As I write this, it’s been a week since the horrific crash of UPS 2976 in Louisville.
It’s easy for a story like this to get lost in the daily stream of crap flooding out of Washington. A passenger jet goes down and it dominates the news cycle for weeks. Three freight-dogs burn up and it barely moves the needle. But hey, that’s why I’m here.
Here’s what we know so far. UPS 2976 was an MD-11 freighter scheduled from Louisville to Honolulu. On takeoff roll the #1 (left wing) engine failed catastrophically and separated from the aircraft. We know this because it was found on the side of the runway.
It gets a little fuzzy after that. There are multiple videos of the crash from multiple angles. It appears that the left wing was on fire. We know that they made it roughly 175 feet in the air before crashing into an industrial park off the end of Runway 17R. As of today the death toll is 11 on the ground plus the three pilots.
You don’t have to worry about flying in one of these because no one is using them to haul passengers any more.
They’re still popular with the freight companies because they can hold so much stuff. Think about how much empty space there was in the last package you had delivered. Now multiply that by, well a whole bunch. The 767 freighter that I fly tends to “bulk out” before we hit our maximum takeoff weight because there’s only so much room inside. The MD-11 has a much bigger fuselage so they can cram a lot more packages in there.
Now I don’t fly the MD-11 but I do ride them to work sometimes. Years ago I had the chance to fly it but the training program sounded pretty painful. It was described to me as three months of “death by simulator”. I've ridden the jump seat many times and it has a nice roomy cockpit with lots of visibility. The flight management software reportedly works really well, better than the 767 for example.
MD-11 cockpit. This doesn’t really show just how big the windows are.
The “Mad Dog” as they call it is generally liked by the pilots. I’m told, however, that it’s one of those planes where you have to bring your “A-Game” every time you fly it. When McDonnell-Douglas built this thing they gave it relatively small control surfaces to reduce drag. To compensate, the software does some weird stuff like trim the horizontal stabilizer in the flare. It also has relatively high final approach speeds, around 155 knots. That’s 10 to 20 knots faster than most other airliners.
I fly the 767 and I find it to be pretty forgiving. If I can get it to 50 feet it pretty much wants to land. You can definitely screw up a landing in the seven-six but it takes some effort. In the MD-11 I’m told you pretty much need to have it nailed crossing the threshold or you should be thinking about going around and trying again.
Another issue with the MD-11 is the landing gear does not like side-loads. The 767 can be landed in a “crab” (facing into a crosswind). Above a certain crosswind component (26 knots I think) the manual actually directs us to land it in a partial crab. The gear is stressed for it.
I previously flew the Airbus A300 and you couldn’t hurt the gear on that thing. I was told “the French are proud of their landing gear”.
The MD-11, on the other hand, wants to be pointed straight down the runway or you can side-load the gear with potentially serious consequences. When I say serious I mean collapsing one of the mains and ending up on your side or on your back. It’s happened more than once.
This was an MD-11 freighter that ended up on its back at Newark Liberty in 1997. Amazingly the crew escaped with minor injuries.
As to what happened in Louisville, we can only speculate right now. I’m sure someone will bring up American Airlines flight 191 back in 1979. That was a DC-10, the plane the MD-11 was developed from. They were on departure from Chicago and had the left engine physically come off the wing, taking hydraulic lines with it. Without hydraulics the leading edge slats on that wing retracted, the left wing stalled and they rolled over. This was just off I-90 on the north side of the airport. I remember seeing the smoke all the way from Schaumburg, about 10 miles away.
After that accident they modified the systems so that this shouldn’t happen again. I think (don’t quote me on this) that the leading edge slats are mechanically locked in place so that they won’t retract with a loss of hydraulic pressure.
Now back to UPS 2976. I can assume the aircraft was pretty heavy. They had enough fuel to fly to Hawaii. Somewhere around 280,000 pounds (40,000 gallons give or take). I don’t know how much cargo they had on board but 100,000 pounds plus is pretty typical for that aircraft.
Some of that cargo may have been hazardous materials, which is why there was a shelter-in-place order for about an hour after the crash. We carry a lot of stuff in the freight world that you should be glad they can’t put in the belly of a passenger jet. Things like pallets of lithium-ion batteries, for example. I had one flight where we regularly carried pallets full of fireworks for one of the big amusement parks.
When they lost the left engine they were probably past “V1” which is our computed go/no-go speed based on various factors like weight, winds, runway length and so on. We calculate this for every takeoff.
If you try to stop going faster than V1 you will likely run off the end of the runway. Think about the amount of energy involved in stopping half a million pounds of jet going 150 knots. It’s literally in the millions of foot-pounds.
Once we reach V1 we’re trained to continue the takeoff unless it’s something so bad that you don’t think the plane will fly. At that point you’re just hoping to run off the end of the runway going slow instead of going fast. Not really a place you want to be.
In this case they may not have known how bad the situation was. You can’t see the wings from the cockpit of the MD-11 so they may not have known they were on fire. I assume they would have noticed the loss of thrust on the left side but I wasn’t there. They may or may not have had a fire indication in the cockpit. It’s possible that the engine took everything with it when it tore off the wing. The #1 engine indications may have just gone blank. We’ll hopefully know more when the Flight Data Recorder and Cockpit Voice Recorder are analyzed.
Now is when it gets really fuzzy. They should have been able to continue the takeoff after losing the left engine but we don’t know what else was going on. All I can do is speculate.
One possibility is they lost hydraulics and thus flight controls either from the fire or the engine tearing away from the wing. In that case they would have been just along for the ride.
Another possibility is debris from the left engine or wing went into the #2 engine, the one up on the tail. In that case they may not have had enough thrust to climb out on just the right engine. Losing two engines on a tri-jet puts you in a world of hurt.
The 727 would fly on one engine, just barely, depending on where you were when you lost the second engine. I think the DC-10/MD-11 will as well, but once again it may depend on where you are in the flight envelope. It’s one thing if you’re “cleaned up” and have flying speed already. In the case that you have the added drag of the landing gear and flaps extended it may not be able to fly.
Where it gets really ugly is I’m sure these guys fought it to the last second and they had just enough time to know they were screwed.
Meanwhile 11 people on the ground were just going about their business when a flaming MD-11 landed on top of them. Others were trapped in buildings while the fire raged outside.
This shows the devastation caused by the crash and fire. This would on the south end of the airport looking north at the runway.
Pilots, as you probably know, tend to be very “Type A” people. When I read about an accident I tend to tell myself “Well I wouldn’t have made that mistake” or “I’m better than those guys, I could have saved it”. It’s the pilot equivalent of whistling past the graveyard.
This looks like one of those times where there wasn’t a damn thing they could have done, and that troubles me.
A quote from my favorite fictional starship captain. Patrick Stewart as Jean-Luc Picard.
For now the MD-11 fleets are grounded by the FAA until they can figure out what happened and hopefully come up with a fix. That’s called an “Airworthiness Directive”.
The only people flying them in any numbers are UPS, FedEx and Western Global. We’re coming up on “peak” season for air cargo and this will cause some problems. Might want to order your Christmas stuff early.
Stay safe out there.
