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Plane flying low. reasons?

Posted: Sat Jan 12, 2019 12:46 am
by Jshank83
I noticed this plane was flying DCA-ORD at 22,000 even though it was planned at 38. All the other flights today between the airports flew higher, even one that left around the same time. Just curious on the reasons it might be doing this and still make the trip without having to land for something mechanical, etc.

https://flightaware.com/live/flight/AAL ... /KDCA/KORD

Re: Plane flying low. reasons?

Posted: Sat Jan 12, 2019 1:28 am
by 747Whale
No idea; they. may have elected to ride lower for turbulence or winds, or it may have been they got better routing lower. That sometimes happens. I've had trips before out there that were filed higher, but which ended up being a lot lower due to traffic.

Re: Plane flying low. reasons?

Posted: Sat Jan 12, 2019 3:27 am
by e38
It is possible that it could have been a pressurization issue.
At one point in my career I flew an aircraft that was equipped with two air conditioning packs (for pressurization).
It was permissible to dispatch the aircraft with one pack inoperative (MEL) but there were certain restrictions that were required to be followed, one of which the maximum altitude allowed with an inoperative pack was Flight Level 250. It could fly revenue trips for three days before the condition HAD to be repaired.

e38

Re: Plane flying low. reasons?

Posted: Sat Jan 12, 2019 4:45 am
by CALTECH
e38 wrote:
It is possible that it could have been a pressurization issue.
At one point in my career I flew an aircraft that was equipped with two air conditioning packs (for pressurization).
It was permissible to dispatch the aircraft with one pack inoperative (MEL) but there were certain restrictions that were required to be followed, one of which the maximum altitude allowed with an inoperative pack was Flight Level 250. It could fly revenue trips for three days before the condition HAD to be repaired.

e38


If other aircraft were flying higher, more than likely a inop pack.

A 737-800 MEL, not necessarily American's, but more than likely the same.

Except for ER operations, one may be inoperative provided:
A. Flight altitude remains at or below FL250.
B. APU operates normally.
C. Both Engine Bleed Air Shutoff Valves (PRSOV) operate normally.
NOTE: If pack airflow/shutoff valve will not close, refer to

Re: Plane flying low. reasons?

Posted: Sat Jan 12, 2019 9:13 am
by aeropix
Sometimes after having carried a bunch of extra contingency fuel, you get airborne and get a much shorter than expected routing. This puts the aircraft above the maximum landing weight, so extra fuel must be consumed enroute to bring the landing weight within limits. One way of doing this is to fly at a lower level, in the low 20's, in order to achieve the required consumption in the given flight time.

This scenario was a frequent occurrence on the EMB-145 in the northeast back when I was flying them.

Re: Plane flying low. reasons?

Posted: Sat Jan 12, 2019 12:48 pm
by Dalmd88
It could be RVSM restricted. If any of the components to meet RVSM rules are on MEL then the plane is restricted to below FL290. Those components tend to get fixed very quickly.
https://en.wikipedia.org/wiki/Reduced_v ... ion_minima

Re: Plane flying low. reasons?

Posted: Thu Jan 17, 2019 2:20 am
by AA737-823
Just to echo above, it's most likely (from my experience in ACMX) a pack issue.
Though RVSM is also a possibility. I once rode in a United 757-222 that was RVSM incapable (around 2011, back when they would actually turn Channel 9 on!) and we got to enjoy every...single..bump... within 500 miles of Denver.

Re: Plane flying low. reasons?

Posted: Tue Jan 22, 2019 6:37 pm
by timh4000
I was on a erj 145 from alb-phl. Don't know the planned altitude, but having taken this trip about a dozen times now, its typically 16000-22000ft. Due to weather the pilot was given clearance to fly at 10k ft. It was still a bit bumpy, but looking upwards you could tell there was a lot of nasty above. It was actually my favorite flight of the ones I've taken on this route due to the low altitude. Great views all the way to Albany.

Re: Plane flying low. reasons?

Posted: Wed Jan 23, 2019 4:58 pm
by Redbellyguppy
I did Chicago to the Bay Area at FL280 the other day because winds at 280 were 80kts as opposed to 150+ at altitude. And, a better ride.

Re: Plane flying low. reasons?

Posted: Mon Jan 28, 2019 2:03 am
by pikachu
Probably didn't realize they were over gross weight when they took off. Only realized it when they couldn't climb any higher.
Happens all the time.

Re: Plane flying low. reasons?

Posted: Mon Jan 28, 2019 5:37 am
by 747Whale
pikachu wrote:
Probably didn't realize they were over gross weight when they took off. Only realized it when they couldn't climb any higher.
Happens all the time.


