Those are short-haul inter-island planes. It would have had to fail early after takeoff in order for the pilots to not have another runway as an option.
The pilots reported they could not maintain airspeed and altitude following the failure of one of two engines on the Boeing 737-200
I initially assumed this must have been a dual engine failure situation, like the famous landing on the Hudson. I know modern airliners are required to be able to climb to I think 5000 feet on one engine in the event one of them fails during takeoff. So the second engine probably wasn’t producing full thrust, I assume? The pilot’s statement that he believed the second engine would also fail seem to corroborate that.
Yeah, there had to be a problem that affected both engines for the plane to come down. The 737-200 is type certified for ETOPS-120. ETOPS stands for Extended-range Twin-engine Operational Performance, and ETOPS-120 means that the aircraft has a demonstrated ability to fly for at least 120 minutes on a single engine.
Colloquially, ETOPS has been defined as, “Engines Turn or Passengers Swim”, so not everyone believes the certification guarantees you’ll make it to your destination or emergency alternate.
Another possibility is that they were flying an overloaded plane, I guess. If the engine quit just after takeoff but before they had the altitude to turn back, perhaps the full fuel load and cargo was just too much for the old bird to handle on one engine.
Captain: You checked the fuel, right?
Copilot: I thought you checked the fuel!
There’s a bit more to ETOPS than that. All passenger airliners can fly until they run out of fuel after an engine failure. What makes an aircraft ETOPS approved is whether the chance of a subsequent critical failure (second engine, or other critical system) is low enough that it is deemed to be an acceptable level of risk to be a certain distance from a diversion airport. ETOPS is about engine reliability, systems redundancy, and maintenance. The 737-200 may be ETOPS approved in general but a company that doesn’t do ETOPS flights will not have ETOPS approval for their aircraft. My old company had non-ETOPS A320s for domestic flying and ETOPS A320s for international flying. An ETOPS plane was only approved for ETOPS if everything necessary for ETOPS was serviceable. For example, I once had to fly Wellington to Sydney via a long non-ETOPS route because one of the engine generators was unserviceable.
From the CNN story:
“We’ve lost number one engine and we’re coming straight to the airport,” a crew member said, requesting that air traffic controllers begin dispatching the airport fire department. “We’re going to lose the other engine, too. It’s running very hot.”
The fact the second engine is running hot is interesting. If you have a hot engine there’s not much else you can do other than reduce thrust to keep the temperatures in limits.
Edit: They’ve started calling ETOPS “EDTO” now, Extended Diversion Time Operations, because it’s not just for twin engine planes, it also covers requirements for planes with more than two engines.
VASAviation on You Tube, which put out air-tower communications, has the accident recording available here: Transair B732 Ditches into Ocean off Honolulu | "We can't maintain altitude" - YouTube
I must say, the words “Mayday Mayday Mayday” right at the beginning there would’ve been helpful. I know it’s not required in the USA, but it seems like it would’ve been useful for immediately getting the controller’s attention. She gave a couple of routine vector/climb instructions to 810 before she understood they had a problem.
Back to GA…
Are you saying calling a “mayday” or even “pan pan pan” in particular situations is not required in the US? Is this an FAA does not require it but your airline might thing?
Are there reasons a pilot would be reluctant to make those calls when things start going wrong?
Their is an expectation that the pilots return with most of the parts they left with. If they don’t then they need to fill out paperwork specifying why.
As I understand it the words “declaring an emergency” are used in the US. Mayday is understood but rarely used. FAA rules.
I think there is a tendency to understate things that can lead to a reluctance to declare an emergency. That said, 810 did declare an emergency early on but it seemed to get lost in the rest of the communications.
If the tower isn’t reacting fast enough it’s the responsibility of the flight crew to get their attention. They have carte-blanche in an emergency. It sounds to me like they did this but they were losing altitude and wouldn’t have made it back. Their May Day would basically be a position report so they know where to look.
Exactly. But the crew are trying to get emergency vectors at the very start of the incident and the Tower is giving them routine departure vectors. She didn’t know they had a problem. “Er, we need a heading of 220 mumble mumble emergency” didn’t get her attention. “Mayday mayday mayday!” Would get her, and everyone else’s immediate attention and get everyone on frequency to shut up.
I don’t think it made a difference in this case to the end result, but it was a fine example of the problem with dancing around the fact that you have a serious problem and need priority.
It will be interesting to see what the engines were doing on takeoff. Since these are island-hopping flights there shouldn’t be much fuel to weigh them down. How bad can a single engine be performing to prevent it from maintaining altitude?
Is this going to be a bird ingestion issue?
Flight attendant: Why, I oughta…
They said they had “two hours of fuel” at some point, so around 10,000 lbs maybe? on short flights it is normally the landing weight that is limiting, not the take-off.
Double engine failure doesn’t HAVE to have a single cause. The failure of one could lead to conditions that produce a failure in the other one for different reasons (extra load on the remaining engine for example). It’s not supposed to happen of course, but 737-200s are OLD aircraft with OLD engine technology and freighters don’t necessarily get all the care and attention they should.
Still, something like birds or contaminated fuel is more likely.
When I watch videos of jets doing precision approaches, there is an audible recording telling the pilot the altitude above the runway. How does it know?
Altimeters and GPS altitudes are not precise enough. My first thought was radar altimeter. But does the plane know every obstacle within the flight path? Can the plane’s computer figure out the altitude by using the GPS horizontal position and the glide-slope receiver’s deflection to triangulate the altitude?
And GPS’s are extremely accurate if you are locked on to enough satellites. There are also terrain databases available for known terrain including towers and other man made structures.
The commercial people can advise what is available in commercial planes.
I’ve flown my antique aviation GPS down to the runway and it was about 1 to 3 ft off centerline and fairly close to altitude. I wasn’t in a position to measure it but I landed the width of the centerline showing on the screen and I was directly on it visually when I landed. It kept track of which satellites it was receiving so it would know when accuracy was lost. If I was lost in the fog I would have felt comfortable flying off the GPS in the hopes of 100 feet of visibility.
The newer systems are much more accurate.
Not all airports have precision approach radar, and they are most common at military bases. These radars have two antennas - one that sweeps vertically and one that sweeps horizontally. They pre-date GPS, and the whole point is that the aircraft doesn’t need to have any navigation gear at all.
I have flown many PAR approaches since my home field was a military base and the controllers enjoyed practicing them when they weren’t busy. The dirctions you get are like this:
“Charlie Bravo Zulu, left of glide path. Commence half rate turn to the right right now.”
“Charlie Bravo Zulu, back on centerline. Cease turn.”
“Chalue Bravo Zulu above glide path, increase your rate of descent.”
“Charlie Bravo Zulu on glide path. Maintain current ratebof descent.”
Etc. In the approach the pilot does not have acknowledge any of these calls They simply get a running stream of instructions until they get to the decision point and call runway in sight.
The radars don’t have to be accurate to the foot - just accurate enough to safely get you to the decision point where you either see the runway or they wave you off. That said, when I’ve flown them they’ve always put me right over the runway, almost exactly at the height my instruments show, and right on the centerline.