I think I froze all my passengers to death! :(

[dho112 17]

I've gotten to the point with the sim where I now want to start retaining the same jet for many multiple flights and start taking advantage of the service based failures based on operating time.There are many routes that I've flown as a passenger in the past and I find it extrememly engaging to now have a chance to simulate what it's like to fly those routes as a virtual captain. I'm finding though that the dizzying amount of information there is to absorb not only with the correct operation of the machine, but also with how it's implemented in the air sharing the space with other planes, that I have A LOT left to grasp :)This evening I spent about 30 minutes in the V/C keying in a flightplan from KSFO to PHNL (Honolulu), The jet was at Gate D4, the whine of the APU in the background was like a comforting song. The jetway was nestled against the side of the aircraft with the door open as in my mind I imagined a steady stream of passengers all excited about their upcoming time on the islands; filled with fun, sun, and warm, fresh air. The plane was set for full fuel, full passengers.I ran thru the checklist a bit hurridly, wanting to make certain that I made my 9pm departure time, and after everything had a satisfactory "feel", I contacted clearance delivery, then ground, then the ground crew for pushback.Everything was going perfectly and I even made it in front of two 747's following nose to tail, heading to parts unknown to me, and all without having to push the issue at the taxiway transition on the way to 28L, ground gave me the go ahead over them :)Cutting to the chase, the take-off was drama free and very smooth, as was the FMC controlled climb to FL310... I had long since dimmed the flightdeck lights to a comfortable level, panning my view out the cockpit windows to get a glimpse of an ocassional aircraft crossing far below and around the San Francisco area.Time passed... I had my book out and was just starting into chapter 5 when suddenly there was a loud alarm horn, the sound of which filled the cockpit from top to bottom... "wah wah wah wah wah wah wah" It droned on as I quickly scanned every instrument and screen readout on the front panel... looking for any sign of "red", "blinking", or wildly fluctuating indicators... Nothing... In a semi panic I jumped into the FMC "Cruise" page, selected .76 mach to replace the .79 I was flying at, and executed the change... The engines dropped off song a bit as the plane slowed, and anticipating it was some kind of overheat engine condition, I was ever more anxious when the alarm continued even with the engines now at a considerably lower percentage of thrust.The Master Caution light wasn't even lit, and frantically pressing it anyway, and the fire alarm cut off next to it did nothing to silence the alarm either..."Why isn't there a failure board on this plane like in military aircraft?!", I said out loud as now I started scanning the overhead panel... no lights out of the ordinary... all switches looked to be in the proper place, and wait a minute!I'm at flight level 310, why does that "Flt Alt" readout on the overhead say "10000"?! Crap! and how do you even read that Pressure differential indicator next to the ALT HORN CUTOUT button? Wait a another sec... *press* The alarm went silent and only the slow drone of the engines was left to lull me into what was perhaps a false sense of safety...I quickly dialed in the proper altitude where I had been for the last 30 minutes or so "31000" and very very slowly the long hand on the differential dial started to climb from just above 10 creeping up ever so slowly until it rested at about "30" I think I was just starting to figure out how I was supposed to read that dial *laughing to myself*The short hand of the dial was almost at "6 and as the long hand went clockwise toward 30, the short hand crept counterclockwise from almost 6 down to a little above 5... That part I would definitely have to pour over the manuals to figure out...And now as I sat there and tried to surmise wether or not I had inadvertantly ended myself and my copilot, dooming the aircraft to continue on, controlled by the FMC to arrive in sunny Hawaii piloted by two dead crewman, I looked up and noticed that the temperature control knobs at the extreme upper right of the overhead panel were not in the auto position...I clicked the temperature readout selector to the different settings for Pack L and R Supply Duct Cont Cab, Fore, Aft, and they all read 21 degrees celsius, but when I switched to the two locations for "Pass Cab Fore" and Pass Cab Aft" both readouts read 0 degress celsius!!! I quickly switched the temperature control knobs to the "AUTO" position and again, the needle for both the Fore and Aft Pass Cab (I'm assuming that stands for "Passenger Cabin"?) crept up very slowly (doesn't anything happen quickly in the cockpit of a 737?) from zero to around 21 celsius just like all the other readouts, when I checked each detente.I've sinced saved the flight at that point, not knowing when I get to the island paradise after I continue, if what I have just simulated is a rather ghastly and grisly discovery for Honolulu Center...I'm loving this simulation! Now I just have to get a LOT better at it!

