BGA Safe Winch Launching Initiative WINCHING OPERATIONS Safe
BGA Safe Winch Launching Initiative WINCHING OPERATIONS Safe Winch Launching
Review • The Safe Winching Campaign has contributed to an improved accident record since 2006 Fatal/serious injury winch accidents 6 years 2006 -2011 4 (none in 2010 or 2011) 6 years 2000 -2005 18 Average 6 year period 1976 -2005 18 Safe Winch Launching
Review • Key Winching Operations campaigns so far: – Safe cable speed – Excessive acceleration Safe Winch Launching
Review • Key Winching Operations campaigns so far: – Safe cable speed – Excessive acceleration Safe Winch Launching
Safe Cable Speed • “Maintain shallow climb until adequate speed (1. 5 Vs) with continuing acceleration” • If winch CAN’T achieve acceleration through 1. 5 Vs we have a problem! • Need a Winch cable speed spec to back-up trained pilot technique • For details see winchcablespeed. pdf on this DVD Safe Winch Launching
Recommended Cable Speed Glider Type 1. 5 x. Vs (1 g) Min. Winch Cable Speed (eg nil headwind) Rec. Winch Cable Speed (eg for hot day/tailwind) Ka 6/Ka 8 45 kt 50 kt 55 kt Ka 13/light single 50 kt 55 kt 60 kt K 21/standard class single 55 kt 60 kt 65 kt Turbo/50 l water 65 kt 70 kt 60 kt The above shows that all winches should be capable of at least 60 kt cable speed in order to launch ALMOST ALL glider types safely in NORMAL conditions 65 kt+ cable speed is beneficial if launching high wing-loading gliders (eg turbo/water ballast) or in worst-case conditions (hot day, light tailwind) <60 kt winches require pilots to take extra care due to reduced energy margins during rotation in nil headwind conditions Safe Winch Launching
Low Speed Winches • Before campaign, over 10 winches in use unable to achieve safe cable speed • Sometimes as low as 50 kt max speed • Regular abandoned launches • Low energy = Difficult recovery • Contributory factor in accident record? Safe Winch Launching
Solutions Used • • • Increase Tost winch rev limit Fit larger diameter drums to Tost winch Change gearing of homebuild diesel Buy used winch from another club Winch rebuilt including cable speed upgrade Safe Winch Launching
Symptoms of <60 kt Winch • • Speed “hovers” at <1. 5 Vs until you climb Abandoned launches in zero headwind K 13 s etc OK but glass pilots not happy Winch drivers using max throttle/revs but feel they still need more If you have these symptoms, the BGA Winching Advisor can assist with winch assessment Safe Winch Launching
Examples of <60 kt Winches • • • 6 cyl diesel Supacat 55 kt Tost IV with 4500 rpm rev limiter 56 kt Wild in 2 nd gear with max 5000 rpm 50 kt Home-made winch ? ? Old diesel winch ? ? Safe Winch Launching
<60 kt Winch Mitigation • • • If occasional tailwind, WAIT! Limit types launched if nil headwind Careful rotation and speed monitoring Winch driver use max revs if needed Take great care with visiting pilots not used to low speed winches Safe Winch Launching
Review • Key Winching Operations campaigns so far: – Safe cable speed – Excessive acceleration Safe Winch Launching
Excessive Acceleration • Excessive winch acceleration cause gliders to pitch up rapidly regardless of stick position • Synthetic 8 -10 mm rope, which stretches during acceleration, can accentuate this • Good winch driver technique can minimise this problem Safe Winch Launching
Excessive Acceleration Diagram courtesy of Steve Longland Safe Winch Launching
Problems With Rapid Pitch-Up - 1 • Reduced margin to stall speed! Safe Winch Launching
Problems With Rapid Pitch-Up - 2 • Glider height and speed are low = low energy • Glider is nose-high = rapid speed decay • EVEN WITH A PERFECTLY FLOWN RECOVERY, A SAFE OUTCOME FROM A LOW LAUNCH FAILURE MAY NOT BE POSSIBLE IN THIS SITUATION. EVEN THE MOST COMPETENT PILOT CAN BE PUT IN THIS SITUATION BY BAD WINCH DRIVING • Think about it! Safe Winch Launching
Solutions – Winch Drivers • • Ensure type to be launched is known Smooth and progressive throttle opening 3 sec acceleration with Skylaunch or similar Extra care with lightweight or stretchy ropes Engine sound assists acceleration judgement Ask for feedback from pilots Read “Don’t force your mate’s crate to rotate” in S&G April/May 2010 Safe Winch Launching
NEW CAMPAIGN Fouling the Cable Safe Winch Launching
Fouling the Cable • Winch accident and incident reports 20062011 reviewed for any trends • 2011 had 6 events of cables fouling gliders; same as 2008/9/10 together • Clearly this needs understanding and addressing, as worst-case cable fouling accidents can be fatal Safe Winch Launching