No, it doesn't.

Re: Plane flying low. reasons?

Posted: Mon Jan 28, 2019 6:15 am
by pikachu
Very easy to overlook in my flight sim experience. When I take off in my 747 at 1.3 million pounds I find the performance rather sluggish.

Re: Plane flying low. reasons?

Posted: Mon Jan 28, 2019 6:59 am
by 747Whale
Ok...on a computer game, perhaps you do that. In the real world, where it actually counts and professionals operate, it doesn't happen all the time, and to suggest that the airline flight in question in this thread took off in an illegal condition is a stupid comment, regardless of what you do on your home computer.

Re: Plane flying low. reasons?

Posted: Mon Jan 28, 2019 9:00 am
by pikachu
Dear Sir,

Did you just imply that I was not a professional?

If I can fly my flight sim DC9 at 495 000 pounds why can't everybody? Fly it at 9 000' and your passengers will be happy they arrive at destination and hug their loved ones.

Re: Plane flying low. reasons?

Posted: Mon Jan 28, 2019 9:12 am
by 747Whale
Ignore-list, then.

Re: Plane flying low. reasons?

Posted: Mon Jan 28, 2019 9:34 am
by pikachu
Somebody is a little sensitive...

Re: Plane flying low. reasons?

Posted: Mon Mar 04, 2019 3:04 pm
by thewizbizman
No honestly, I get exactly where 747whale is coming from. I am a big flight simmer, and fly real aircraft as well. There are rules and regulations. In flight sim, you can make mistakes and illegal shortcuts. In real life, those mistakes cost lives. In conclusion, he's not sensitive, you're just oblivious to the fact of how much work goes into making a real life flight safe and legal.

Re: Plane flying low. reasons?

Posted: Mon Mar 04, 2019 3:43 pm
by stratclub
747Whale wrote:
Ignore-list, then.



You throttle jockeys use flight sims to good effect for training so they do have a place in the grand scheme of things. I would think that they are great for trying "what if" scenarios. I don't think I have ever put anyone on an ignore list and have found that Oh, O.K. to be a great response to someone that tries to push my buttons. Not pushing back is way more effective in dealing with some folks. If they are hell bent on being an imbecile, I say let them. It's great entertainment.

Re: Plane flying low. reasons?

Posted: Mon Mar 04, 2019 6:07 pm
by 747Whale
The desktop computer games that kids play on, that have pictures of airplanes, aren't simulators.

We do use simulators for training, but I don't see any particular value in the computer games, other than entertainment.

Some years ago I actually fielded a resume from a pilot claiming experience on several types, and with several airlines. I didn't recognize the name of one, and when asked, the applicant said it was a virtual airline.

I'd never heard of a virtual airline. Apparently there were large numbers of people on a network around the world who would actually put on an airline uniform, go sit at their computer, and pretend to fly a scheduled trip from A to B, as if they were employed by an imaginary airline to fly an imaginary airplane. This joker actually logged the time and then tried to use it for a pilot position.

I put the previous poster on the ignore list because his comments were nothing more than flame-bait, and not scarcely worth my time.

Re: Plane flying low. reasons?

Posted: Mon Mar 04, 2019 7:27 pm
by stratclub
Well, there is that. After all even for entertainment value, it is a big waste of time messing with a Trolls feeble brain.

I agree, the algorithms written into a consumer desk top sim would be highly suspect as far as how closely they match real flying. I flew one of Boeings 777 full motion sim once and always wondered other than training for procedure, how close a full motion sim is to flying an actual 777?

I wonder if I spent a few months dressing up as a garbage truck driver and drove a garbage truck sim, could I get a job as a garbage truck driver? Since I'm to old to fly for the airlines, sounds like a good plan to me. :biggrin:

Re: Plane flying low. reasons?

Posted: Mon Mar 04, 2019 8:18 pm
by trpmb6
stratclub wrote:
Well, there is that. After all even for entertainment value, it is a big waste of time messing with a Trolls feeble brain.

I agree, the algorithms written into a consumer desk top sim would be highly suspect as far as how closely they match real flying. I flew one of Boeings 777 full motion sim once and always wondered other than training for procedure, how close a full motion sim is to flying an actual 777?

I wonder if I spent a few months dressing up as a garbage truck driver and drove a garbage truck sim, could I get a job as a garbage truck driver? Since I'm to old to fly for the airlines, sounds like a good plan to me. :biggrin:


Call up your local school district and you could probably be driving a school bus next week.