MOC VTOL.2250(e) Doors, canopies and exits

1.      Scope and Definitions

(a)      This paragraph applies to: All doors, hatches, openable windows, access panels, covers, etc., on the exterior of the vehicle.

(b)     However, this paragraph does not apply if the door requires a specific tool to both open and close the door.

(c)      This paragraph also does not apply if the opening of the door, in any flight phase, would not cause an event worse than Minor, as defined in VTOL.2510. The potential of persons inadvertently falling from the vehicle, and the physiological effect on passengers, should be included in the event classification, in addition to any effects on the vehicle structure, systems, controllability etc.

(d)     Latches are movable mechanical elements that, when engaged, prevent the door from opening.

(e)     Latched means the latches are engaged with their structural counterparts and held in position by the latch operating mechanism.

(f)      Structural aspects of Door design, and Emergency Egress from the vehicle are out of scope of this paragraph. Refer to VTOL.2315(a) for emergency egress and Subpart C for the structural aspects.

2.      Relevance to ASTM F3061 – 16a

(a)      Paragraph 13.11.1 should be applicable, and complements Section 4 below.

(b)     Paragraph 13.11.9 could be a means of compliance to Section 4 below, but need not be a separate point.

3.      Occupant Retention

A seatbelt, or other occupant retention device, should not be considered an adequate alternative or mitigation against compliance with this paragraph.

4.      Door Latching

(a)      For all doors within the scope of this paragraph, there should be means for latching and for preventing their opening in flight inadvertently or as a result of mechanical failure.

(b)     Acceptable features to prevent inadvertent operation by occupants are, for example:

(1)     recessing door handles; and

(2)     door handles that are moved/rotated up to open the door and moved/rotated down to close the door.

(c)      Means to prevent inadvertent door opening in flight due to "mechanical failure" should be provided through multiple door latches and multiple load path door locking mechanisms so that the door will remain locked after a single failure.

(d)     Care should be taken in the design of multiple load path latches and mechanisms to assure independence of all failures to consider the consequences of common-mode failures and errors, and to consider the effort of deflections after failures (if a failure allows deflections into the airstream sufficient to increase aerodynamic loads, the increase in loads should be accounted for; if a failure allows significant movement of latching components, the deflections should be accurately accounted for to assure that disengagement of non-failed latches does not occur).

5.      Direct Visual Inspection

There should be means for direct visual inspection of the latching mechanism by flight crew members to determine whether the external doors (including passenger, crew, service, and cargo doors) are fully latched.

6.      Flight Crew Indication

There should be visual means (combined with other attention-getters as appropriate, refer to MOC VTOL.2605(b) ) to signal to appropriate flight crew members when doors within the scope of this paragraph are not closed and/or not fully latched.

7.      Particular Risk Aspects

The door mechanisms should be designed such that the door will not open in case of a bird strike or other Particular Risk effect.