Aeronautics and astronautics – Aircraft structure – Fuselage and body construction
Reexamination Certificate
1999-11-12
2001-11-27
Barefoot, Galen L. (Department: 3644)
Aeronautics and astronautics
Aircraft structure
Fuselage and body construction
C244S158700
Reexamination Certificate
active
06322022
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an insulation system for aircraft fuselages and, in particular, to an insulation system for increasing the burn through resistance of aircraft fuselages to provide passengers with additional time within which to evacuate an airplane in the event of an external fuel fire.
Currently, the Federal Aviation Administration (the FAA) is testing various aircraft fuselage sidewall constructions to determine if they can demonstrate a significant increase in burn through resistance in a simulated exterior fire condition. For example, the test simulates a situation where the aircraft is on the ground and a jet fuel fire ignites next to the outside of the fuselage.
The baseline fuselage sidewall construction in current use combines an interior trim panel with one or more layers of Microlite AA fiberglass insulation blanket, encapsulated in a reinforced Mylar film, that is positioned in the framework of an aircraft with an exterior aluminum skin. The fiberglass blanket currently used in the baseline construction is 0.42 pound per cubic foot (pcf)×1 inch (6.7 Kg/m
3
×25.4 mm) or 0.6 pcf×1 inch (9.6 Kg/m
3
×25.4 mm) Microlite AA. In some constructions used by aircraft manufacturers, one or all of the Microlite AA fiberglass blanket layers are replaced with a 0.3 pcf×1 inch to a 0.6 pcf×1 inch (4.8 Kg/m
3
×25.4 mm to 9.6 Kg/m
3
×25.4 mm) polyimide foam.
In a real or simulated fire condition, all of the individual fuselage components melt away quickly and permit flame to penetrate into the passenger compartment The baseline fuselage construction typically provides only a couple of minutes of burn through protection in these tests. There are many ways to improve burn through protection in an aircraft fuselage. However, the most obvious solutions require a significant addition of weight which is undesirable in aircraft construction.
SUMMARY OF THE INVENTION
By replacing the current two to three layers of 0.42 pcf×1 inch (6.7 Kg/m
3
×25.4 mm) or 0.6 pcf×1 inch (9.6 Kg/m
3
×25.4 mm) Microlite AA blanket insulation system, described above, with the burn through resistant system of the present invention, the length of time it takes to burn through the insulation portion of the system has been shown to increase from a couple of minutes to more than five minutes and preferably more than 7 minutes. The burn through resistant system of the present invention has one or more coating or interleaf barrier layers of high temperature resistant material included in the encapsulated multilayered construction of fiberglass blanket layers and/or foam insulation layers.
To provide good results in the simulated fire condition of a full scale FAA simulated burn through test, the system must also be able to withstand moderate air pressure fluctuations attributed to the pulsing flame front or wind. The burn through resistant system of the present invention is able to withstand such moderate air pressure fluctuations.
REFERENCES:
patent: 3814659 (1974-06-01), Nadeau
patent: 4314682 (1982-02-01), Barnett et al.
patent: 4576857 (1986-03-01), Gannett et al.
patent: 5030518 (1991-07-01), Keller
patent: 5038693 (1991-08-01), Kourtides et al.
patent: 5277959 (1994-01-01), Kourtides et al.
patent: 5373305 (1994-12-01), Lepore et al.
patent: 5595817 (1997-01-01), Schaefer
patent: 5598989 (1997-02-01), Ross et al.
patent: 6013361 (2000-01-01), Seal et al.
patent: 0736373 (1996-10-01), None
patent: 94 25180 (1994-11-01), None
Fay Ralph Michael
Stacy James Walter
Townsend Jeffrey Canon
Volenec Steven N.
Wulliman Rebecca Sue
Barefoot Galen L.
Johns Manville International Inc.
Touslee Robert D.
LandOfFree
Burn through resistant systems for transportation,... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Burn through resistant systems for transportation,..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Burn through resistant systems for transportation,... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2591104