routing and an alternative clearance if VFR − on − top is not reached by a specified altitude. 

c. A pilot on an IFR flight plan, operating in VFR conditions, may request to climb/descend in VFR conditions. 

d. ATC may not authorize VFR − on − top/VFR conditions operations unless the pilot requests the VFR operation or a clearance to operate in VFR conditions will result in noise abatement benefits where part of the IFR departure route does not conform to an FAA approved noise abatement route or altitude. 

e. When operating in VFR conditions with an ATC authorization to “maintain VFR − on − top/maintain VFR conditions” pilots on IFR flight plans must: 

1. Fly at the appropriate VFR altitude as prescribed in 14 CFR Section 91.159. 

2. Comply with the VFR visibility and distance from cloud criteria in 14 CFR Section 91.155 (Basic VFR Weather Minimums). 

3. Comply with instrument flight rules that are applicable to this flight; i.e., minimum IFR altitudes, position reporting, radio communications, course to be flown, adherence to ATC clearance, etc. 

## NOTE 

Pilots should advise ATC prior to any altitude change to ensure the exchange of accurate traffic information. 

f. ATC authorization to “maintain VFR − on − top” is not intended to restrict pilots so that they must operate only above  an obscuring meteorological formation (layer). Instead, it permits operation above, below, between layers, or in areas where there is no meteorological obscuration. It is imperative, howev- er, that pilots understand that clearance to operate “VFR − on − top/VFR conditions” does not imply cancellation of the IFR flight plan. 

g. Pilots operating VFR − on − top/VFR conditions may receive traffic information from ATC on other pertinent IFR or VFR aircraft. However, aircraft operating in Class B airspace/TRSAs must be separated as required by FAA Order JO 7110.65, Air Traffic Control. 

## NOTE 

When operating in VFR weather conditions, it is the pilot’s responsibility to be vigilant so as to see − and − avoid other aircraft. 

h. ATC will not authorize VFR or VFR − on − top operations in Class A airspace. 

## REFERENCE − 

AIM, Paragraph 3 − 2 − 2 , Class A Airspace 

## 4 − 4 − 9. VFR/IFR Flights 

A pilot departing VFR, either intending to or needing to obtain an IFR clearance en route, must be aware of the position of the aircraft and the relative terrain/obstructions. When accepting a clearance below the MEA/MIA/MVA/OROCA, pilots are responsible for their own terrain/obstruction clear- ance until reaching the MEA/MIA/MVA/OROCA. If pilots are unable to maintain terrain/obstruction clearance, the controller should be advised and pilots should state their intentions. 

## NOTE 

OROCA is an off − route altitude which provides obstruc- tion clearance with a 1,000 foot buffer in nonmountainous terrain areas and a 2,000 foot buffer in designated mountainous areas within the U.S. This altitude may not provide signal coverage from ground − based navigational aids, air traffic control radar, or communications coverage. 

## 4 − 4 − 10. Adherence to Clearance 

a. When air traffic clearance has been obtained under either visual or instrument flight rules, the pilot − in − command of the aircraft must not deviate from the provisions thereof unless an amended clearance is obtained. When ATC issues a clearance or instruction, pilots are expected to execute its provisions upon receipt. ATC, in certain situations, will include the word “IMMEDIATELY” in a clearance or instruction to impress urgency of an imminent situation and expeditious compliance by the pilot is expected and necessary for safety. The addition of a VFR or other restriction; i.e., climb or descent point or time, crossing altitude, etc., does not authorize a pilot to deviate from the route of flight or any other provision of the ATC clearance. 

b. When a heading is assigned or a turn is requested by ATC, pilots are expected to promptly initiate the turn, to complete the turn, and maintain the new heading unless issued additional instructions. 

c. The term “AT PILOT’S DISCRETION” included in the altitude information of an ATC clearance means that ATC has offered the pilot the option to start climb or descent when the pilot wishes, 