[monitron 7]

Been there, done that.Luckily its only a sim and I didn't kill myself for real!

[Jeff_B 8]

Great write up thanks for sharing always interesting to hear others experiences with this advanced aircraft.

[paulyg123 135]

This sadly happened in real life and the plane crashed. I agree, there should be a very visable annunciator display showing that the cabin pressure is too low. That annoying wah, wah, wah was silenced in the accident. I's like a master caution alarm to say "Check the cabin pressure or you'll die soon" Or better yet, make it automatically adjust the cabin pressure - never give the pilot a chance to screw up by not adjusting the atl or forgetting to have the know on auto.Since most of us screwed up this before, we all know what that wah, wah means.

Edited March 2, 2012 by paulyg123

[Sekstifire 10]

Always follow the check list and this should be impossible

[VOR_Active 4]

This sadly happened in real life and the plane crashed

You mean Helios?

[El padrino 2]

Probably yes.

[VOR_Active 4]

I think these are two different cases. With Helios was pilot's incapacitation due to hypoxia

[Spin737 102]

I think these are two different cases. With Helios was pilot's incapacitation due to hypoxia

Caused by not having the pressurization panel set to AUTO.

I'm at flight level 310, why does that "Flt Alt" readout on the overhead say "10000"?! Crap! and how do you even read that Pressure differential indicator next to the ALT HORN CUTOUT button? Wait a another sec... *press* The alarm went silent and only the slow drone of the engines was left to lull me into what was perhaps a false sense of safety...I quickly dialed in the proper altitude where I had been for the last 30 minutes or so "31000" and very very slowly the long hand on the differential dial started to climb from just above 10 creeping up ever so slowly until it rested at about "30" I think I was just starting to figure out how I was supposed to read that dial *laughing to myself*

Thanks for taking the time to write up your flight.Check out what you wrote versus the FCOM. The "long needle" is the differential (PSID) and it should go up as you climb.I'm still wondering about this and the AUTO mode. I thought that the differential pressure should sit on the schedule, whether or not you've set the correct FLT ALT. If I understand the system :( then with the FLT ALT at 10,000, then the PSID should be at 7.45, which should still provide enough to keep the CABIN ALT fine.

[rquick 19]

Though we mourn the loss of our virtual passengers, we celebrate their bravery and willingness to perish so that we may hone our skills as virtual captains.

[dho112 17]

Caused by not having the pressurization panel set to AUTO.Thanks for taking the time to write up your flight.Check out what you wrote versus the FCOM. The "long needle" is the differential (PSID) and it should go up as you climb.I'm still wondering about this and the AUTO mode. I thought that the differential pressure should sit on the schedule, whether or not you've set the correct FLT ALT. If I understand the system :( then with the FLT ALT at 10,000, then the PSID should be at 7.45, which should still provide enough to keep the CABIN ALT fine.

