Adding to what Cooter, Fearless Tower and others have stated, below an excerpt from the linked IFR Magazine article (SD is spatial disorientation):
http://www.ifr-magazine.com/issues/1_22/features/219-1.html
Departure Disorientation
Accidents attributed primarily to SD are the next ones under our microscope, with seven percent of the total accidents and 100-percent lethality. Of these, four were cases where the pilots lost control en route or early on approach for no clear reason, and one more appears to be instrument failure inducing SD.
The remaining nine accidents—64 percent of the total SD accidents—were SD during takeoff and climb, or during a climb from VMC into IMC while en route. This isn’t counting another 14 accidents during takeoff that didn’t appear to be cases of SD, and isn’t including VFR-into-IMC accidents where pilots entered the clouds inadvertently and lost control.
That’s a disturbingly high number of pilots intentionally entering the clouds and then failing to maintain basic attitude instrument flying.
To be fair, one of these could be a case of instrument failure, but the fact that the pilot reported it right after entering the clouds makes it questionable whether it was the instruments or the pilot’s disbelief of what the instruments were saying. Then again, two fatal go-around crashes may have some aspect of SD in them as well, so the number may be a bit higher than we’re reporting here.
No matter what the exact count is, SD after entering IMC is a recurring theme. The accident sequence is often quick, as you can see in the summary of one Aero Commander: “Less than two minutes after the airplane departed the airport, the controller observed the airplane in a right turn and instructed the pilot to report his altitude. The pilot responded he thought he was at 3500 feet and he thought he had lost the gyros.” Maybe he did, but post-crash analysis and Occam’s razor point to simple disorientation.
A Cessna 310 had a similar tale: “The pilot departed from the airport under instrument meteorological conditions on an instrument flight rules flight plan. Weather included a 300-foot overcast cloud layer and one-mile visibility with light rain and mist. Shortly after takeoff, the air traffic controller lost radio contact with the pilot, and witnesses observed the airplane rolling under full power as it descended out of the clouds.”
These were experienced pilots of piston twins, so this isn’t just an accident for the novice or non-proficient. One of the other accident pilots in this group had an IPC days before the wreck.
Another recurring departure problem that surprised us with its prevalence is best described as a general failure to climb. One aircraft that departed in “calm winds, a 1/4-mile visibility in fog and a vertical visibility of 100 feet. Shortly after takeoff for the instrument-flight-rules flight, the airplane made a slight turn to the left and impacted the tops of 25-foot trees about a 1/2 mile from the runway.” Another accident had a similar summary: “After departing Runway 24, the airplane collided with the top conductor of a telephone line an estimated 2500 feet from the departure end of the runway. The estimated elevation of the line was 245 feet.”
If you’re thinking these were climb-challenged, overloaded aircraft, think again: They were both King Airs. Piston twins and singles were members of this group as well, again with experienced pilots. Perhaps that’s part of the problem: Entering the clouds is routine, so it’s easier to let your attention wander to other cockpit tasks and away from just maintaining a positive rate of climb...