Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
BAE-146 And Avro Without Leading Edge Slats  
User currently offlineFalconBird From United States of America, joined May 2007, 1262 posts, RR: 1
Posted (6 years 3 months 2 weeks 1 day 21 hours ago) and read 4176 times:

Forgive me if this has been posted before, but why didn't BAE fit the 146 and the Avro with leading edge slats for possible extra lift on shorter runways?


Vector, Victor... Clearance, Clarence...Roger, over...under...done...
13 replies: All unread, jump to last
 
User currently offlineStarlionblue From Greenland, joined Feb 2004, 16976 posts, RR: 67
Reply 1, posted (6 years 3 months 2 weeks 1 day 16 hours ago) and read 4129 times:

They have enough lift anyway?

My guess is that the extra weight and complexity negated the savings.



"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlineTristarSteve From Sweden, joined Nov 2005, 3971 posts, RR: 34
Reply 2, posted (6 years 3 months 2 weeks 1 day 14 hours ago) and read 4121 times:

A lot of the smaller jets don't have slats.
Fokker 100, Gulfstreams, Smaller DC9s, BAC 111.
Slats are heavy and complicated, makes sense. It becomes a problem in the winter as these aircraft are much more sensitive to frost and ice on the wings and need care when deicing.


User currently offlineHotelmode From United Kingdom, joined Jan 2007, 460 posts, RR: 1
Reply 3, posted (6 years 3 months 2 weeks 1 day 12 hours ago) and read 4105 times:

The 146 wing is optimised for take off performance not high cruise speeds, so it simply doesnt need them.

User currently offlineTroubleshooter From Germany, joined Feb 2005, 423 posts, RR: 5
Reply 4, posted (6 years 3 months 2 weeks 7 hours ago) and read 4013 times:



Quoting Hotelmode (Reply 3):
The 146 wing is optimised for take off performance not high cruise speeds, so it simply doesnt need them.

Correct. Originally, the BAe146 was designed as a military freighter with short take off and landing capabilities.



This job sucks!!! I love this job!!!
User currently offlineJetlagged From United Kingdom, joined Jan 2005, 2541 posts, RR: 25
Reply 5, posted (6 years 3 months 2 weeks 2 hours ago) and read 3978 times:



Quoting Troubleshooter (Reply 4):
Correct. Originally, the BAe146 was designed as a military freighter with short take off and landing capabilities.

The 146 was not designed as a military freighter. The freighter design came much later. It was originally intended as a feederliner (the term "regional jet" had not yet been coined). It was specified to be capable of operation from rough strips. It was also designed to be quiet. LE devices would be prone to damage on rough strips and reverse thrust could kick up a lot of debris. Both features increase noise.



The glass isn't half empty, or half full, it's twice as big as it needs to be.
User currently offlineAirgypsy From United States of America, joined Nov 1999, 130 posts, RR: 2
Reply 6, posted (6 years 3 months 1 week 6 days 20 hours ago) and read 3930 times:

The constant radius leading edges made their appearance on LearJets and were very effective and efficient. I'm supprised more aircraft aren't sporting them.

The secret of lift on the BAe-146 is the aft translation of the flaps prior to lowering. Large wing area increase. Its part of that race car sound that passengers enjoy. Caused by the trailing edge seals on the ground spoilers vibrating against the top of the flaps as they go by. A large stainless steel reed instrument.

A quirky aircraft that was fun to work on. Especially if it had a smile on it.
Airgypsy


User currently offlineViscount724 From Switzerland, joined Oct 2006, 24643 posts, RR: 22
Reply 7, posted (6 years 3 months 1 week 6 days 20 hours ago) and read 3922 times:



Quoting Troubleshooter (Reply 4):
Originally, the BAe146 was designed as a military freighter with short take off and landing capabilities.

Do you have a source for that? I can't ever recall reading that in any history of BAe146/Avro RJ development. Everything I've seen says that the original design was intended as a high-wing feeder-liner, with no mention of military or cargo applications.


User currently offlineBAe146QT From United Kingdom, joined Sep 2006, 996 posts, RR: 0
Reply 8, posted (6 years 3 months 1 week 6 days 5 hours ago) and read 3872 times:



Quoting Airgypsy (Reply 6):
Its part of that race car sound that passengers enjoy. Caused by the trailing edge seals on the ground spoilers vibrating against the top of the flaps as they go by. A large stainless steel reed instrument.

Is that what that is? I never really found it noteworthy, but it sounds like a very raspy V6.

Quoting Viscount724 (Reply 7):
Everything I've seen says that the original design was intended as a high-wing feeder-liner, with no mention of military or cargo applications.

I agree. The original De Havilland design called for a short-range (and mostly domestic) airliner to cope with routes/journeys that cars or trains might normally be used for, back in the days when we used to burn kerosene for our amusement and everyone was supposed to fly about the place. HS (and later, BAe) obviously found a market for it despite OPEC sticking their hand up everyone's skirt.

The 146-STA was the military bird and was a production-line conversion.



