine about it.
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In a light aircraft the 1.3Vs is all that is required, far too much is made of approach speed by those who want to make themselfs feel important by turning flying into a black art.
While I agree the effects of inertia are far less on a light aircraft, why should you not safeguard yourself against such an event by a moderate increase in airspeed?
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I still dabble around at teaching advanced flight skills and here is what I prefer to using the airspeed indicator as my safe speed profile.
Alpha System Lift Reserve Indicator
Alpha System Lift Reserve Indicator
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--Feeling the force, improving awareness of the plane is all admirable and should be practised but I'm not sure how that helps when you need a buffer in gusty conditions. My understanding is that it is done by pilots repeatedly testing "buoyancy" levels through the response to small inputs and is a problem for FBW to replicate; but with gust induced windshear I suspect reaction times are such that you could easily overstep the mark.
--Alpha indicators good idea only instrument on the Wright Flyer. However if the variation in aircraft weight is minimal I suspect the ASI is as good in which case it's the same question asked a different way. What airspeed would you target as opposed to what AOA would you target?
--Like other posters I am not looking at endless additions just ideas on altering approach speed / AOA to leave exceptable safety margins in gusty conditions. Safe so as not to stall out on approach nor to overshoot the end due to excess energy.
TIM
--Alpha indicators good idea only instrument on the Wright Flyer. However if the variation in aircraft weight is minimal I suspect the ASI is as good in which case it's the same question asked a different way. What airspeed would you target as opposed to what AOA would you target?
--Like other posters I am not looking at endless additions just ideas on altering approach speed / AOA to leave exceptable safety margins in gusty conditions. Safe so as not to stall out on approach nor to overshoot the end due to excess energy.
TIM
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Do what you like on thousands of yards of tarmac BUT try some additions to approach speed into a short strip and be quick to execute a go around or else find the far hedge. Get your speed right on the approach and make sure your approach is long enough to get it right. Oh and of course make sure you are familiar with the aircraft you are flying.
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If you're doing a homebuild/permit aircraft and get the Dynon EFIS with the AoA pitot head, you've got the same system. It measures AoA through a pressure differential between two ports placed at a different angle. Not very much unlike your ASI, which measures a pressure differential too.
If you're not making much over-the -ground speed, you're unlikely to hit the far hedge. You're likely to lose a lot of airspeed with windshear. Know your strip as well as your plane. 20+ knots wind along the runway has a big effect on landing and take-off distance for light aircraft. Trees etc will produce turbulence and downdraft.
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I have been spending some time at my local licensed airfield drinking tea and watching the landings. I would say that a lot of the approaches are much too fast, so adding even more speed would be a really bad idea. I was talking to one pilot after who was saying he had been told to approach at 75kn. I used to own an identical aircraft and the correct speed was 65kn. Why keep adding more and more speed?
Rod1
Rod1
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If you're not making much over-the -ground speed, you're unlikely to hit the far hedge
Damned sure i'd rather go through the far hedge at 20 knots than the near one vertically and just under VS.
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one dot right
I have flown with the Airbus "groundspeed mini" and dont like it, I would rather fly the Boeing way but these are aircraft with far more inerta to overcome and GS mini is not relivent to light aircraft with no next to inerta.
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Chuck: Some seriously good advice on your link under Mountain Flying. Alpha System Lift Reserve Indicator
I will have the vertical led light projected on the windshield so it will be right in the line of vision during the approach.
If using an AOA indicator is good enough for carrier landing it should be good for any other airplane.
With the led light AOA indicator the target is the blue light which is optimum Alfa.
As to wind gusts yes there are circumstances where carrying extra airspeed is an added safety margin....but if it becomes necessary to add speed not only above optimum Alfa but also above 1.3 of stall you won't be doing a very short landing.