poteroo Posted January 2, 2015 Posted January 2, 2015 Just a technical question, would the sudden attempt of opening the door by the photographer at very slow speed (to get a better shot) create a stall condition with the airflow disturbance (obviously already flying at a slow speed)? If the aircraft has a 'door off approval' - then there is a constant,small degradation of performance - which is increased by any out-of-balance flying. In a lightly loaded C172, this isn't any particular concern. It's more usual to remove the window limit strut screw, and allow the RH window to float up against the bottom of the wing. At around 70KIAS, it holds up there quite steadily - allowing your photographer to shoot into clear air without any noticeable degradation in performance of the aircraft. Right hand turns are actually safer as the extra power which should be used in any slow, low level turn does not roll the aircraft into the turn - rather, it tends to roll it level. So the nose drop effect you encounter in a powered left turn is quite dangerous - but RH turns are 'safer'. These power effects are more marked with increased HP engines, eg, the 230HP in C182's. Pre-emptive power use and in balance flying are essentials for safer LL flight. You'll be taught these in any good course. happy days, 2 2
bexrbetter Posted January 2, 2015 Posted January 2, 2015 not normally, as these aircraft fly well with no rear door, or custom photography door. If the aircraft has a 'door off approval' - Sorry, out of habit I write my posts in Chinese sometimes, I'll try it in English this time ... "... would the sudden attempt of opening the door by the photographer ..." 1
Happyflyer Posted January 2, 2015 Posted January 2, 2015 Bexrbetter, sudden opening of the door would of course cause more drag but would not of itself cause a stall unless the angle of attack is increased. However opening the door would be hard and achieve nothing, the best shot is with the window up as stated earlier. To get a better shot photographers will ask the pilot to raise the wing in a turn, so some shots are taken by flying out of balance to have a higher wing, if you then stall you may be in a bit of strife. 1
turboplanner Posted January 2, 2015 Posted January 2, 2015 Good words HITC, I do some photography for Planning purposes, hiring a 172 and a pilot, some at 500 feet. My instructions to the pilot is that he is totally controlling the aircraft including Navigation, altitudes/levels etc, not me,and max turns are rate 1 regardless. I get him to fly an offset track, and fly past the shot. If I miss the shot, bad luck, we fly another pattern. Over time the system has become so predictable I rarely miss a shot. 1
kaz3g Posted January 2, 2015 Posted January 2, 2015 I did some unpaid flying 30 years ago for my university. They wanted an aerial pictology of a fuel reduction burn at the Healesville Sanctuary. I used a C172 with door off (allowed in the FM) and had the photographer with movie camera in the back seat. I was circling over the fire, orbiting the convection column, when I realised he was just behind me. He had undone his seat belt and was kneeling in the starboard doorway!!! I remember banking savagely to port and he literally fell inside again. Some very cross words ensued. I don't remember any degradation in performance but I do remember degradation in my hearing. In those days we didn't have headsets and just used a microphone hanging under the instrument panel with a loudspeaker beside it. The increased engine noise with the door off was huge. Now we have ANR and other good things but the damage is already done... Kaz
bexrbetter Posted January 2, 2015 Posted January 2, 2015 Bexrbetter, sudden opening of the door would of course cause more drag Thanks for the replies. Wasn't drag I was referring to, loss of lift as the airflow under the wing is disturbed and reduced.
rankamateur Posted January 2, 2015 Posted January 2, 2015 Now we have ANR and other good things but the damage is already done...Kaz What did you say?
Head in the clouds Posted January 2, 2015 Posted January 2, 2015 What did you say? KAZ SAID THE DAMAGE IS ALREADY DONE ... 1
Happyflyer Posted January 2, 2015 Posted January 2, 2015 Thanks for the replies.Wasn't drag I was referring to, loss of lift as the airflow under the wing is disturbed and reduced. I see what you mean but just try and open the door at 70 / 80 knots and see how far you get, let alone try for a photo. Stall is caused by separation of the airflow from the top of the wing.
