113.—(1) Subject to paragraphs (3) and (4), an AOC holder must ensure that every large aeroplane that is a pressurised aeroplane, and that is to be operated above flight level 100, carries a supply of oxygen sufficient for a duration that is the greater of —| (a) | the duration of time that is calculated in accordance with its Operations Manual before the commencement of the flight, being the period or periods which it is reasonably anticipated that the aeroplane will be flown in the circumstances of the intended flight at a height where such requirements apply and in calculating the duration account must be taken of —| (i) | the possibility of depressurisation when flying above flight level 100; | | (ii) | the possibility of failure of one or more of the aircraft engines; | | (iii) | any restrictions due to required minimum safe altitude; | | (iv) | the fuel requirement; and | | (v) | the performance of the aeroplane; or |
| | (b) | the duration of time that is calculated in accordance with the following Table 5 for the circumstances that the aeroplane is to be operated in. | | Table 5: Oxygen supply for a pressurised aircraft |
| | | | | | | | | (1) | When flying above flight level 100 but not exceeding flight level 250 |
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| | | 30 minutes or whenever the cabin pressure altitude exceeds 10,000 ft, whichever is the greater. |
| | | | Every cabin crew member and 10% of passengers |
| | (a) | When the aeroplane is capable of descending and continuing to its destination as specified in Capability 1, 30 minutes or whenever the cabin pressure altitude exceeds 10,000 ft, whichever is greater. |
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| (b) | When the aeroplane is not capable of descending and continuing to its destination as specified in Capability 1, whenever the cabin pressure altitude is greater than 10,000 ft but does not exceed 12,000 ft. |
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| | | | | Every cabin crew member, and all passengers |
| | When the aeroplane is not capable of descending and continuing to its destination as specified in Capability 1, and the cabin pressure altitude exceeds 12,000 ft, the duration is the period when the cabin pressure altitude exceeds 12,000 ft or 10 minutes, whichever is the greater. |
| | | | (2) | When flying above flight level 250 |
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| | | 2 hours or whenever the cabin pressure altitude exceeds 10,000 ft, whichever is the greater. |
| | | | | | Whenever the cabin pressure altitude exceeds 10,000 ft and a portable supply for 15 minutes. |
| | | | | | Whenever the cabin pressure altitude exceeds 10,000 ft, but does not exceed 12,000 ft. |
| | | | | | Whenever the cabin pressure altitude exceeds 12,000 ft, but does not exceed 15,000 ft. |
| | | | | | If the cabin pressure altitude exceeds 15,000 ft the duration is the period when the cabin pressure altitude exceeds 15,000 ft or 10 minutes, whichever is the greater. |
| | | | | 2% of passengers or 2 passengers, whichever is the greater, being supply of first‑aid oxygen which must be available for simultaneous first‑aid treatment of 2% or 2 passengers wherever the passengers are seated in the aeroplane |
| | Whenever after decompression, cabin pressure altitude exceeds 8,000 ft. |
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(2) In Table 5, “Capability 1” means that, at the time when a failure to maintain cabin pressurisation occurs, the aeroplane is capable of —| (a) | descending to flight level 130 within 4 minutes, in accordance with the emergency descent procedure specified in the relevant aircraft flight manual and without flying below the minimum altitudes for safe flight specified for the aeroplane in the AOC holder’s Operations Manual or equivalent; and | | (b) | continuing at or below that flight level to its place of intended destination or any other place at which a safe landing can be made. |
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(3) An AOC holder may, in lieu of complying with paragraph (1), comply with paragraph (4) if the large aeroplane —| (a) | has a Certificate of Airworthiness that was first issued (whether in Singapore or elsewhere) before 1 January 1989; and | | (b) | is provided with means for maintaining a pressure greater than 700 hPa throughout the flight in the flight crew compartment and in the compartments in which passengers are carried. |
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(4) The supply of oxygen to be provided for the purposes of paragraph (3) is —| (a) | in every case where a large aeroplane is to be flown above flight level 350, a supply of oxygen in a portable container sufficient for the simultaneous first‑aid treatment of 2 passengers; and | | (b) | in the event of failure to maintain a pressure greater than 700 hPa in accordance with paragraph (3)(b) in the circumstances specified in columns 1 and 2 of the following Table 6, a supply of oxygen sufficient for continuous use by the persons specified in column 3 for the period specified in column 4 of that Table. | | Table 6: Alternative oxygen supply |
