How was that possible?

[LGA]

I'm not sure how many of you guys here are familiar with that AeroPeru 757 that crashed after maintenance crews taped up the static ports, but for those who are, ever since reading the CVR transcript and the story, I ask myself, how in the world were they even able to take off? They had no airspeed indicator or basic instruments, so how were they able to determine V speeds? I just don't understand how they were not able to detect that their airspeed indicators were not operational during the takeoff roll. The only thing that I can think of is that they were getting readings from some wheel mounted system to measure speed in mph, such as in a car or bike, but I don't think they have that on aircraft. Does anyone have any ideas?

[jcmissionary]

An ASI will still work with plugged static ports, but it will give inaccurate information. The DG and AI will still function as well. A plugged static port only affects the Airspeed indicator, Altimeter, and VSI. So a problem with a plugged static port would only readily be visible after takeoff, when the VSI and Altimeter fail to move after takeoff.

[link:www.dreamfleet2000.com|http://www.dreamfleet2000.com/gfx/im...UM_HOWELL.jpg]
PPL-ASEL
Instrument Rated
CPL student

"As employees, pilots are a difficult lot. They are masters of their vessels, answerable to no one for as long as the engines are running. Airline presidents have the power to control entire fleets, to decide where and when every plane shall fly. But once those decisions are made, no one tells the pilot how, or even whether, to fly."

[LGA]

Understood J.C. That makes sense as they were getting airspeed indications, obviously very innacurate ones. I wonder how innacurate the airspeed indicators were during the take-off run. I mean, these guys read out their V speeds and rotated. Maybe at that point the readings were not inaccurate enough to be noticeable which is lamentable. I figure if they had been very innacurate and let's say they rotated at 95kts thinking they were doing 140kts or whatever the Vr speed was, perhaps the pilot would've realized something was definately wrong when the plane would obviously take too long to rotate.

[FlyingKiwi]

I believe one of the airspeed indicators was reading too low, the other too high, so presumably if they were using the one with a high reading on takeoff, they wood have gotten off the ground ok.

I don't think they realised that both ASI's were faulty until they started getting stall warnings and excessive speed warnings at the same time.