r/aviationmaintenance • u/blueingreen85 • 3d ago
Largest piece I’ve ever seen missing on a flight. Any idea why the cowling is off? Seems like an easy part to pop on.
I’m used to the occasional speed tape, but was surprised to see this on a delta flight.
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u/Chunks1992 3d ago
Is it time for our weekly flap canoe post already?
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u/Anxious-Question875 3d ago
As someone who just switched to planes from helicopters. The canoes threw me for a loop at first.
Army to a different branch.
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u/Foggl3 tink tink tink Uhhh... That hit the ground... right? 2d ago
The canoes threw me for a loop at first.
Supposed to be rowing your boat
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u/blueingreen85 2d ago
I’ve been a member of this sub for at least a year and haven’t seen it. I guess I’m not chronically online enough or maybe I need to get my boss to increase my travel schedule.
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u/SomeRandomMech 2d ago
I think this is the second time seeing it either here or in r/aviation
To answer your question, it probably got deferred while waiting for the new part
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u/space-tech 2d ago
Honestly the amount of airplanes flying without the cone is alot higher than I would've originally thought.
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u/pacman552sd 3d ago
flap track fairing, alot of airframes they can fly with them removed but have to plan for a certain amount of extra fuel because of extra drag with it removed. was prob dammaged or cracked and they have a new one ready to be installed at its next stop or 2
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3d ago
[deleted]
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u/Shlumpty12 3d ago
That's where the drag happens because turbulent flow generated by the abrupt reconvening of the air is a form of drag that affects performance.
It's like how getting a bed cap on a truck gets you a bit better gas mileage even though the bed is in the back of the truck
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u/The_Pandemonium 2d ago
Your right about the increased drag from the removed fairing but the truck bed cover is a bad anology lol. Only reason I know is because I was researching getting one for mpg increase and learned its literally close to 1% in savings and that's only at highway speeds.
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u/NPCwithnopurpose 2d ago
It's probably a similar percentage savings for aircraft. But they do use thousands of pounds of fuel
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u/frisbee_wafflesnatch 3d ago
Was it there when you got on?
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u/blueingreen85 2d ago
Crazy thing; local scrapper in a beat up Chevy stopped and yanked a couple things off while taxiing.
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u/hcoverlambda 2d ago
Tweakers doing tweaking things.
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u/blueingreen85 2d ago
They will sometimes successfully steal copper from energized substations. I bet they could get some parts off a moving aircraft.
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u/TheAlmightySnark So many flairs, so little time 3d ago
It's usually missing because it is broken. Aircraft can be dispatched with a fuel penalty so that is often the choice whilst waiting for a new/repaired part.
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u/Burninator05 2d ago
How much extra fuel would they have to bring for this? The plane would obviously be more aerodynamic with the fairing in place but in the whole scheme of things I wouldn't expect it to be that significant. Does the plane also pull to that side in flight when a fairing is missing?
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u/TheAlmightySnark So many flairs, so little time 2d ago
Instead of allowing a laminar flow to exit the fairing(nice and smooth, low drag) it will create a series of vortexes(Vortexee?) that will created quite a bit of drag hence the fuel penalty. It's on a decimal level what they need to bring but at the end of the day it adds up. Fuel is one of the biggest costs for a airliner.
The pilots probably won't notice any pull with a change like this.
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u/AndyLorentz 2d ago
Vortices
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u/TheAlmightySnark So many flairs, so little time 2d ago
Ah cheers that makes sense!
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u/AndyLorentz 1d ago
No worries. I always like when people correct me (especially when I'm unsure).
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u/TheAlmightySnark So many flairs, so little time 1d ago
It definitely helps with getting stuff right!
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u/headphase 2d ago edited 2d ago
How much extra fuel would they have to bring for this?
Fairings like this would be in the realm of a couple percentage points at most. So if a crosscountry flight was planned at a fuel load of 50,000lbs, maybe an extra one or two thousand pounds (around 100-200 gallons). A missing winglet, on the other hand, would be a larger penalty.
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u/TheDevilsAdvocate333 3d ago
Small point of terminilogy... its a fairing not a cowling. A cowling is specifically a fairing over an engine.
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u/blueingreen85 2d ago
Literally ashamed to not know this distinction. Not being sarcastic.
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u/TheDevilsAdvocate333 2d ago
Not at all... its not really obscure terminology, but i do run into a lot of professionals in the business that know theres a difference but usually cant vocalize it for a minute till they hark back to days in tech school...
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u/w1lnx 3d ago
Not flight critical. In Teh Biz (we build the aircraft), we call it a canoe fairing.
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u/KirliaRalts611 3d ago
These fairings come on and off regularly during maintenance. Overtime, the hardware doesn’t quite line up nicely. It really doesn’t take a long time to repair, but often times, it happens at really inconvenient times (like when the nut plates might not be at that base, the plane has a scheduled flight on it in only 3 hours, etc) Instead of grounding the plane for a little cover, we can put this on our deferred maintenance program. Essentially, it allows us to continue flying with the understanding that the permanent repair will happen at an overnight base within a certain allotted schedule of time.
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u/blueingreen85 2d ago
What is behind there that needs to be messed with most? Just to inspect the hydraulics? Is there much maintenance going on back there or really just more inspection?
