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Experiences on UA with aborted takeoffs, landings, go-arounds, .... [Consolidated]

Experiences on UA with aborted takeoffs, landings, go-arounds, .... [Consolidated]

Old Aug 21, 15, 2:06 pm
  #31  
 
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Originally Posted by choefman View Post
V1 and Vto are the same thing...
I'd defer to one of United's finest, but I don't think that's necessarily true.

Admittedly, my piloting experience is limited to aircraft of the small single-engined Cessna variety, but my understanding is that "Vto" is at most a shorthand catch-all term to refer to all varieties of takeoff speeds.

By contrast, V1 (like other takeoff speeds) is defined in the FAA Regulations (as may be adapted by manufacturers and airlines in consultation with the FAA).

Section 25.107 of the FAR's defines V1 as follows:

(a) V1 must be established in relation to VEF as follows:
(1) VEF is the calibrated airspeed at which the critical engine is assumed to fail. VEF must be selected by the applicant, but may not be less than VMCG determined under 25.149(e).
(2) V1, in terms of calibrated airspeed, is selected by the applicant; however, V1 may not be less than VEF plus the speed gained with critical engine inoperative during the time interval between the instant at which the critical engine is failed, and the instant at which the pilot recognizes and reacts to the engine failure, as indicated by the pilot's initiation of the first action (e.g., applying brakes, reducing thrust, deploying speed brakes) to stop the airplane during accelerate-stop tests.
http://www.gpo.gov/fdsys/pkg/CFR-201...-sec25-107.xml

Other regulators define it differently.

Perhaps you were thinking of V LOF, which is really a statement of fact, rather than a calculated number?

The FAR's (same link, Sec. 25.107) define V LOF as:

the calibrated airspeed at which the airplane first becomes airborne
Of course, I could be wrong, and I'd love to hear a real pilot explain it.

Greg
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Old Aug 21, 15, 2:27 pm
  #32  
 
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Well all this talk about V speed is fun...

Here is what happened from me as a passengers perspective.... I boarded this flight, we were going down the run way really fast, were about to rotate when all of a sudden the plane slowed down really fast... we taxied back to the gate, I called the 1K desk, got of the plane, ran to the other side of the airport, boarded a different flight and made it home safe 30 minutes or so later than originally planned, thanks United
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Old Aug 21, 15, 2:33 pm
  #33  
 
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Originally Posted by choefman View Post
Well all this talk about V speed is fun...

Here is what happened from me as a passengers perspective.... I boarded this flight, we were going down the run way really fast, were about to rotate when all of a sudden the plane slowed down really fast... we taxied back to the gate, I called the 1K desk, got of the plane, ran to the other side of the airport, boarded a different flight and made it home safe 30 minutes or so later than originally planned, thanks United
Good outcome, regardless of the speed...

Greg
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Old Aug 21, 15, 2:56 pm
  #34  
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Originally Posted by WineCountryUA View Post
THought V2 and Vto were the same thing and V1 was lower than V2,
V1 is the fastest you can reject the takeoff, no rejected takeoffs after this speed
Vr is rotation speed, nosewheel leaves the ground
Vlof is lift off speed, mains leave the ground
V2 is takeoff safety speed, you can safely leave the ground with OEI
V4 is steady initial climb speed, supposed to be here by 400 ft AGL
V3 is flap retraction speed

Yes, 3 and 4 are "out of order".

Vto is not a regulatory speed, but it should be the same as Vlof AFAIK.
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Old Aug 21, 15, 7:52 pm
  #35  
 
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I fly B737s and have never heard of a lot of the things that you guys are talking about. LOL

Speeds used by the pilots on takeoff are:

V1 - Takeoff Decision Speed
Vr - Rotation Speed
V2 - Takeoff Safety Speed

Flaps are retracted in increments when reaching the minimum maneuvering speed for the current flap selection and accelerating.

A low-speed call-out is made to cross check airspeed indications and define the beginning of the high-speed reject regime. United uses 100kts, some airlines use 80kts.

I have no idea what happened on this particular flight but the description sounds like the engine "torched". That happens sometimes during an engine start, when the engine first lights off when some of the fuel has traveled into the exhaust section before igniting, and is unlikely to causes damage. Rarely happens to an engine that is already running unless there is a compressor stall but that would have been quite obvious to the crew.
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Old Aug 21, 15, 7:54 pm
  #36  
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Originally Posted by LarryJ View Post
I fly B737s and have never heard of a lot of the things that you guys are talking about. LOL

Speeds used by the pilots on takeoff are:

V1 - Takeoff Decision Speed
Vr - Rotation Speed
V2 - Takeoff Safety Speed

Flaps are retracted in increments when reaching the minimum maneuvering speed for the current flap selection and accelerating.

A low-speed call-out is made to cross check airspeed indications and define the beginning of the high-speed reject regime. United uses 100kts, some airlines use 80kts.
Thank you. These are the ones I recognize and remember too.
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Old Aug 21, 15, 9:00 pm
  #37  
 
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Originally Posted by choefman View Post
Well all this talk about V speed is fun...