What Can Happen? • Low launch failure - Parachute inflates - Cable hits or becomes tangled with glider • Weak link break – Strop recoils into glider • Take Up Slack jerk – Strop around wheel • Landing near a moving cable/parachute • Crossed cables • Winch driver launches glider or moves cable when gliders/people on cable run Safe Winch Launching
SAFER LAUNCH FAILURE TRAINING Safe Winch Launching
Instructors – Simulated Cable Breaks • Low launch failure training by pulling the release carries a high risk of fouling the cable • ULTRA-LOW launch failures (<50’) are DEMO ONLY and are simulated by winch driver “power chop” • BUT what about other height launch failures? • What are the pros and cons? Safe Winch Launching
Instructors – Power Chops • A “power chop” is an option at all heights • Less chance of glider/cable conflict. The parachute falls away dead, behind the glider • BUT instructor not fully in control of timing: – Tricky to achieve requested height/position – Committed to receiving the failure. What if pupil over-rotates or another hazard develops? Safe Winch Launching
Instructors – Bung Pulling! • Fully in control of height/position for failure • If not safe to pull it, not committed – can delay • BUT Parachute WILL initially inflate, until winch driver reacts – Possible hazard for landing ahead • If “pulling the bung” for a low launch failure, brief winch driver to stop immediately and be ready to avoid the parachute! Safe Winch Launching
Comparison Diagram • Typical sequences for both methods of launch failure training are shown in the next diagram • In both cases, the failure occurs in position 2 Safe Winch Launching
typical locations of glider and parachute after recovery has commenced Safe Winch Launching Diagram courtesy of Steve Longland
• Clearly, the chance of the glider contacting the cable or parachute is reduced if the “power chop” method is used for training low failures Safe Winch Launching
Instructors – Decisions! Always consider both methods for launch failures Medium & High failures not normally a problem Low/Land-ahead failures require consideration Height? Cable angle? Wind? Landing options? Parachute reaction? Winch braking distance? Pupil experience? Instructor experience? • Choose the best option for each exercise • Be confident with both methods • • Safe Winch Launching
Recommendation • Purely from the point of view of minimising cable fouling accidents, power chops are recommended for launch failure training <200’ • If other factors outweigh this recommendation and you wish to pull the bung at <200’, then brief the winch driver and avoid the parachute • Always weigh up the risks and benefits associated with each launch failure method at different heights and positions Safe Winch Launching
Still not convinced that power chops improve parachute separation? WATCH THIS VIDEO. . Safe Winch Launching
Click on picture to replay. Click outside picture to advance to next slide Safe Winch Launching
The parachute drops safely below and behind the glider, and doesn’t inflate until well clear. Bloggs would have to try very hard to hit it! Safe Winch Launching
Real Launch Failures • Unfortunately, we can’t arrange for real launch failures <200’ to all be power chops! The power may fail gradually or be inadequate from the start, or any part of the cable system may fail • At low level, these scenarios can result in the parachute inflating near the glider • Real launch failures at low level can be caused by errors from the ground team. Be “switched on” in the winch and at the launch point Safe Winch Launching
COMMON FACTORS IN CABLE FOULING ACCIDENTS Safe Winch Launching
Common Factors – Fouling Cable • • • No STOP signal, delayed or not spotted Parachute/strop arrangement poor Slow initial launch – abandoned Cable towout not straight Parachute not untwisted before launch Incorrect winch driver reaction to problem Safe Winch Launching
Common Factors – Fouling Cable • • • No STOP signal, delayed or not spotted Parachute/strop arrangement poor Slow initial launch – abandoned Cable towout not straight Parachute not untwisted before launch Incorrect winch driver reaction to problem Safe Winch Launching
Possible Reasons for STOP After All-Out • • Wing Drop Cable fouls glider Cable, weak link, parachute, shackle failure Abandoned launch Uncommanded cable release inc. hook failure! Crossed cables – another cable moves Low simulated cable break Conflict with landing or overflying aircraft Safe Winch Launching
