Jammed Controls - Instances?
I can recall two from the UK's AAIB reports over the years, but can't find the actual reports after a quick search through the bulletins - if my memory is incorrect, pease correct me 
One a Westland Scout where the pilot noticed a rearwards cyclic restriction, assumed hydraulic failure, ended up in a diver training lake, occupants wet but otherwise unharmed. Turned out it was a map in the passenger's lap causing the restriction.
Two - a Gazelle with the front pax seat straps not properly secured, the substantial buckle fell forward, restricting aft cyclic in the hover. Crashed, no injuries IIRC.
One a Westland Scout where the pilot noticed a rearwards cyclic restriction, assumed hydraulic failure, ended up in a diver training lake, occupants wet but otherwise unharmed. Turned out it was a map in the passenger's lap causing the restriction.
Two - a Gazelle with the front pax seat straps not properly secured, the substantial buckle fell forward, restricting aft cyclic in the hover. Crashed, no injuries IIRC.
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I wasn't in the aircraft but back in the mid nineties one of our Sea Kings was getting fuel on a Nimitz class US carrier. When they lifted off to depart they moved off over the side, lost ground effect and when they pulled more power the collective jammed. So, they disappear over the side of the carrier and the air boss hits the crash alarm...
the Navigator jumps out of his seat behind the pilots and finds the problem. It was common for us to hang our helmet bags on the opposite pilot seat so we could retrieve various bits in flight. The copilot had his flight publications in his bag and one thick but small book had jammed between the collective and the seat.
Happily it is a long way down from the deck of a carrier. You can imagine the message traffic...LOL oops.
the Navigator jumps out of his seat behind the pilots and finds the problem. It was common for us to hang our helmet bags on the opposite pilot seat so we could retrieve various bits in flight. The copilot had his flight publications in his bag and one thick but small book had jammed between the collective and the seat.
Happily it is a long way down from the deck of a carrier. You can imagine the message traffic...LOL oops.
A simple one after all those dit’s!
The BK117 has a pair of sliding yaw pedals, and when flying with the duals removed a cover over them becomes a footrest for the front seat passenger.
Cue a long day out to fire lines with a full load of VIPs, pre start a quick push check for full and free on the pedals showed a marked lack of movement. Needless to say the apprentice had been given the job of installing the cover and not moved the pedals along their bars to the furthest forward position, hence they were nicely jammed against the inside of the cover.
Good start to the day, easily fixed and on our way
Re the earlier query about control movement check with engine running: the Sea King has an accessory drive which bypasses the MGB and gives hydraulic and AC power with stationary rotors, so a full and free after spreading the blades is/was part of the start checks. I imagine that other Sikorsky products would have something similar?
The BK117 has a pair of sliding yaw pedals, and when flying with the duals removed a cover over them becomes a footrest for the front seat passenger.
Cue a long day out to fire lines with a full load of VIPs, pre start a quick push check for full and free on the pedals showed a marked lack of movement. Needless to say the apprentice had been given the job of installing the cover and not moved the pedals along their bars to the furthest forward position, hence they were nicely jammed against the inside of the cover.
Good start to the day, easily fixed and on our way
Re the earlier query about control movement check with engine running: the Sea King has an accessory drive which bypasses the MGB and gives hydraulic and AC power with stationary rotors, so a full and free after spreading the blades is/was part of the start checks. I imagine that other Sikorsky products would have something similar?
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S61 engaged in vertical reference operation in 200' hover.
Aircraft began short sharp vertical jumps -R/H pilot suspects coll. bounce but collective was immobile - friction not needed.
L/H Pic says controls are siezed.
Primary and auxiliary hydraulic caution lights begin flashing - both hyd. press. guages show very rapid on/off indications.
R/H pilot selects pri.hyd. switch off - controls still siezed - pri.hyd. selected back on and aux. hyd. switched off.
Aircraft stops vertical jumps and controls are operational again.
