23.791 Passenger information signs
No policy available as of September 30, 2003.
There is no corresponding rule in CAR 3 or the Airship Design Criteria.
23.803 Emergency evacuation
There is no corresponding rule in CAR 3 or the Airship Design Criteria.
Amendment 23-34 and Subsequent
See AC 20-118A, “Emergency Evacuation Demonstration,” for information on how to conduct an emergency evacuation demonstration of a commuter category airplane.
If there is a project for a litter installation for non-ambulatory passengers, then the airplane should be evaluated for compliance with the applicable egress requirements.
It is for those passengers who can exit the airplane under their own power per § 23.803. This evaluation can be a simple engineering judgment if it is clear the litter installation will not prevent the safe egress of all non-litter passengers within the allotted time. If there is doubt, a new demonstration should be run that evaluates the ability of non-litter passengers to exit the airplane with special attention to the litter installation and possible obstructions to safe exit.
Amendment 23-46 and Subsequent
This amendment adds a requirement for emergency lighting per § 23.812 to be the only lighting used in an emergency evacuation demonstration. This is when certification of emergency exits is done per § 23.807(d)(4). AC 20-118A is still applicable except for paragraph 5a(3)(vi).
23.805 Flight crew emergency exits
There is no corresponding rule in CAR 3.
The corresponding rule in the Airship Design Criteria, FAA-P-8110-2, Change 2, is section 4.36.
Amendment 23-46 and Subsequent
Section 23.805 requires two crew compartment exits or a singular hatch if the passenger exits are not convenient and readily accessible to the crew.
Section23.807(a)(3) requires a single crew compartment exit if there is a door that is likely to block the crew's access to the passenger exits. If a crew compartment exit is necessary under § 23.807(a)(3), the more rigid requirements of § 23.805 are also applicable. In other cases, the crew compartment exits may be required by § 23.805 independent of § 23.807(a)(3). Crew compartment exits that comply with the requirements of § 23.805 would also comply with § 23.807(a)(3) without further showing.
Amendment 23-49 and Subsequent
Crew compartment exits that comply with the requirements of § 23.805 would provide an equivalent level of safety to § 23.787(c). According to the preamble to Amendment 23-49, which added § 23.787(c), “this requirement would provide increased assurance that flight crews of all cargo airplanes will have ready access to an emergency exit.”
23.807 Emergency exits
The corresponding rule in CAR 3 is CAR 3.387.
The corresponding rule in the Airship Design Criteria, FAA-P-8110-2, Change 2, is section 4.36.
Original Issue and Subsequent
“Seating Capacity” as used in this regulation is defined as the number of occupants, both crew and passengers, for which the airplane is certificated. Thus, removal of installed seats is not justification for removal of certificated emergency exits.
The regulation requires a clear and unobstructed opening. An exemption per 14 CFR, part 11 to § 23.807(b), is acceptable for a seatback that protrudes into the opening if it can be easily pushed forward to clear the exit without requiring an action to unlock/unlatch the seat. If a seatback clears the exit when upright but not when reclined, it is acceptable to placard the seat to be upright during takeoff and landing.
Emergency exits should allow escape without crowding in any probable crash attitude. The inverted position is considered probable for both tail wheel and tricycle gear airplanes. This applies to airplanes with doors, forward sliding canopies, rearward sliding canopies and jettisonable canopies. If escape in an inverted attitude is not obvious or is questionable, then compliance should be shown.
It is not acceptable for certification purposes, except for acrobatic airplanes (§ 23.807(b)(5)), to rely on an emergency procedure requiring canopy jettisoning before an accident occurs. On the acrobatic category, if the canopy is not jettisonable, it should be shown that the canopy could be opened far enough in flight between VSO and VD to enable the occupants to safely exit the airplane. If jettisonable, it should be shown that the canopy trajectory would not cause injury to the occupants while separating from the airplane between VSO and VD. Also, if the canopy is jettisonable, it should be demonstrated that the airplane can be safely flown without the canopy, or that an inadvertent jettisoning is shown to be improbable.
