Too high on final
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Worth considering a check in POH about prolonged slips when fuel tanks are less than ¼ full. This is certainly true of my low wing PA23.
Stabilised approaches tend to lead to stable landings – no issues about throwing a landing away if you are staring at 4 whites but the trick is to use one’s superior judgement to avoid using one’s superior skills etc
My colleague at work used to drive 737’s for BMI and recalls as a very green FO – he ended up with a hot and high approach at Glasgow: quite properly instigated a missed approach but had the obligatory tea and biscuits talk afterwards (see judgement/skills ratio above)
Stabilised approaches tend to lead to stable landings – no issues about throwing a landing away if you are staring at 4 whites but the trick is to use one’s superior judgement to avoid using one’s superior skills etc
My colleague at work used to drive 737’s for BMI and recalls as a very green FO – he ended up with a hot and high approach at Glasgow: quite properly instigated a missed approach but had the obligatory tea and biscuits talk afterwards (see judgement/skills ratio above)
Last edited by UL730; 23rd Jul 2012 at 09:15.
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There are plenty of ways of getting down in a hurry, but you need to be proficient to do it safely due to close proximity of the granite! One other method is to get on the back of the drag curve....I.e. slow right up, so you are just above stall. This causes a lot of drag and lower forward speed so you get quite a steep angle of decent with low airspeed.
I would stress this is advanced stuff and to do it safely you need to know your aeroplane 100% and be 100% sure of your abilities, but you could always ask your FI to show you.
I would stress this is advanced stuff and to do it safely you need to know your aeroplane 100% and be 100% sure of your abilities, but you could always ask your FI to show you.
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1 does not work, and is working of a flawed assumption..
Pushing down may seem tempting but think about it..lowering the nose == lower angle of attack == less lift == less drag and much more speed!! These are all the things you dont want when trying to land, basically be prepared for a float /balloon fest.
Coversley however pitching the nose up == higher nose = nailing approach speed == higher aoa = more drag = steeper decent.
If im not coming down quick enough, I make sure I have the nose not down, but up!
Pushing down may seem tempting but think about it..lowering the nose == lower angle of attack == less lift == less drag and much more speed!! These are all the things you dont want when trying to land, basically be prepared for a float /balloon fest.
Coversley however pitching the nose up == higher nose = nailing approach speed == higher aoa = more drag = steeper decent.
If im not coming down quick enough, I make sure I have the nose not down, but up!
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Chipmeister, have you forgotten about parasite drag? It doesn't vary with the AoA, but increases exponentially with your airspeed. And flaps are an incredible effective device to create parasite drag. That drag is what gets rid of the excess energy, not the induced drag from creating lift.
Of course your airspeed will increase so you will need to aim well short of the runway and do the two-stage flare to get rid of the excess airspeed. But this method will get you down steeply without becoming another stall/spin statistic.
Of course your airspeed will increase so you will need to aim well short of the runway and do the two-stage flare to get rid of the excess airspeed. But this method will get you down steeply without becoming another stall/spin statistic.
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Pushing down may seem tempting but think about it..lowering the nose == lower angle of attack == less lift == less drag and much more speed!! These are all the things you dont want when trying to land, basically be prepared for a float /balloon fest.
In real life, however, in a 152 or 172 with full flap you can shove the nose down quite a long way and you get lower but you don't get much faster, in particular it's dead easy to get a lot lower with no significant risk of getting faster than the flap limiting speed.
There has been considerable discussion as to whether or not this results in a pretty approach (and I would agree that it doesn't), but nobody who has tried it in those particular aircraft is claiming that it doesn't work. Because it does.
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Just a caution with regard to slipping, it stresses the vertical stabilizer and in particular the fixings that hold it in place.
In an emergency, it's a good option, but do you really want to do it regularly?
In an emergency, it's a good option, but do you really want to do it regularly?
Last edited by Final 3 Greens; 23rd Jul 2012 at 20:54. Reason: Clean up
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Could we please have some faith in the design of certified aircraft?
Yes, I slip regularly, and to full pedal deflection. I keep it slower than Va though...
We who certifiy aircraft designs, and write flight manuals, carefully confirm that the design requirements have been shown, and with adequate margin for careless piloting technique, and consider what needs to be written in the flight manual. If there is no warning about maneuvering, keep the plane within the stated limitations, prevent it from stalling, fly within your skill set, and slip it all you want. That's what it was designed for!
The prevailing design requirement reads: (my bold)
Sec. 23.441
Maneuvering loads.
(a) At speeds up to VA, the vertical tail surfaces must be designed to withstand-
(1) A sudden displacement of the rudder control (with the airplane in unaccelerated flight with zero yaw) to the maximum deflection allowed by the control stops or by pilot strength, whichever is critical;
(2) A yaw angle of 15 degrees with the rudder fully deflected (except as limited by pilot strength) in the direction tending to increase the slip; and
(3) A yaw angle of 15 degrees with the rudder control maintained in the neutral position (except as limited by pilot strength).
(b) The average loading of B23.11 and figure 1 of Appendix B and the distribution in figures 7, 6, and 8 of Appendix B may be used instead of the requirements of subparagraphs (a)(1), (a)(2), and (a)(3), respectively.
(c) The yaw angles specified in paragraph (a)(3) of this section may be reduced if the yaw angle chosen for a particular speed cannot be exceeded in--
(1) Steady slip conditions;
(2) Uncoordinated rolls from steep banks; or
(3) Sudden failure of the critical engine with delayed corrective action.
it stresses the vertical stabilizer and in particular the fixings that hold it in place. In an emergency, it's a good option, but do you really want to do it regularly?
