MOSCOW — Feb 13, 2018, 12:47 PM ET

Russia: Human error, faulty sensor behind deadly plane crash


Human error may be to blame for the Russian plane crash that killed 71 people, Russian investigators said Tuesday, noting that the plane's pilots failed to turn on the heating unit for its measuring equipment, resulting in flawed speed data.

After studying the An-148's flight data recorder, the Interstate Aviation Committee said that Sunday's crash near Moscow occurred after the pilots saw conflicting data on the plane's two air speed indicators.

The flawed readings came because the pilots failed to turn on the heating unit for the plane's pressure measurement equipment prior to takeoff, the committee said.

The pilots had placed the An-148 on autopilot after taking off from Moscow's Domodedovo Airport but took its manual controls back when they heard alarm signals warning of conflicting speed data. One indicator showed the plane's speed at zero, investigators said.

The pilots then performed a series of maneuvers and eventually took the plane into a dive at 30-35 degrees. It plummeted into a snowy field outside of Moscow six minutes after takeoff, killing all 65 passengers and six crew onboard.

The committee said it is continuing to study the data, but noted that "erroneous data on the pilots' speed indicators may have been a factor that triggered the special flight situation."

It emphasized that the flawed speed data resulted from the "icing of pressure measurement instruments that had their heating systems turned off."

The RBC news outlet quoted pilot Andrei Litvinov as saying the pilots probably took the plane into a dive because of low speed readings to avoid stalling and didn't have time to correct their mistake at such a low altitude.

Earlier reports indicated the plane's captain had chosen not to have the plane undergo de-icing before takeoff. The crew decides whether to have the plane sprayed by de-icing liquid, depending on weather conditions and the state of the plane.

Saratov Airlines, which operated the plane, said its captain had more than 5,000 hours of flying time, 2,800 of them in an An-148, and the other pilot had 812 hours of experience, largely in that model.

The aviation committee's description of the Moscow crash resembled the 2009 crash of an Air France Airbus 330 over the Atlantic Ocean, which killed all 228 people aboard. Ice crystals blocked pressure sensors responsible for air speed indication, and erroneous speed readings misled the pilot, who pitched the Air France plane sharply up instead of down as it stalled and lost control.

A crash of another An-148 in March 2011 during a training flight in Russia that killed all six crew members on board was also linked to a faulty pressure instrument resulting in wrong speed readings, prompting the confused crew to exceed the permissible speed limit.

The An-148 model itself has a very spotty safety record, with two crashes and a string of major incidents in which pilots struggled to land safely. Saratov Airlines has grounded other An-148s in its fleet pending the Moscow crash investigation.

News - Russia: Human error, faulty sensor behind deadly plane crash

RRelated Posts


  • c0reDump

    That was an amazingly fast investigation...

  • GorillaMyDreams

    "Deadly plane crash caused by pilots' error on heat"

    Is it just me, or did that headline not make a lot of sense?

  • Impetus

    Electronic IV pumps in the hospital have programming that alerts the nurse when something isn't within pre-programmed parameters. Couldn't we wire planes that way? Like "it's -7 Celsius outside, and the heater for this thing isn't on, is that okay? Sincerely, the plane". I know the checklist would solve the issue, but...

  • Marvin Ogravel

    Rule #1 - Fly the plane. I think that training (simulation) with bad instruments should be mandatory. Being able though the situation and to work as a team is what saves lives. We only read about the crashes. Crews who "fly the plane" and work the problem, don't get the press but they are the ones who bring people home.

  • Raymond Laramie

    In December 1974 Northwest Airlines flight 6231, a B727 with only 3 crew aboard, crashed north of New York City after departing JFK on a ferry flight to BUF. The aircraft stalled at approximately 24,000 feet as a result of conflicting airspeed and overspeed warnings. The crew failed to activate the pitot heat on departure. As the aircraft climbed the trapped and constant pressure in the blocked (frozen over) pitot tubes became increasingly higher relative to the outside static pressure (which decreases with increasing altitude), driving the air data computer to display higher and higher airspeed, and activate the overspeed warning. The pilot tried to control the “increasing” (erroneous) airspeed by raising the nose until the aircraft stalled and became unrecoverable. Checklist, checklist, checklist …

  • Fatesrider

    Something a lot of folks don't know but the AN-148 was built by both Russia and the Ukraine. The proxy war between Russia and the Ukraine (which continues unabated since the Russian government is headed by a man who basically wants to reform the old Soviet Union), has had a major impact on the parts supply line for the AN-148 models. So much so that dozens of scheduled flights to and from Cuba were cut or seriously delayed in 2017.

    It's also rather telling that they'd come out and announce this finding so quickly when most such investigations usually take months (even for the Russians).

    The Russian government would be exceptionally embarrassed if a parts problem due to its war on the Ukraine had anything to do with the crash. The AN-0148 has a spotty safety record in the first place, and it's possible that a dearth of spare parts had nothing to do with the crash (there was an AN-148 crash in 2011 caused by exactly the same problem), but the speed at which they've made this announcement seems suspiciously like propaganda rather than the results of a thorough investigation.

  • Bobby Edwards

    I said when this was first reported, look at the de-icing and the pitot tubes given the conditions, and where it crashed after take off, both stood out.

  • GP

    Have to use the checklist - all the time - every time no matter if its the first flight or 10,000th flight. Actually checklist help with many routine process to ensure that all the steps are taken. Get the audiobook for "The Checklist Manifesto; How to Get Things Right".

    Turns out in many cases the more experienced operator is the one most likely to forget or gloss over a step because they have done it some many times before.

  • Dicazi

    If the plane type has such a poor safety record, maybe the heater wasn't working.
    Wasn't it snowing? Seems rather stupid to not get de-iced or at least turn all heaters on.

  • Quantez Williams

    For any non pilots out there: When flying in instrument meteorological conditions, outside visibility is limited, obscuring normal references, such as mountains, lakes and the ground below. In these conditions, pilots rely on the cockpit instruments in order to tell up from down and left from right.

    One very important instrument is the airspeed indicator. When the power setting is constant, an aircraft will lose speed when climbing and gain speed descending. Thus, the airspeed indicator can be used to determine if the plane is in a nose-high attitude or a nose-low attitude. There is a little tube with an opening called a "pitot tube." As the aircraft (and thus, the tube) move through the air, the pressure in the tube is converted into an airspeed reading.

    But when the tube is blocked due to icing conditions, then the readings will be inaccurate. in this case, the pilots thought they were in an extremely nose-high attitude (due to the very low airspeed shown) and immediately pushed down the nose in order to correct it. However, the plane was more than likely traveling at a level attitude the entire time. When the pilots lowered the nose (and probably added power as well), they inadvertently dived the plane into the ground.

  • Russ Tanner

    That is what happens when you do not use the checklist. Though I haven't flown in years, it was drilled into me to use the checklist, every time. Simple little things like turning on the fuel, or pitot tube heaters, which is what is the outside pressure sensor for air speed. Kinda important when taking off in winter....