On doors between the pilots' compartment and the passenger compartment that are likely to block the pilots' egress in a minor crash landing, there should be an exit in the pilots' compartment. This does not apply to curtains suspended from a rod at the top and made of flexible material without slats on any side.
Doors or folding doors with rigid-frangible materials may jam in a minor crash.
Acceptance of frangible doors can be shown by the evacuation procedure in section 23.807(a) below or by the conditions for acceptance of rigid doors in section
23.807(b) below. Rigid doors are only acceptable by placarding the doors to be 125
latched in the open position for takeoff and landing, providing the conditions in section 23.807(b) below are in compliance.
a. The purpose of the test is to show the door between the pilots' compartment and the passenger compartment will not block the pilots' escape if the door is jammed.
Acceptable means of compliance is by showing the door is frangible and the flight crew can egress the airplane without help within the 90-second time limit.
(1) The test should be conducted in an airplane or a mockup that conforms to the production airplane interior configuration that contains a bulkhead and door to be tested. The door should be closed to simulate jamming. If fragments from the broken door could obstruct the escape route of passengers and an emergency evacuation demonstration is required by either airworthiness or operating rules, then consideration should be given to including passenger participants in the test. In this case, refer to § 23.803 for guidance.
(2) Two participants representing a pilot and a copilot will be used in the test.
They should be people with no particular escape abilities. The estimated stature and weights for the participants should be a female 60-inches tall weighing 102 pounds and a male 74-inches tall weighing 210 pounds (fifth to 95th percentile). The female participant will break the door and be the first person through the exit without help from the male participant. Instructions for improving the egress should be limited to those instructions that are provided in either the FAA approved AFM or on related placards, or both.
(3) Determine the lighting simulates night lighting with no moonlight or starlight.
Lighting may be allowed at ground level to aid in leaving the area near the airplane providing the lighting is kept low and is shielded so it does not aid in evacuating the airplane.
(4) Participating personnel should be told of the purpose of the demonstration and of the safety precautions. Safety of participants is the responsibility of the applicant and safety procedures should protect the applicants without impacting the test results. Participants may wear protective gear such as helmets, but such gear, tools, or any other device should not be used to break through the door.
(5) The time limit is 90 seconds whether or not passenger participants are used in this demonstration.
(6) Information advising the flight crew the door is frangible should be placarded on the door(s) and should be noted in the limitations section of the AFM.
b. Rigid doors (those with stiff members that may jam in a minor crash) may be approved providing they are placarded to be latched open during takeoff and landing and under the following conditions:
(1) The opening and latching should be included in the Normal Procedures Section under the Before Takeoff and Before Landing Checklists of the AFM.
(2) With the door latch in the fully open position, the latch should be able to withstand the loads from the ultimate forces on the surrounding structure, per § 23.561.
(3) Flight crew members should be able to open and latch the door with their safety belts/shoulder harnesses fastened, if required by either airworthiness or operating rules.
(4) If certification for night operation is sought, the pilots' compartment—with the doors open—should be free from glare and reflections that could interfere with a pilots' vision, per § 23.733.
(5) The doors should be placarded in accordance with § 23.1557. The placards should state the doors are to be latched in an open position before takeoff and landing. Placard information should be in the imitations section of the AFM.
The following should be considered when approving STCs for cargo conversions (no passenger seating) on airplanes with a certification basis of 14 CFR, part 23, including commuter category airplanes:
• Unless otherwise mentioned, the airplane “seating capacity” is defined as the number of occupants, both crew and passenger, for which the airplane is certificated. Simply removing seats from the seat rails does not change the seating capacity.
• The § 23.807(a)(3) conditional requirement for one crew compartment exit is applicable to all airplanes with a part 23 certification basis, including commuter category.
• Airplanes with a crew compartment door that may block the pilots exit must have an exit in the crew compartment. In this circumstance, a normal, utility, or aerobatic category airplane with a certificated passenger seating capacity of zero (cargo only), a minimum of a single accessible exit in the cargo compartment in addition to the crew compartment exit is necessary (reference § 23.807(a)(3).