We who certifiy aircraft designs, and write flight manuals, carefully confirm that the design requirements have been shown, and with adequate margin for careless piloting technique, and consider what needs to be written in the flight manual. If there is no warning about maneuvering, keep the plane within the stated limitations, prevent it from stalling, fly within your skill set, and slip it all you want. That's what it was designed for!
The prevailing design requirement reads: (my bold)
Sec. 23.441
Maneuvering loads.
(a) At speeds up to VA, the vertical tail surfaces must be designed to withstand-
(1) A sudden displacement of the rudder control (with the airplane in unaccelerated flight with zero yaw) to the maximum deflection allowed by the control stops or by pilot strength, whichever is critical;
(2) A yaw angle of 15 degrees with the rudder fully deflected (except as limited by pilot strength) in the direction tending to increase the slip; and
(3) A yaw angle of 15 degrees with the rudder control maintained in the neutral position (except as limited by pilot strength).
(b) The average loading of B23.11 and figure 1 of Appendix B and the distribution in figures 7, 6, and 8 of Appendix B may be used instead of the requirements of subparagraphs (a)(1), (a)(2), and (a)(3), respectively.
(c) The yaw angles specified in paragraph (a)(3) of this section may be reduced if the yaw angle chosen for a particular speed cannot be exceeded in--
(1) Steady slip conditions;
(2) Uncoordinated rolls from steep banks; or
(3) Sudden failure of the critical engine with delayed corrective action.
Just a caution with regard to slipping, it stresses the vertical stabilizer and in particular the fixings that hold it in place
I sideslip because you can add/take off sideslip without taking a hand off the controlls - and it is used in crosswind landings.
G
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(1) A sudden displacement of the rudder control (with the airplane in unaccelerated flight with zero yaw) to the maximum deflection allowed by the control stops or by pilot strength, whichever is critical;
Maneuvering Speed and Broken Airplanes | Left Seat
Quote from the article:
What the Airbus crash taught us—or at least should have taught us—is that Va certification standards, and certification flight test results, protect the airplane from only a single control input in only one direction at a time. Any combination of control inputs that rotate the airplane around more than a single axis creates loads for which Va does not necessarily consider or test.
Flying slower than Va also only protects the airframe from moving a flight control – elevator, ailerons, or rudder – to its full travel in a single direction, not from stop to stop. So certification calculations and flight testing show that moving the ailerons fully and abruptly full left at a speed slower than Va, for example, will not break the airplane. But if the ailerons are suddenly moved fully back to the right without the airplane stabilizing in a steady attitude, Va offers no guarantee.
Flying slower than Va also only protects the airframe from moving a flight control – elevator, ailerons, or rudder – to its full travel in a single direction, not from stop to stop. So certification calculations and flight testing show that moving the ailerons fully and abruptly full left at a speed slower than Va, for example, will not break the airplane. But if the ailerons are suddenly moved fully back to the right without the airplane stabilizing in a steady attitude, Va offers no guarantee.
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Backpacker, I agree, but I would think that a sideslip entered or maintained by rudder motion from stop to stop is going really wrong already!
Though the Airbus event is a definite example of bad, it's not really relevant to GA aircraft. There are inertial forces in larger aircraft which really are not present in smaller aircraft. More simply, parts of light aircraft don't really "wag" the way they can on large ones. I am not aware of any failure of a V stab in a GA aircraft resulting from sideslipping.
If all the people who are so concerned about the security of the V stab, would assure that they do not push down on the H stab, while moving the Cessna on the apron, we'd be even better off. After all, the V stab on nearly all C 150/152's is attached to the H stab - then to the fuselage! What you do to the H stab, you do to the V stab too!
Though the Airbus event is a definite example of bad, it's not really relevant to GA aircraft. There are inertial forces in larger aircraft which really are not present in smaller aircraft. More simply, parts of light aircraft don't really "wag" the way they can on large ones. I am not aware of any failure of a V stab in a GA aircraft resulting from sideslipping.
If all the people who are so concerned about the security of the V stab, would assure that they do not push down on the H stab, while moving the Cessna on the apron, we'd be even better off. After all, the V stab on nearly all C 150/152's is attached to the H stab - then to the fuselage! What you do to the H stab, you do to the V stab too!
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Quote:
Originally Posted by Final 3 Greens
Just a caution with regard to slipping, it stresses the vertical stabilizer and in particular the fixings that hold it in place.
In an emergency, it's a good option, but do you really want to do it regularly?
Quite right, just as becoming airborne stresses the horizontal mainplain and tailplane, and their attachment bolts, so should also be kept to a minimum.
G
Originally Posted by Final 3 Greens
Just a caution with regard to slipping, it stresses the vertical stabilizer and in particular the fixings that hold it in place.
In an emergency, it's a good option, but do you really want to do it regularly?
Quite right, just as becoming airborne stresses the horizontal mainplain and tailplane, and their attachment bolts, so should also be kept to a minimum.
G
Moderator
Quite right, just as becoming airborne stresses the horizontal mainplain and tailplane, and their attachment bolts, so should also be kept to a minimum.
But back to the topic... Today in the Caravan, I got a big thermal while turning final = high approach. With the engine at idle, and some slip, I had to add a smidge of power before I flared.... Slipping is extra draggy in the Caravan, 'cause you get a bit of spoiler too!
