Cross linked - irradiated polyolefin is used for wire insulation used in locomotives because it is pretty much immune to diesel fuel, hydraulic fluid and other chemicals.
The trade name of one such wire is "Exane". Might lead you to some literature.
MIL-W-5088L Appendix A lists all the wire types allowed on military aircraft and polyolefin insulation is not on this list and would not be approved for use.
Polyolefin heatshrink eg. MIL-I-23053 (M25053/x) is approved for military aircraft use and where some fuel contact is likely.
Many manufacturers supply chemical compatibility tables. You may need to do some research to find an appropriate table. Some additional specifics are likely required. There are many polyolefins and each behave differently. Also, there are many different fuels.
Although thinking aviation fuels, there might be t esting applicable to the assorted ASTM grades. Also consider the Mogas issue for substitute aviation gasoline. Be suspicious of the oxigenated motor fuel additives such as MTBE, ETBE, TAME, methanol, ethanol, TBA, etc.
Polyolefins include several grades of each polyethelene, polypropylene, polybutylene, etc. Do you also consider the assorted O-ring materials such as Viton, Buna-N, nitrile, ...?