| | | | | | | | | | Aeroplane to operate at altitudes |
| | Capability of aeroplane to descent (where relevant) |
| | Persons for whom oxygen is to be provided |
| | Period of supply of oxygen |
| | | | | | In addition to any passenger for whom oxygen is provided as specified below, every crew member. |
| | 30 minutes or the period specified at Condition A, whichever is greater. |
| | | | Above flight level 100 but not above flight level 300 |
| | Aeroplane is either flying at or below flight level 150 or is capable of descending and continuing to the destination as specified at Condition X |
| | | 30 minutes or the period specified at Condition A, whichever is greater. |
| | | | | Aeroplane is flying above flight level 150 and is not capable of descending and continuing to the destination as specified at Condition X |
| | | 10 minutes or the period specified at Condition B, whichever is greater. |
| | | | | | | 30 minutes or the period specified at Condition C, whichever is greater. |
| | | | Above flight level 300 but not above flight level 350 |
| | Aeroplane capable of descending and continuing to the destination as specified at Condition Y |
| | | 30 minutes or the period specified at Condition A, whichever is greater. |
| | | | | Aeroplane is not capable of descending and continuing to the destination as specified at Condition Y |
| | | 10 minutes or the period specified at Condition B, whichever is greater. |
| | | | | | | 30 minutes or the period specified at Condition C, whichever is greater. |
| | | | | | | 10 minutes or the period specified at Condition B, whichever is greater. |
| | | | | | | 30 minutes or the period specified at Condition C, whichever is greater. |
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(5) In Table 6 —| “Condition A” means the whole period during which the aeroplane flies above flight level 100, after the occurrence of a failure to maintain a pressure greater than 700 hPa in the control department and in the compartments in which passengers are carried; |
| “Condition B” means the whole period during which the aeroplane flies above flight level 150, after the occurrence of a failure to maintain a pressure greater than 700 hPa in the control department and in the compartments in which passengers are carried; |
| “Condition C” means the whole period during which the aeroplane flies above flight level 100 but not above flight level 150, after the occurrence of a failure to maintain a pressure greater than 700 hPa in the control department and in the compartments in which passengers are carried; |
“Condition X” means that, at the time when a failure to maintain a pressure greater than 700 hPa in the control department and in the compartments in which passengers are carried occurs, the aeroplane is capable of —| (a) | descending to flight level 150 within 6 minutes, in accordance with the emergency descent procedures specified in the relevant aircraft flight manual and without flying below the minimum altitudes for safe flight specified in the Operations Manual relating to that aeroplane; and | | (b) | continuing at or below that flight level to its place of intended destination or any other place at which a safe landing can be made; |
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“Condition Y” means that, at the time when a failure to maintain a pressure greater than 700 hPa in the control department and in the compartments in which passengers are carried occurs, the aeroplane is capable of —| (a) | descending to flight level 150 within 4 minutes, in accordance with the emergency descent procedures specified in the relevant aircraft flight manual and without flying below the minimum altitudes for safe flight specified in the Operations Manual relating to that aeroplane; and | | (b) | continuing at or below that flight level to its place of intended destination or any other place at which a safe landing can be made. |
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(6) An AOC holder must ensure that a large aeroplane —| (a) | that is intended to be operated above flight level 250; or | | (b) | that is not capable of descending from an altitude of up to flight level 250 to flight level 130 within 4 minutes, in accordance with the emergency descent procedures specified in the relevant flight manual and without flying below the minimum altitudes for safe flight specified for the aeroplane in the AOC holder’s Operations Manual, |
| is equipped with suitable and sufficient apparatus to enable the persons for whom oxygen is supplied to use the oxygen, including automatically deployable oxygen equipment with a quantity of oxygen dispensing units that exceeds the number of passenger and cabin crew member seats by at least 10%. |
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| (7) An AOC holder must ensure that, in every large aeroplane that is a pressurised aeroplane and that is to be operated above flight level 250, each flight crew member at a flight duty station has ready access from the crew member’s normal seating position to a quick‑donning type of oxygen mask which will readily supply oxygen upon demand. |
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