My Socata Wants to Kill Me!
I must confess that it is a long time since I last flew any of this series of aircraft but there was a time when I flew them regularly including instructing on them. From memory I wouldn't expect the slats to deploy much above 55 kts, certainly not when turning onto final at speeds close to 70 kts, why would they need to. The aircraft ASI should be checked in the first instance in my view. An over reading ASI is not uncommon.
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I must confess that it is a long time since I last flew any of this series of aircraft but there was a time when I flew them regularly including instructing on them. From memory I wouldn't expect the slats to deploy much above 55 kts, certainly not when turning onto final at speeds close to 70 kts, why would they need to. The aircraft ASI should be checked in the first instance in my view. An over reading ASI is not uncommon.
Best,
SSS
Can you reproduce the behaviour at a safe altitude?
If so, can you rig a pair of cameras, such as GoPros to see what the slats on each wing are doing, as per the video in an earlier post?
If the cameras don't have audio you would need a synchronising signal to align the two videos in time such as a simple camera flash illuminating the cockpit interior fired off before and after the events you're interested in.
This way you can determine whether there is any uneven movement or, more importantly, asymmetrical operation of the slats.
If you're really keen, you could film either the cockpit controls or the rudder (ailerons already being in view of a camera filming the slats) to check for unconsious/inadvertant control inputs. Mind you, I'm not sure where you would put a camera to see the rudder from a Socata cockpit!
Obviously if you can assess the slat synchronisation visually, without cameras, do that first!
If so, can you rig a pair of cameras, such as GoPros to see what the slats on each wing are doing, as per the video in an earlier post?
If the cameras don't have audio you would need a synchronising signal to align the two videos in time such as a simple camera flash illuminating the cockpit interior fired off before and after the events you're interested in.
This way you can determine whether there is any uneven movement or, more importantly, asymmetrical operation of the slats.
If you're really keen, you could film either the cockpit controls or the rudder (ailerons already being in view of a camera filming the slats) to check for unconsious/inadvertant control inputs. Mind you, I'm not sure where you would put a camera to see the rudder from a Socata cockpit!
Suggest you try going to altitude and do some straight stalls,power on and off,making sure you are balanced..Check which slats operate first,or together. Is the aircraft in trim,or are you holding a wing up...?Are the u/c fairings `square`...?Possibly got a snake in one wing,fuel balanced,etc....might be an idea to check the ASI...? make right turn only...!
Last edited by nonsense; 4th Jun 2019 at 02:36. Reason: Added quote from sycamore and following comment
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Oh, and obviously, while you are investigating this issue, DO NOT let yourself get into the same situation as before. So make sure the aircraft is fully settled in the approach configuration (slats extended, flaps extended, power properly set for flight in that envelope) before you descend below the altitude from which you can safely recover from a wing drop. If at all possible, try to avoid having to make turns once below that altitude, so try to fly a long final, traffic permitting. An ILS-like profile, where you are in the landing configuration and at a reasonable approach speed, 6 nm/2000' out, would be ideal.
I'm not sure I see the relevance of being at 2000ft and 6nm from the threshold in a Rallye. In fact, it seems like a very poor idea, as with slats out, flaps down and any sort of headwind you could be on final for about eight minutes!
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Legend has it that ace French test pilot Maurice Seree once got a Rallye to go backwards at a particularly windy Biggin Air Fair...
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They are lovely aeroplanes. You have time to watch the world go by underneath. I had a flight in one many years ago and have a mutual acquaintance with the owner of one of the older examples on the UK register - hoping for a ride, it's an old friend from my spotting and spotty school days!
Hope you sort the slats out without much bother.
Hope you sort the slats out without much bother.