STOP! - Winch Drivers • Keep watching light signals while accelerating, until you get a good view of the airborne glider • Always be ready for a Take Up Slack or All Out to change to STOP and ensure radio is audible • SKYLAUNCH actions: CLOSE throttle instantly, PULL Drive lever back to Neutral, BRAKE HARD until drum stopped • Watch glider and assess situation – Consider Guillotine, Drum Neutral, Engine off etc • What are the STOP actions for your winch? Safe Winch Launching
STOP! - Launch Signaller • Be ready to change signal to STOP! at any time • Continue to monitor launch after All Out • With lights, understand that winch driver will be focussing on glider soon after All Out • Always back up a STOP light with a loud radio call to ensure prompt response from winch • Preferable to have radios with good aerials, decent battery life and a clear channel Safe Winch Launching
Common Factors – Fouling Cable • • • No STOP signal, delayed or not spotted Parachute/strop arrangement poor Slow initial launch – abandoned Cable towout not straight Parachute not untwisted before launch Incorrect winch driver reaction to problem Safe Winch Launching
Recommended Cable Setup • • • Tost rings or equivalent “Strop” 3 m (+/- 0. 5 m) Weak link in holder, with slot towards glider “Trace” 17 m (minimum 12 m, no maximum) Parachute – minimum usable size for site Max chute open diameter 1. 5 m steel/1. 2 m synthetic Swivel if needed, then winch cable Reduce metalwork where possible System has parachute at least 15 m from glider Safe Winch Launching
Safe Winch Launching Diagram courtesy of Steve Longland
Recommended Cable Material • For 3 m “Strop” from Tost rings to weak link…. • Rope (eg polypropylene – min stretch) 14+mm diameter, ideally encased in hose or pipe • 4. 5 -6 mm steel cable encased in hose or pipe • 5 mm+ Dyneema encased in hose or pipe • Hose/pipe in good condition – no bare cable! • Minimum diameter 12. 5 mm (½”) garden hose • Same materials for 17 m “Trace” from weak link to parachute, but if using 14+mm rope, hose/pipe not needed Safe Winch Launching
Advantages of Recommended Setup • Weak link and any bare cable clear of nosewheel/skid – less chance of hangup • Weak link break/recoil - Less stored energy in short 3 m strop than if weak link at parachute • Diameter/material of strop less likely to catch in mainwheel during overrun • Distance between parachute and glider allows time to react and avoids distraction Safe Winch Launching
Example Setup Safe Winch Launching
What Can Go Wrong – An Example Cable setup with only 5 m from glider to ‘chute 15 kt headwind Cable break before takeoff, at around 30 -40 kts ‘Chute flew back over the canopies obscuring the pilots’ view, then wrapped around cockpit • Main wheel jammed and instructor trapped • If the glider had been airborne, would have been a tricky landing with view obscured • Club now uses recommended setup! • • Safe Winch Launching
Safe Winch Launching
Common Factors – Fouling Cable • • • No STOP signal, delayed or not spotted Parachute/strop arrangement poor Slow initial launch – abandoned Cable towout not straight Parachute not untwisted before launch Incorrect winch driver reaction to problem Safe Winch Launching
Slow Initial Launch Incidents • Typically launching light gliders in a headwind • Parachute inflates in front of glider due to low tension OR pilot releasing due to low speed • Both caused by winch driver providing insufficient speed for glider to rotate safely • ½ of incidents = Skylaunch with throttle stops • ½ of incidents = other types without stops Safe Winch Launching
Skylaunch: Headwind > 10 kts • Throttle stop setting may be ideal once glider in full climb, but may be insufficient to give normal acceleration through wind gradient • Throttle stop is JUST A GUIDE to approx power • Always be ready to adjust throttle as needed • LISTEN TO ENGINE - smoothly increase throttle if engine sounds laboured/doesn’t accelerate • WATCH GLIDER - smoothly increase throttle if glider doesn’t enter full climb normally Safe Winch Launching
Skylaunch: >10 kt Headwind Option 1 Underestimate Headwind by 1 notch/5 kts Eg In 20 kt headwind select 15 kt setting Accelerate smoothly to throttle stop Watch glider and listen to engine for feedback – adjust power if required • Be ready to smoothly reduce power once glider is through wind gradient • Rest of launch normal • • Safe Winch Launching
Skylaunch: >10 kt Headwind Option 2 • Select correct headwind • Accelerate smoothly to throttle stop then slightly beyond (5 -10 mm normally sufficient) • Watch glider and listen to engine for feedback – adjust power if required • Be ready to smoothly reduce power once glider is through wind gradient • Rest of launch normal Safe Winch Launching
