qatarairways
Posts: 864
Joined: Sun Sep 07, 2008 6:02 pm

Communications Equipment Bulge On Top Of Aircraft

Sat May 25, 2002 11:07 pm

I have noticed many private aircrafts such as the Oman 747SP with a bulge on top of the fuselage. This holds some communications equipment. It is also found in some commercial aircraft like JetBlue's A320s so they can receive DirecTV transmissions.

No I have some questions:

-How do these bulges affect aero-dynamics?
-Are they installed as options from manufacturers or are they added later?
-Are they fitted on with heavy work such as drilling etc. or is it simple?

I also have noticed a sort of bulge on QR's A332.


View Large View Medium
Click here for bigger photo!

Photo © Garry Lewis



If you enlarge the picture you'll see that there is a sort of bulge in the top of the aircraft near the front section of the fuselage. Is this a bulge or part of a cloud in the background. If it is, is this normal in the A330s or is this a possible indication of Email/Internet or Live TV on board?

Regards,
QatarAirways
http://www.aviationgulf.com
 
pmk
Posts: 609
Joined: Wed May 26, 1999 10:07 am

RE: Communications Equipment Bulge On Top Of Aircraft

Sat May 25, 2002 11:38 pm

Okay,

First of all the OMAN 747SP's bump is not for communications, it is for a Chandelier! Let it not be said that these people make sacrifices....That bump is quite pronounced and probably does cause some drag, however in that role it makes little difference. Now the antennas on other aircraft are low enough to be under the A/C's boundary layer and cause almost no drag.
 
qatarairways
Posts: 864
Joined: Sun Sep 07, 2008 6:02 pm

RE: Communications Equipment Bulge On Top Of Aircraft

Sat May 25, 2002 11:44 pm



A chandelier, wow. Well I guess economics are not an issue with the Sultan. What I meant waws the bulge that you see on the JetBlue A320s


 
pmk
Posts: 609
Joined: Wed May 26, 1999 10:07 am

RE: Communications Equipment Bulge On Top Of Aircraft

Sun May 26, 2002 1:46 am

Probably for inflight telephones.
 
qatarairways
Posts: 864
Joined: Sun Sep 07, 2008 6:02 pm

RE: Communications Equipment Bulge On Top Of Aircraft

Sun May 26, 2002 2:08 am

I said:

"No I have some questions:"

What I meant was: "Now I have some questions:"

Just wanted to make things clearer
 
AWspicious
Posts: 2780
Joined: Fri Sep 14, 2001 7:47 am

RE: Communications Equipment Bulge On Top Of Aircraft

Sun May 26, 2002 2:13 am

PMK;
Happy 3rd. anniversary here on Airliners.net  Big thumbs up

aw
Nevermind political correctness - Envision using your turn signals!
 
Leezyjet
Posts: 3541
Joined: Sun Oct 14, 2001 7:26 am

RE: Communications Equipment Bulge On Top Of Aircraft

Sun May 26, 2002 4:16 am

I always thought they were for the satellite telephones......

The bulge on the Oman 747sp, is quite a bit larger than those on commercial a/c like the one shown on the QR 330 pic above.


View Large View Medium
Click here for bigger photo!

Photo © Torsten Maiwald

"She Rolls, 45 knots, 90, 135, nose comes up to 20 degrees, she's airborne - She flies, Concorde Flies"
 
User avatar
PW100
Posts: 2748
Joined: Mon Jan 28, 2002 9:17 pm

RE: Communications Equipment Bulge On Top Of Aircraft

Sun May 26, 2002 5:02 am

All KLM 744, 743 and M11 [not sure about the 767] have bulges on top of their fuselage. They are satelite comunications antennes [ie. for GPS nav; on-board telephones, irect TV-not on KL, etc].
There are different types:
The small vertical white-plates are for VHF radio-cummunications from and to the cockpit, and can be found both under the fuselage as on top of the fuselage:

View Large View Medium
Click here for bigger photo!

Photo © Martin Boschhuizen


This pic also clearly shows the large white bump on top of the fuselage at the Nr.4 door. I belive this one is to serve on-board telephones.

Just behing the bump of the upper deck there are two small antennea bumps, don't know what they serve, maybe HF communications:

View Large View Medium
Click here for bigger photo!

Photo © Peter Unmuth - Vienna Aviation Photography



Rule of thump: these bumps usually are antenneas. If they are on top of the fuselage, they serve satelites [or HF com, signals which bounce of between the earths atmoshere, and can bounce round the world]. If they are under the fuselage, they serve earth bound stations...

PW100
Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"