15

I am intimately familiar with that incident. The airplane only had FDR recording the left PFD so they don't really know what was showing on the right one based on FDR. The only pitch angle protection is the shaker/pusher. They didn't get that slow. The AP runs off the Flight Director it's selected to. This is normally the FD of the pilot flying.The ...


10

It is the Ram Air Inlet Duct for the cabin air system. It normally acts as cooling air for the packs but can also be used as an alternate vent source in an emergency. The cooling efficiency of each air conditioning pack is enhanced by ram air cooling via a heat exchanger. Ram air enters through an inlet at the abse of the vertical stabilizer and ...


9

Normally there is some kind of barrier, a bulkhead or curtain, separating the business class and the common folk in steerage. In such a case the sign is to indicate that there is an exit somewhere down yonder beyond the bulkhead. In this case the curtain is not there so the sign kind of hangs there with its nonsensical implication that maybe there is an ...


9

I know the exact answer, even if 2 years late. Firstly, Collins makes their own displays. Secondly, it was a conscious decision during CRJ700 development to remain CRT, solely for the reason that airlines already had spares supplies of the CRT displays for the CRJ200 fleet. Changing to LCD in the 700, 900, and 1000 would require two different spares ...


9

This is just an educated guess, but it was too much info for comments. Maybe someone can come up with a specific answer, but it seems it's probably a certification delay. The CRJ's all use the Rockwell Collins Pro Line 4 avionics suite, which uses CRT's. In 2000 Rockwell Collins introduced the Pro Line 21 suite which uses LCD screens. They have been slowly ...


6

Judging by an exit photo here, you're right. When there is an opening in the fuselage (e.g., where the emergency hatch would go) the surrounding area needs extra strengthening. Below is a high-res example for an Airbus fuselage: (source) Notice the extra and deeper stringers to the left of the door, and the lack thereof away from the door where the windows ...


5

It's absolutely normal. Above is how the manufacturer even depicts the nose tire in the airport planning manual (.pdf, page 42). The pressures are checked by line engineers typically before leaving the hub, as well as an inspection by a flight crew member before every flight. While not available on the CRJ900, there are many jetliners that have tire ...


5

Can't speak for the Lear, which I believe has manual controls anyway, but the CRJs DO NOT have manual reversion. The RJs are designed to a technical level similar to the Boeing 767. The control surfaces are purely hydraulically operated. For elevator and rudder, which have 3 PCUs each, you'd have to lose all 3 hydraulic systems to lose the surfaces. For ...


5

It's important to understand that Bombardier Transportation/Aerospace, while ostensibly a company separate from the original Bombardier family (which only retained a minority stake when it was split off from Consumer Products - snowmobiles, watercraft, etc), is still actually controlled by the family due to a bizarre dual class share structure where the ...


4

The reason they are selling aircraft manufacturing lines to improve profit margin is because their aircraft business has a relatively low-profit margin. One of Bombardier most successful products is this: Bombardier Zefiro. Source: Bombardier It looks somewhat like an aircraft but it is missing the wings. It is called a "train". Bombardier calls itself "...


3

High tire pressure means less rolling resistance at least on a good road. However it also reduces grip that makes braking less efficient (source). Hence high pressure may make sense for a bicycle but not for a plane where the power is more than abundant.


2

The provision of lots of flaps settings is motivated in part by the desire to provide as many profile optimizations as possible. Generally, the less the flap extension for takeoff, the more efficiency you have in a departure plus better engine failure performance, but you need the longest runway, so you would use the least extension allowable for a given ...


2

Indeed the CRJ can use reduced takeoff thrust setting. Flex power is selected by entering an assumed temperature on the PERF MENU page of the FMS CDU. If the FMS is not available, the assumed temperature can be entered on the EICAS menu page using the EICAS control panel. It's set up using the CDU or the EICAS control panel. That control panel is on the ...


2

The Aircraft Flight Manual or Flight Crew Operating Manual will specify the timeframe during which engine oil may be checked after engine shutdown. For the CF34-3B engine on a Challenger 605, checking must be done between 15 minutes and 2 hours following shutdown. If done outside of this window, the engine must be dry-motored (cranked without introducing ...


1

This is the weight in an operational condition(with engine oil, hydraulic fluid, unusable fuel in the tanks[maybe also with a specific usable amount like 30 minutes], and some other misc items), zero cargo, with minimum crew. The minimum weight at which the airplane can fly. You may also have maximum zero fuel weight, maximum landing weight, maximum takeoff ...


1

I don't know the specifics for that plane, but in general you do oil changes with the oil warm so that it is less viscous, so there's a minimum amount of dirty, old oil left inside the engine (and so you don't have to wait hours for it to drain). However it's generally a bad idea to do it while the engine is still at operating temperature, because then the ...


1

When the engine is running, it sucks up the oil from the reservoir and puts it in all the galleries, ie the oil's all in the right places to lubricate the engine. When you shut the engine down, the oil starts returning to the reservoir by gravity. So there's a gentle drip-feed back into the reservoir, which means that the apparent oil quantity measured at ...


1

At max differential it's 8000 ft. The controller operates on an automatic program schedule that lets the cabin pre-pressurize to about 300 ft below field elevation at the start of the takeoff to minimize the initial pressure drop sensation following liftoff. It then lets the cabin altitude rise 500-800 fpm, about 1/4 of the airplane's actual climb rate, ...


1

Neither car nor aircraft tires are supposed to be inflated to the point where only a small percentage of the tire is in contact with the ground. If you can think of a scientific argument why they should be, post it. It's very common knowledge that inflating tires to maximum pressure reduces sidewall effectiveness and overall tire performance.


1

No RAM AIR VALVE can open if the cabin pressure exceeds the outer pressure. For the CRJ the RAM AIR VALVE is directed so that a dynamic component of the aircraft speed helps its opening, but this is much lower than the difference of pressure between cabin pressure and the outside pressure at high altitude. So no danger of depressurization whatsoever.


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