Flying Officer Reynolds was flying combat air patrol just north of Cairo.
He sighted a Ju86P with two pilots sitting securely in a pressure cabin. He then pursued the Ju86 north towards Alexandria at ever increasing height.
At 37,000 ft he closed in and began to zigzag to prevent overshooting past the Ju86, the Ju86 zigzagged in the same way trying to stay above the Spitfire and force it to lose height.
The duel continued to 40,000 ft where Reynolds realised he could not climb any higher until the aircraft weight was lightened.
Calculating how much fuel he could use and still reach home safely, he threw out his life jacket and dingy, keeping only the parachute.
In the middle of these calculations he temporarily blacked out having only sufficient time to turn his oxygen supply to full emergency to bring himself around.
BT_PO 1.36 Discuss the physiological effects of hypoxaemia
BT_RT 1.11 Describe the physiological consequences of hypoxaemia
The time of useful consciousness is the “time interval after loss of pressurisation or mask function during which the crew member is able to recognise and take action to correct the situation”
<18,000 ft = hours/days
18,000 ft = 20 – 30 min
25,000 ft = 3 – 5 min
30,000 ft = 1 – 2 min
35,000 ft = 30 – 60 sec
>43,000 ft = 9 – 12 sec
As you can see from this photo, taken recently at airliner cruising altitude, if there is a sudden depressurisation, you will have less than 30 seconds to get to your oxygen mask.
TRUE/FALSE Hypoxaemia caused by ascending to altitude results in a left shift of the oxygen haemoglobin dissociation curve
TRUE/FALSE In cerebral hypoxia, acidosis causes more damage than depletion of high energy compounds
In an airliner:
TRUE/FALSE when the oxygen masks drop down from the ceiling put you child’s mask on first
TRUE/FALSE oxygen is already running when you put on the mask