Be-1900D

[7212wing]

Can anybody give me some kind of comment regarding Be-1900D? I really appreciate.
(1) Why did the manufacturers remove the Blue line marking (Be-1900C) from the D? Is it because it is heavier and certified under a different category?
(2) Is there any impairment if you turn off the following items after landing ,while taxing? The EFIS power supply , the AC BUS power and Aux Battery .

[Shaunny]

Well im by no means an expert but thought I might give it a try.

(1) I don’t have a clue as to the correct answer! My guess is Vyse changes; and they have published the Vyse decreasing by 2Kts every 5000’ in the “D” model so I would assume that it doesn’t make sense to draw the blue line which would fit only one weight and altitude. Although that being said some of the other turboprops I have flown do indicate the range on the ASI?!

For practical purposes though we use Venr (One Engine-Inoperative En Route Climb) rather than Vyse to climb following an engine failure. This speed also changes according to weight and has to be calculated before each take off so possibly the combination of the two made the blue line redundant!


(2) The Raytheon Normal procedures states you should only shut down the EFIS power supply, AC Bus and Aux power during the shutdown so I would think its written in that way for a reason but from what I can see:

EFIS power: You will loose your EADI and EHSI, I guess you don’t need it taxing in. In my company however after switching the A/C bus off we give the EFIS 2 minutes to cool down before switching off the power. I haven’t found this in the Raytheon manuals but I dare say it could be a Collins requirement (or just company good sense).

A/C Bus: You will lose various items such as flight data recorder, radar, some engine gauges and avionics (The ground power switch will not work if the master switch is on).

Aux Power: I can’t see any reason why it would make a difference :confused:

[fernytickles]

I know nothing about the aeroplane type, but just general thoughts....

1) - Can you try contacting BE directly & ask them?

2) See above. And also, if this is not SOP for the aircraft according to the SOP manual, then you (generic "you") probably should not be doing it. It is as easy to operate an aircraft correctly according to the manufacturer's procedures as it is to operate it incorrectly. If corners start being cut in one area, it will only be a matter of time before they start creeping into other areas too.

[aviatorhi]

My understanding of the "blue line" (and I'm going to keep this simple) is that it's required on the ASI of "GA type" light twins.

The 1900C is essentially that (albeit a "big-light twin") and is equipped as such. It's certified under SFAR 41C.

The 1900D on the other hand is certified under FAR 23 in the commuter category, which places more "transport-like" requirements on the aircraft (some silly things include dual bulb lighting in some places and so on). This mainly concerns peroformance, and sparing a long drawn out discussion of the subject, you don't typically see a blue line on a transport like the 767 (though I believe you do on a DC-4 or DC-6, though that plane was certified under a completley different "rulebook").

The difference in certification provides for a difference in how the airplane is "flown" (or at least placarded/striped). From an operational standpoint the blue line is of little consequence as most operators will elect to use some sort of a profile for an engine failure that is applicable at all weights (not just gross). My former company used V2 to 400 feet then V2+20 to 1500 feet then troubleshoot, odviously there will be differences from operator to operator.

Anyway, that's my take on it.

As far as shutting down the electrics, I don't remember what you'd lose, but you would most certainly lose the power steering (if equipped), if it isn't (or is and is shut down) then the nosewheel is being steered via rudder pedals via mechanical linkage, so that wouldn't be lost.

Probably a good idea not to mess with the electric busses at night though, in case everything goes dark (I forget of the lights are on the AC or DC system).

