Chapter 4
Airworthiness Standards
Airworthiness standards, operating limitations, placards, and pilot awareness for normal, utility, and acrobatic airplanes.
Airworthiness Standards
400. Operating Limitations
Operating limitations are imposed for the safety of pilots and their passengers. Operations contrary to these restrictions are a serious compromise of safety. It is important that all pilots and flight and ground instructors, and pilot examiners apply the following information on spins to pilot training and flight operations.
a. Normal Category
These airplanes are not approved for performing acrobatic maneuvers, including spins, and are placarded against intentional spins. However, to provide a margin of safety when recovery from a stall is delayed, normal category airplanes are tested during certification and must be able to recover from a one turn spin or a 3-second spin, whichever takes longer, in no longer than one additional turn with the controls used in the normally used for recovery or demonstrating the airplane’s resistance to spins. In addition for airplanes demonstrating compliance with one turn or 3-second requirements:
- For both the flaps retracted and flaps extended conditions, the applicable airspeed limit and positive limit maneuvering load factor must not be exceeded;
- No control forces or characteristic encountered during the spin of the recovery may adversely affect prompt recovery;
- It must be impossible to obtain uncontrollable spins with any use of the flight or engine power controls either at the entry or during the spin; and
- In extended condition, the flaps may be retracted during recovery but not before the rotation has ceased.
b. Acrobatic Category
An acrobatic category airplane must meet the spin requirements for normal category aircraft and the following additional requirements:
- The airplane must recover from any point in a spin, up to and including six turns, or any greater number of turns for which certification is requested, in no more than one and a half additional turns after initiation of the first control action for recovery. However, beyond three turns, the spin may be discontinued if spiral characteristics appear.
- The applicable airspeed limits and limit maneuvering load factor must not be exceeded. For the flaps extended configuration for which approval is requested, the flaps must not be retracted during recovery.
- It must be impossible to obtain uncontrollable spins with any use of the flight or engine power controls either at the entry or during the spin.
- There must be no characteristics during the spin (such as excessive rates of rotation or extreme oscillatory motion) that might prevent a successful recovery due to disorientation or incapacitation of the pilot.
c. Utility Category
A utility category airplane must meet the spin requirements for both normal and acrobatic category airplanes and the applicable emergency exit requirements of § 23.807 if the aircraft is approved for spins.
401. Placards
Under § 23.1567, all airplanes type-certificated under part 23 must have a flight maneuver placard containing the following information:
- For normal category airplanes, there must be a placard in front of and in clear view of the pilot stating, “No acrobatic maneuvers, including spins, approved.”
- For utility category airplanes that meet the spin requirements, there must be a placard in front of and in clear view of the pilot stating, “Acrobatic maneuvers are limited to the following (list approved maneuvers and the recommended entry speed for each).”
- For utility category airplanes that do not meet the spin requirements for acrobatic category airplanes, there must be an additional placard in clear view of the pilot stating: “Spins Prohibited.”
- For acrobatic category airplanes, there must be a placard in clear view of the pilot listing the approved acrobatic maneuvers and the recommended entry airspeed for each. If inverted flight maneuvers are not approved, the placard must include a notation to this effect.
- For acrobatic category airplanes and utility category airplanes approved for spin, there must be a placard in clear view of the pilot listing the control actions for the recovery from spinning maneuvers; and stating that recovery must be initiated when spiral characteristics appear, or after not more than six turns or not more than any greater number of turns for which the airplane has been certificated.
402. Pilot Awareness
The pilot of an airplane placarded against intentional spins should assume that the airplane may become uncontrollable in a spin. In addition, stall warning devices should not be deactivated for pilot certification flight tests in airplanes for which they are required equipment.