PDA

View Full Version : BAE 146/Avro?


GOH
13th Oct 2002, 09:48
Hi

Why does the BAE 146/Avro have what seems to be wire going from the middle of the aircraft to the top of the tail?

Thankyou:D

Fourpuffs
13th Oct 2002, 10:01
Its the emergency standby elevator control system. In the unlikely event of the elevator jamming, and the primary control separator failing. a signal is sent from the tertiary 'Q' pot simulator which effectively drives elevator control from the First Officer's control run, using the 'G' weight system.

The elevator is then automatically operated through the Flap Trim Compansator mechanism. It's a bit coarse, but better than no elevator control at all.
Darned clever these boys from Woodford!:D

Hope that helps - you won't see it on all aircraft, as it was superceded by the quadruple autopilot backup Channel 'C' installed on the RJs.:)

BlueEagle
13th Oct 2002, 10:43
If fitted, where does the HF aerial/antenna on a 146 go?:(

Fourpuffs
13th Oct 2002, 12:57
It normally runs from the ceramic AOA probe under the nose to the APU eflux distractor, aft abeam the port tailplane.

Any more questions chaps?:cool:

CH146
13th Oct 2002, 13:26
Fourpuffs-wrong again. The HF ant from 1982 onwards when ordered from BAE, was installed on a reel between the aft loo and the rear galley and was usally controlled by the senior cabin crew member when so instructed by the flt deck.

When fully unravelled it could reach a length of 500m!. You can imagine the embrassment this caused if it was still deployed on landing. Many an unhappy time I've spent trying to get it untangeled from the tail on a dark winters night.

I hope this answers the original question.

Lucky Strike
13th Oct 2002, 19:42
Odd, I once ferried an ex Thai 146 back to Woodford which had to have a ferry HF set fitted for the trip. The antenae was a wire between the top of the fueselage around the flt deck area and the top of the tail.

Now about this tertiary Q pot...

Fourpuffs
13th Oct 2002, 21:10
CH146, absolutely right; but from 1987 onwards the antenna was reinforced, and actually projected forward from just ahead of the nose gear door. This removed the problem of a trailing link, and although projecting 500m forward of the fuselage did pose some formation and in-flight refuelling problems for Crabair, it was generally considered to be a good design. It had auto retract coupled to the gearbrakes-on-retract system fitted to the nosegear, so as to avoid the embarrassment of landing with it extended. There was a famous case in Canada where the antenna actually speared a Greylag goose at FL 150, and jammed the retraction mechanism. Story in "I learned about flying from that" went on to describe the best way to pluck and spit roast a goose!:p

faq
14th Oct 2002, 09:55
It must have been a strong bit of wire to project 1/2 kilometre in front of the aircraft in flight and support the weight of a duck.

Nightrider
14th Oct 2002, 12:10
the strongest bit was actually the glasfibre re-inforced centre thread around the metal wire. On the RJX, unfortunately the production never took off, the centre spine duct was re-engineered to accomodate the HF aerial, investigations are presently under way, if this achievement would allow for attachements for easy under-roof hangarage....

Fourpuffs
14th Oct 2002, 17:13
Before we cancelled our RJX order, we were told that the RJX had a Flight Deck airbag which could double as an inflatable hangar - at least as long as the roof was retracted first?:confused:

kabz
17th Oct 2002, 00:56
Maybe it was the emergency tow rope ... :D

chiglet
17th Oct 2002, 17:36
C'mon Guys
We all know that it's to hang it from your bedroom ceiling :D
we aim to please, it keeps the cleaners happy