At 3/22/11 04:45 PM, All-American-Badass wrote:
At 3/22/11 07:44 AM, SkeletonGimp wrote:
Desert air, coupled with the high tempo of these raids and the location of the crash landing lead me to believe this was likely a mechanical fault, most common for these theatres being engine stall by dust clogging and/or engine fatigue. It'd make even more sense if this F15 has seen service in Afghanistan recently. F15's are old and only getting older.The thing with the F15s though is they have alot of failsafes to prevent them from just crashing out of mid air due to mechanical failures but engine fatigue would be the most likely of any explanation if pilot error wasn't a factor.
This is true, F15s, specifically F15E's do indeed operate failsafe systems, but these are mostly for the event of electronic failure, such as the controls frying up. Think of it as running yourcomputer on 'Safe Mode' since the failsafes act as a kind of back up aircraft control system.
Mechanical failure is that, the physical mechanics break down and unless these are reduntant (ie a wing piece where using Fly By Wire the other wing and tail panels can compensate) any issues mechanically aren't going to be fixed electronically.
An educated guess would be that there are two main issues that resulted in the crash.
One is that high levels of dust clogged up moving parts in the air intake, resulting in loss of airflow and therefore loss of power. This would then result in a stall, and if not fixed before a safe altitude the pilots did right to eject. Large quantities of dust, especially in sand storms or dust clouds, can literally stick to surfaces inside jet engines like glue and stop them from moving effectivelly or moving at all. Get enough dust in your intake fans and you're fucked, however unless there's some heavy dust cover in the skies above Libya or the airforce base/carrier these fighters are operating from, I'd be suprised if dust clogging was the case considering how early into the operation this crash occured.
The other is engine fatigue/failure. This could be a result of dust damage to the air intakes (different from clogging, rather then 'freezing' the parts up in a sheet of thick dust, dust damage causes metal parts to rust and/or decay out of shape and occurs over time, usually over a period of a week or two in high intensity air campaigns. At high speeds, it's surprising how much dust can eat away at the surfaces of paint and metals) It could also be a result of aircraft over-use, maintenance failure/human error in repairs, or simply old componants finally giving up. As I already said, F15s, even the E series, are getting old. Cannibalising parts from stockpiled F15's is comman practice I hear from USAF pilots I've met since its seen as too expensive and time consuming to replace many engine componants outside of the usual cycle of refits/retrofits/upgrades, but this is heresay so don't take my word as fact.
The latter seems more likely if it's a mechanical and not electronic issue, but unless this particular aircraft has been involved in intense fighter runs in afghanistan recently it's unlikely dust damage was the cause.