Yes, you absolutely right, it was 23/05 -- bad memory ! I did my first solo from that runway in a 'cornflake' Rallye. Also had a jammed elevator control in a later flight from that runway due to stones from breaking up surface. Do you remember my Fournier RF4 -G-AWBJ that we kept at Sportair/Biggin, before moving to Tiger Club at Redhill --- the best days of my flying !!