• It is not acceptable to remove emergency exits by modifying an existing exit so it no longer complies with 14 CFR, part 23 airworthiness requirements. However, under certain circumstances, such as in an airplane with more than two exits, it may be permissible to block exits with cargo provided one or more exits remain accessible on each side of the airplane. Implicit within the definition of “readily accessible” is a requirement the unblocked emergency exits have no obstacles such as cargo nets or cargo. Obstacles pose an impediment to the emergency evacuation process that cannot be quantified, when consideration is given to the effect of a post-crash environment. An emergency evacuation demonstration, therefore, is not acceptable as an ELOS since it is not meant to allow alleviation or deviation of specific requirements.
If the airplane is configured for passenger and cargo (Combi), the requirements of this section should be met for the passenger compartment. In addition, cargo should be located: 1) so it does not obstruct either access to or use of any required emergency or regular exit; 2) so it does not obstruct the use of the aisle between the crew and passenger compartment; and 3) so it meets the additional requirements of § 135.87.
Amendment 23-7 and Subsequent A proposed revision to NPRM 67-14 explains this amendment as follows: “Section
23.807 (a) (1) exempts all airplanes with five-or-less occupants from the requirement to have an emergency exit opposite the main door. For airplanes with engines mounted on the wings or on the side of the fuselage, the main door may be blocked by engine fire regardless of the number of occupants. Therefore the five-or-less exemption would be discontinued for these aircraft but would be continued for single engine airplanes and centerline thrust twins.”
Amendment 23-10 and Subsequent Multiseat airplanes must have a second exit on the opposite side from the main door, per § 23.807(a)(1). Both exits must be accessible and must not be blocked with cargo.
Amendment 23-34 and Subsequent A proposed revision to NPRM 83-17 added Amendment 23-34. “The source for this revision is part 135, Appendix A., sections 32(a) and (b); SFAR 41, section 5(e), Doors and Exits, paragraphs (g), (i), and (j)”. This amendment added emergency exit requirements for commuter airplanes. Included are emergency exit marking requirements as well as those in §§ 23.783 and 23.1557. The additional emergency exit marking requirements in § 23.1557(d) on the red operating handle and placard that provides door opening instructions are not mandatory for the passenger entrance door. However, § 23.807(b)(3) requires markings for easy location and 128
operation of the exit even in darkness, and § 23.811(b) requires illuminating the exit sign. As an added safety feature, it is recommended the operating handle be selfilluminated and marked with a red arrow and the word “OPEN” in red letters placed near the head of the arrow. If necessary, other relevant instructions for opening the door should also be in red.
This amendment requires three emergency exits as well as the entrance door for commuter airplanes with passenger seating from 16 to 19. Part 25, § 25.807 requires two Type III emergency exits on opposite sides of the cabin. It is possible for an applicant to use part 25 for emergency exits. To do so requires a petition for exemption for part 11, and compliance to part 25, §§ 25.807, 25.561(b) (3)(iv),
25.783, 25.809, 25.811, 25.812, 25.813, 25.815, and 25.817.
An integral stair, if installed at an entrance door, should be designed so it does not reduce the effectiveness of the door as an emergency exit: 1) under the inertia forces of § 23.561 and 2) following the collapse of one or more legs of the landing gear. A demonstration of this failure mode is beyond the intent of this rule. It should be shown by orthographic drafting techniques or test (that is, ground plane under an airplane to simulate various attitudes) that with the various combinations of collapsed landing gears and resulting airplane attitudes, the exit effectiveness is not reduced.
This is done with no fuselage deformation.
There are no standards for ejection seats in part 23. If an applicant needs an ejection seat to meet the emergency exit requirement in § 23.807, an ELOS will have to be justified.
Emergency Exit Size and Shape Background
For a commuter category airplane with a certificated passenger seating capacity of zero (cargo only), two emergency exits (one on each side) are required as well as the main door (reference § 23.807(d)(1)(i)) regardless of the crew compartment door configuration.
CAR 3.387 and 14 CFR, part 23, § 23.807, have required that all emergency exits have enough size and shape to admit a 19 x 26 inch ellipse. Time to egress through an exit is related to the total open area and the most critical dimension of the exit.
