What are the rules for flight over clouds?

Note that "on top" and "over the top" are two different things. VFR "on top" simply means that you have an IFR clearance, but are currently in VFR conditions and are flying as if you were under VFR regulations. There may or may not be clouds below you. VFR "over the top" is always above a cloud layer and is pure VFR, no flight plan or IFR clearances are needed.

A student pilot may fly VFR, but must have visual contact with the ground. This rules out VFR over the top. Since a student pilot cannot fly IFR, he cannot fly VFR on top either, since that requires an IFR clearance.

A private pilot without an instrument rating my fly VFR over the top of a cloud layer. He need not have visual contact with the ground. However, this is suicide if he cannot be assured of a safe descent under VFR conditions.

Any instrument rated pilot may request VFR on top if he is flying under an IFR clearance and finds himself in VFR conditions. Note that commercial and military pilots may have special rules that restrict under what conditions they can do this. A pilot does not have to request this if he doesn't want do, nor does he have to accept it if ATC offers it and he does not wish it.

that must be an Army Reg.

FAR;s

Class A- must be on IFR Flight plan, so no cloud clearance requirements apply

Class B- Clear of clouds

Class C- 1000' above

Class D- 1000' above

Class E- 1000' above above and below 10,000 msl

Class G- Day below 10000msl, clear of clouds below 1200AGL, Night - 1000' above below 1200AGL, 1000' above 10000msl day and night above 1200AGL, with the exception in the vacainty of an airport where it is clear of clouds.

If the pilot is IFR and is in class C or D airspace, can be issued a Special VFR, and has to remain clear of clouds.

VFR on top, is a IFR Clearance to climb above the clouds, and then the cloud clearance requirements of what ever airspace the aircraft is operating in and altitude.

The 30 miniute restriction is not FAA mandated. I cant say if it is a military restriction.

VFR-over-the-top is not addressed in 14 CFR Part 91, so only the basic VFR weather requirements of Section 91.155 [Basic VFR weather minimums] apply."

If you are operating under part 135...

Sec. 135.211 - VFR: Over-the-top carrying passengers: Operating limitations.

Subject to any additional limitations in §135.181, no person may operate an aircraft under VFR over-the-top carrying passengers, unless --

(a) Weather reports or forecasts, or any combination of them, indicate that the weather at the intended point of termination of over-the-top flight --

(1) Allows descent to beneath the ceiling under VFR and is forecast to remain so until at least 1 hour after the estimated time of arrival at that point; or

(2) Allows an IFR approach and landing with flight clear of the clouds until reaching the prescribed initial approach altitude over the final approach facility, unless the approach is made with the use of radar under §91.175(f) of this chapter; or

(b) It is operated under conditions allowing --

(1) For multiengine aircraft, descent or continuation of the flight under VFR if its critical engine fails; or

(2) For single-engine aircraft, descent under VFR if its engine fails.

Sec. 135.181

Aircraft operated over-the-top or in IFR conditions.

(a) Except as provided in paragraphs (b) and (c) of this section, no person may--

(1) Operate a single-engine aircraft carrying passengers over-the-top; or

(2) Operate a multiengine aircraft carrying passengers over-the-top or in IFR conditions at a weight that will not allow it to climb, with the critical engine inoperative, at least 50 feet a minute when operating at the MEAs of the route to be flown or 5,000 feet MSL, whichever is higher.

(b) Notwithstanding the restrictions in paragraph (a)(2) of this section, multiengine helicopters carrying passengers offshore may conduct such operations in over-the-top or in IFR conditions at a weight that will allow the helicopter to climb at least 50 feet per minute with the critical engine inoperative when operating at the MEA of the route to be flown or 1,500 feet MSL, whichever is higher.

(c) Without regard to paragraph (a) of this section, if the latest weather reports or forecasts, or any combination of them, indicate that the weather along the planned route (including takeoff and landing) allows flight under VFR under the ceiling (if a ceiling exists) and that the weather is forecast to remain so until at least 1 hour after the estimated time of arrival at the destination, a person may operate an aircraft over-the-top.

(d) Without regard to paragraph (a) of this section, a person may operate an aircraft over-the-top under conditions allowing--

(1) For multiengine aircraft, descent or continuance of the flight under VFR if its critical engine fails; or

(2) For single-engine aircraft, descent under VFR if its engine fails.