AAIB Bulletin: 1/2008 HGM and GDP EW/C2006/10/02 ACCIDENT Aircraft Type and Registration: ) Schebe SF27 glder, HGM 2) Schlecher ASW 9 glder, GDP No & Type of Engines: ) None 2) None Year of Manufacture: ) 1965 2) 1979 Date & Time (UTC): 2 October 2006 at 55 hrs Location: Sutton Bank, North Yorkshre Type of Flight: ) Prvate 2) Prvate Persons on Board: ) Crew - Passengers - None 2) Crew - Passengers - None Injuries: ) Crew - (Mnor) Passengers - N/A 2) Crew - (Fatal) Passengers - N/A Nature of Damage: ) Arcraft destroyed 2) Arcraft destroyed Commander’s Licence: 1) British Gliding Association (BGA) Gliding Certificate 2) British Gliding Association (BGA) Gliding Certificate Commander’s Age: ) 50 years 2) 48 years Commander’s Flying Experience: ) 733 hours Last 90 days - 20 hours Last 28 days - 5 hours 2) 280 hours Last 90 days - 0 hours Last 28 days - hour Information Source: AAIB Feld Investgaton wth assstance from the Brtsh Gldng Assocaton (BGA) Synopsis Two glders, a Schebe SF27 and a Schlecher ASW 9B, able to escape from hs arcraft and parachute to the were flying close to Sutton Bank, North Yorkshire, when ground: the plot of the ASW 9 was not able to release they were n collson close to a bank of cloud. Both hs cockpt canopy and was klled. The engneerng glders lost portons of wng n the mpact and were nvestgaton ndcated that both arcraft were servceable rendered incapable of flight. The pilot of the SF27 was untl the moment of collson. © Crown copyrght 2008 90 AAIB Bulletin: 1/2008 HGM and GDP EW/C2006/10/02 Two Safety Recommendatons were made shortly after 920 ft amsl and ts geographcal stuaton provdes the the event and a further two are made n ths report. opportunty for rdge soarng, whlst the presence of the Pennne hlls to the west means that wave lft s also History of the flight often present. Orographc cloud often forms over the The two plots, and others, were members of a group from ste, sometmes rapdly, when a most westerly ar stream the Welland Gldng Club, whch regularly organsed exsts n the area. expeditions to fly at the Yorkshire Gliding Club at Sutton Bank; the club hosts many such expedtons each year On the day of the accdent, the weather at Sutton Bank from clubs around Brtan. The group arrved on the was changeable. Three training flights took place in Saturday before the accdent, ntendng to spend the the morning but a rain shower then stopped flying for week gldng and socalsng. a tme. Once the ran shower had passed, operatons recommenced, wth aerotow launches. The ASW 9 The gldng club ste s stuated on top of a rdge, whch (GDP) was launched at 447 UTC and the SF27 (HGM) forms around a bowl on ts western sde (see Fgure ). drectly afterwards at 458 UTC. The ste has two takeoff and landng ‘runs’, north/south and east/west. The east/west run was n use on the day No evidence was available of the flight of the ASW 19 of the accdent, wth the launch pont establshed just from the end of the aerotow launch until the final south of the club buldng. The elevaton of the ste s moments before the collson. Figure 1 Accdent ste © Crown copyrght 2008 9 AAIB Bulletin: 1/2008 HGM and GDP EW/C2006/10/02 The survvng (SF27) plot recalled releasng from the The SF27 plot then felt a cold rush of ar, and hs arcraft aerotow at 2,000 ft above the ste and soarng near, and rolled to the rght to an nverted poston. He dd recall predomnantly to the south of, the ste, durng whch operatng the canopy jettson lever, but the canopy dd not tme he was concerned about a bank of cloud to the part from the glder. A substantal part of the canopy had west‑south‑west of the airfield, drifting towards it. Shortly been destroyed n the mpact and the plot later remembered before the collson he was trackng roughly north along the kckng hmself free of the cockpt and beng momentarly rdge to the west of the ste, at about ,500 ft. Immedately delayed n locatng hs parachute release, before operatng pror to the collson, he recalled beng n a gentle left t. He heard the parachute canopy deploy and then looked turn, skrtng around a cloud mass, the edge of whch up to check that t had deployed correctly. He made an was somewhat broken and “scuddy”. Hs ntenton was uneventful parachute descent, landng n a wooded area. to manoeuvre towards the Thrsk area, where the weather Hs parachute canopy caught n the trees and he found was clearer. He recalled that hs speed was about 45 kt