Why would airline instructors disable the airspeed instrument in the simulator on short final on a Boeing?

Question

I mean, chances that the airspeed instrument fails on a short final approach is low, and even if it would fail, you have in bigger jets 3 different airspeed instruments, so why to teach how to land with none, if this case can actually not come (the chances are more than low)...?!

Answer 1

Possibly what the instructor was trying to do is what is called "loading" you up.  On short final you are mentally quite busy  and the slightest little thing can break that good rhythm and concentration that you have therefore throwing off your entire approach and forcing a go around or a crash.  I used to do this sort of thing to my students all the time on short final.  It teaches you in what order to deal with things.  If you start to focus on the failure of the airspeed indicator and fly in to the ground well that is going to be a problem.  If you see the failure and announce it then go to a back up, great you didnt load up.  It is just another way to check good instinctual decision making.

I had a check airman fail a generator on me when I was on short final to a pinnacle, confined landing are with obstacles. I announced the failure to let him know I saw it and just shot the approach like normal, knowing I had more than enough time on the battery to not worry about it.  Once we landed I began the rest procedures and was congratulated for doing the correct thing even-though it is not what you were "supposed" to do. He told me that had I started doing the reset procedure on the approach I would have failed.

So its a good way to check someones decision making skills when there head is already full.

Answer 2

The pilot should be versatile and resourceful.  The instructors failed the airspeed indicators on short final?  That's not an emergency.  Just land, or go around.

Answer 3

You know how low the chance of an engine fire is? And we practice them all the time.

Answer 4

Doing critical maneuvers without the basic reference instruments helps pilots eliminate complacency and build confidence.  It is also done in actual aircraft check rides, Boeing and otherwise.

Discovering that you can still judge your airspeed well enough to get it on the ground in one piece makes you humble, cautious, and a little more confident in your skills.

Answer 5

happened once, plane came out of the hangar and the engineers had covered the static ports with some type of tape stuff and forgot to pull them off. anyway, plane took off and lo n behold no airspeed or altitude info. it crashed. maybe he was emulating that?

Answer 6

I get trained the same way in my 172 ;). I'm just getting ready to solo and 1 of my lessons took me through a Towered airport (fly out of one normally anyways). and I had to fly a pattern with my six pack dead, and only a flimsy Magnetic compass to guide me.

Answer 7

If there is any possibility that it could actually occur, then you should expect it to occur in the simulator. In fact, you should also expect it to occur and be prepared for it in the air.

What is a simulator for if not to rehearse such "improbable" occurrences in an environment that will not kill you if you make the wrong choices?

Answer 8

Chances of it happening in real life be LOW, but it is not zero chance. Final is not the time to pull out a check list on what to do pilot MUST already know. Plane crashed in Florida because Both pilots were checking a burned out light bulb.

Answer 9

I'd have to say that the chances of the airspeed indicator malfunctioning is probably GREATER at a low altitude just from the number of foreign objects, i.e. bugs, birds, etc.

Aside from that, the instructor may just be trying to drive home the point that an aircraft's attitude plus it's power setting equals a certain view out the cockpit window--in other words, "With the power set here, and the pitch set here--this is what you should see."

Additionally, the idea mentioned of having to use standby instruments or ancillary instruments such as Angle of Attack is a valid one.  There's too little time short final to dig into a checklist to select another Air Data Computer or worse yet, exchange controls to the other pilot.  

Many airlines also require that a pilot know how to deal with flight instrument failures, and while the likelihood of it happening IS extremely low, the training still has to occur.  Call it "checking a box."