Addison airplane crash
 

This King Air was carrying 10 souls and crashed just after takeoff. One person, Steve Thelen, was a friend. He was one of the best people I've ever known. This video has just been released. There are reports of a problem with the left engine. This vid shows the plane in what appears to be a radical side slip and possible stall? What do you airplane knowledgeable folks think?


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I'm sorry for the loss of your friend.

It looks like the pilot gunned it (side slip), and then used full right rudder and ailerons while trying to climb which slowed the plane too much to recover (stall and roll).

Is it possible he could have held it in a long circle while maintaining altitude and gaining some airspeed? idk what I would do in that situation. Got a lot of respect for the people who do that as a profession.

Massive yaw in the last moments, likely induced by full throttle on one engine and not enough rudder airflow, and not enough elevation to bank right.
Left engine out at just the wrong moment. (novice speculation)

Sad.

classic VMC roll

lost a friend to this earlier last month.

+1

Asymmetric thrust + below Vmc + little/no altitude = bad news.

Just speculation, but weight & balance might have been a contributing factor. Sounds like it was at/near max capacity, and given the destination I am guessing the tanks were full.
The relatively high wing loading of that A/C probably didn't help matters, and the density altitude might have been a bit up there as well.

Ughh, I hate hearing about these. Sad indeed...

That crew had precious few seconds to do what they needed to do to correct the problem. They correctly identified which engine was at fault but I noticed the gear was still down, so it doesn’t look like they reacted fast eough to get the plane stabilized in a straight climb. I always hate takeoffs when I’m riding in a twin.

My condolences to the loss of your friend and everyone else on board that plane. Truly sad.

Had to look that up. . . V_mc = Velocity, minimum controllable.

https://flightsafety.org/ap/ap_june05.pdf

^^Interesting read, I was trying to do quick research to see if the King Air can actually be configured to climb with one engine. From the flight safety link It looks like take off rotation is around 90 knots, and minimum speed to climb on one engine is around 107... Recommendation looks like aborted take off if the engine fails below 107 *even if it means crashing off the end of the runway*. Who knows when the engine failed in this case, but I bet the chances of getting it right were pretty low for the pilot. Power loss on take off is pretty much a nightmare scenario.

They stopped climbing almost immediately so I would guess it failed just after rotation. All he could do at that point was get the nose down which didn't happen for some reason and he didn't have enough rudder authority at that speed to fly straight. Pulling the power would have helped keeping it straight and may have allowed him to get the nose down.

Hard to say what happened since we were not there and some situations you don't have much control over. I am sure the pilot was not sitting in the cockpit thinking "Hmm, now what?".

This is a good example of why they aren't going to a single engine per pod in the B52 as it barely has enough rudder to deal with an engine out as it is.

From what I’ve read, a King Air can climb with one engine but there’s not a lot of margin between typical rotation speeds and the minimum controllable speed. Cleaning up the airframe quickly and perhaps even a power reduction on the good engine might be needed. If I remember correctly, that runway is pretty long and a better response might’ve been to put the thing back on the ground.

A Google search will pull up quite a few incidents like this for that type of plane.

Sorry for the loss of your friend. Every one of these tragedies affects someone on a personal level but most of the time, it's someone we don't know. I've lost a few people in small plane crashes. At least it's very sudden. RIP.

I don't think he had time to clean it up and if they had reduced power and were able to go straight ahead, they would have probably wanted the gear down.

Had the left engine quit before VMC, they would never reach VMC so your options are pretty limited.

Most twins can climb on one, but they better have the speed needed before they become a single engine.

All the pilots I have flown with retract the gear just after they get airborne, so whatever happened probably occurred within a second or two after he got airborne.

Vmc is probably 5 knots below rotation speed so if it failed before that the only response is to abort the takeoff.

It’s really hard to watch the video of that.

Also, to me it looks like there is fire just before impact. A fellow pilot friend looked and saw the same. If so, that might explain a lot.

Normally you retract as soon as you have established your climb. I know some pilots that have ground contact switches put the gear lever up during the takeoff roll so the gear go up as soon as they take off. This works almost all the time.

The lack of climb makes me think the engine died as they broke ground or immediately after. Some situations have no answer.

I didn’t notice any fire but it looked like I saw some white smoke.

Thanks all for your thoughts.Steve was one of the most successful and well respected commercial real estate brokers in Dallas. Always had his act together and highly organized. It hurts to think what he and the other souls went through the last few seconds.

Best to you and Steve's family...

I have chaired a few accident boards and I can guarantee you they will drill down on this because the King Air is ubiquitous in aviation, they are everywhere for a good reason.

Don't obsess on the video, trust me, I know.

I lost a friend once in a collision between two biplanes at an air show. It was hard to think about what happened.

Sorry for the loss of your friend. RIP.
Findings from a similar King Air accident in Australia last year.
https://www.atsb.gov.au/media/5775073/ao-2017-024-final.pdf

Wow - that is eerily similiar

Whew. With 10 people on board they would have been heavy.
Even at gross weight the aircraft should be able to maintain altitude on 1 engine.
So many factors. Weight. Temperature. Density altitude.
Sometimes even in a turbine you are better off retarding the power on the operating engine, and landing straight ahead.
A good lesson to practice is go to 4000’. Pull the power back on 1 engine. And slowly pull back. Try keep the a/c straight with rudder.
Eventually you’ll run out of rudder and the aircraft will roll and yaw.
You can recover by either lowering the nose and gain airspeed. Or reduce the power on the operating engine. Either way your going to lose altitude.

I feel bad for the people on this flight. Loss of an engine right after takeoff is every pilots worst nightmare. Looks like he didn’t have many options.