facthunter Posted January 3, 2015 Posted January 3, 2015 I don't think the door could be pushed open against the airflow very far. It wouldn't be as bad as having a couple of parachutists hanging out the door opening where a fair bit of rudder is needed, and you are usually flying close to stall at the drop with little power on. A few years ago at Lake Boga VIC, I watched a C-172 doing powerline inspections at a height higher than this one but not much. I commented to my wife I considered the operation not safe the way it was happening. I think next day the same plane crashed and the pilot was killed. I also did a search for a missing fisherman near Caves beach in rough conditions in a 172 at very low height It's critical flying and no room to have your attention distracted even momentarily even though a 172 is pretty docile, it doesn't take much to be all over. Nev
motzartmerv Posted January 3, 2015 Posted January 3, 2015 Classic Moose stall it seems. Sad, and preventable.
alf jessup Posted January 3, 2015 Posted January 3, 2015 I'd call it a death stall, that's what the end result was
djpacro Posted January 3, 2015 Posted January 3, 2015 Classic Moose stall it seems. Maybe but the classic moose stall requires a 360 deg turn. Some types are prone to this in specific flap/power combinations where flying through their own wake the horizontal tail stalls resulting in a violent nose down pitch. 1
rankamateur Posted January 3, 2015 Posted January 3, 2015 Is that what happened to this one? http://www.courts.qld.gov.au/__data/assets/pdf_file/0011/296435/cif-sweetnam-g-mitchell-a-20141015.pdf "the aircraft conducted one 360 degree flat turn, which took approximately 26 seconds. Shortly afterwards, a rapid reduction in height without a build up of speed occurred."
motzartmerv Posted January 3, 2015 Posted January 3, 2015 Maybe but the classic moose stall requires a 360 deg turn. Some types are prone to this in specific flap/power combinations where flying through their own wake the horizontal tail stalls resulting in a violent nose down pitch. Sorry Dave, maybe I'm confused. I was talking about this type of moose stall. http://generalaviationnews.com/2013/06/30/beware-the-moose-spiral/ The classic low, slow, looking back in a turn.. In Alaska it happens so much while guys are looking at wildlife they named it a ' moose spiral. Or moose stall'
poteroo Posted January 3, 2015 Posted January 3, 2015 Is that what happened to this one? http://www.courts.qld.gov.au/__data/assets/pdf_file/0011/296435/cif-sweetnam-g-mitchell-a-20141015.pdf"the aircraft conducted one 360 degree flat turn, which took approximately 26 seconds. Shortly afterwards, a rapid reduction in height without a build up of speed occurred."[/QUOTed Sorry Dave, maybe I'm confused. I was talking about this type of moose stall.http://generalaviationnews.com/2013/06/30/beware-the-moose-spiral/ The classic low, slow, looking back in a turn.. In Alaska it happens so much while guys are looking at wildlife they named it a ' moose spiral. Or moose stall' What we call a 'mustering stall' is the same as the 'moose stall' It happens when the aircraft is turning steeply and slowly around a fixed point, (more often in wind), and where the pilot is asked to 'lift your wing' so that the pax or cameraman can see the target. In nil wind - it's easy to fly a constant angle-of-bank turn, and remain in position over the target. In a high wing, this keeps the target 'under' the wing, and provide the aob and balance remain constant - it's as safe as you can make it. However, once a pilot applies 'top' rudder to yaw the aircraft enough to lift the inside wing - then the IAS decreases rapidly, and if the aircraft stalls, it rolls 'up' and out of the turn into a spin. The nose drops alarmingly and recovery requires a lot of clear air! The opposite of the 'mustering' or 'moose' stall is where the rudder is applied excessively in a turn, causing the aircraft to stall in a 'skidding turn, then spin 'under' or into the turn. This is more likely where the pilot is trying to increase the rate of turn, (usually base-to-final). It can occur during low level ops but is far more likely if the aircraft is being manoeuvred around a point in winds of 15-30 kts and the pilot has not the skill to fly a varying angle-of-bank turn to keep the cameraman with a constant view of the target. If you are very low, the spin can't develop further than the nose dropping rapidly 'into' the turn. This doesn't always happen - it's entirely possible a pilot can just allow the nose to fall into a left hand turn as power is applied - and in a split second the aircraft impacts nose and left wingtip. Aircraft not stalled or spun - just 'uncontrolled descent' into the water. Low level manoeuvring around a ground target is incredibly dangerous unless the pilot can fly variable a-o-b turns in gusty, windy weather, and never have the stall warning squark once. It requires very good power and balance co-ordination, and is something which needs to be practised often. A 30 min session at 150-200 ft, x 60-70 KIAS doing 30-45 aob turns - in wind - is essential every 2 months or so. LL endorseed pilots still need to practise. The endo is not a skill that serves you longer than 6 months really. 1 1 10
djpacro Posted January 3, 2015 Posted January 3, 2015 Perhaps I am using a too narrow a definition (maybe from my limited focus and out of date. Still, what I said about the characteristic of some types is true.
