loop, the controllers must also clearly understand the pilot’s  readback and other responses. Pilots can help enhance the  controller’s understanding by responding appropriately and  using standard phraseology. Regulatory requirements, the  AIM, approved flight training programs, and operational  manuals provide information for pilots on standard ATC  phraseology and communications requirements. A flight filed for a short distance at a relatively low altitude  in an area of low traffic density might receive a clearance  as follows: “Cessna 1230 Alpha, cleared to Doeville airport direct,  cruise 5,000.” The term “cruise” in this clearance means a pilot is authorized  to fly at any altitude from the minimum IFR altitude up to  and including 5,000 feet and may level off at any altitude  within this block of airspace. A climb or descent within the  block may be made at the pilot’s discretion. However, once  a pilot reports leaving an altitude within the block, the pilot  may not return to that altitude without further ATC clearance. When ATC issues a cruise clearance in conjunction with  an unpublished route, an appropriate crossing altitude is  specified to ensure terrain clearance until the aircraft reaches a  fix, point, or route where the altitude information is available.  The crossing altitude ensures IFR obstruction clearance to  the point at which the aircraft enters a segment of a published  route or IAP. Once a flight plan is filed, ATC issues the clearance with  appropriate instructions, such as the following: “Cessna 1230 Alpha is cleared to Skyline airport via  the Crossville 055 radial, Victor 18, maintain 5,000.  Clearance void if not off by 1330.” Or a more complex clearance, such as: “Cessna 1230 Alpha is cleared to Wichita Mid- continent airport via Victor 77, left turn after takeoff,  proceed direct to the Oklahoma City VORTAC.  Hold west on the Oklahoma City 277 radial, climb to  5,000 in holding pattern before proceeding on course.  Maintain 5,000 to CASHION intersection. Climb to  and maintain 7,000. Departure control frequency will  be 121.05, Squawk 0412.” Clearance delivery may issue the following “abbreviated  clearance” which includes a departure procedure (DP): “Cessna 1230 Alpha, cleared to La Guardia as filed,  RINGOES 8 departure Phillipsburg transition,  maintain 8,000. Departure control frequency will be  120.4, Squawk 0700.” This clearance may be readily copied in shorthand as follows: “CAF RNGO8 PSB M80 DPC 120.4 SQ 0700.” The information contained in this DP clearance is abbreviated  using clearance shorthand (see appendix 1). The pilot should  know the locations of the specified navigation facilities,  together with the route and point-to-point time, before  accepting the clearance. The DP enables a pilot to study and understand the details  of a departure before filing an IFR flight plan. It provides  the information necessary to set up communication and  navigation equipment and be ready for departure before  requesting an IFR clearance. Once the clearance is accepted, a pilot is required to comply  with ATC instructions. A clearance different from that issued  may be requested if the pilot considers another course of  action more practicable or if aircraft equipment limitations  or other considerations make acceptance of the clearance  inadvisable. ATC provides the pilot on an IFR clearance with separation  from other IFR traffic. This separation is provided: ATC does not provide separation for an aircraft operating: Clearance Separations A pilot should also request clarification or amendment, as  appropriate, any time a clearance is not fully understood  or considered unacceptable for safety of flight. The pilot  is responsible for requesting an amended clearance if ATC  issues a clearance that would cause a pilot to deviate from  a rule or regulation or would place the aircraft in jeopardy. 1.  Vertically—by assignment of different altitudes. 2.  Longitudinally—by controlling time separation  between aircraft on the same course. 3.  Laterally—by assignment of different flightpaths. 4.  By radar—including all of the above. 1.  Outside controlled airspace. 2.  On an IFR clearance: a)  With “VFR-On-Top” authorized instead of a  specific assigned altitude. b) Specifying climb or descent in “VFR conditions.” c)  At any time in VFR conditions, since uncontrolled  VFR flights may be operating in the same  airspace. 10-4 Examples