УСЛОВИЯ НА АВАРИЙНО КАЦАНЕ

(a) The rotorcraft, although it may be

damaged in an emergency crash landing, must be

designed to reasonably protect each occupant

when –

(1) The occupant properly uses the

provided in the design; and

(2) The occupant is exposed to the

loads resulting from the conditions prescribed

in this paragraph.

(b) Each seat type design or other seating

device approved for crew or passenger occupancy

during take-off and landing must successfully

complete dynamic tests or be demonstrated by

rational analysis based on dynamic tests of a

similar type seat in accordance with the following

criteria. The tests must be conducted with an

occupant, simulated by a 77 kg (170-pound)

anthropomorphic test dummy (ATD), sitting in

the normal upright position.

(1) A change in downward velocity of

not less than 9.1 metres per second (30 ft/s)

when the seat or other seating device is

oriented in its nominal position with respect to

the rotorcraft’s reference system, the

rotorcraft’s longitudinal axis is canted upward

60° with respect to the impact velocity vector,

and the rotorcraft’s lateral axis is perpendicular

to a vertical plane containing the impact

velocity vector and the rotorcraft’s longitudinal

axis. Peak floor deceleration must occur in not

more than 0.031 seconds after impact and must

reach a minimum of 30 g.

(2) A change in forward velocity of not

less than 12.8 metres per second (42 ft/s) when

the seat or other seating device is oriented in its

nominal position with respect to the rotorcraft’s

reference system, the rotorcraft’s longitudinal axis

is yawed 10° either right or left of the impact

velocity vector (whichever would cause the

greatest load on the shoulder harness), the

rotorcraft’s lateral axis is contained in a horizontal

plane containing the impact velocity vector, and

the rotorcraft’s vertical axis is perpendicular to a

horizontal plane containing the impact velocity

vector. Peak floor deceleration must occur in not

more than 0.071 seconds after impact and must

reach a minimum of 18.4 g.

(3) Where floor rails or floor or sidewall

attachment devices are used to attach the seating

devices to the airframe structure for the conditions

of this paragraph, the rails or devices must be

misaligned with respect to each other by at least

10° vertically (i.e. pitch out of parallel) and by at

least a 10° lateral roll, with the directions

optional, to account for possible floor warp.

(c) Compliance with the following must be

shown:

(1) The seating device system must

separation intended as part of its design.

(2) The attachment between the seating

device and the airframe structure must remain

intact, although the structure may have

exceeded its limit load.

(3) The ATD’s shoulder harness strap

or straps must remain on or in the immediate

vicinity of the ATD’s shoulder during the

impact.

ATD’s pelvis during the impact.

(5) The ATD’s head either does not

contact any portion of the crew or passenger

compartment, or if contact is made, the head

impact does not exceed a head injury criteria

(HIC) of 1000 as determined by this equation.

Where: a(t) is the resultant acceleration at the

centre of gravity of the head form expressed as a

multiple of g (the acceleration of gravity) and

t2-t1 is the time duration, in seconds, of major

head impact, not to exceed 0.05 seconds.

(6) Loads in individual upper torso

[harness straps must not exceed 7784 Newtons]

(1750 pounds). If dual straps are used for

retaining the upper torso, the total harness strap

[loads must not exceed 8896 Newtons]

(2000 pounds).

(7) The maximum compressive load

measured between the pelvis and the lumbar

column of the ATD must not exceed

[6674 Newtons (1500 pounds).]

(d) An alternate approach that achieves an

equivalent or greater level of occupant protection,

as required by this paragraph, must be

If certification with ditching provisions is

requested, structural strength for ditching must

meet the requirements of this paragraph and JAR

27.801 (e).

(a) Forward speed landing conditions. The

rotorcraft must initially contact the most critical

wave for reasonably probable water conditions at

forward velocities from zero up to 30 knots in

likely pitch, roll and yaw attitudes. The rotorcraft

limit vertical descent velocity may not be less

than 1.52 m (5 feet) per second relative to the

mean water surface. Rotor lift may be used to act

through the centre of gravity throughout the

landing impact. This lift may not exceed twothirds

of the design maximum weight. A

maximum forward velocity of less than 30 knots

may be used in design if it can be demonstrated

that the forward velocity selected would not be

exceeded in a normal one-engine-out touchdown.

(b) Auxiliary or emergency float conditions:

(1) Floats fixed or deployed before

loads in sub-paragraph (a) of this paragraph,

each auxiliary or emergency float, or its

support and attaching structure in the airframe

or fuselage, must be designed for the load

developed by a fully immersed float unless it

can be shown that full immersion is unlikely.

If full immersion is unlikely, the highest likely

float buoyancy load must be applied. The

highest likely buoyancy load must include

consideration of a partially immersed float

creating restoring moments to compensate the

upsetting moments caused by sidewind,

unsymmetrical rotorcraft loading, water wave

action, rotorcraft inertia and probable

structural damage and leakage considered

under JAR 27.801(d). Maximum roll and pitch

angles determined from compliance with JAR

27.801(d) may be used, if significant, to

determine the extent of immersion of each

float. If the floats are deployed in flight,

appropriate air loads derived from the flight

limitations with the floats deployed shall be

used in substantiation of the floats and their

attachment to the rotorcraft. For this purpose,

the design airspeed for limit load is the float

deployed airspeed operating limit multiplied by

1.11.

or partial immersion prescribed in subparagraph

(b) (1) of this paragraph. In

addition, each float must be designed for

combined vertical and drag loads using a

relative limit speed of 20 knots between the

rotorcraft and the water. The vertical load may

not be less than the highest likely buoyancy

of this paragraph.

