I've a simple question regarding the rare case of the failure of all airspeed indicators (ASI) including the co-pilots's indicator. Say the airspeed indicators were to fail during rotation, what would be the standard procedure then?

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    $\begingroup$ The answer depends a great deal on the aircraft. $\endgroup$ Commented May 28 at 16:34
  • $\begingroup$ Details vary but I would think regardless of aircraft type you would continue the takeoff and climbout using pitch and power as your cues until you're able to regain reliable and accurate airspeed indications or just stay in the pattern and come back and land. Angle of attack indications would be nice but not required. $\endgroup$
    – AeroAndy
    Commented May 28 at 18:36
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    $\begingroup$ This question is related: aviation.stackexchange.com/questions/105181/… and so is this: en.wikipedia.org/wiki/Birgenair_Flight_301 $\endgroup$ Commented May 29 at 3:11
  • $\begingroup$ I think it depends a lot if it happens on a Cessna 172 in the daytime or on a jetliner at night on the ocean $\endgroup$
    – sophit
    Commented May 29 at 20:04

2 Answers 2


Step 1 in any emergency: Fly the airplane.

Thrust and pitch control your airspeed. A good pilot knows the settings for each phase of flight. It may not be exact, but it will keep the airplane flying.

Step 2: Determine the problem. Refer to checklist.

The crew alerting system will tell you if there are any detected faults and in which system. For Airspeed, you can also cross check between CAPT and FO and with IRS/GPS ground speed. And in an air transport aircraft, there's a third air data unit (sometimes AD3 or Standby or SAARU).

Step 3: Take corrective action.

Declare an emergency. Fly to an safe altitude and area to determine next actions. Prepare for a landing as soon as practical (May require dumping fuel or alternate airport.)

  • $\begingroup$ Thank you for your reply!, I found it quite helpful. $\endgroup$ Commented May 29 at 6:44
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    – Bianfable
    Commented May 29 at 7:35

In a light aircraft we're taught "pitch plus power equals performance" - and to an extent the same is true from a tiny Cessna up to a giant Airbus.

My instrument instructor reminded me that I neither need an RPM gauge nor a speedometer to know when to change gear in a car (yes we used to drive manual cars!) as you just could feel, with some experience, when was the right time to do so.

This holds true in a light aircraft for airspeed, with some experience you can feel the speed - especially approaching a stall as the controls start to get "mushy" a good 5-10 knots before the stall.

So taking off with an inoperative ASI is fairly benign. Power is typically at or near full, and you pitch as you normally would for a climb. Pitch + Power = performance.

Landing is slightly more work, its still pitch + power, but it certainly helps to have a good amount of experience of that type so you can feel if you start to get too slow. When I tried it with an instructor who had covered my ASI he asked me on final what speed I thought I was doing, and I correctly guessed within 5 knots. It was the absolute normal approach speed I had done a hundred times before.


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