BAe146 - Why not a twin?
 

I've often wondered...

With twins 'ETOPSing' transatlantic, what's the thinking behind four engines, esp on something so small? Sounds like more build cost & maintenence to me (not that I'd actually know)... only upside I can think of is better stability in asymetric.

reminds me of a joke -

why has the 146 got 4 engines

- because the wing was'nt long enough for 6.

GR

What most people overlook is that the 146 was built for airports that have obstacles on climb out or short strips and so on (true 'regional' airports such as LCY etc). Four engines are so that it can maintain the performance required or better after an engine failure. That is also the reason it is a bit slow and has a low ceiling. You can't have everything and the compromise with the 146 is on the short strip side of things rather than than the fast and high side of things. The maintenance required on 4 instead of 2 engines is just another case of the compromise between performance and costs. Also, it is quieter. Jet noise is a lot higher if the jet eflux is faster (ie the difference between the still air and the jet is high). If you can slow the air down (4 slow streams of air as opposed to 2 high speed streams), you will have a much quieter aircraft that can operate into city type airports with less complaints.

The job it is designed for it does very well - quite a few pilots complain about certain aspects of the 146, but I hear it is very easy to fly and it certainly does the job it was designed for well.

J-R

Good question, often wondered the same myself.

The thing that keeps me awake at night is how anyone can justify the expense. On one of the threads about the Ryanair takeover of Buzz, someone said that the monthly lease of the 146 was TWICE that of the 737. If it takes less Pax and costs twiceas much not to mention the additional running costs how did they ever think they could make money. I suppose that was why they got in the trouble they did?

On course I was told that you could fly the 146 with three engines without missing a revenue flight. I once went to pick one up and we flew home without flaps and only three engines. Also a very rugged machine. Built like a brick outhouse.

Reminds me of a joke too.

Q: What does BAE stand for?
A: Bring another engine.

It's all in the history books.
 

If you look back to the 1970's the original concept for the aircraft was done by Hawker Siddeley at Hatfield hence the type designation HS-146. This followed on from their earlier 3 engined type HS-121 Trident (Sorry to use the T word!). At the time there were no power plants of sufficient thrust that were light enough or quiet enough. Imagine a couple of Spey's roaring into LCY!! So a newly developed mini fan jet was used, but they had to fit 4 to get enough puff.
As the market was not yet mature enough the project was put on hold for a few years until Bae was created so when launched the aircraft became the BAe 146. It only became an Avro when production was moved to the Lancaster factory at Woodford (WFD)
When Avro's planned the upgrade to RJX they did produce some twin engined studies but I'm pretty certain none flew....

Think I'm right in saying that the 146 was originally a De Havilland design, that was shelved and re-activated several times, throughout the changes from DH to HSA to BAe.

5 APU's, built in overtime generators, what a machine, sorely missed.

Back in my early days of training(late seventies)I seem to remember seeing a model of an aircraft very similar to the 146 with just TWO engines in RAF colours. Maybe it was considered by the RAF but changed to four engines at a later date when no suitable power plants could be found?

Just to clarify: That would be three WORKING engines right?

:}

To: Bral
I went to recover the machine fro Churchill, and what I remember was we had an asymetry problem and the flaps locked up and the original problem was with the engine makeing metal. So we flew the machine back home, the lease we had planed for it fell through and it went to another operator.

To: Onan
That's what they said. I never operated the type. Just worked 3rd party overhaul on them.

spekesoftly

I think the 146 design concept goes right back to a Handley Page project!

The "Fisher-Price Starlifter" is indeed a nice aircraft to fly...

It was launched in Aug '73 as the HS-146; originally started life as a D.H. development project - the DH 123.

I believe at one time it was slated to have RR-M.45 501 fans, as on the VFW614 (7700lbs thrust), but they'd gone by the time BAe resurrected the project in '78. Hence the 4 weed-whacker motors...

A two -engine version was looked at in the '80's - no development money, and Textron worked hard to improve the 507's and cover extra maintenance costs over a CFM twin.

