HAWK21M From India, joined Jan 2001, 31457 posts, RR: 57 Posted (7 years 5 months 2 weeks 6 days 3 hours ago) and read 1547 times:
How Effective are Supplemental Heating Systems on Todays commercial Aircraft.
eg. On the B752.The Foot,Shoulder & Pax Door Area heating.
If there was no Foot & Shoulder heating,but Control Cabin temp was varied to comfort level.Would that not suffice.
Also Is the Door heating retained on most Pax converted Freighters.
MechEngineer From Germany, joined Jun 2006, 46 posts, RR: 0 Reply 1, posted (7 years 5 months 2 weeks 6 days 1 hour ago) and read 1534 times:
As in a car, where in (a Bavarian) winter you have the choice of either seeing through the windscreen where you're going, OR not having hot, dry air blowing into your eyes, zonal heating/cooling still isn't really satisfactorily sorted out in passenger aircraft.
The FD 728 prototype was sold to the DLR to serve as a test fuselage to investigate solutions for just this problem, and I recall the 328 having extra heating in the forward door area for FAs as a customer option.
N8076U From United States of America, joined Jun 2006, 425 posts, RR: 9 Reply 3, posted (7 years 5 months 2 weeks 5 days 21 hours ago) and read 1509 times:
I don't think this would be considered "supplemental" but the upper deck zone on the classic 747s did not have its own trim air valve like the other main deck zones, and so the upper deck area had electric heaters instead, to warm up the supply air to the correct temperature.
Jetlagged From United Kingdom, joined Jan 2005, 2509 posts, RR: 24 Reply 7, posted (7 years 5 months 2 weeks 4 days ago) and read 1419 times:
The 747-200 Combis had side cargo door heating, presumably for when there were passengers seated in the cargo area. I assume this is because the side door won't have any air-conditioning vents and risers and therefore quite a large area which would be much colder without such supplemental heating.
Most 747-200's had trim air valves for the cockpit and upper deck zones. Early aircraft, such as 747-100's did not and had the electric heaters mentioned by N8076U.
The glass isn't half empty, or half full, it's twice as big as it needs to be.
Tod From Denmark, joined Aug 2004, 1699 posts, RR: 3 Reply 12, posted (7 years 5 months 2 weeks 3 days 2 hours ago) and read 1378 times:
Quoting HAWK21M (Reply 11): Could the Different STCs have contribute to the Cost Variation.
Yes, the cost of getting an STC issued can vary quite a bit.
The variables include, but are not limited to whether you go through a DAS or an FAA ACO, which FAA region you are dealing with, your working relationship with the FAA and of course whether you are ammending an existing STC or starting from scratch.
That said, in the case of these freighter conversions, I don't believe that the certification costs are what drove the pricing differential, but since I was not privy to all the sales related price/cost data, that is just a guess.
Tod From Denmark, joined Aug 2004, 1699 posts, RR: 3 Reply 18, posted (7 years 5 months 2 weeks 2 days 3 hours ago) and read 1334 times:
Quoting HAWK21M (Reply 17): During a B757 conversion to Freighter.What Items do you normally Knock off typically
All interior furniture
All entertainment systems
Lav/galley vent system
gasper system (if present)
Pax oxygen systems
Unused conditioned air branches
Unused portions of water supply and drains.
all but one potable water tank
all but one excape slides
Doorway heated air
unused wiring and electronics
stairway and cartlift (747 only)
modify/replace waste system
modify/replace one water tank
modify/replace one lav
replace/modify main conditioned air ducting
modify fwd lower deck heating
modify hydraulics to add cargo door actuator system
modify smoke detection system
reroute misc hydraulic and pitot lines
replace sidewalls with cargo lining
replace floor panels
add 9g bulkhead
add lots of floor structure
add cargo handling system
add cargo door (except on some package freighters)
add structure for door and bulkhead
add overboard lav venting
add cargo floor drain system
add supernumerary seating and stowage
add one small galley
add emergency equipement
add flightdeck ram air inlet (747 only - IIRC)
add crew ladder (747 only)
I am sure there is a bunch more, but as you can see by my list, I am a mechanical systems guy and tend to see the plane through that little funnel.
Feel free to pile on
Not on the first one of a new design and not if it is the first one a mod facility has done. A big factor in the timeline is the quality of the engineering and the quality of the mod facility and the resources that they put toward the program. I've seen things get ugly and go well over six months.
The problem with a net is that you have to allow for a lot of deflection and place the net much further back in the aircraft. It is not uncommon to get one more container position with a rigid bulkhead.
MechEngineer From Germany, joined Jun 2006, 46 posts, RR: 0 Reply 22, posted (7 years 5 months 1 week 6 days 1 hour ago) and read 1287 times:
It also depends on what is in front of that bulkhead or net. If it's a cargo courier area or cross aisle to the cockpit you may need a gas-tight bulkhead to contain the fire depressing gas (halon) that is released into the cargo bay if there is a fire there.
Tod From Denmark, joined Aug 2004, 1699 posts, RR: 3 Reply 23, posted (7 years 5 months 1 week 6 days 1 hour ago) and read 1285 times:
Quoting MechEngineer (Reply 22): If it's a cargo courier area or cross aisle to the cockpit you may need a gas-tight bulkhead to contain the fire depressing gas (halon) that is released into the cargo bay if there is a fire there.
In that situation, the bulkhead must be able to pass an FAA smoke penetration test.