If a static vent or a pitot tube blocks up you will get erroneous pressure instrument readings. From a Cessna 152 to a Boeing Dreamliner all use dynamic and static pressure inputs from nothing more than a small hole on the side of the aircraft or in the case of a pitot tube on the front of the aircraft. Guess what? Small holes block up easily and the cause can be a variety of things from ice to insects. These sort of blockages lead to incidents and sadly accidents and are as old as aviation itself. Despite these problems being very well known pilots still seem to get caught out on a regular basis, even experienced professionals are deceived by something which should be elementary knowledge to every student before first solo.
1. NEVER TRUST ONE MAN, ONE GAUGE OR ONE ENGINE
2. POWER PLUS ATTITUDE = PERFORMANCE
All the professional pilots below failed to diagnose the simplest of aviation problems and caused the unneccessary deaths of all their passengers, so remember the two maxims above, they come from the DC3 era of flying when aircraft and pilots were both basic and flew more by the seat of their pants. The irony is that todays modern computer based jet aircraft still have the capability to be flown like a basic simple aircraft so when it all goes wrong-stay cool and go back to basics and FLY THE AIRCRAFT TO A SAFE PLACE and that applies to any aircraft
1 December 1974—Northwest Airlines Flight 6231, a Boeing 727, crashed northwest of John F. Kennedy International Airport during climb en route to Buffalo Niagara International Airport because of blockage of the pitot tubes by atmospheric icing.
6 February 1996—Birgenair Flight 301 crashed into the sea shortly after takeoff due to incorrect readings from the airspeed indicator. The suspected cause is a blocked pitot tube (this was never confirmed, as the airplane wreck was not recovered).
2 October 1996—AeroPeru Flight 603 crashed because of blockage of the static ports. The static ports on the left side of the aircraft had been taped over while the aircraft was being waxed and cleaned. After the job was done, the tape was not removed.
1 June 2009—Air France Flight 447 is believed to have had a pitot tube error while in flight over the Atlantic Ocean and subsequently crashed with the loss of all aboard.
As your instructor should show you before first solo you don’t need an ASI to fly a circuit and land-understand that power plus attitude = performance. For one power setting in straight & level flight you can only be flying at two different airspeeds, why two? Well if you do not know that you had better contact me as you should not be flying if you do not understand that, it’s very important!