Aircraft returned to landing barge - artificial horizon(eyeball) was seen to be spinning very fast during return flight.
Suspected cause - rapid erroneous AFCS inputs overpowered hyd. systems.
Aircraft began short sharp vertical jumps -R/H pilot suspects coll. bounce but collective was immobile - friction not needed.
L/H Pic says controls are siezed.
Primary and auxiliary hydraulic caution lights begin flashing - both hyd. press. guages show very rapid on/off indications.
R/H pilot selects pri.hyd. switch off - controls still siezed - pri.hyd. selected back on and aux. hyd. switched off.
Aircraft stops vertical jumps and controls are operational again.
Aircraft returned to landing barge - artificial horizon(eyeball) was seen to be spinning very fast during return flight.
Suspected cause - rapid erroneous AFCS inputs overpowered hyd. systems.
I don't want to hijack this thread, however, this can not go unchallenged. As an AS350 instructor since 1995, having performed literally countless AS350 aircraft and simulator stuck pedals, I find your statement inconceivable. But certainly, don't take my word for it:
etc...
Note: the official Airbus Helicopter’s video (first one) demonstrates a condition where the linkage between the pedals and T/R has been severed. The pedals are free to move, however, the T/R is in a “fixed pitch” position.
LAX07IA115
Last edited by JimEli; 15th Jun 2020 at 23:26. Reason: added video explanation
S61 engaged in vertical reference operation in 200' hover.
Aircraft began short sharp vertical jumps -R/H pilot suspects coll. bounce but collective was immobile - friction not needed.
L/H Pic says controls are siezed.
Primary and auxiliary hydraulic caution lights begin flashing - both hyd. press. guages show very rapid on/off indications.
R/H pilot selects pri.hyd. switch off - controls still siezed - pri.hyd. selected back on and aux. hyd. switched off.
Aircraft stops vertical jumps and controls are operational again.
Aircraft returned to landing barge - artificial horizon(eyeball) was seen to be spinning very fast during return flight.
Suspected cause - rapid erroneous AFCS inputs overpowered hyd. systems.
Aircraft began short sharp vertical jumps -R/H pilot suspects coll. bounce but collective was immobile - friction not needed.
L/H Pic says controls are siezed.
Primary and auxiliary hydraulic caution lights begin flashing - both hyd. press. guages show very rapid on/off indications.
R/H pilot selects pri.hyd. switch off - controls still siezed - pri.hyd. selected back on and aux. hyd. switched off.
Aircraft stops vertical jumps and controls are operational again.
Aircraft returned to landing barge - artificial horizon(eyeball) was seen to be spinning very fast during return flight.
Suspected cause - rapid erroneous AFCS inputs overpowered hyd. systems.
Hughes 500 stiff yaw controls. During avionics installation they tyrapped the aerial cable to the underfloor control rod!!!
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Wessex in NI going into a field on goggles, my Browning 9mm fell out of my (legal) shoulder holster and jammed between the seat and the collective. Between 500 and 100 feet not detected but when chap in the right hand seat started to pull collective at the bottom, total restriction apparent. Naturally in accordance with our training the handling pilot calmly announced, 'Captain to crew, control restriction'. His unfortunate speech impediment made it sound more like, 'F@cking hell, the collective's stuck!'. I slapped my left tit with my right hand to discover a missing gat but managed to locate the bowden cable and gave it a jolly good tug. Luckily it freed and we were going to hit the ground anyway so it was just a question of how hard. I'm sure we pulled more than the cheeky 14,000 but who was looking at the torque gauge at that point?
Got away with it and reported it to the boss. No more James Bond shoulder holsters after that. I suppose that even with approved and properly used kit, loose articles can and will occur.
Got away with it and reported it to the boss. No more James Bond shoulder holsters after that. I suppose that even with approved and properly used kit, loose articles can and will occur.
