Figure 10-5 .  Drift correction in holding pattern. ATC instructions are also issued whenever: The entry procedures given in the AIM evolved from  extensive experimentation under a wide range of operational  conditions. The standardized procedures should be followed  to ensure that an aircraft remains within the boundaries of  the prescribed holding airspace. When a speed reduction is required, start the reduction when  3 minutes or less from the holding fix. Cross the holding fix  initially at or below the maximum holding airspeed (MHA).  The purpose of the speed reduction is to prevent overshooting  the holding airspace limits, especially at locations where  adjacent holding patterns are close together. All aircraft may hold at the following altitudes and maximum  holding airspeeds: Standard Entry Procedures The following are exceptions to the maximum holding  airspeeds: 10-11 2.  Holding fix (the fix may be omitted if included at the  beginning of the transmission as the clearance limit) 3.  Radial, course, bearing, airway, or route on which the  aircraft is to hold. 4.  Leg length in miles if DME or RNAV is to be used  (leg length is specified in minutes on pilot request or  if the controller considers it necessary). 5.  Direction of turn, if left turns are to be made, because  the pilot requests or the controller considers it  necessary. 6.  Time to expect-further-clearance (EFC) and any  pertinent additional delay information. 1.  It is determined that a delay will exceed 1 hour. 2.  A revised EFC is necessary. 3.  In a terminal area having a number of NAVAIDs  and approach procedures, a clearance limit may not  indicate clearly which approach procedures will  be used. On initial contact, or as soon as possible  thereafter, approach control advises the pilot of the  type of approach to expect. 4.  Ceiling and/or visibility is reported as being at or  below the highest “circling minimums” established  5.  An aircraft is holding while awaiting approach  clearance, and the pilot advises ATC that reported  weather conditions are below minimums applicable  to the operation. In this event, ATC issues suitable  instructions to aircraft desiring either to continue  holding while awaiting weather improvement or  proceed to another airport. for the airport concerned. ATC transmits a report of  current weather conditions and subsequent changes,  as necessary. 1.  Holding patterns from 6,001 to 14,000 feet may  be restricted to a maximum airspeed of 210 knots  indicated airspeed (KIAS). This nonstandard pattern  is depicted by an icon. 2.  Holding patterns may be restricted to a maximum  airspeed of 175 KIAS. This nonstandard pattern is  depicted by an icon. Holding patterns restricted to  175 KIAS are generally found on IAPs applicable to  category A and B aircraft only. 3.  Holding patterns at Air Force airfields only—310  KIAS maximum, unless otherwise depicted. 4.  Holding patterns at Navy airfields only—230 KIAS  maximum, unless otherwise depicted. 5.  The pilot of an aircraft unable to comply with  maximum airspeed restrictions should notify ATC. Altitude Mean Sea Level (MSL)  Airspeed (KIAS) Up to 6,000 feet  200 6,001 – 14,000 feet 230 14,001 feet and above  265