Path: utzoo!news-server.csri.toronto.edu!rutgers!att!cbnews!cbnews!military From: stevenp@decwrl.pa.dec.com (Steven Philipson) Newsgroups: sci.military Subject: Re: Aircraft turnaround and maintenance Message-ID: <1991Mar13.003754.8063@cbnews.att.com> Date: 13 Mar 91 00:37:54 GMT References: <1991Feb18.053845.10992@cbnews.att.com> <1991Feb13.221910.6268@cbnews.att.com> <1991Feb15.071907.11518@cbnews.att.com> Sender: military@cbnews.att.com (william.b.thacker) Organization: DEC Palo Alto Lines: 66 Approved: military@att.att.com From: stevenp@decwrl.pa.dec.com (Steven Philipson) > In article <1991Feb15.071907.11518@cbnews.att.com> adh@doc.ic.ac.uk (Adam Hebblewhite) writes; [re: carrier aircraft launching from ground bases] > In fact, the plane could probably get away with a larger payload > from a land base, given that during carrier ops a larger safety factor > probably is necessary (in case the catapult partially loses power). No "probably" about it -- an aircraft can almost always takeoff at a higher gross weight from a long runway than from a carrier deck. The catapult has a limited weight capacity, as does the aircraft itself. A non-catapult launch puts a lot less strain on the aircraft for takeoff at any given weight. As for "safety factor", there ain't much. If the catapult fails during launch, the aircraft goes into the drink, and the crew must punch out. I've read of cat-shots where the speed at the end of the cat is a mere 8 knots above the stall speed of the aircraft. That's not much. > [...] What is the usual length of afterburner "burn" for a > high-performance jet fighter/bomber on take-off, and is it shorter > for a carrier jet than for a land-based jet? The length of afterburner use varies depending on the conditions (aircraft weight, density altitude, runway length, obstacles, need to get somewhere fast). It can be as short as no AB at all, to several minutes. The fuel burn with AB is incredible. Aviation Week reported that 30 seconds of AB on an F-14 consumes 20 minutes worth of cruise fuel. > 2. I am aware of air-to-air refueling as a way to increase combat > range, but do the air services use it as a way to increase payload? > I.e., do planes ever take off with a full bombload and partial > fuel load, and then rendezvous with a tanker to top their tanks > once aloft? Yes. B-52's routinely launch this way. Their max flight weight is above their max takeoff weight. In carrier ops, takeoff weight can be limited by low wind speed. In that case, there's an operational advantage to launching with reduced fuel load, then topping the tanks after takeoff. > How does the Navy cope with catapult failures? With redundancy. There are multiple catapults. If they all fail, the carrier is not able to operationally launch its attack aircraft. > And does the Navy have any way to transfer planes off a crippled > carrier to another carrier other than flying them off? They can be lifted off with cranes, like any other cargo. It may also be able to use the entire length of the carrier deck for non- catapult launches, but this'd be pretty dicey. Aircraft would likely have to launch at minimum weight (i.e., no armament, and limited fuel). It would still be necessary to steam to do this. If the carrier is dead in the water, the aircraft won't be going anywhere under their own power. Steve (the certified flying fanatic) stevenp@decwrl.dec.com