(b)
Each system mustbe calibrated todeterminethe system error(thatis,the relation between IAS and CAS) in .ight and during the accelerated takeo. ground run. The ground run calibration must be determined–
(1)
From 0.8 of the minimum value of V1 to the maximum value of V2, considering the approved ranges of altitude and weight; and
(2)
With the .aps and power settings corresponding to the values determined in the establishment of the takeo. path under Sec. 25.111 assuming that the critical engine fails at the minimum value of V1.
(c)
The airspeed error of the installation, excluding the airspeed indicator instrument calibration error, may not exceed three percent or .ve knots, whichever is greater, throughout the speed range, from–
(1)
VMO to 1.23VSR1 with .aps retracted; and
(2)
1.23VSR0 to VFE with .aps in the landing position.
(d)
[From 1.23 VSR to the speed at which stall warning begins, the IAS must change perceptibly with CAS and in the same sense, and at speeds below stall warning speed the IAS must not change in an incorrect sense.
2
(e) From VMO to VMO + (VDF .VMO), the IAS must change perceptibly with CAS
3
and in the same sense, and at higher speeds up to VDF the IAS must not change in an incorrect sense.
(f)
There must be no indication of airspeed that would cause undue di.culty to the pilot during the takeo. between the initiation of rotation and the achievement of a steady climbing condition.
(g)
The e.ects of airspeed indicating system lag may not introduce signi.cant takeo. indicated airspeed bias, or signi.cant errors in takeo. or accelerate-stop distances.
(h)
Each system must be arranged, so far as practicable, to prevent malfunction or serious error due to the entry of moisture, dirt, or other substances.
(i)
Each system must have a heated pitot tube or an equivalent means of preventing malfunction due to icing.
(j)
Where duplicate airspeed indicators are required, their respective pitot tubes must
befar enough apartto avoiddamagetobothtubesin a collision with abird.] Amdt. 25-109, E.. 1/13/2003
FAR 25.1325 : Static pressure systems.
(a)
Each instrument with static air case connections must be vented to the outside atmospherethrough an appropriatepiping system.
(b)
Each staticport mustbedesigned andlocatedin such mannerthatthe staticpres-sure system performance is least a.ected by air.ow variation, or by moisture or other foreign matter, and that the correlation between air pressure in the static
′
Elodie Roux. Septembre 2003
Subpart F : Equipment
pressuresystem and true ambientatmosphericstaticpressureis notchanged when the airplane is exposed to the continuous and intermittent maximum icing condi-tions de.ned in Appendix C of this Part.
(c)
The design and installation of the static pressure system must be such that–
(1)
Positive drainage of moisture is provided; cha.ng of the tubing and excessive distortion or restriction at bends in the tubing is avoided; and the materials used are durable, suitable for the purpose intended, and protected against corrosion; and
(2)
It is airtight except for the port into the atmosphere. A proof test must be conducted to demonstrate the integrity of the static pressure system in the following manner :
(i)
Unpressurizedairplanes.Evacuate the staticpressure system to apressure di.erential of approximately 1 inch of mercury or to a reading on the altimeter, 1,000 feet above the airplane elevation at the time of the test. Without additionalpumpingfor aperiod of1 minute, theloss ofindicated altitude must not exceed 100 feet on the altimeter.
(ii)
Pressurized airplanes. Evacuate the static pressure system until a pres-sure di.erential equivalent to the maximum cabin pressure di.erential for which the airplane is type certi.cated is achieved. Without additio-nal pumping for a period of 1 minute, the loss of indicated altitude must not exceed 2 percent of the equivalent altitude of the maximum cabin di.erential pressure or 100 feet, whichever is greater.
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本文链接地址：FAA规章 美国联邦航空规章 Federal Aviation Regulations 4(19)
