[electromagnetic]

With an altimeter, an artificial horizon and an airspeed indicator, you would expect a VFR pilot to be able to get through any light cloud safely.

Untrained, never having touched the cockpit of a plane, I can get the meaning from these instruments. Is it simply that pilots fly without these, or that they simply disregard them during flight?

[ispolin]

Neither. In US, your plane has to have the 6 basic instruments to be certified as airworthy by FAA. The reasons pilots die in non-visual flight conditions are twofold.

As the original article pointed out, the first reason is that the sensations are so compelling that doing what the instruments tell you will feel VERY unnatural and you will keep thinking that your instruments are broken or stuck (hence you HAVE to trust your instruments). And even if you remember not to trust your instincts, you will still often unconsciously apply slight pressure to the controls.

The second reason is that for every change in the plane's orientation and speed, several instruments will start moving at once. Without training it is very hard to integrate what the 6 instruments are telling you into a complete mental picture of what's going on with your airplane.