General Category > Unofficial F/A-18 Acceleration Pack board
F/A-18 Approach speed
SpazSinbad:
neutrino, Would you do me a big favour please and make a screengrab or scan of the relevant Optimum or AoA info pages please? TIA. Here is the LSO NATOPS info for the Hornet. This LSO manual used to be online same place as the Hornet NATOPS but sadly now taken offline. Neutrino drop me an e-mail for more info.
Question about speedbrakes: AFAIK it is standard operating procedure (SOP) to have S/Bs out, full flap since about the 1960s with the early Skyhawks and then for all jets. It was discovered then that for a few extra pounds of fuel with slightly higher drag (S/Bs don't have that much effect at slow speed) the extra engine RPM required to be at optimum parameters meant faster engine response (to full power especially) which is a good thing when needed. Perhaps now in individual aircraft cases this may no longer be the case; but I have not researched this aspect for the Hornet / Super Hornet. I will do that later.
SpazSinbad:
Some random pages here from a Google book online may help answer questions but because of random nature of pages presented there does not seem to be info about the Hornet S/B issues: http://books.google.com/books?id=D-ctX2Q-CSIC&pg=PA196&lpg=PA196&dq=Hornet+Speedbrake+out+for+carrier+approach&source=bl&ots=sf9w2DV2zw&sig=edwtvgnRGgKA8bOTWJyCGtWYYds&hl=en&ei=eP2iSozwOILYsQPEsYiNDw&sa=X&oi=book_result&ct=result&resnum=1#v=onepage&q=&f=false
Good discussion here (which may not be totally accurate regarding S/Bs and other stuff but...): http://fsxproblueangels.com/phpBB3/viewtopic.php?f=15&t=224
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Good stories here about Hornet Ops in USN, specific quote about the break and dirty up on downwind (no mention of putting the S/Bs back in):
http://www.neptunuslex.com/2005/10/18/rhythms-part-xxxiv/
"After counting off 19 seconds from the lead’s break turn to downwind, the wingman started his own left break- much less aggressively than his lead, but still a good turn, the g-forces pulling at his head, his forearms, pushing him down in his seat. He brings the throttles smoothly back aft to flight idle, thumbing the speedbrake out. Under the combination of idle power, high “g” and speedbrake deployment, the jet rapidly decelerates, and at 250 kts he lowers the landing gear and flaps. The landing gear make abrupt hydraulic coughs and grinding sounds in their transition, the sound instantly overcome by the wind noise as they fall into the windstream while the flaps cause the jet to pitch bobble up a bit. Gear down and locked and the sound goes to a reduced, but still elevated pitch from normal flight. With the gear down and verified locked, and the flaps down, he must continuously trim the jet’s nose back up as she slows down to approach speed.
Established now on downwind now the timeline seems to accelerate, and the wingman races to complete his landing checklist, dial his radar altimeter warning bug down to 400 feet (the LSO warning: “Never go below 400 feet without a ball” flits in his head). His abeam distance is 1.3 nm – a little tight – and he drops the right wing for a moment to build some separation before reversing back to the left to start his descending approach turn as the carrier’s fantail goes by, this time in the opposite direction." CONTINUED HERE: http://www.neptunuslex.com/2005/10/23/rhythms-part-iiiv/
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SpazSinbad:
Apologies for incorrect assumption regarding Hornet S/B use. Always pays to ask a Hornet pilot! Here is the response to my question: "Does a Hornet use S/Bs for a carrier approach"?
"By no means, in fact the speedbrakes automatically retract when the
gear or flaps are lowered. They have to be manually thumbed out and
held out in those cases. They disrupt the airflow over and around the
rudders.
As you may know, in the Super Hornet there are no speedbrakes per se,
but rather the ailerons, flaps and rudders feather in opposition to
one another."
Not having a Hornet NATOPS to refer to is just sad. ;D Often I have seen reference to the S/Bs being deployed for the break into a carrier circuit (SOP) but then no mention of them again during the subsquent carrier approach. Oh well. ::)
SpazSinbad:
Nothing like a good NATOPS diagram. [The colour text is my amendment + title.] I believe this one is from an appropriate model NATOPS (awaiting a confirmation from former Hornet pilot). Anyway the online PDF is pretty good for the Falcon 4 sim Hornet C model. However having nothing to compare it with I have no idea about accuracy but it looks appropriate, especially the injunction to select S/Bs in going downwind (after S/Bs out - optional for the break): http://www.cockpits.net/files/FA-18Cv3.0_MANUAL.pdf (1.2Mb)
Here is comment from a former Hornet pilot about the diagram (I guess the diagram we see has been modified for the Falcon 4 sim settings required): (I had asked: Is this diagram close to 'real thing' from NATOPS)
"Pretty close. I think that downwind level power was closer to 85-87%,
maybe 82-83% in the approach turn. Whatever got you 300FPM rate of
descent to the 90, increasing to 500FPM to the 45 and 750 or so in the
groove. Which looked more like "right wingtip of the velocity vector
on the zero pitch line" for the first part of the turn, gradually
increasing to 3 degree negative pitch on final. And as I mentioned,
the speedbrake retract was an automatic function, not a checklist
item. Unless you were really hauling the chilly (>400kts, e.g.) you
wouldn't even use it. She bled down readily at idle power with any
kind of g on. We also used 25-27 degrees AOB from the 180 rather than
30. If you were at 30 degrees AOB (especially in autothrottles) you'd
practically be guaranteed a wrapped up, fast nose down start, or (in
manual) an angling approach."
SpazSinbad:
EVERYTHING YOU MAY WANT TO KNOW ABOUT WHYs and WHEREFOREs of CARRIER LANDINGS PDF ;D
http://www.robertheffley.com/docs/HQs/NAVAIR_2002_71.pdf (3Mb)
"4.4.10 SPEED BRAKES page 75 (of 220)
Many historic Navy aircraft extended speed brakes on CV approach. This provided several benefits.
First, the increased drag of the speed brakes moved the bottom of the drag bucket to a lower speed,
moving the Vpa closer to the frontside of the power-required curve, and thus improving the
flightpath stability. Next, the additional drag necessitated a higher mean power setting, with two
consequent benefits. A higher mean power point enabled faster, more linear thrust response, thereby
improving GS tracking. Furthermore, the higher mean power setting permitted a quicker transition to
full power in the event of either bolter or waveoff. This, together with simultaneous stowage of the
speed brakes, permitted more rapid achievement of the maximum excess power. While not deployed
by the F/A-18A-D models on approach, speed brakes remain a viable means of improving the
handling and performance on approach (e.g., operationally deployed EA-6B and F-14)."
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