Todos mis dominós son totalmente pegajosos
User currently offlinePrebennorholm From Denmark, joined Mar 2000, 6374 posts, RR: 54
Reply 9, posted (6 years 3 months 1 week 6 days 4 hours ago) and read 3869 times:



Quoting FalconBird (Thread starter):
...why didn't BAE fit the 146 and the Avro with leading edge slats for possible extra lift on shorter runways?

BAe chose a wing profile with the shape of "half of a leading edge slat extended".

It has a lot of benefits: Lower weight, lower MX costs, much simpler icing management to name a few. And it is of course much cheaper to build.

They sacrifice on cruise speed. And on fuel efficiency on longer routes.

But for a plane, which is intended for short routes, the benefits can easily outdo the disadvantages. On short routes the weight advantage alone will easily neutralize the fuel efficiency disadvantage.

On a 500nm sector a BAe-146 is typically five minutes slower than an MD-80 or A319.

Often they gain (most of) those five minutes by not taxiing the last 2-3,000 feet to the runway end for take-off, but begin take-off roll somewhere on the middle of the runway. That saves a lot of fuel as well.

The BAe-146 wing airfoil section is a disaster at high Mach numbers. So they just keep it well below Mach 0.7.



Always keep your number of landings equal to your number of take-offs, Preben Norholm
User currently offlineTroubleshooter From Germany, joined Feb 2005, 423 posts, RR: 5
Reply 10, posted (6 years 3 months 1 week 4 days 6 hours ago) and read 3757 times:



Quoting Viscount724 (Reply 7):
Do you have a source for that?

I did my 146 maintenance course nearly eight years ago. Our english instructor was a former worker on the 146 with British Aerospace and he told us about the development.

Look at the landing gear and tell me if you find any other civil jet with a similar strong gear fitted.

But as I don´t know it for sure and have no "waterproof" source to quote, I will stand corrected if somebody knows it better.



This job sucks!!! I love this job!!!
User currently offlineBAe146QT From United Kingdom, joined Sep 2006, 996 posts, RR: 0
Reply 11, posted (6 years 3 months 1 week 4 days 5 hours ago) and read 3757 times:



Quoting Troubleshooter (Reply 10):
any other civil jet with a similar strong gear fitted.

It certainly wasn't designed with the military as it's primary customer, (unlike the 747!) but I'm with you there on that monster trailing link system, so I can see the logic. However, this was orignally for short and (possibly) rough field performance in the civil sector. But who knows? Maybe the designers did have military applications in mind - it would make sense from a commercial point of view.

But it's still true that the STA came well after the first -100 flew.

BTW, I'm currently scratch-building a 146-3 in 1:25 scale, which gives a fantastic opportunity to model that gear. It's only taken four attempts to get it right.  Yeah sure The only thing I have seen that comes close was designed to land on a carrier - the F/A-18.



Todos mis dominós son totalmente pegajosos
User currently offlineJetlagged From United Kingdom, joined Jan 2005, 2541 posts, RR: 25
Reply 12, posted (6 years 3 months 1 week 4 days 5 hours ago) and read 3754 times:



Quoting BAe146QT (Reply 11):
BTW, I'm currently scratch-building a 146-3 in 1:25 scale, which gives a fantastic opportunity to model that gear.

That's quite a monster, over 4 ft long. What are you building it out of? At that scale you could use real hairdryers for the engines.  Wink



The glass isn't half empty, or half full, it's twice as big as it needs to be.
User currently offlineTdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 13, posted (6 years 3 months 1 week 3 days 21 hours ago) and read 3724 times:



Quoting BAe146QT (Reply 11):
It certainly wasn't designed with the military as it's primary customer, (unlike the 747!)

The 747 was never designed for the military. That was the C-5 and Boeing's equivalent entry (which was a different plane than the 747). The 747 looks like it does because, at the time, Boeing thought it would be shortlived as a passenger aircraft due to the development of the SST and Boeing assumed they'd be selling it mostly as freighters later in life. Turned out they were right, just off by about 30 years.

Tom.


Top Of Page
Forum Index

Reply To This Topic BAE-146 And Avro Without Leading Edge Slats
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
757-200 And BAe 146: Danger? posted Sun Feb 4 2007 14:55:50 by BA787
Does The BAe 146/Avro RJ Use The Coanda-effect? posted Tue Sep 20 2005 20:40:09 by AmericanB763ER
Bae 146/Avro RJ Horizontal Stabilizer posted Fri Jun 3 2005 00:11:07 by AOMlover
Rvsm In Europe And Avro BAE Aircraft posted Sat Aug 31 2002 13:23:40 by Pressclub
Technical Data Of BAe 146-Avro RJ85/100 posted Thu Dec 6 2001 02:07:52 by Cpt. Caveman
BAe 146/Avro Interactive Training posted Wed Sep 26 2001 20:07:43 by Starline
BAE 146/Avro RJ Troubleshooting Guide posted Wed Aug 29 2001 16:04:51 by Starline
Where Are The APU's Located On The BAe 146/Avro RJ posted Mon Aug 20 2001 01:27:53 by BA
Leading Edge Of 744 And 743 posted Fri Apr 13 2001 10:29:58 by Cathay pacific
Why The Avro RJ/ BAE 146 Have Wing On Top? posted Mon Jan 15 2001 04:57:26 by TurboTristar

Sponsor Message:
Printer friendly format