[7212wing]

Finally!! Thank you all for precious advise. Aviatorihi, welcome back I was wondering where you were all this time?
I am convinced about the first question well and good .Being under different certification, however I have a confusion regarding the following.
Multi Engine 12,500lbs or less Blue line (Vyse) Best rate of climb with one engine inoperative. (Vsse) Minimum safe single engine speed (Multi) Provides a reasonable margin against an unintentional stall when making intentional engine cuts during training and VFS - final segment speed (jet)with critical engine inop. Acceleration to Vfs at 400ft. Nonetheless ,both the C and D are more than 12,500lbs and in our company we use then as commuter. Did I miss somr thimg here?Or confused as usual?
The second questioning regarding switching the EFIs power while taxiing is debatable for the following reasons..
The EFIS-84 system requires fan forced cooling to lower the operating temperature of the display processor units (DPU) and the electronic flight displays (EFD). To satisfy this requirement a series of cooling fans are installed in the 1900D aircraft.
The DPUs are cooled by rack-mounted fans blowing air into a plenum on the bottom of the mounting rack. The air is then directed up through cooling holes in the plenum and through the DPU to exhaust out through the top and sides of the DPU.
An exhaust fan is also located in the nose avionics bay to exhaust warm air from the nose wheel well.
The EFDs contain internal cooling fans and are also supplied with cooling air from a single cooling blower located on the left side of the cockpit sidewall up under the instrument panel. A series of hoses are connected to the cooling fan outlet to direct air at the individual EFDs.
The EFIS fans are all 28VDC powered from the DPU circuit breakers via the EFIS power switches when selected on. The pilot’s display processor circuit breaker normally powers the fans by the energized DC select relay or if this power source fails the copilot’s display processor circuit breaker, power is used, via the relaxed contacts of the DC select relay.
Fuses located on the avionics junction box protect the fans’ circuits. The display blower also has a 1-amp slow blow in-line fuse in its’ circuit blower.
This fuse protects the fan motor from overheating in the event of motor seizure. The 3-amp fast-acting fuse will not blow with normal motor startup current, allowing the motor to temporarily overheat and protecting the display blower in the event of a motor seizure.
The EFIS power system provides electrical power to operate all the EFIS component that require 28 VDC for their operation. To backup the pilot’s EFIS system a standby battery power system is also installed.
The pilot’s EFIS system is powered from the left generator bus while the copilot’s EFIS system is powered from the right generator bus. Power for the pilot’s and copilot’s EFIS system components are controlled by EFIS power switches; two for the pilot’s system, and two for the copilot’s system.
One switch for each system is labeled DSPL PRCSR provides power to the DPU, the cross side DPU transfer relays, the EFIS cooling fan system and external DPU transfer relays.
The other switch for each system is labeled EADI /EHSI and provides power to the low voltage power supplies located in each DPU, one for the EADI and one for the EHSI. This power is also provided to the EADI and EHSI power monitor input to shut down the high voltage power when power is removed. The low voltage power supplies in the DPU provide all the operating voltages to the EADI and EHSI.
Power for each DSP come from the triple fed avionics bus for the pilot’s DSP and the right generator avionics bus for the copilot’s DSP.
So my dilemma is what is the harm if I switch only the video part (CRT) since the remote processor unit and system control units retain all the data to drive the CRT in order to save the display even farther? Assuming there is no steering system (the manual I am referring mention that steering is on left generator bus.)
The company that is producing these CRT is not going to do it any more, Hence some Companies are contemplating in changing to all Glass cockpit panel(ELD) It is a wise decision before spare parts get scarce.

[aviatorhi]

I haven't flown the D model and I'm not familiar with the avionics suite in that aircraft, but I'll keep it simple for you, what do you need to taxi the airplane?

Propulsion and Steering and probably Radios/Avionics (depending on the environment).

Whatever you remove power from just make sure you don't need it and it doesn't adversely affect the controllability of the aircraft. Most manufacturer's manuals don't take into account later developments with an aircraft (like lack of parts support) when they are written, good systems knowledge and experience will help keep you safe.

If you are accurate in saying that you are only turning off the display portion then I don't see any undesirable side effects based on my knowledge of the C model.

[7212wing]

Thank you very much for your reply. Ours does not have steering. I hope some one from New Zealand will shade some light on the matter ie fitting all their fleet with a Glass Cockpit.However,the information I had was passed to me from a guy who used to work for a Company down there. They were either planning or weighting their options.
Cheers!