LGA mounting angle

[Flyingtiger01]

To whom it may concern.
The latest RTCA DO-262B will specify a mounting angle of vertical +- 1 degree therabouts.
I might agree with this for new production however a retrofit application will play hell with the crown structure along with additional ICA for corrosion inspection requirements.
This is a 15,000 dollar hole for a 2 thousand dollar antenna.
I want to put this between s2 and s3 on the left side. This is 10 degrees off vertical, sorry B747 freighter. Here a doubler will be great.
For Iridium the constallation viewing angle is 8 degrees above the horizon all the way around the airplane. My question is what is the cruise deck angle and how well are we holding roll to vertical in a typical flight excluding turns of course.
Thanks
Flyingtiger01

[Zaphod Beblebrox]

http://i.imgur.com/1rl0kKz.jpg

Is a turboencabulator appropriate for this application? That may solve the multi-formic response requirement for stability while maintaining the required articulation and stability you seek. The original device had a base-plate of prefabulated amulite, surmounted by a malleable logarithmic casing in such a way that the two spurving bearings were in a direct line with the pentametric fan. The main winding was of the normal lotus-o-delta type placed in panendermic semi-boloid slots in the stator, every seventh conductor being connected by a nonreversible tremie pipe to the differential girdlespring on the 'up' end of the grammeters.


Sorry I couldn't resist.....

[Amadis of Gaul]

I'm at a loss for words. This is not common.

[Uplinker]

Love the picture of the monkey working on the four barrel carburretor !

But the OP just wants to know this:

My question is what is the cruise deck angle [of a 747] and how well are we holding roll to vertical in a typical flight excluding turns of course.

[Zaphod Beblebrox]

I actually hold the US A&P and FCC General, (the license required for US avionics work). I would submit that the poster find any major manufacture data on a blade antenna installation which, even if it doesn't answer the question directly, would direct the reader to the appropriate Boeing data. If not Boeing then perhaps some other airframe or major avionics manufacturer may have data on non optimum antenna placement.

[sin5k4]

I'm not common poster but simply couldn't resist.This thread is pure gold!

[NZScion]

Sounds like for a clear case of adjustment of the thronomisters. The interface with the turboencabulator will result in synergies enabling your RTCA DO-262B to be installed with negligible changes in both thrust and drag.

[Amadis of Gaul]

Sounds like for a clear case of adjustment of the thronomisters. The interface with the turboencabulator will result in synergies enabling your RTCA DO-262B to be installed with negligible changes in both thrust and drag.

I tend to agree.

[underfire]

more curious why this is being mounted on a 747F....

https://www.youtube.com/watch?v=_ePTZezN_Iw

[Zaphod Beblebrox]

Or we do understand and we just want to mess with everyone. The Turboencabulator is an engineers game. A couple of companies got involved to see who could do the best techno-Bu*ls&it.

Here are some examples:
https://en.wikipedia.org/wiki/Turboencabulator

https://www.youtube.com/watch?v=rLDgQg6bq7o

https://www.youtube.com/watch?v=wwmdf5m9khg

[underfire]

poor OP just trying to drill holes in a 747F......that you workin on the carb?

[Zaphod Beblebrox]

No that's not me working on that carb, that's my sister, I do avionics work.

Now to attempt to answer the question, I have been having a bit laugh at the OP's expense and so I have done a small amount research. The Standard RTCA DO-262B refers to Radio Technical Commission for Aeronautics and DO-262B is: RTCA DO-262 MINIMUM OPERATIONAL PERFORMANCE STANDARDS FOR AVIONICS SUPPORTING NEXT GENERATION SATELLITE SYSTEMS (NGSS) CHANGE 1 TO DO-262B IRIDIUM APPENDIX D.

I have no experience with large aircraft antenna installation work but the following Advisory Circulars do address antenna installation on Large Aircraft :

http://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_20-150B.pdf
AD 20-150B
This advisory circular (AC) provides guidance on airworthiness approval for designers,
manufacturers, and installers of Satellite Voice (SATVOICE) equipment supporting air traffic service (ATS)



http://www.faa.gov/documentLibrary/media/Advisory_Circular/AC%2021-16G.pdf

This advisory circular
(AC) identifies RTCA Document No. (RTCA/DO)-160 versions
D E, F, and G,
Environmental Conditions and Test Procedures for Airborne Equipment
, dated July 27, 1997, December 20, 2005, December 6, 2007, and December 8, 2010, respectively, as containing acceptable environmental qualifications to show compliance with certain airworthiness requirements.

These two AC's and some manufacturers data may give you the information you seek. I am sorry I cannot be of more help.

[underfire]

Getting the low altitude to work is tough enough when mounted on the top of the tube...

perhaps the OP should look at a tail mount

(still wondering why a 747F needs this, but who knows)

[Zaphod Beblebrox]

Underfire,

That is a good suggestion. That type of installation may require some type of amplifier as the coax will be much longer. However it does do away with drilling into the pressure vessel. Does the unit manufacturer have an antenna design suitable to be installed in the leading edge of the Vert Stab? Some antennas are designed for just this type of installation.

[underfire]

Why would a F need IFE?

[plhought]

I suspect the installation is for a Satphone installation, not IFE. Lots of practical use of a smartphone on a 'F' model.

I understood exactly what the OP was asking. He really just needs you 747 drivers out there to give him a rough idea on what your pitch is in cruise, so he can determine an ideal antenna installation looking up at the fancy space radio thingers.