an engine washing by a fancy new truck rig designed by P&W ("EcoPower") has been said to improve fuel consumption etc on the order of 1% by removing grime and stuff from the blades. My question is, look at the photo of the setup, a couple of high pressure nozzles I guess, positioned just before the intake fan -- how does the water reach anything but the outer largest fan blades and do its job without any chemicals/cleaning agents? And how is this any different than just flying through a rain cloud? OK, I accept that it works based on the cup of dirty fluid caught streaming out of the engine, but I wish I could understand how it's doing it!
an engine washing by a fancy new truck rig designed by P&W ("EcoPower") has been said to improve fuel consumption etc on the order of 1% by removing grime and stuff from the blades. My question is, look at the photo of the setup, a couple of high pressure nozzles I guess, positioned just before the intake fan -- how does the water reach anything but the outer largest fan blades and do its job without any chemicals/cleaning agents? And how is this any different than just flying through a rain cloud? OK, I accept that it works based on the cup of dirty fluid caught streaming out of the engine, but I wish I could understand how it's doing it!
Well, first of all we try to avoid the heavy rain showers, so we don't normally fly through a large rain shower to clean the engines.
Secondly, I have no idea how this contraption works or if it works well. I know engines do get an engine wash at certain hours, but not sure how it helps the performance since anything having to do with grime and fuel coking would be in the combustion chamber which this wouldn't reach. So, sorry, I can't really expound on how this helps that much, although I'm sure in some ways it does.
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If the OP was in visual conditions, the landing might have been an autolanding soley for the purpose of maintaining the airplane currency. I'm fairly certain a/c certified for autolandings have to perform one at a minimum once every 90 (?) days. Quite often during quiet times you'll hear a/c requesting an autolanding (which means greater spacing requirements, stable flight parameters, no a/c in the ILS critical zone, etc.) even though it is severe clear.
I have an article saved somewhere detailing the operating systems of General Aviation GPS's and some of them do run on embedded Windows. Then again, the 'for use' cases is very limited compared to the standard desktop windows personal computer.
Different carriers address low-visibility approaches differently. There are three different approach categories, Cat I, II, and III, and some subcategories. Which type of approach and landing depends on all of these, and more. It depends on the visibility, equipment available on the airplane and landing runway, and a host of other things. United requires the use of the auto-land system, which on the 757/767 consists of:
3 autopilots
2 operating generators
1 autothrottle system
2 radio (not radar, sonar, or laser-beam) altimeters
certain flight instrumentation that is supplied by independent symbol generators
3 hydraulic systems
3 Inertial Reference Systems
2 thrust reversers, an operative anti-skid system
2 windshield wipers
rollout guidance on the forward instrument panel
2 autoland status annunciators
The list of operative ground equipment is similarly comprehensive.
Oh, yeah, and runway condition, length, surface type, and wind componentry must meet certain criteria, too.
Certain components of both airborne equipment and ground equipment may be inoperative depending on the approach category, with precious little for Cat III, where a Cat I doesn't require as much.
As was mentioned in this thread, very few landings are autolanded because
a) the reported visibility must be less than about ⅜ statute mile before we are required to use the autoland system, and
b) it's a lot less work and more fun to hand-fly an approach and landing.
Probably half of autolands are done in better than required weather because the airplanes need to be autolanded within a certain timeframe to remain legal and current.
All United flight crews are recertified on low-viz approaches and a few other attention-getting tasks every 9 months during our little visit to our training center for a fun-filled episode of "You Bet Your Job".
Sometimes, a law degree would be nice to help sort out all the legalities and criteria that must be met to do these, as well as all the other stuff we are required to know.
Not all airlines are certifies for Cat III operations. Not all Cat III airlines use an autoland system. Some use a Heads Up Display for very precise hand-flying to a landing.
Minimum visibility, even for Cat III approaches, is different among the airlines. United, for example, and I'm leaving a lot out for brevity, can actually land with ZERO visibility legally and safely. some unique conditions have to be met for this but I've done it on the line, and we've all done it in the Sims.
What I've described here is by no means a complete accounting of all the requirements, conditions, legalities, and variations of the low-visibility approach and landing.
When I am preparing for that one in a hundred autoland, I make a cabin announcement that we will be making a very "electronics-intensive" approach and landing, and if anyone has "forgotten" to turn off their electronic devices or phones, now is a good time. When you were last told is even better.
