This ARP covers the basic criteria for the design of cabin pressure control systems (CPCS) for general aviation, commercial and military pressurized aircraft.
1) Concern: the slight difference in 7.2.3 and 7.2.4 acceptance criteria (60 vs 75 slf) causes uncertainty when reporting comfort compliance or non-compliance for pressure bumps between 60 and 75 slf 2)Concern with ARP1270B Eqs. 5a and 5b Concern: the above equations are only valid for H<11000 m (36089.24 ft), but, this limitation is not stated Suggestion: either add text to clarify the altitude limitation or add alternate formulations to address H>11000 m (36089.24 ft) 3) Suggested clarification: ARP1270B should state that only unfiltered rate values should be used for comparison with ARP1270B Figure 10. Comparing filtered rates can lead to erroneous results. 4) Suggested clarification: Clarify the vertical axis label of ARP1270B Figure 10 to indicate the rates are based on a sea-level pressure (which is consistent with the text used in sections 3.4, 4, 4.3.2, 18.104.22.168, and 7.2.4 describing comparison with Figure 10)