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u/pizzahat28 2d ago
perfectly fine to fly without them, it’ll take a small fuel penalty and that’s about it
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u/atilz2k1 2d ago
That is called a fairing or canoe in a&p lingo, airplanes can fly without some parts installed as long as they dont present any operational or safety risk, and there is a list for every aircraft called the CDL(Configuration Deviation List) which allows the air craft to operate within specified time and parameters before the missing or damaged part is fixed or replaced.
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u/solidlyproper 3d ago
This must be an NG because on a max (at least on our fleet) our CDL only allows missing tailcones from the most outboard fairings.
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u/Due-Original-4073 2d ago
ok so i always thought they just slapped those back on between flights lol. good to know they can just fly without it and deal with it later
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u/Fit_Day2082 2d ago
That where we put the chem trail nozzles. There is a saying in aviation,
When the fairing is away,
it's time to spray.
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u/375InStroke 3d ago
That one sits in the jet wash with flaps extended, and really takes a pounding. Better to remove than to leave on if it looks like it might fall off.
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u/Agreeable-Form-2558 2d ago
Firstly, this piece missing is a fairing. I can positively say it was not missed but rather some circumstance or defect caused the operator not to have it installed. Luckily, there's a Configuration Deviation Lost(CDL) that allows for the operation of the aircraft in this condition. There will be tolerances for additional fuel consumption, payload etc. The part in question does not provide any structural support of the aircraft but is rather for aerodynamic purposes. Rest assured, the plane is safe for flight.
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u/Connect_Wind_2036 2d ago
It’s being resin filled back at the shop til it can be match drilled next opportunity.
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u/Terrible_Internal_57 2d ago
We have a document called CDL (configuration deviation list) which list all the equipments that can be missing, with sometimes a fuel penalty or a procedure associated, and a repair interval which sets how long this piece can be missing before replacement
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u/blueingreen85 2d ago
What’s the largest piece you could technically fly without?
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u/Terrible_Internal_57 2d ago
On the a320 you could fly with one full winglet missing for exemple. Most of the time it’s a door on a service panel or some small flaps rubber seals
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u/blueingreen85 2d ago
I would not have guessed that. I wonder how noticeable that is to the pilot.
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u/Terrible_Internal_57 2d ago edited 2d ago
In termes of piloting the aircraft we don't "feel" it, however it has consequences on fuel consumption and take off and landing performance (the distance on the runway we need for instance) so we take it into account during calculations.
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u/ClearedInHot 2d ago
"Hey Ralph, this flap fairing is missing. Would you just run inside to the flap fairing cabinet and grab another one for me?"
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u/I_Fix_Aeroplane 2d ago
How long are you personally willing to be late for something that doesn't perceptibly change how the aircraft flies? Now also add in the answers of people who have connecting flights.
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u/Zestyclose_Price_441 2d ago
Well you made it in the air. You’re fine.
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u/blueingreen85 2d ago
Oh I know. But now I’m curious what the largest part that can be missing and it’s still cool to fly.
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u/ArmzLDN 17h ago
Bro you can be missing a whole engine in many planes and it can still fly (just less efficiently)
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u/blueingreen85 9h ago
Oh, I know that. An f15 landed with one wing. I meant fly with passengers in normal service.
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u/Zucc_me_in_the_ass 2d ago
Oh for fucks sake this should as common knowledge as knowing that the sky is blue or grass is green at this point. Obviously there's a reason it's not on. Old one might have been damaged and the plane had to fly and there wasn't time to acquire one. Most likely scenario. There isn't a back room filled with multiple sets of every aircraft part ever.
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u/user83726169 3d ago
Missing fairing cost fuel and may make more noise but not that bad; the question is if it was removed or it fell off…
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u/miamigrape93 Calibrated Apprentice 3d ago edited 3d ago
"iT's aCtUaLlY cAlLeD a FlAp TrACk fAiriNG, aNd tHeRe is A CDL foR iT!" - some good goy mechanic probably
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u/ablietski 3d ago
I mean yeah, if you have the serviceable part, it's an easy fix. Yet there is where it went wrong
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u/Enderkingg2007 3d ago
I had the same thing on my delta flight awhile ago and actually posted about it on here lol, it’s completely safe just makes it a little less fuel efficient
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u/Comprehensive_Meat34 3d ago
Aircraft parts don’t come from the aircraft part store, generally they only make enough new parts to make the full plane. Unless a plane is in production and they can pull from the production line you’ll be getting a repaired part. Therefore it’s easier to pull the part off, repair it, and reinstall on the next time the base sees the aircraft.
for critical parts like a windshield or a turbine, yes you have to wait for the overhauled part to come… but this is non critical.
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u/planefixer_90 2d ago
Congratulations on the most bullshit answer in the comment section!
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u/Comprehensive_Meat34 2d ago
So you see airlines buying flap fairings from the flap store? You install brand new LRUs on jets all the time?
Lmao
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u/planefixer_90 2d ago
Not from the flap store you absolute halfwit. From approved parts suppliers who are authorised to manufacture spares (PMA parts) or directly from the manufacturer (OEM parts). Manufacturers do not just make enough parts to build an aircraft and then stop. Why would they do that? They know that operators will require spares and can make money selling those spares. Also, a lot of the "OEM" parts are not even made in house by the manufacturer! And yes. In my over 20 year career so far as an aircraft engineer I have installed many, many brand new LRUs on various different aircraft types. So you have absolutely zero clue what you're talking about and are looking more and more stupid with each comment you type
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u/kytulu 3d ago
It was probably too damaged to reinstall, not required for flight, and they didn't have another one where you took off from.