Here is what happened from me as a passengers perspective.... I boarded this flight, we were going down the run way really fast, were about to rotate when all of a sudden the plane slowed down really fast... we taxied back to the gate, I called the 1K desk, got of the plane, ran to the other side of the airport, boarded a different flight and made it home safe 30 minutes or so later than originally planned, thanks United
just curious-no unusual noises like a car backfiring?
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Old Aug 22, 15, 12:10 pm
  #38  
 
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My wife was on a plane years ago when she saw one of the engines on fire. They had departed from JFK and were over the Atlantic on their way to Heathrow. Both engines were out on one side, but they were able to turn back to JFK. Things like that don't upset my wife too much and she went back to sleep, but only after some of the others stopped their unnecessary screaming. She was confident in the pilots and the ability of planes to fly without some engines. Although, the landing was interesting with quite a tilt. The one wing was really fried, so the trucks were there to spray the foam all over as soon as they landed.
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Old Aug 22, 15, 2:15 pm
  #39  
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Originally Posted by LarryJ View Post
I fly B737s and have never heard of a lot of the things that you guys are talking about. LOL

Speeds used by the pilots on takeoff are:

V1 - Takeoff Decision Speed
Vr - Rotation Speed
V2 - Takeoff Safety Speed

Flaps are retracted in increments when reaching the minimum maneuvering speed for the current flap selection and accelerating.

A low-speed call-out is made to cross check airspeed indications and define the beginning of the high-speed reject regime. United uses 100kts, some airlines use 80kts.

I have no idea what happened on this particular flight but the description sounds like the engine "torched". That happens sometimes during an engine start, when the engine first lights off when some of the fuel has traveled into the exhaust section before igniting, and is unlikely to causes damage. Rarely happens to an engine that is already running unless there is a compressor stall but that would have been quite obvious to the crew.
What about cockpit warnings? Shouldn't the pilots have known about a possible fire before a plane behind them did? What if there wasn't a plane back there? Would they have climbed out? And then what?
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Old Aug 22, 15, 2:23 pm
  #40  
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Originally Posted by NewportGuy View Post
What if there wasn't a plane back there? Would they have climbed out? And then what?
They quite possibly could have climbed out normally and had a normal, routine flight, given what Larry said about a bit of fuel in the exhaust and the low chance of damage. @:-)
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Old Aug 22, 15, 5:57 pm
  #41  
 
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Originally Posted by LarryJ View Post
I fly B737s and have never heard of a lot of the things that you guys are talking about. LOL
This was a FT 737!
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Old Aug 22, 15, 7:24 pm
  #42  
 
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Originally Posted by NewportGuy View Post
What about cockpit warnings? Shouldn't the pilots have known about a possible fire before a plane behind them did?
If it is "torching" or excess fuel burning as it exits with the exhaust then there is no indication. Not much different from an afterburner expect the afterburner is intentional and through a nozzle so as to produce additional thrust. It would be a very temporary condition.

If there is a fire within the engine nacelle then it is detected by heat sensing detector loops and can be extinguished by cutting off all fuel, hydraulic fluid, and pneumatic pressure to the nacelle and flooding the nacelle with Halon.

Once again, there's nowhere near enough information to say what might have happened on this flight. I'm just talking about the only things that the limited descriptions posted might suggest. It was probably something very different.
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Old Aug 22, 15, 7:38 pm
  #43  
 
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Originally Posted by choefman View Post
Well all this talk about V speed is fun...

Here is what happened from me as a passengers perspective.... I boarded this flight, we were going down the run way really fast, were about to rotate when all of a sudden the plane slowed down really fast... we taxied back to the gate, I called the 1K desk, got of the plane, ran to the other side of the airport, boarded a different flight and made it home safe 30 minutes or so later than originally planned, thanks United
Yep, that's how I think of these too.
Glad you and everyone are ok. I've only had one aborted takeoff (at MSP), and it was pretty startling, but then 2 seconds later you realize you're ground the ground and taxiing.

I've had a few aborted landings and one in particular, at ATL, was quite scary. Hearing the engines rev at what feels like 20 feet above the runway will make your heart skip a couple beats.
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Old Dec 1, 15, 10:49 pm
  #44  
 
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UA995 PDX-SFO, go-around on landing [Dec. 1, 2015]

So, kind of weird happenings on UA995 PDX-SFO just now. We had a go-around on the landing -- after a few minutes pilot gets on and says they had a warning in the cockpit and had to go-around. Okay, then.... given the relatively sharp ascent, that wasn't exactly the most relaxed I've ever been on a plane, but fine. Then, when we pull up to the gate, they call a specific passenger up by name to deplane first. The rest of us deplane and there are a bunch of police in the jetbridge with the woman who was called up.

No clue what happened (I'm assuming the two things are related, but maybe not?). And no clue if I'll ever find out. But, certainly a first....
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Old Dec 2, 15, 12:03 am
  #45  
 
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Sounds related. Police were not ready at the jetbridge so they told the plane to go around?

But than they could have just had the plane circle around on the taxiway
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