Deviation Request #1 ETSO-C78 Crewmember Oxygen Mask and ETSO-C89 Oxygen Regulators, Demand

Changed marking, changed inward leak test, changed inspiratory resistance, combination of tests, changed diluter schedules
Consultation closed
With Comments
Consultation Type
ETSO Deviation
Deadline for comments
02/04/2007

(1) Deviation #1: ETSO‑C78 §4.1 General (Marking)/TSO C78 – (b) marking

The regulator being mask-mounted to compose a single piece of equipment, Intertechnique has added the markings required in ETSO-C78 §4.1/TSO C78 (b) to the markings required in ETSO-C89 §4.1/TSO C89 (b) on plates attached to the regulator. Intertechnique claims that these deviations have already been approved by the FAA for LODA for mask-regulator MC10 series by letter MCB/11/26 dated Nov. 26, 1973.

(2) Deviation #2 ETSO-C78 FAA standard associated with ETSO‑C78 §3.3 (a)/TSO C78 §3.3 (a)

The regulator being mask-mounted to compose a single piece of equipment, Intertechnique has performed the inward leakage test on the mask-regulator assembly and cumulated the maximum mask inward leakage (0.1 L/min STPD as in ETSO-C78 FAA standard associated with ETSO-C78 §3.3 (a)/TSO C78 §3.3 (a)) and the maximum regulator inward leakage (0.1 L/min STPD as in ETSO-C89 FAA Standard associated with ETSO-C89 §4.4 (a)/TSO C89 §4.4 (a)). Though, the maximum mask-regulator inward leakage considered for the tests was 0.2 L/min STPD. Intertechniqueclaims that the deviation has already been accepted by the FAA in LODA for mask-regulator MC10 series by letter MCB/11/26 dated Nov. 26, 1973.

(3) Deviation #3 ETSO‑C78 FAA standard associated with ETSO‑C78 §3.4 (a)/TSO C78 §3.4 (a) and ETSO‑C89 FAA Standard associated with ETSO‑C89 §4.1 (a)/TSO C89 §4.1 (a)

The regulator being mask-mounted and so integrating the whole inspiratory circuit, Intertechnique has performed the inspiratory resistance test on the regulator only and cumulated the maximum mask inspiratory resistance (ETSO C78 FAA standard associated with ETSO-C78 §3.4 (a)/TSO C78 §3.4 (a)) and the maximum regulator inspiratory resistance (ETSO C89 FAA Standard associated with ETSO-C89 §4.1(a)/TSO C89 §4.1 (a)).
The maximum mask-regulator inspiratory resistance considered for the test is defined as follows:

Flow

(L/min STPD)

Suction pressure (inches H2O)

as per TS0 C78 § 3.4 (a)

Suction pressure (inches H2O)

as per TS0 C89 § 4.1 (a)

Suction pressure (inches H2O)

maximum value
considered for the test

20

0.6

0.4

1

70

1.5

0.8

2.3

100

2.5

1.0

3.5

Intertechnique claims that the deviation has already been accepted by the FAA in LODA for mask-regulator MC10 series by letter MCB/11/26 dated Nov. 26, 1973.

 

(4) Deviation #4 ETSO‑C89 FAA Standard associated with ETSO‑C89 §4.4 (c)/TSO C89 §4.4 (c) and ETSO‑C89 FAA Standard associated with ETSO‑C89 §4.4 (d)/TSO C89 §4.4 (d)

The exhalation valve being an integral part of the regulator, the regulator outlet leakage (ETSO C89 FAA Standard associated with ETSO-C89 §4.4 (c)/TSO C89 §4.4 (c)) and the regulator overall leakage (ETSO C89 FAA Standard associated with ETSO-C89 §4.4 (d)/TSO C89 §4.4 (d)) cannot be measured separately. Intertechnique has performed only one regulator leakage test and cumulated the maximum outlet leakage (0.01 L/min STPD as per ETSO C89 FAA Standard associated with ETSO-C89 §4.4 (c)/TSO C89 §4.4 (c)) and the maximum overall leakage (0.01 L/min STPD as per ETSO C89 FAA Standard associated with ETSOC89 §4.4 (d)/TSO C89 §4.4 (d)).
Though, the maximum regulator leakage considered for the test was 0.02 L/min STPD.
Intertechnique claims that the deviation has already been accepted by the FAA in LODA for mask-regulator MC10 series by letter MCB/11/26 dated Nov. 26, 1973.

 

(5) Deviation #5 ETSO C89 FAA Standard associated with ETSOC89 §4.2 (a)/TSO C89 §4.2 (a)

As customers unanimously reject the excessive oxygen consumption below 25 000 ft, for Diluter Demand Pressure Breathing Regulators, resulting from paragraph 4.2 (a), Intertechnique proposes to apply, below 25 000 ft, the diluter schedule as requested or Diluter Demand Regulator, except for 0 ft, 5 000 ft and 10 000 ft where 10% of added oxygen is proposed to guaranty a safety level adapted to human physiology.
 
For the table see the pdf-file.

This diluter schedule proposal results from a recent study analyzing the hypoxia protection to 45 000 ft according to the pre-breathing dilution schedule and the& altimetric pressure breathing. This study has been exposed to the SAE A10 (Aircraft Oxygen Equipment Committee) group members in May 2006. This study is attached as a complete file in Annex 1.

 

(6) Deviation #6 ETSO‑C89 FAA Standard associated with ETSO‑C89 §4.3 (a)/TSO C89 §4.3 (a)

The pressure schedule proposed by Intertechnique deviates from ETSO/TSO requirement:
 
Altitude
(ft)		 Minimum Positive pressure
(H2O Inch)
Per TSO C89 §4.3 (a)		 Minimum Positive pressure
(H2O Inch)
Per IN/div>Pressure schedule>		 Maximum Positive pressure
(H2O Inch)
Per TSO >C89 §4.3 (a)		 Maximum Positive pressure
(H2O Inch)
Per IN pressure schedule

30000

0

0

3.5

3.5

40000

0

1.8

5.0

12

42000

4.5

5.6

7.5

12

44000

9.0

8.6

11.0

12

45000

11.0

10.0

12.0

12
 
The minimum pressure-breathing schedule results from a recent study (refer to Annex 1) analyzing the hypoxia protection to 45,000 ft according to the pre-breathing dilution schedule and the altimetric pressure breathing. This study has been exposed to the SAE A10 (Aircraft Oxygen Equipment Committee) group members in May 2006. This study is attached as a complete file in Annex 1. As IN maximum pressure-breathing schedule is higher than the ETSO/TSO one, Intertechnique claims that this is beneficial to the crew tracheal O2 partial pressure.
Thus, Intertechnique considers that the mask-regulators comply with the ETSO/TSO requirements by providing an equivalent level of safety.