hmself suspended by hs canopy and harness, hs toes just and he was experencng a lttle lft. He was montorng touchng the ground. He released hs harness and made communcatons on the Sutton Bank gldng frequency, hs way to a clearng n the trees where he used hs moble 29.975 MHz, on hs rado. He heard no communcatons telephone to call the club, before walkng out of the wood whch related to the ASW 9 after hs launch. towards a nearby road and beng met by the emergency servces. He sustaned a broken bone n one hand, and The SF27 plot suddenly saw the orange wng tp and cuts and bruses. nose of another glder at between hs one and two o’clock poston2, and he realsed that a collson was nevtable. The ASW 9 and ts plot fell to the ground. The plot Instnctvely he entered a descendng left turn, wth the was found close to the wreckage of hs glder, hs harness objectve of preventng a cockpt-to-cockpt collson was found unfastened and the canopy release mechansm (whch he thought hghly probable and lkely to be had been operated. He was wearng a parachute but t fatal). He recalled that the other arcraft “may have been had not been operated. The mpact wth the ground was descendng out of scuddy cloud”, and that t may have not survvable. been flying fast and straight towards him. He ducked his head as the other arcraft’s wngtp was about to mpact Staff and vstors at the club called the emergency servces hs canopy, and mmedately heard a loud bang. as soon as they heard the collision. A flying instructor, arborne n a motor glder, made a ‘Mayday relay’ The two arcraft collded almost head on, each arcraft’s call addressed to the Dstress and Dverson cell at the canopy beng severely damaged by the other’s wng. The London Area Control Centre, whch was relayed to the wng structure of the SF27 separated from the fuselage; cell by a commercal arcraft arborne near London. The one wng of the ASW 9 separated approxmately half nstructor selected 7700 on hs transponder3 to assst ATC way along ts span. n dentfyng the locaton of the accdent. Footnote Glder plots operatng at Sutton Bank commonly refer to ther vertcal poston as heght above the ste. The ste s 920 ft amsl. 2 Relatve poston of another arcraft s frequently expressed by Footnote ‘clock code’: an arcraft straght ahead s at 2 o’clock, one to the rght at three o’clock, drectly behnd at sx o’clock, and to the left at 3 The ‘Mayday’ code, which alerts air traffic controllers using nne o’clock. Other ponts are referred to n order. secondary radar to an arcraft n dstress. © Crown copyrght 2008 92 AAIB Bulletin: 1/2008 HGM and GDP EW/C2006/10/02 Witness recollections Recorded data There was only one eyewtness to the collson. The Both glders had a GPS recever coupled to a glder partner of another glder plot was standng n the car logger. The GPS recevers and the loggers had the park besde the gldng club, and observed three glders ablty to record the track of the arcraft to memory. In arborne: the ASW 9, the SF27, and her partner’s glder. all cases, a battery was requred to mantan the memory. In due course, she saw two glders “headng towards The GPS from the SF27 was never recovered; the glder each other n thn msty cloud” and then colldng. She logger was recovered but had faled to record the track saw wreckage fallng, and one parachute openng and of the accident flight due to a low battery. descendng. The GPS from the ASW 9 was recovered but was Another plot, the partner of the eyewtness, was not operatonal. Investgaton revealed that the power arborne at the tme. Pror to the collson, he recalled crcutry had been dsrupted durng the accdent, such flying along the ridge, and attempting to make radio that the battery powerng the memory quckly depleted, contact with the ASW 19 pilot, first on the Sutton Bank losng any track nformaton that may have been recorded. frequency 29.975 MHz and then on 30.4 MHz, the However, the glider logger had sufficient battery power ‘cloud flying’ frequency. He intended to inform him to mantan ts memory but was too damaged for a normal of a “squall wth a band of cloud” approachng the ste. download of the unt. The memory was extracted wth He recalled that he was flying at approximately 1,000 ft the assstance of the Bureau d’Enquetes et d’Analyses above the ste, below “an upper, broken layer of cloud, (BEA - equvalent to the AAIB n France) and decoded base approxmately ,350 to ,400 ft above the ste”.