Skylaunch Throttle Stops • Useful guide and training aid - consistency • Work well in light winds, but more judgement needed in stronger headwinds • Drivers who can only “launch by numbers” are not fully trained winch drivers! • Drivers should have sufficient judgement to be able to adjust power as required Safe Winch Launching
Other Winch Types • Same principle applies to most winch types • In a strong headwind, the lower power-setting required in the full climb may not be sufficient for the glider to rotate safely • Need to accelerate the glider through the wind gradient first, then adjust power in full climb • If glider doesn’t rotate normally or engine sounds laboured, smoothly increase throttle • Ask your winchmaster for advice specific to your type of winch Safe Winch Launching
Diagram of Headwind Launch • The following diagram illustrates option 2 for driving a Skylaunch in >10 kt Headwind • Option 2 is selecting the correct headwind, but initially accelerating slightly beyond the throttle stop for the first part of the launch • The general principle applies to most winches • Don’t forget that the windsock indicates the wind strength at 10 -15 ft above the ground. Glider headwind below this height is likely to be less than indicated by the windsock Safe Winch Launching
Diagram courtesy of Steve Longland Safe Winch Launching
Common Factors – Fouling Cable • • • No STOP signal, delayed or not spotted Parachute/strop arrangement poor Slow initial launch – abandoned Cable towout not straight Parachute not untwisted before launch Incorrect winch driver reaction to problem Safe Winch Launching
Crossed Cables - Causes Towout not straight Cables not separated at launch point Glider queue too close to cables Winch driver launches with previously used cable too close to the cable in use. Has to abandon launch when cables tangle • Towout driver hooks cables up incorrectly • Winch driver moves winch with multiple cables out on field! • • Safe Winch Launching
Wonky Towout? • • • Drive full length and ensure separation If clear, launch cable inside of bow first If doubt, wind inside cable in - launch 2 nd only DO NOT be pressured into launching Rebrief/retrain/replace towout driver! • If using a single cable in a large bow (eg winter ops), ensure no landed gliders, people or vehicles are within the bow before launching! Safe Winch Launching
Common Factors – Fouling Cable • • • No STOP signal, delayed or not spotted Parachute/strop arrangement poor Slow initial launch – abandoned Cable towout not straight Parachute not untwisted before launch Incorrect winch driver reaction to problem Safe Winch Launching
Parachute Not Untwisted • Any twisted part of the cable system can create a jerk during acceleration and rotation • This can be enough to briefly open parachute, or alarm the pilot sufficiently for him to lower the nose or release at low level • To avoid these incidents ALWAYS ensure cable system untwisted before hooking on Safe Winch Launching
Common Factors – Fouling Cable • • • No STOP signal, delayed or not spotted Parachute/strop arrangement poor Slow initial launch – abandoned Cable towout not straight Parachute not untwisted before launch Incorrect winch driver reaction to problem Safe Winch Launching
Winch Driver Reaction • With low launch failures, glider/cable separation CAN’T be guaranteed – CABLE MUST BE STOPPED IMMEDIATELY • SKYLAUNCH actions: CLOSE throttle instantly, PULL Drive lever back to Neutral, BRAKE HARD until drum stopped • Watch glider and assess situation – Consider Guillotine, Drum Neutral, Engine off etc Safe Winch Launching
REVIEW Safe Winch Launching
Cable Fouling Review • • • Power chop for ultra-low launch failure demo Power chops recommended for failures <200’ Think about best method each time Improve STOP communication and procedures Use recommended cable setup Use sufficient throttle for rotation in headwind Straight cable towouts and untwisted ‘chutes STOP drum immediately with low failures Train winch drivers fully – not “by numbers” Safe Winch Launching
Summary • Gliders being fouled by winch cables is a threat • There is plenty we can do to reduce the risk • If everyone is “switched on” we can all help • Target is to revert to downward trend of “hit cable” incidents and accidents from 2013 on • Keep reporting winch accidents/incidents to help our work to understand reduce them • Thank you Safe Winch Launching
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