As far as "nice" landings vs "crappy" landings, I'll cop to it right now: I slammed one on about 2 years ago in DEN. It was in an A-320. Weather was great, no unusual circumstances, no vicious winds or anything, density altitude not a player, nothin', just a case where the runway was about 2 feet higher than I thought.
My copilot was laughing so hard he couldn't even talk to ground control. I was reliving my past and feelin' the pain in my back. On a scale of 1 to 10, that was a ⅝. Now, not too long ago, I did one in IAD that was almost good enough to fool the air-ground sensors on the landing gear. That, my passengers told me, was a 35.
I'm averaging 8.
Once, many moons ago, as a cope in the 737-200, my captain did a great landing, and as he was standing at the door saying goodbye, a cute young lady told him, "That was the nicest landing I've ever had!". He said thanks, and thanks for coming. She said, "It wasn't THAT nice!".
That's NOT urban legend, I was there!
Freshairborne
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Quote:
Originally Posted by aluminumdriver
......We have to auto-land the aircraft once weather goes below a normal Category 1 ILS approach (1800 RVR for United). If you hear on CH 9 that weather is below 1/2 mile or 1800 RVR, then expect an auto-land then........
so my question is.....
last saturday while on approach to iad with ch9 on...... fog and an rvr of iirc 500. we are on final to 19 or 1 (i forget which) and the captain pulls a missed approach ("tower, united 44 heavy-we're going around as we didn't break out where we should have) . we pull up and enter the pattern for runway 30 and then ch9 goes off. we landed on the next approach and when we did break out just before landing, i will say that the fog was as close to the deck as i have seen in a very long while (maybe 300')
so with all of that (and i hope i got the runways listed correctly)-it sounded like we were on an auto land approach where the capt and/or f/o decided to abort the auto land and go around
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just my humble opinion but i used to try and stop hockey pucks so what do i know . Nighthawks fans are everywhere
last saturday while on approach to iad with ch9 on...... fog and an rvr of iirc 500. we are on final to 19 or 1 (i forget which) and the captain pulls a missed approach ("tower, united 44 heavy-we're going around as we didn't break out where we should have) . we pull up and enter the pattern for runway 30 and then ch9 goes off. we landed on the next approach and when we did break out just before landing, i will say that the fog was as close to the deck as i have seen in a very long while (maybe 300')
so with all of that (and i hope i got the runways listed correctly)-it sounded like we were on an auto land approach where the capt and/or f/o decided to abort the auto land and go around
Since I don't know the specifics, I can only guess. They might have had a mechanical irregularity pop up that prevented the autoland, so they went around. They were then able to fix it and try and again and landing.
Another scenario is they briefed a Cat II autoland, but on the approach it went to Cat III and they hadn't pre-briefed it and went around to set it up. I usually brief a CAT III auto-land anyways, just in case it goes down below Cat II on the approach.
Not being there, I really don't know. There are many reasons an approach can be broken off for on a coupled-approach.
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These views are my own and do not represent the views of United Airlines or the ALPA.
...United requires the use of the auto-land system, which on the 757/767 consists of:...
...
2 radio (not radar, sonar, or laser-beam) altimeters
...
thanks for such a detailed and informative post! That is really interesting.
the radio altimeters, though, are based on radar, isn't that correct? I've noticed this a few times near airports where a plane on approach flies directly overhead, and sets off car radar detectors like crazy...
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Posts: 10,128
Quote:
Originally Posted by aluminumdriver
Since I don't know the specifics, I can only guess. They might have had a mechanical irregularity pop up that prevented the autoland, so they went around. They were then able to fix it and try and again and landing.
Another scenario is they briefed a Cat II autoland, but on the approach it went to Cat III and they hadn't pre-briefed it and went around to set it up. I usually brief a CAT III auto-land anyways, just in case it goes down below Cat II on the approach.
Not being there, I really don't know. There are many reasons an approach can be broken off for on a coupled-approach.
thanks and from what you described, it sounds like a cat II becoming a cat III and they weren't set up for it
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just my humble opinion but i used to try and stop hockey pucks so what do i know . Nighthawks fans are everywhere
This is a fascinating thread. Thanks to all the pilots who have participated. I attempted a search, but didn't see anything on this, so here's my rather mundane question...
Do you ever forget to turn the "fasten your seatbelt" light off?
Is there any kind of timer to remind you to check it on long flights?
The reason I ask is I sat in my seat for LONG period of time on a trans-Atlantic recently when I really needed to go. The flight attendants were walking around a bit and since the flight had been smooth for a while I asked if the pilots really needed the light on. She went up to the front of the plane and sure enough "Ding!"
thanks for such a detailed and informative post! That is really interesting.
the radio altimeters, though, are based on radar, isn't that correct? I've noticed this a few times near airports where a plane on approach flies directly overhead, and sets off car radar detectors like crazy...