Hello Matt,I have no idea how the dial works or exactly how to read it :) I'm still working on how to efficiently and correctly use the FMC :) But I think I will get there eventually!From what I saw, the long needle was down at 10, and I didn't notice it start to move until I selected 31000 with the FLT ALT knob next to it (the altitude I was cruising at for more than 30 minutes...)As the long needle wound clockwise (agonizingly slowly I might add), the short needle went from almost 6 (reading on the numbers on the inside arc of the dial) down to almost "5"I'm going to go over the other operating manuals included with the SIM and find out exaclty what the operation of this dial is and how to read it correctly...The AUTO setting I was talking about in the account was not with the FLT ALT setting but with the three knobs in the upper right of the overhead next to the Celsius temp readout dial. When those three knobs are in the 12 o'clock position they are pointing to the AUTO label on the panel, with C at the extreme left and W on the extreme right settings and OFF at the six o'clock position Two of those knobs were in the extreme C direction and the middle one (If I remember correctly) was in the off position presumably because I was absentmindedly spinning them as I was playing around in that area preflight and I forgot to return them to the AUTO position before takeoff :(... when you rotate the selector knob to the different positions I think they were (this is from memory) Pack R, Pack L, Pass Cab Fore, Pass Cab Aft, Cont Cab, etc the Celsius readout moved to show you what I assume is the temperature in those areas... When I rotated the selector to Pass Cab Aft and Pass Cab Fore, both those areas read zero celsius! where all the other one's read 21 degrees Celsius...I know that it was a tragic mistake on my part if indeed that causes the passenger to experience temperature life at 31,000 feet, but it was also odd to me that such a critical function is not something that has a failsafe before altitude it reached (I mean besides hearing the passengers screaming and the flight attendant banging on the door screaming for help)If the VNAV button won't even engage unless you are within 5 degrees of the VNAV path before take off, why would you be allowed to have the FLT ALT set to 10000 when your FMC was programmed for a FL310 cruise? I know the pilots need to be very alert about this kind of stuff and preflight checks take care of it 99.9% of the time, but it just seems like such an important aspect to be left to the "checklist" :)Don't worry though, I won't be making this mistake again :)The more I train with this SIM the more I realize its not as important to learn how to do everything right as much as it is important to learn how important it is not to do something wrong :)

Though we mourn the loss of our virtual passengers, we celebrate their bravery and willingness to perish so that we may hone our skills as virtual captains.

LOL!

[willywonka 36]

Long needle is the pressure differential. It should not exceed 9.1psi ( Limitations L.10.4 or FCOM Vol2 2.40.1). The small needle is the cabin altitude which should not exceed 8000 ft.Sounds like the "long" needle was moving up so you eventually pressurized the plane.By the way, the entire range of the temperature knob is AUTO. It's badly labeled, making the pilot think that only the middle position is "auto". The knob allows you make a bit of adjustment to AUTO to be a bit cooler or warmer. I forget the range at the moment.

Edited March 2, 2012 by willywonka

[Guest dlrk]

Again, I'd like to ask why PMDG chose not simulate the CABIN ALTITUDE light. It would have been VERY easy to do

[dho112 17]

Long needle is the pressure differential. It should not exceed 9.1psi ( Limitations L.10.4 or FCOM Vol2 2.40.1). The small needle is the cabin altitude which should not exceed 8000 ft.Sounds like the "long" needle was moving up so you eventually pressurized the plane.By the way, the entire range of the temperature knob is AUTO. It's badly labeled, making the pilot think that only the middle position is "auto". The knob allows you make a bit of adjustment to AUTO to be a bit cooler or warmer. I forget the range at the moment.

Hello Preston,Apologies, again, I was reading the dial incorrectly! :( Here is a screenshot... sorry about the nightflight aspect :)I was looking at it as the long needle reading 30 which is wrong now I see and it is reading 7.6ish I think what was confusing me was that, reading the inner scale it read 10 and then after I set FLT ALT to 31000 it moved to close to "30" on the inner scale and so my mind just went with that because it seemed in a way to correlate to what I just did even though the outer scale was the correct one to read with the long needle...At any rate, it was down about 3, and when I corrected the FLT ALT it moved slowly to where it is in the picture. I'm hopeing after finding the subject matter in the Flight documentation, I'll have a much better understanding about how it works :)Thanks for the reply!

[IFR7700 228]

Though we mourn the loss of our virtual passengers, we celebrate their bravery and willingness to perish so that we may hone our skills as virtual captains.

Unfortunately, by the time we sufficiently hone our skills to the necessary levels, there may be no virtual passengers left to buy a virtual ticket.