Guest ozzie Posted January 3, 2015 Posted January 3, 2015 Door off, a wind deflector is usually called for. Simple device that fits into the hinge fittings, stops buffet in the aircraft and lessons the risk of CO2 poisoning. maybe a good argument for the use of drones now.
poteroo Posted January 4, 2015 Posted January 4, 2015 a wind deflector is usually called for. Simple device that fits into the hinge fittings, stops buffet in the aircraft and lessons the risk of CO2 poisoning They help, but cannot prevent a ham-footed pilot creating a buffet in the cabin by flying out of balance. Never heard of the CO issue - but as I always fly with full fresh airflow directed towards me - probably avoided it. Have never heard of a CO detector card indicating the presence of CO in any Cessna cabin, ever. Might be an issue in cold climates where heaters are left on full chat all flight? BTW, CO is the bad stuff. CO2 is the good stuff that makes plants grow faster than Canberras' debt! cheers,
facthunter Posted January 4, 2015 Posted January 4, 2015 Buffet in any Cessna I've flown with the door off can be stopped by just placing one finger half out of the opening at the front. Volkswagens used to do it with the windows down. Nev
Guest ozzie Posted January 5, 2015 Posted January 5, 2015 Hundreds of jumps in Cessnas with door off. Approval in POH calls for deflector. We hired a "nice" 182 once, ripped the door off and seats out but left the carpet in, no deflector, the air just swirled in and after we got out the pilot had to fight with the carpet to stop it going out the door. Not to mention the freezing cold winter air on the 30 minute flight to the demo. Exhaust is just in front of the door nice burnt avgas smell when you power off and start to climb out. Vivid memories of my first jump right on sunset hanging on the strut watching flame popping out the exhaust and the smell. CO2 warning was from the old DOT days. Nowadays we have in flight doors. Major will have some good old days yarns of no door cessnas.
Rotorwork Posted January 6, 2015 Posted January 6, 2015 Update from ABC Video of the Aircraft being loaded onto the Barge Kulanda, The wreckage is now being transported to Hobart. http://www.abc.net.au/news/2015-01-06/police-begin-second-attempt-to-recover-plane-crash-bodies/6002060 The wreckage of a light plane that crashed into waters off Tasmania's south-east more than a week ago has been retrieved. The Cessna 172, which nose-dived into the sea near Cape Raoul on December 29, has been winched onto a barge that is now returning to Hobart. The bodies of pilot Sam Langford, 29, and photographer Tim Jones, 61, are still inside the wreckage. Police said forensics officers would recover the bodies from the wreckage. After crashing, the plane settled upside down on the seabed under 90 metres of water, which was beyond the operating depth of police divers. Last Wednesday an underwater remotely operated vehicle (ROV) was used to thread rope around the plane's landing gear. But after the plane was winched to a depth of 15 metres the rope snapped and it returned to the sea floor. Calm conditions this morning allowed a second recovery attempt and the ROV was again used to attach a winching line. The plane was capturing photographs of yachts racing in the Sydney to Hobart Yacht Race when it went down. A number of yachts diverted from the race to offer assistance after seeing the plane go down. The crash is being investigated by the Australian Transport Safety Bureau.
David Isaac Posted January 6, 2015 Posted January 6, 2015 Very sad and unnecessary. Steve, it is CO (carbon Monoxide), not CO2 (carbon Dioxide). 1
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