Nope. Only one radar in the plane; weather-detection radar.
Freshairborne
__________________
These are my own observations and/or opinions, and not necessarily those of the Air Line Pilots Association or UAL Corp.
This is a fascinating thread. Thanks to all the pilots who have participated. I attempted a search, but didn't see anything on this, so here's my rather mundane question...
Do you ever forget to turn the "fasten your seatbelt" light off?
Is there any kind of timer to remind you to check it on long flights?
The reason I ask is I sat in my seat for LONG period of time on a trans-Atlantic recently when I really needed to go. The flight attendants were walking around a bit and since the flight had been smooth for a while I asked if the pilots really needed the light on. She went up to the front of the plane and sure enough "Ding!"
Thanks!
Sure, it happens. We may get sidetracked talking to ATC or with each other. If the flight is smooth for a while and the seatbelt sign is still on, just ask a FA to call us and ask if it can come off. We might have indeed forgotten.
Quote:
Originally Posted by GoingAway
freshairborne - great post but why if you're "auto" land would you need
I know the crew obviously need those but what does it have to do with an autoland requirement? The machine isn't looking at the scenery. (is it )
It's for when you land and are on the runway. The pilot has to taxi clear and to the gate, so windshield wipers might be necessary. So, they made it a requirement.
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These views are my own and do not represent the views of United Airlines or the ALPA.
This is a fascinating thread. Thanks to all the pilots who have participated. I attempted a search, but didn't see anything on this, so here's my rather mundane question...
Do you ever forget to turn the "fasten your seatbelt" light off?
Is there any kind of timer to remind you to check it on long flights?
The reason I ask is I sat in my seat for LONG period of time on a trans-Atlantic recently when I really needed to go. The flight attendants were walking around a bit and since the flight had been smooth for a while I asked if the pilots really needed the light on. She went up to the front of the plane and sure enough "Ding!"
Oh, heck, yeah, we forget. All those buttons & switches and stuff you expect us to remember all that?
Kidding of course, but yes, I forget sometimes. The seat belt sign is, to me, the most "psychological" switch in the cockpit. If you are too lenient or not lenient enough, it looses some effectiveness. If you leave it on too much, people don't take it seriously. It's most likely on in smooth air because we anticipate a lumpy patch up the road and we want people in their seats as opposed to making a last blue-room run or getting stuff out of the overhead bin when it hits. Leave it off to much and someone could get hurt.
If I'm going to leave it on for a while after takeoff and it seems smooth to you, I'll make an announcement that we're expecting a few more bumps, so no, we didn't forget you, we just have more info than you do.
Flight attendants are authorized to be up during certain chop & turbulence conditions where passengers are not.
There are very specific rules as to when we turn it on or off, but actually knowing 100% what kind of rides we're in for is a total crap shoot. Experience is the best teacher. Common sense, reports from other aircraft, knowledge of weather reports, etc. all are players, too.
I tend to do a lot of checking on various websites before I fly, and I actually use my iPhone for reports from my favorite weather website when I don't have time to run into the terminal, find a computer, and check it out.
What's kind of ironic is that, in a part-time flying job I do, I fly a 30 year old bizjet with old flight instrumentation, but realtime graphical weather data uplinks. I'll take that over the stuff United has any day (plus, I get to wear shorts and flip-flops in that gig).
Freshairborne
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These are my own observations and/or opinions, and not necessarily those of the Air Line Pilots Association or UAL Corp.
Last edited by FlyinHawaiian; Jun 12, 08 at 11:24 am.
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I'm wondering if any of the pilots would be willing to share some information about their procedures during mechanical delays, if it's not too much trouble.
Here's a recent scenario I encounterd:
I was flying on a 777 out of LAX; we were on the taxiway and just received position and hold clearance for the takeoff runway when the pilots discovered a problem with the high stage bleed valve on the #1 engine. Understandibly, Channel 9 was turned off at this point. We taxied back to our departure gate where we were met by mechanics and sat on the plane while the valve was repaired. We took about a 90 minute ground delay and then were on our way.
So, here are some procedural questions:
Is there a maintenance "hotline" that is radioed when there are warning lights or faults?
What area determines which gate we return to and how are they notified?
What area determines how our flight plan is to be refiled and dispatched, and how are they notified?