They are very good aeroplanes. Rugged, good visibility, great load carriers and forgive much. Even their best friend wouldn't accuse them off being fast or light on the controls. BTW, slats extend around 110 kph. I've usually got full flap and engine to idle by then. It will probably make a slight difference to slat extension speed but I've never bothered to look. Do your own conversion to your preferred units. Then just fly enough nose up that they don't retract again until you are ready to round out. Close your eyes and pull hard. Return for the next glider while opening the canopy for a breath of air, setting flaps to half and doing whatever you need to with the fiddly bits.
maybe don't do that if it's not flying right though.....
Seriously, if it rolls into a turn at 70 knots something is very wrong. Where are you based? I fancy a bit of a cross country with the not a Cub.
maybe don't do that if it's not flying right though.....
Seriously, if it rolls into a turn at 70 knots something is very wrong. Where are you based? I fancy a bit of a cross country with the not a Cub.
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They are very good aeroplanes. Rugged, good visibility, great load carriers and forgive much. Even their best friend wouldn't accuse them off being fast or light on the controls. BTW, slats extend around 110 kph. I've usually got full flap and engine to idle by then. It will probably make a slight difference to slat extension speed but I've never bothered to look. Do your own conversion to your preferred units. Then just fly enough nose up that they don't retract again until you are ready to round out. Close your eyes and pull hard. Return for the next glider while opening the canopy for a breath of air, setting flaps to half and doing whatever you need to with the fiddly bits.
maybe don't do that if it's not flying right though.....
Seriously, if it rolls into a turn at 70 knots something is very wrong. Where are you based? I fancy a bit of a cross country with the not a Cub.
maybe don't do that if it's not flying right though.....
Seriously, if it rolls into a turn at 70 knots something is very wrong. Where are you based? I fancy a bit of a cross country with the not a Cub.
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The only way of satisfying the condition of the slats is following a full inspection of them of course. I'm not sure from what you say if the engineers have done this.
You say the slats deploy during the turn at: "less than 70 kts" what do you mean by that? The slats should not be activating at speeds around seventy knots.?
I would not expect the slats to deploy until approaching the stall. The slats are aerodynamic and activated by the angle of attack. They are a fantastic and reliable indicator of the approach to the stall. The wing drop to the left during a turn to the left is symptomatic of a stall. HAVE THE ASI CHECKED BEFORE YOU FLY AGAIN, this is quick and simple check for the engineers to perform and could save your life.
You say the slats deploy during the turn at: "less than 70 kts" what do you mean by that? The slats should not be activating at speeds around seventy knots.?
I would not expect the slats to deploy until approaching the stall. The slats are aerodynamic and activated by the angle of attack. They are a fantastic and reliable indicator of the approach to the stall. The wing drop to the left during a turn to the left is symptomatic of a stall. HAVE THE ASI CHECKED BEFORE YOU FLY AGAIN, this is quick and simple check for the engineers to perform and could save your life.
I logged lots of flight time on type, both flying and instructing, and the stall characteristics are quite benign. Nice safe draggy little airplane. Very good for short landings.
BTW, according to the flight manual, you should not turn final much under 70 kt.
The slats usually open in short final.
Not sure I can post pictures or links to the flight manual
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I would agree 100% with the above.
I logged lots of flight time on type, both flying and instructing, and the stall characteristics are quite benign. Nice safe draggy little airplane. Very good for short landings.
BTW, according to the flight manual, you should not turn final much under 70 kt.
The slats usually open in short final.
Not sure I can post pictures or links to the flight manual
I logged lots of flight time on type, both flying and instructing, and the stall characteristics are quite benign. Nice safe draggy little airplane. Very good for short landings.
BTW, according to the flight manual, you should not turn final much under 70 kt.
The slats usually open in short final.
Not sure I can post pictures or links to the flight manual
70 knots for the final turn sounds right for max weight. A bit less solo and half tanks. Should be nowhere near the stall at that, so I'm coming round to the idea of an asi problem. Though I would definitely look for something bent as well, as they are (should be) very docile at the stall. What does the attitude look like?: And is the stick close to the back stop? Hong Kong is a wee bit far to come and take a look, sorry.