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Pootling along in the South West of England in a Wessex 5 when the rudder pedals locked. I disengaged the ASE but no change. I thought about switching off the hydraulics in turn but thought, no. I did a straight in approach to St Mawgan and ran on at around 80 knots, turned off the runway into dispersal using brakes and shut down on the run in. Re-started - problem gone...............never did find out what happened.
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Words that convey a sense of going somewhere with no particular sense of urgency or direction. I'll start:
Pootling
Bimbling
Arbing (as in abitrary)
Bowling
Mozeying
Er, that's all I have.
Pootling
Bimbling
Arbing (as in abitrary)
Bowling
Mozeying
Er, that's all I have.
For those that operate Transport Category machinery -
I think it must be a recent thing as some older designs might struggle with that one.
FAR Part 29.671 General
(c) A means must be provided to allow full control movement of all primary flight controls prior to flight, or a means must be provided that will allow the pilot to determine that full control authority is available prior to flight.
(c) A means must be provided to allow full control movement of all primary flight controls prior to flight, or a means must be provided that will allow the pilot to determine that full control authority is available prior to flight.
Collective friction seizing in an S61 has occurred more than once, and lead Bristow to install a pip pin in a modified friction strut, so it could be pulled rapidly in the event of seizure. The incident leading to this change had supposedly been resolved using the saw blade on a Swiss army knife in true Macgyver fashion to sever the strut. Of course there is always the instances of the S61 flying off with the tail rotor gust lock still installed as well. And one of my friends experienced an alarming incident when the cyclic on his jetranger snapped off at the socket as he was starting it up one day, which probably would be classified as a total loss of control!
Well, not really jammed but two instances I experienced myself.
First solo on Gazelle ;-)
Took off and set forced trim for acceleration. And then I had a problem.
Radioed my instructor and did a short circuit to land.
By the time he got to me and jumped in my muscles already ached.
I warned him - and he was still surprised about the forward force, when he said:"I have control"
We flew back from the training to the main airfield, changing control in-between.
Back at base a technician came out, had a short look and pressed a circuit breaker back in......
Second incident - on BK117.
We had to change helicopters.
When I jumped in as Co-Pilot in the already running return helicopter I used a well trained technique,
moving my right feet over the seat. (I have fairly great shoes, so its safer than fideling it between stick and seat)
I went through the pre take off checks and shortly after take off, I said to the pilot - we have to go back.
He looked with a big question mark on his face and his eyes followed my finger, pointing to the stick - still - he didn´t caught it at first.
Then he saw it as well - the stick was installed front to back - the notch/bend in the stick, through which you can fidel your foot to get in - pointed backwards toward the seat.
Imagine, the seat not totally back - and flying solo - that would have restricted the movement.
as always PPPPPP (proper preflight prevents piss poor performance) ;-)
First solo on Gazelle ;-)
Took off and set forced trim for acceleration. And then I had a problem.
Radioed my instructor and did a short circuit to land.
By the time he got to me and jumped in my muscles already ached.
I warned him - and he was still surprised about the forward force, when he said:"I have control"
We flew back from the training to the main airfield, changing control in-between.
Back at base a technician came out, had a short look and pressed a circuit breaker back in......
Second incident - on BK117.
We had to change helicopters.
When I jumped in as Co-Pilot in the already running return helicopter I used a well trained technique,
moving my right feet over the seat. (I have fairly great shoes, so its safer than fideling it between stick and seat)
I went through the pre take off checks and shortly after take off, I said to the pilot - we have to go back.
He looked with a big question mark on his face and his eyes followed my finger, pointing to the stick - still - he didn´t caught it at first.
Then he saw it as well - the stick was installed front to back - the notch/bend in the stick, through which you can fidel your foot to get in - pointed backwards toward the seat.
Imagine, the seat not totally back - and flying solo - that would have restricted the movement.
as always PPPPPP (proper preflight prevents piss poor performance) ;-)