(а) Условия на кацане с постъпателна скорост. Ророркрафтът трябва първоначално да влезе в контакт с най-критичната вълна за разумно вероятни водни условия при постъпателни скорости от нула до 30 възела при възможни пространствени тангажи, наклони и завъртвания около вертикалната ос. Граничната вертикална скорост на спускане на ророркрафта не трябва да е по-малка от1.52 метра в секунда , спрямо средна водна повърхност. Тягата на носещия винт може да се използва да действа през центъра на тежестта при удара при кацане. Тази тяга не трябва да надвишава две трети от проектираното максимално тегло. Може да се използва максимална постъпателна скорост по-малка от 30 възела при проектиране, ако може да се демонстрира, че избраната постъпателна скорост няма да бъде надвишена при докосване на повърхността при нормално изключен един двигател.

(b) Условия на използване на помощни или аварийни поплавъци

(1) Фиксирани поплаваци или поплавъци,спускани преди първоначален контакт с водата. В допълнение към натоварванията при кацане в подпараграф (а) на този параграф, всеки помощен или авариен поплавък или неговата подпорна и закрепваща конструкция към корпуса на ророркрафта или фюзилажа, трябва да бъдат проектирани за товара, който се образува при напълно потопен поплавък, освен ако не може да се покаже, че няма вероятност за пълно потапяне. Ако пълното потапяне не е вероятно, то тогава трябва да се приложи най-високото натоварване при задържане на повърхността на водата. Най-високото натоварване при задържане върху повърхността на водата трябва да отчита частично потопен поплавък, създаващ възстановяващи моменти за компенсиране на моментите , създадени от вълните, причинени от страничен вятър, несеметрично натоварване на ророркрафта, дейсвието на вълните на водата, инерцията на ророркрафта и вероятностното разрушаване на конструкцията и изтичане на течности, разгледани в JAR 27.801 (d). Максималните ъгли на наклон и на тангажа, определени при отговаряне на изискванията на JAR. 801 (d) могат да се използват, ако са значителни, за определяне на степента на потапяне на всеки поплавък. Ако поплавъците се спускат по време на полет, ще се използват подходящи въздушни натоварвания, извлечени от летателните ограничения при спуснати поплавъци, за привеждане на основания за поплавъците и тяхното прикрепяне към ророркрафта. За тази цел проектната летателна скорост за максимално натоварване е експлоатационото ограничение за летателната скорост при спуснат поплавък, умножено по 1.11.

(2) Спускане на поплавъците след първоначален контакт с водата. Всеки поплавък трябва да бъде проектиран за пълно или частично потапяне , предписано в подпараграф (b) (1) на този параграф. В допълнение, всеки поплавък трябва да бъде проектиран за комбинираното въздействие на вертикални натоварвания и натоварвания при спиране при използване на относителна максимална скорост от 20 възела между ророркрафта и водата. Вертикалното натоварване не може да бъде по-малко от вероятното натоварване при задържане върху повърхността на водата, определено в подпараграф (b) (1) на този параграф.

(a) General. Each portion of the flight

structure (the flight structure includes rotors, rotor

drive systems between the engines and the rotor

hubs, controls, fuselage, landing gear, and their

related primary attachments) the failure of which

could be catastrophic, must be identified and must

[be evaluated under sub-paragraph (b), (c), (d), or ]

(e) of this paragraph. The following apply to each

fatigue evaluation:

(1) The procedure for the evaluation

must be approved.

(2) The locations of probable failure

must be determined.

(3) In-flight measurement must be

included in determining the following:

(i) Loads or stresses in all critical

conditions throughout the range of

limitations in JAR 27.309, except that

manoeuvring load factors need not

exceed the maximum values expected in

operation.

(ii) The effect of altitude upon

these loads or stresses.

(4) The loading spectra must be as

severe as those expected in operation

including, but not limited to, external cargo

operations, if applicable, and ground-airground

cycles. The loading spectra must be

sub-paragraph (a) (3) of this paragraph.

(b) Fatigue tolerance evaluation. It must be

shown that the fatigue tolerance of the structure

ensures that the probability of catastrophic fatigue

failure is extremely remote without establishing

replacement times, inspection intervals or other

[procedures under paragraph A27.4 of Appendix ]

A.

(c) Replacement time evaluation. It must be

failure is extremely remote within a replacement

Appendix A.

(d) Fail-safe evaluation. The following

apply to fail-safe evaluation:

(1) It must be shown that all partial

[failures will become readily detectable under

inspection procedures furnished under ]

paragraph A27.4 of Appendix A.

(2) The interval between the time when

any partial failure becomes readily detectable

[under sub-paragraph (d) (1) of this paragraph,]

and the time when any such failure is expected

to reduce the remaining strength of the

structure to limit or maximum attainable loads

(whichever is less), must be determined.

(3) It must be shown that the interval

this paragraph is long enough, in relation to

the inspection intervals and related procedures

[furnished under paragraph A27.4 of]

Appendix A, to provide a probability of

detection great enough to ensure that the

probability of catastrophic failure is extremely

remote.

(e) Combination of replacement time and

evaluated under a combination of sub-paragraphs

(c) and (d) of this paragraph. For such component

it must be shown that the probability of

catastrophic failure is extremely remote with an

approved combination of replacement time,

inspection intervals, and related procedures

furnished under paragraph A27.4 of Appendix A.