AirSpeedIndicator or Speedtape

[pioupiou]

Did you fly on B737-400 without any
air speed indicator, only with speedtapes?
what about your MEL in your airline?
the Boeing MMEL is not clear
thanks

[Slasher]

Speed tape has realy nothing to do with MEL because the FMC and/or SG can fail at anytime. So MEL only applys to the 3 analog ASIs. Of course theres nothing to stop you utilising the speed tape if you lost your ASI anytime after pushback.

Our Company MEL says:

* Captains ASI: can be US till arriving at the base where repair/replacements can be made. Standby ASI must be serviceable.

* FOs ASI: can be US until next check. Both the Standby and Captains ASIs must be serviceable.

* Standby ASI: must be serviceable at all times (obviousley). Aircraft grounded until repaired.

I agree the Boeing MEL can be a bloodey badly-written bucket of worms at times.

[pioupiou]

OK, I was not clear
I have NO air speed indicator on board,
except the standby.
ONLY speedtape!
plane coming from Holland.

[boxmover]

pioupiou

can you give a clue where these aircraft are going?

[AlbertRoss]

I used to fly 300/400's without ASI's, in Holland, but my last two operators 73's DO have ASI's. The difference with the Dutch one's was that they had upgraded, or douuble (?) batteries so with a double gen failure you still have full Capt's EFIS.

[pioupiou]

thanks a lot albert
I will check

[Iceair]

My company has it's 737-400 with only speedtape, standby power connected to all screens and upgraded batteries. Bloody good, and we don't miss the metal thing a bit!
One little thing. Our MEL states that BOTH tapes must be operative. But...we're spoiled.

[White Knight]

Avro RJ's that we fly have speedtapes and a mickey mouse standby ASI, that looks like an old ribbon DI...

[Slasher]

Im curious about that. WRT 737-EFIS without ASIs, what happens if the FMC itself goes tits up? Do your have 2 FM Computers fitted instead of one for redundancey? Do you still have the standby ASI?

[Iceair]

Slasher.
The 737s with only speedtape do have the standby clocks. I think it's a certification matter. Correct me if I'm wrong on that.

[Iceair]

Slasher.
The 737s with only speedtape do have the standby clocks. I think it's a certification matter. Correct me if I'm wrong on that.

[Sick Squid]

My mob have double batteries (giving one hour on standby), an upgraded APU and analog ASI's plus speedtapes all round.... wasn't it great once being state owned!

Slasher, does the feed for the ASI and Speedtape not come directly from its ADC, with only the target airspeed sent from the FMC? That would mean that two FMC's would be desirable, but not essential, to the extent that dispatch would still be likely with none. The signal generator in this case is more limiting, (as are the ADC's of course,) and the MEL of such an aircraft would most likely reflect that.

Standby instruments are generally most critical, however, as Slasher intimated.

Just some thoughts off the top of my head...

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Disappears in a cloud of black ink...

[This message has been edited by Sick Squid (edited 27 November 2000).]

[static]

Hi there,
My first posting, I couldn`t resist any longer....
At our airline we fly both the -400 and -300 in the EFIS style. We have no ASI`s, other then tapes and the standby. The standby is the cheap drum-type, with its own ports.
The tapes get their speed info from their respective Air Data Computers. The input from the FMC to these tapes is of minor importance; upper and lower yellow bands.

We have captains EFIS on standby-power for a minimum of 30 min.

Regards