In cases of delay, would that area seek to obtain a more direct routing and/or less-than-optimal cruise altitude/speeds? (Our pilot informed us that our new routing was a little lower than normal and we were adding more fuel to make our destination. I think we ended up at FL 35 at .84 mach).
As part of the repair process, we did an engine start at the gate. Once the valve was fixed, we did a little extra process before take-off which our captain said was a little unusual and also alerted the tower that we would need a little extra time after we were in position on the departure runway. It sounded like they did a full power run up and we held on the runway for about 15 seconds before the brakes were released. I am assuming the pilots were checking the bleed airflow under power; can you please explain what this process was?
When we arrived at our destination, we taxied up to our gate, only to have to wait around 15-20 min because there was no gate agent to operate the jetway. I assume at some point, our pilot radioed the appropriate airport operations area and let them know a gate agent was needed, correct?
Thanks again for taking the time to answer these questions.
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Last edited by FlyinHawaiian; Jun 16, 08 at 12:38 pm.
I'm wondering if any of the pilots would be willing to share some information about their procedures during mechanical delays, if it's not too much trouble.
Here's a recent scenario I encounterd:
I was flying on a 777 out of LAX; we were on the taxiway and just received position and hold clearance for the takeoff runway when the pilots discovered a problem with the high stage bleed valve on the #1 engine. Understandibly, Channel 9 was turned off at this point. We taxied back to our departure gate where we were met by mechanics and sat on the plane while the valve was repaired. We took about a 90 minute ground delay and then were on our way.
So, here are some procedural questions:
Is there a maintenance "hotline" that is radioed when there are warning lights or faults?
What area determines which gate we return to and how are they notified?
What area determines how our flight plan is to be refiled and dispatched, and how are they notified?
In cases of delay, would that area seek to obtain a more direct routing and/or less-than-optimal cruise altitude/speeds? (Our pilot informed us that our new routing was a little lower than normal and we were adding more fuel to make our destination. I think we ended up at FL 35 at .84 mach).
As part of the repair process, we did an engine start at the gate. Once the valve was fixed, we did a little extra process before take-off which our captain said was a little unusual and also alerted the tower that we would need a little extra time after we were in position on the departure runway. It sounded like they did a full power run up and we held on the runway for about 15 seconds before the brakes were released. I am assuming the pilots were checking the bleed airflow under power; can you please explain what this process was?
When we arrived at our destination, we taxied up to our gate, only to have to wait around 15-20 min because there was no gate agent to operate the jetway. I assume at some point, our pilot radioed the appropriate airport operations area and let them know a gate agent was needed, correct?
Thanks again for taking the time to answer these questions.
Hello, I'll try to answer some of these. I'm not a 777 guy but know some of this.
A) Some airports we have maintenance at, like our domiciles. If we have maintenance there, we can call them directly for help when we are at the gate. Once we are off the gate, we have to contact our maintenance in SFO for assistance. We can call them directly on a cell phone, or go through ACARS and text message them, or through our dispatch and phone patch with them. It depends on the severity of the situation. We'll see if there is a fix that can be done to fix it, or defer the item. If we can't fix it and it's not derferable, we have to go back to the gate to be fixed.
B) If you have to go back to the gate, we have to talk to Zone Control and they will advise us what gate we can go back to.
C) If we won't be delayed too long, we can inform ATC to keep our flight plan on file. If there is a long delay, then dispatch will refile us a new flight plan.
D) Just because you are delayed doesn't mean we get a more direct routing. Usually it will be the same routing as you had before. You might fly a little faster if you can make up some good time, but if you're real late, it would be just as planned. Your new routing was probably due to traffic or weather.
E) Your guess is probably correct. Not knowing all that was involved, a bleed air issue might ask for a high power run-up to verify the fix.
F) Yeah, this happens sometimes where the CSR is not at the gate. Usually we can get them down there pretty quickly. 15-20 min is way too long. It might have been you surprised them coming in on such a long delay and they didn't have a CSR set up for your arrival. Who knows, but someone dropped the ball there.
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These views are my own and do not represent the views of United Airlines or the ALPA.
Once, many moons ago, as a cope in the 737-200, my captain did a great landing, and as he was standing at the door saying goodbye, a cute young lady told him, "That was the nicest landing I've ever had!". He said thanks, and thanks for coming. She said, "It wasn't THAT nice!".
That's NOT urban legend, I was there!
Freshairborne
That's officially the funnest thing I've read today. Kudos to anyone that was able to remain upright as I fear I would have lost it on that one.
. Nighthawks fans are everywhere
)
