Semi-related. Navy F/A-18 pilots were issued Garmin watches which have a built-in barometer/altimeter because the cabin altimeter gauge of their aircraft was difficult to read due to its size and location, and "its audible warnings are ineffective through the flight envelope." The watches, once issued to pilots, will alert them when cabin altitude reaches a preset threshold.

https://www.military.com/daily-news/2017/06/16/the-navy-is-i...

Then, allegedly a pilot crew was able to use the watch's compass to help navigate in an emergency after their cabin instruments frosted over:

https://www.defensenews.com/breaking-news/2018/02/23/flying-...

Intercom buttons are one thing... I was less enthused to read about the impeller fan. It's all fun and games until it shatters under load and blows up a turbine.

Short-term, that's not the worst thing on earth when you've got a combat mission to execute, and you need working tanks.

Long-term, you're absolutely right. Somebody needs to solve the problem.

Good way of thinking of something like that is that it's a "spare tire". It's not meant to completely replace the busted part, but just last long enough until you can get a proper replacement installed. In the military, that could be the difference between life and death.

A guy who had been in the air force told me about their electrical generators. They used them to set up temporary air traffic control installations to guide fighters to targets and stuff. The generators would kick off after X hours of continuous operation, to protect them from destroying themselves (due to heat, I presume). That's standard on civilian versions of the generators. But the air force wouldn't buy them unless there was an override. If you need that generator so that you can control the 10 more minutes of an air battle, even if it destroys the generator, you can get it.

Generally known as BattleShort

https://en.wikipedia.org/wiki/Battleshort

Or, Id rather damage the bilge pump, than not have it when we're flooding...

Older military aircraft used to have a 'War emergency power' setting (WEP), it produced more than 100% of the engine's normal rated power but it decreased the operating life of the engine substantially and could only be run for a few minutes.

When it's acceptable and when it's not is an important question. And the fundamental problem of command/management is that you want that decision made by the lowest level of command/management who is fully competent to make it.

Well it's being used to clean the air filter so presumably any failure will be caught by said filter.

I would think that a fan that has the purpose of cleaning the filter would have to blow in the reverse direction to blow the trapped dirt out. It would probably be on the clean side of the filter in that case, and any shrapnel it spewed off would go right into the turbine inlet.

It's likely drawing bypass air.

Here's a prefilter for a tractor or something:

https://www.youtube.com/watch?v=_P3u7wgiy-c

It's using air flow to blow the particles out before they hit the filter. If I understand correctly, the part in question does similar, pulling debris out of the intake stream without being in series with it.

Marines think outside of the box because we rarely have enough boxes and the ones we do get don't have lids. That's why we have the unofficial motto of "Improvise, Adapt, and Overcome".

> asked him what kind of tech he wanted most. "Better batteries"

Yes, but. As I recall the story, when a fuel-cell consumer powerbrick startup, with a working production prototype, and the broader impact of expanding the envelope of consumer-scale parts supply in several areas (eg air pumps), went looking for $10M to start their supply chain, and avoid dying, ARPA responded "we can do $1M, but our budget is tight just now, and we can't do 10." What people say they want, and what they're willing to pay for, are often poorly correlated.

> Better batteries would change everything [...] Cost-to-orbit

Yes. Also small durable high-torque electric motors.

Just because ARPA could buy in whole hog doesn't mean they weren't interested.

https://federalnewsradio.com/defense-main/2018/01/how-the-co...