The Terrifying Loss of Control of Air Astana Flight 1388

Air Astana Flight 1388

What does it feel like to be trying to fly a plane you can't control? This flight took place 11 November 2018, and the resulting investigation took a year and a half.

During a heavy maintenance, the control cables for the ailerons were replaced, and accidentally reversed.

When the pilots did their pre-flight check, apparently they should have noticed the ailerons moving in the opposite direction they were supposed to move, but they didn't notice that.

Ailerons and flight spoilers normally work together to turn the aircraft. If there were no flight spoilers, the aircraft would have been controllable by just moving the controls in the opposite direction the pilot wanted to turn. But the flight spoilers still functioning normally made the aircraft practically uncontrollable. a command to turn left would have the flight spoilers trying to make a left turn, and the ailerons trying to make a right turn, working against each other.

So the pilots and passengers had a wild roller coaster ride, sometimes flying inverted, going into steep dives, and unable to maintain a consistent heading. The pilots realized soon after takeoff there were control problems so they requested to return to the airport, but they couldn't control the aircraft enough to do that. Then apparently they decided ditching the aircraft in the sea was the best option since it was uncontrollable and apparently they didn't want to kill people on the ground when it crashed. The air traffic controllers kept authorizing them to fly west toward the sea, but they couldn't maintain a heading so they never made any progress toward the sea.

Here's a screenshot from a video showing the unusual flight path:


You don't see that very often, do you?
That's at 10:42 in this nicely organized video from Mentour Pilot's youtube channel, but there's an ad in the video.

00:00 - Intro
00:27 - Chapter 1: Routine Maintenance
01:43 - Chapter 2: Cable Issues
02:48 - Chapter 3: Roll Axis
03:40 - Chapter 4: A Hybrid Aircraft
04:41 - Chapter 5: The Crew
05:16 - Chapter 6: The Flight Crew
05:52 - Chapter 7: Pre-Flight
06:53 - Chapter 8: Taxi
07:47 - Chapter 9: Takeoff
08:46 - Chapter 10: Rollercoaster From Hell
10:25 - Chapter 11: The Ride Continues
14:38 - Chapter 12: Two's Company
15:59 - Chapter 13: Landing Attempt 1
16:54 - Chapter 14: Landing Attempt 2
17:22 - Chapter 15: Third Time Lucky?
18:07 - Chapter 16: Sickbags At The Ready
19:01 - Final Chapter: What Went Wrong?

Eventually, the pilots were clever enough to find a little sweet spot in the flight envelope where the flight spoilers didn't seem to do as much, giving them more control with the ailerons, though not complete control, but enough to land the plane. Some F-16's from Portugal's air force were dispatched and they assisted guiding the flight to land on a military base runway. After two go-arounds due to continuing lack of control, they made a third attempt and still couldn't line up with the intended runway due to lack of control, but they were accidentally lined up with a parallel less forgiving runway, so they landed on that.

The roller coaster flight vastly exceeded the plane's design limits and only the first 1/3 of the aircraft was undamaged, so it was written off as a total loss. One passenger had a minor injury.

These links have the audio with air traffic control. It's gut-wrenching to listen to the pilots keep asking for a heading to ditch the plane at sea, indicating they thought the situation was pretty hopeless, and it seemed even more hopeless when they couldn't follow a heading so they couldn't even do that.

Air Astana has SERIOUS FLIGHT CONTROL ISSUES-part 1
www.youtube.com...

Air Astana has SERIOUS FLIGHT CONTROL ISSUES-part 2
www.youtube.com...

While I didn't see any official recommendation related to pre-flight checks, I'll bet those pilots will pay more attention on their future pre-flight checks. While they missed the problem, I'm impressed they managed to land the plane, it sounds like a nightmare experience.

Air Astana Flight 1388

The investigation blamed the manufacturer of the airplane for the poorly made maintenance instructions, the supervising authorities for lack of oversight over the maintenance crew, who lacked the skill to perform the heavy maintenance, and the pilots for failing to perform pre-flight checks which would have allowed them to notice the control problems.

Looking into DCS currently and I can already boot up an F18/c, take off, land and I know how to select the correct weapons and how to engage with them. Reading this coupled with my "experience in DCS" makes the hair on my neck stand up. So much things to consider.

To the aviation pros here, did the flight computer prevent most critical flight maneuvers? It seems like a miracle to me the plane didn't break up mid air!

I didn't know about that. Maybe it didn't make much news but at any rate that is absolutely terrifying.

I am so glad they got on the ground safely.

Kazakhstani eh...

a reply to: Arbitrageur

Hard on the pilots' nerves, to be sure ... but they remained in control of themselves and brought the craft to ground safely.

Cheers

a reply to: ThatDamnDuckAgain

The FCM was part of the problem. They disabled the FCM and put the aircraft into direct law. That allowed them more control, but they still had issues with the roll axis but it improved the situation.

a reply to: chris_stibrany

It was a positioning flight. The passengers were three technicians travelling with the plane due to it being a post maintenance flight.

a reply to: Zaphod58

Aha. no wonder it wasn't in the news

a reply to: Zaphod58

Thank you for answering!

I finished the video and it answered the question like you did, but I have a follow up question, to check on my understanding.

In the video they said that, the aircraft reacted better with direct law mode. They said small inputs would give them a bit of inverted control, but a bit more or sudden jerks, it would get out of control again.

I suppose this is due to the differences in angle and deploy speed between the ailerons at the tip and the spoiler closer to the fuselage, combined with the leverage they put on the wings. Because the ailerons were inverted and counteracting the spoilers, both curves overlap, cancel each other out, but small movements did the trick because the ailerons are on the outside, giving more leverage?

I ask because I know there is going to be trouble in DCS. That I have to troubleshoot in flight and I want to train that troubleshooting and understanding.

a reply to: ThatDamnDuckAgain

You're basically right. A simplified explanation is that the ailerons go up on one wing and down on the other to push the wings into a turn. The spoilers deploy to basically slow the wing, helping with the turn. Big inputs mean more spoiler and more aileron. With the aileron being inverted and the spoilers not, you'd have to put left turn input to get the ailerons to go right, but the spoilers are trying to go left. If you put a gentle turn input in, there's less movement of the spoilers, so less disruption over the wing.

a reply to: Zaphod58

If you put a gentle turn input in, there's less movement of the spoilers, so less disruption over the wing.

That was what I tried to figure out by looking at the behavior between big and small inputs

Yeyh! I have basic understanding Small steps!

originally posted by: Zaphod58
a reply to: chris_stibrany

It was a positioning flight. The passengers were three technicians travelling with the plane due to it being a post maintenance flight.

I was wondering if the three technicians were the same ones who worked on that plane, or not. If a technician flies on the post-maintenance flight for the aircraft he worked on, it might be some additional incentive to do a good job, wouldn't it?

a reply to: Arbitrageur

The military used to have flying crew chiefs for multiple aircraft. They even had a few fly combat missions over Vietnam on B-52s.