True enough for the extremely risk-averse FAA.
> there are lots of sensitive measurement devices, like a pitot tube, that I imagine could fail if a balloon hit it. (For reference, Aeroperu 603 was brought down by tape that wasn't removed from the plane.)
Tape over all of the multiply-redundant static ports on the aircraft. We don't treat tape as a critical threat to aircraft.
The 737-MAX has three pitot tubes and six static ports, deliberately placed on both sides of the aircraft. (https://www.researchgate.net/figure/Boeing-737-NG-and-MAX-pr...)
Most likely.
Even more so for lighter than air aircraft. An airliner traveling at Mach 0.8 would most most likely push this tiny thing out of the way like a feather even if it was in the flight path.
Note that, regarding your pitot tube example, they are _pointy_. And heated. Assuming the balloon would even be hit and have its fabric intact, it would still be punched right through.
Remember, 90000 pound aircraft traveling at Mach 0.8 (for an average 737) against a lighter than air balloon where the most rigid components are small circuit boards and thin solar panels. There isn't even an electronics case in most instances.
Maybe engines would ingest it, but they wouldn't even notice.
Someone once told me, but I can't remember whether it was an aviator or an ornithologist, that a bird with a metal ring on its leg could cause total destruction of a jet engine. Of course they don't attach metal rings to birds any more and haven't done so for a long time, and I'm not sure how big the risk was even with the chunkiest of old-fashioned rings.
(What about a bird with an arrow stuck through it, I wonder? https://en.wikipedia.org/wiki/Pfeilstorch )
>they wouldn't even notice
What?
Imagine an aircraft sitting stationary on the runway and you fire a circuit board at it at mach 0.8, which is 988km/h or 274m/s. It's the same thing.
From google, an arduino pro micro, which is a small circuit board, about the size of a usb flash drive, weighs 13g.
From wikipedia, a .22 bullet weighs 1.3 to 3.9 g, so about 1/10 of that small circuit board, and goes at a velocity of 175 to 533 m/s.
Do you really think that's safe?
Would you be happy to fly in a plane where they shot at it with ten rifles before you get in?
In the case of Aeroperu, it was being serviced, and so _all_ the static ports were taped over with duct tape. Which is an extremely unusual maintenance procedure and resulting failure mode, and in flight you wouldn't expect all of them to fail simultaneously, even after an impact with an foreign object.
And critically, in their case, the ground radar warning system was working; however, due to all the other failures and alarms occurring on the flight deck, they did not notice or did not pay attention to this alarm.
Modern aviation is so filled with redundancies and double checks that most disasters are the result of a long sequence of chained failures, and not due to a single piece of equipment becoming inoperative.
Thats just a 2lb drone and it rips into the leading edge of a small craft, imagine at 500+ mph.
Another good example is the Columbia disaster; it was just a piece of foam
Icy foam knocking a tile loose is not a critical problem for an airplane.
If it penetrates the wing, can it hit the fuel tank?
And 6lb of metal hits different than 6lb of goose, depending on what it hits. Hail can destroy a radome.
> The above poster is saying that even small problems can lead to catastrophic consequences in complicated machines.
That's a very generic statement. Are you sure that was their real point? Not something more specific to air strikes?
If a drone penetrates the wing, we don't really know if it can make it to the fuel tank when it hits at 500...
Sure, but they picked an example that's outside of this kind of aircraft's spec, so it's not clear that it's applicable. Bad examples deserve to be called out.
Sure, it _could_ happen with a single bird, but it probably won't.
Now they have to send them into the 'most critical area' of the engine, but depending on engine size the largest bird tested could still be 4 or 6 lbs.
[1] https://www.ntsb.gov/investigations/accidentreports/reports/...
And I guess cleaning up afterward also?
Not for ingesting a large Mylar balloon with a mass tied to one end, necessarily.
If I’m remembering correctly, I think the typical “speed limit” is 250 kts below Class A airspace, which is a far cry from a Mach number.
edit: I also recall that the testing allows for destruction of the engine as long as shrapnel does not penetrate the fuselage. Engines are not happy ingesting a goose regardless of speed or altitude. There’s a liner surrounding the turbine blades the must remain intact to pass the test.
One engineer suggests that they probably defrost the chicken first.
If these have low radar signature, and they are below 60k feet then they could be a problem at least at night, and maybe during the day too
It's because that's half the weight of a Canadian Goose.
"As part of the required certification testing, the GE90 successfully completed both the 2.5 and 8 lb. (1.13 and 3.63 kg) bird ingestion tests on the engine’s composite blades. In October 94, four 2.5 lb. birds were ingested with the engine running at speeds required to produce 85,000 lb. (377.8 kN) of thrust at takeoff on a hot day. There was no thrust loss and the engine responded to all throttle commands during the required 20 minutes of operation following the ingestion."
https://www.easa.europa.eu/en/downloads/7799/en https://www.kimerius.com/app/download/5781574315/The+GE90+-+...
https://www.youtube.com/watch?v=rNqU8jfAJMQ
Here's that didn't take down the plane, but made a big hole in the canopy spewing blood and guts all over the person in the back seat with the body hitting them in the shoulder.
That small drones and hobby R/C planes need fucking transponders in the US is bloody insane.
Seeing aliens or Soviets in every birthday balloon that escapes into the wild blue yonder is ridiculous.
I doubt a balloon with a circuit board could cause an engine to fail, but there are lots of sensitive measurement devices, like a pitot tube, that I imagine could fail if a balloon hit it. (For reference, Aeroperu 603 was brought down by tape that wasn't removed from the plane.)
I'm all about hobbyists hobbying, but it does seem like there should be at least some so of registration system so we know what people are launching into shared airspace.