I took a quick look at the initial NTSB report and refreshed my memory of the airport. It looks like the tanks were topped off before flight and luggage was loaded into the aft compartment, so the plane was probably close to full weight. Minimum takeoff distance at standard conditions (which are way better than summer in Dallas, density altitude that day was about 2225ft) is about 3,300 feet, so it probably lifted off just past the underground tunnel (at best), for those of you that are familiar with that facility. That puts it about 1,500 feet from where it went down, or less. A couple details from the report:

"One witness stated that as the airplane went down the runway, it seemed more quiet than normal and sounded like it did not have sufficient power to takeoff. After the airplane lifted off, witnesses observed the airplane drift to the left, and then roll to the left before colliding with the hangar. Several security cameras captured the drift to the left immediately after takeoff and then a roll to the left."

The initial review of the cockpit voice recorder information indicated: "Crew comment consistent with confusion occurred about 12 seconds before the end of the recording. Crew comment regarding a problem with the left engine occurred about eight seconds before the end of the recording."

That tells me that they probably knew they had a problem right before, or right at liftoff.

Possibly even prior to rotation (Vr) but just after the "commit" speed (V1) was reached.

Gear up only after positive rate of climb confirmed.
Typically it's: V1 (go/no go) > Vr (rotate) > positive rate > gear up.
Positive rate is established via cross-checking the altimeter with the VSI or radar alt.
However there can be a couple seconds of lag time after the gauges come alive.
Yep, potentially an engine failure just after V1 (basically the worst possible time/phase of flight to have an issue/failure).
If that video was in real-time, it looks like there was about 10 seconds total, between Vr and impact.

Also, if the 350 is the same as previous evolutions, the left engine is the critical engine. If you are going to have an engine fail, you'd want it to be the right one if you had a choice (p-factor).

Another potential contributing factor may have been the prop auto-feather system.
If it wasn't armed or not working properly and didn't feather the prop immediately as it should have, it would have induced a ton of drag on the left side.

All that said, if flown by the numbers with no other issues, it should have been plenty capable of a (critical) engine-out take off. They likely found themselves committed (past V1), but couldn't get it to V2 (engine-out climb speed).
That is where things like weight/balance issues, density-altitude, etc. reduce your (already narrow) margin for error.


Side note:

I've been in a twin Beech that had an engine out at altitude, just above Vmc while slowing to idle power (skydiving jump-run).
The roll/yaw was pretty immediate. We all got the eff out of the plane, and the pilot brought it back to an uneventful landing.
That was at 12K+ ft. though, with plenty of time/altitude to deal with it...

Definitely a VMC rollover..

Usually what happens in these types of accidents are:
Pilot complacency (everything is going to be just fine attitude), lack of proficiency ( timeline and quality of last sim event) , and lack of correctable action taken (took too long to act, or did not do something required or did something to make it worse).

That being said, even if you do everything right, sometimes you just cant overcome a mechanical failure no matter what you do.

:(

I keep wondering if the age of the pilot had anything to do with the accident. Reports have him at 69 or 70. I'm a few years behind him but my reaction time certainly is not what it was in past.

Sorry for the loss of your friend. I have lost friends and a few family to air crashes and I understand the desire to review and "what-if" the causes leading to the crash. It's probably not all that useful but it is what we do. The King Air is a personal favorite aircraft.

My quick observations:
The plane was heavy and the air was thin. The worst possible time to lose an engine on takeoff. They quickly developed unrecoverable yaw followed by a VMC roll and nobody walks away from this one. The pilot ran out of options vey quickly. Tragic.

http://forums.pelicanparts.com/uploa...1563479377.JPG

Looks like there was some runway left.

Did the final rolling over of the plane result from loss of lift or the torque of the engine?

Doesn't a twin need to stay on the ground or just off it until the blue line is reached?

I just saw a B-25 Mitchell video where they rotate at 100mph and then stay just above the runway until they reach blue-line at 140mph climbing out. wow!

Do you have a link to a copy of that video?

Runway Cam

I'm pretty sure the 300's are cert'd under Part 23 (Commuter), with a type rating required.

Yes, and I think this was a 350.

A twin gets a fair amount of lift from the propwash off of the engines. If you have significantly less thrust on one side, you’re going to have assymmetrical lift which will tend to roll the plane towards the dead engine and it will also yaw to that side, as well. There are a lot of other factors, but that’s the gist of it.

This plane was pretty heavily loaded, the density altitude was pretty high that day and the CG was probably pretty far aft. These guys had one chance and that was to put it right back on the ground. I think the problem was present no later than when they lifted off of the ground; it may have started before that and only became apparent to them once they were in the air.

https://www.flyingmag.com/pilot-reports/turboprops/beech-king-air-350-just-load-it-and-go/

The takeoff performance of the 350 is even more impressive when you consider that it is certified in the commuter category of FAR Part 23. That means pilots must have a type rating to fly it and must observe minimum runway requirements that assure a margin of safety if an engine fails during takeoff, just as the rules do in jets.

The 350 has automatic propeller feathering and rudder boost to immediately feather the prop if an engine fails on takeoff and to step on the proper rudder to overcome the asymmetric thrust. An engine failure in the 350 is virtually identical to the loss of an engine in a jet because the autofeather immediately eliminates the drag of the windmilling propeller on the failed engine. As you can imagine, autofeather and rudder boost are required items, and that means they need to be tested once each day.

The V1 decision speed was 97 knots, with rotation at 104 knots, and V2 engine-out climb speed at 111 knots. Those speeds are for a flaps-up takeoff. As in most airplanes, using flaps reduces takeoff speeds a few knots and shortens runway roll in the 350, but also reduces engine-out climb performance, so it's a trade-off. With plenty of runway and climb reserve, I like the flaps-up takeoff better. I think it makes for a smoother rotation and initial climb, but the choice is up to each pilot.