Let's say you are out on a flight and the weather isn't forecasting what you expected. In front of you is a low layer of clouds (that you are well above) and you are about to fly over them. If you no longer have references to the ground are you still within VFR limitations? Are you IFR? Let's take a minute to review what constitutes VFR and IFR flying and the options in between. VFR vs. IFR
Visual Flight Rules (VFR) is simply when you operate an aircraft in visual meteorological conditions (VMC). In other words, nice and clear weather. Instrument Flight Rules (IFR) is the opposite of VFR and most all flights may operate in instrument meteorological conditions (IMC)—clouds, heavy precipitation, low visibility, and otherwise adverse weather conditions.
VFR Over the Top
In this particular situation even though there are clouds, it is actually perfectly legal to fly above them. This is called VFR-over-the-top. According to FAR 91.507 Equipment requirements: Over-the-top or night VFR operations:
"No person may operate an airplane over-the-top or at night under VFR unless that airplane is equipped with the instruments and equipment required for IFR operations under § 91.205(d) and one electric landing light for night operations. Each required instrument and item of equipment must be in operable condition."
The regulations don't specify much more then that. It is required still for you to maintain VFR weather minimums. Due to the fact you are not in ATC positive control as you would be under an IFR flight plan, there are quite a few things you need to consider. For example, in the event of an engine failure, where are you going to land? Have you planned an alternate airport along the way? Although this is legal, it should not be your first go to option for safety reasons.
VFR On Top
Do not confuse VFR over the top with VFR on top. VFR on top allows you to climb above a layer of clouds, smoke, haze, or other meteorological formations while operating on an IFR flight plan. According to FAR/AIM chapter 4-4-8 to maintain "VFR-on-top" the following conditions must be met:
• 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.
There you have it. You can still maintain VFR in several different situations. A lot depends on aircraft equipment, pilot qualifications, and what you as the pilot filed or clearances via ATC.