The area of a 19 x 26 inch ellipse is 388 square inches. Studies for emergency evacuation demonstrations with the standard ellipse have shown: 1) the duration to egress was equal or less with other exits having a total open area equal to or greater than 388 square inches and 2) the most critical dimension, width or height, greater than 19 inches, but lacking the shape to admit a 19 x 26 inch ellipse.
Acceptable Means of Compliance Alternatives for compliance to the airworthiness standards are allowed by an ELOS.
One method for determining compliance by an ELOS is by the test procedure below.
Demonstrations have shown the emergency exit size and shape affect the time and ease of an emergency evacuation. An ELOS should only be considered if the exit meets the logical limits that correspond to the standard exit. That is, the total open area is equal or greater than 388 square inches and the most critical dimension, width or height, is not less than 19 inches. These limits for area, width, and height were established after considering human factors, evacuation demonstrations, and existing airworthiness standards.
Test Procedure Area of opening. The following factors should be considered when measuring or computing the area of opening:
a. Firm protrusions that would hamper egress should be removed from the minimum required exit opening. Examples are seals or escape latches that will not easily compress, move, or fold out of the opening with the motion of a person moving through the opening.
b. When a compressible seal protrudes into an opening, the seal may be in the compressed condition when measuring or computing the opening area.
c. During the comparison test, the emergency exit opening used as a standard is an opening that will allow passage of a 19 x 26 inch ellipse with a major axis being in a vertical position, a horizontal position, or any other position.
d. The area leading to the opening should be clear and unobstructed. Minor obstructions could be acceptable if there are compensating factors to preserve the effectiveness of the exit. That is, a total effective open area of 388 square inches and the most critical dimension, width or height, not less than 19 inches. For example, soft seatback cushions may constitute minor obstructions: if the cushion can be readily moved away from the exit and the exit can be easily opened, and 2) if the cushion in its normal position does not prevent identification of the exit or obscure the exit marking.
Comparison Test Conditions. The comparison test will determine the difference in mean escape time between either the proposed and standard exit or exits.
a. A mockup of a section of the fuselage may be used. The arrangement of exits, passenger seats, and the step-up and step-down distances from the sill to the wing or step may be simulated. Ramps or stands are allowed to help participants in descending from a wing when over-wing exits are used if the acceptance rate of 130
the ramp or stand is no greater than that of the assist means of the airplane in a crash landing situation. Mats may be used on the floor or ground to protect participants. No other equipment that is not part of the airplanes emergency evacuation equipment may be used to aid the participants in reaching the ground.
b. At the start of each trial, participants should be seated as called out in AC 20-118A, “Emergency Evacuation Demonstration.”
c. Participants should not be allowed any “practice” runs, but they may be briefed on the purpose of the test to show a rapid emergency evacuation of the airplane.
They should not be briefed that the test is to compare exits. An example of an acceptable instruction would be to pass through one foot first, followed by the head and the other foot. The briefing should be the same for each trial.
d. The test should be conducted under dark or simulated dark conditions for both standard and proposed exit configurations for the compliance inspection requirements of AC 20-118A.
e. The participant composition should be as specified in AC 20-118A.
Statistical Design. An acceptable statistical design is as follows:
a. There should be 15 or more participants for each exit configuration to be tested, including the standard configuration.
b. The participants should be assigned to the number of subgroups corresponding to the number of exit configurations to be tested. As noted in paragraph a, each subgroup should have at least 15 people unless the seating configuration is less than 15. In this case the following procedures should be used:
(1) The subgroups should be divided into sub-subgroups of approximately equivalent size where the sub-subgroup size is equal to or less than the seating capacity of the airplane. The egress time of the sub-subgroups is totaled to constitute the subgroup time.
(2) When a mockup for an airplane is used, even if the number of passenger seats is less than 15, the total subgroup of 15 participants may participate at the same time. This is providing the increase of space from the standard mockup for the additional subjects does not degrade the comparison tests. Under these conditions, the participants with the least physical agility should be in the most critical positions.
c. The subgroups should be as neatly alike as possible for physical agility, age, sex, and weight. This can be achieved by first dividing the group by age and 131
sex then subdividing each age/sex group at random into the required number of subgroups.
d. Each subgroup should test each configuration, but the order of trials should be different for each subgroup as well as chosen in accordance with the Latin Square Principle. This principle is that each configuration be tried once by each subgroup and appear once in each possible order. Thus if there are two configurations to be tested and, therefore, two subgroups A and B, then Subgroup A should first try the standard configuration followed by the proposed configuration; Subgroup B should perform the trials in the reverse order. This arrangement removes the effects of an individuals learning, fatigue, and agility.