Cheers... :8

Bral:

Have done a few 3-engine ferries in the -100....none in the -200/300.

One was a similar situation to rwm, the engine chip detector looked like a shaving brush...We took off on 4 (unfortunately, full pwr was required as it was a poor-quality gravelly short strip), immediately shut the sickie down when safely airborne, and flew across the Andes on a good-wx day to SCL for an engine change with the assistance of LAN-Chile. All perfectly safe; the -100 had bags of extra poke. 2-eng stab height was OK to get us through the mountains if necessary, or onto escape routes. And that was Royal...no other choices to keep the mission going...no other way of getting a spare engine to us.

As to flapless: yes, done those, too, and eng-out for practice but only on low-overshoots or rollers, never on T/O. The 146 wing is actually a higher min-speed airfoil clean at average weights than some other much bigger jets I've flown. The first flap position (18? my memory fails me) is a lot of mechanical whirring and whining out-there....those who've flown it will attest to the massive trim change on flap extention/retraction. I seem to remember some pretty high approach speeds flapless, whereas many other jets may still have slats available in a FLAPLESS situation.

And as to Yellow-system failure requiring a chicane-wrist-flick to deploy the roll-spoilers symmetrically...it's British and it works...

Churchill....been there...one must have an intense dislike for polar-bears to be desperate enough to depart no-flap/eng-out...yikes! Hope it wasn't a -300...maybe you mean Ch. Falls?:uhoh: :\

I can remember when the USAF were closely considering the 146 as a transporter aircraft. The demonstrator (STRA) aircraft was closely studied by their numerous experts. In the end they declined but look what came out of it............. C17!! I am convinced the basic design layout for the 146 was the basis of that aircrafts design.

RRAAMJET Uumm, this sounds like you are saying there is a stand-by system that:

In the even of losing most hyd. power, you can extend two spoilers to lose speed/height. These are retained in the wing by a latch that is released by a specific movement that is not a part of normal handling. Specifically, to flick the (say) port wing high and immediately low and then return to level?

It does sound very British and dashed ingenious! :)

I flew the more "modern" Avro RJ100 for 2 years - what a lovely aeroplane to pole....Yes, only did M0.70, but it was comfortable to spend 3 hour sectors in. Loads of head and legroom.
Four engines for short airfields - that is the WHOLE point of the 146. Lose an engine and it still goes up at a decent rate. Only decent size jet into places like London City. I'm sorry but you can't call the Embraer Barbie things real size jets, or the canadian thingy.
:p :p :p

PAXboy:

to explain the roll-spoiler thingy:
(bare in mind this is from nearly 2 decades ago, so my memory is under severe stress here!)

When operating with a complete loss of yellow system hydraulics, on approach it was recommended that, in order to prevent assym. spoiler float, the roll spoilers be deliberately fully deployed by a short application of full aileron in either direction. There is no hyd. pressure involved - they are unlocked by wheel position (10degrees?) and aerodynamic pressure deploys them to full up. That way you know what position they are in; no suprises on finals. From having flown in close formation and watching as it was done into Chester, believe me, it works. :ooh:

Don't know if that's still the procedure, or if it was just our military way of doing things (although it's in one of my airline QRH's as well), but better the Devil you know, as it were....

Help me out, those of you still flying the 1-fuselage4-engines6-wheels.... :uhoh:

Thank you, Bral....I get muddled easily, these days....can't remember handwheel angles so much anymore! Nowadays in the 777 I just send a telephone call to some flt-control elves in the electronics bay by way of the wheel and various thingies move by magic. Unless the elves have croaked, in which case secondary elves-in-training are backed-up by direct-elves who, if they all croak, leave me praying with a 146-ish cable connected to spoilers 4&11 and a stab-trim elf also on a cable....hmmmmm

We used to practice it at Benson for real, by turning off the main and AC pump, just to get used to the feel - flew fine, sloppy, as you say. :ok:

Re 3 engine/flapless

If the runway is long enough wouldn't 3 eng flapless give you better second stage performance, and with the higher IAS give you more controlability wrt Vmca?

Performance never my strong point so expecting to be shot down;)