Recording of Trials. Recording should be done as follows:
a. Motion pictures or video recordings, sound or silent, should be made to analyze the trials for difficulties with an exit, individual escape times, and other performance factors.
b. A large clock with a second hand should be placed in the camera field so time can be recorded or synchronized electric cameras may be used with the time superimposed in the film processing. A signal light to show the beginning and end of each trial should also be arranged in view of the camera.
c. Evacuation time should be rounded to the nearest second. The timed demonstration is performed per the Evacuation section of AC 20-118A.
Evaluation of Results. The evaluation should be performed as follows:
a. The effectiveness of the proposed exit or exits compared with the standard exit or exits is determined by comparison of the average time of the subgroups to pass through each exit tested. The effect of subgroup learning is canceled by the Latin Square Principle.
b. It may be possible one group contains one or two persons who find it difficult to go through the exits. The Latin Square Principle will cancel such unbalance between subgroups.
c. It may happen that an individual may, through chance, have considerable difficulty with an exit, but their performance may compare with average performance of other individuals. A study of the individual escape times will enable such events to be evaluated and will aid in the final determination of the acceptability of the proposed exit or exits.
d. A proposed exit configuration is acceptable when its egress time is equal to or less than the time required to pass through the standard exit.
Type Certificate Data Sheet (TCDS). An equivalent level of safety should be part of the type certification basis and noted on the TCDS. Suggested wording is, “Equivalent Safety Findings: Section 3.387 of the CAR and Section 23.807 of 14 CFR part 23, emergency (particular) exit in accordance with AC 23-17, Systems and Equipment Guide for Certification of Part 23 Airplanes.”
Amendment 23-36 and Subsequent This amendment is explained by Notice 86-19 as follows: “The issue of number and location was addressed by one proposal to require that for all airplanes with a seating capacity of two or more, excluding airplanes with canopies, have at least one emergency exit on the opposite side of the cabin from the main door specified in Section 23.783. There have been egress difficulties experienced with center line engine airplanes with a seating capacity of two or more, excluding those airplanes with canopies, and no emergency exit or door opposite the main cabin door. In some cases, occupants have had to kick out windows to egress the airplanes after survivable accidents.”
Amendment 23-46 and Subsequent A proposed revision to NPRM 90-20 explains this amendment as follows: “For standardization between the airworthiness requirements for commuter category and transport category airplanes, and to simplify the alternate emergency exit standards proposed in this notice, the FAA proposes to move certain requirements of Sec.
23.807(d)(1) to a new paragraph (f) in Sec. 23.783 and proposes a new paragraph
(d)(3) in Sec. 23.807. The standards in proposed Sec. 23.783(f) require that each passenger entry door qualify as a floor level emergency exit and provide requirements for integral stairs when installed at a passenger entry door. The standards in proposed 23.807(d)(3) require that each emergency exit that is not a floor level exit either be located over the wing or, if not less than six feet from the ground, have an acceptable means to assist the occupants in descending to the ground. There are no substantive differences between the requirements in proposed Sec. 23.783(f) or in proposed Sec. 23.807(d)(3) and those requirements proposed to be removed from Sec. 23.807(d)(1).”
A proposed revision to the NPRM explains the following: “This notice proposes new requirements for emergency exit ditching provisions for multiengine airplanes that are type certificated to the airworthiness standards of part 23. The FAA anticipates an increase in the use of commuter category airplanes and multiengine normal category airplanes in over water operation. Airports developed near large bodies of water increase the number of departures and approaches that are conducted over water. Since ditching provisions may be critical for occupant egress following an emergency landing in water, the standards in proposed Sec. 23.807(e) ensure the availability of exits for emergency egress following an emergency landing in water.”