FA18E/F vs. A6E comparison
From: hornet265@aol.com (HORNET265)
I recently posted performance data on the new Hornet with respect to the
Intruder. Probably like many of you I read only selected topics on this
newsgroup because the volume is so high, and frankly, many of the subjects
are pretty inane. So I don't expect my posts to be widely read. However
I did think my information would catch the eye of most of the Hornet
bashers out there. Guess not. Still a lot of folks making unsupported
statements on this subject that are incorrect. If it's a qualitative
opinion I shall respect it. I won't tell people what to like or dislike.
Quantitative statements should be supported with relevant data.
Now, to review the facts.
Payload:
The A6E has five stores stations. The Aero7A bombrack can carry 3600
lbs. The Intruder has 4. The Aero7B rack can carry 3700 lbs. There's
one on the centerline station. Add these up and you get 18,100 lbs. Nice
number. Makes good PR. Won't work. Why? It exceeds max gross weight.
Max cat gw is 58,600 lbs. Empty weight is about 28,000 lbs
(FLIR/SWIP/ECM/composite wing all add to this number). Internal fuel is
16,000 lbs (9K fuselage and 7K wing). The Intruder cannot take a cat shot
with partial fuel in the wing, so it's either full or empty. We just
don't launch with empty wings unless it's a CQ evolution. So add the 28K
and the 16K and you get 44K. Subtract the 44K from 58.6K and you get the
max payload: less than 15,000 lbs. For recovery the max trap weight is
36K. This leaves a maximum of 8K for bringback, including fuel.
The F/A18E has five stores stations like the A6, but with BRU32
bombracks attached to the pylons. Same max weight capability. BUT...the
new Hornet has 2 more wing stores stations, each with 1100 lbs capacity.
AND...it has 4 more stores stations for weapons/sensors (2 wingtip AIM9
and 2 fuselage AIM7/AIM120/NavTgt FLIR). Total stores stations equal
11, giving MUCH greater flexibility. The F/A18E max cat weight is 66,000
lbs. The weight of the F/A18E with pilot, 400 rnds of 20mm, & full
chaff load is 32,000 lbs (actually it's 31,983 for a 205 lb pilot). Full
internal fuel is 14,460 lbs (and likely to be 15K due to some design
optimizing). Planned max external load is 17,750 lbs. Better number.
And it works. If you do the math, you come up to about 64.2K on the cat,
well within the 66K limit. The difference, about 1800 lbs, is for planned
growth, so we can add new systems for years to come and not reduce the max
payload. The carrier bringback is specified at 9,000 lbs at 42.9K max
trap weight. Notice again the math works in the Hornet's favor: 42.9
minus 32.0 gives us 10.9K bringback. Factor in recovery fuel (4K day & 5K
night) and there's plenty left to recover with expensive weapons. By the
way the F/A18F has the same numbers, except internal fuel is reduced by
215 lbs.
Comparative Loadout Example: 4 Mk 84 LGB
A6E: Weapons on parent racks stations 1,2,4 & 5
300 g fuel tank on station 3 (18K total fuel)
54 to 55K launch weight
F/A18E: Weapons on parent racks stations 3,4,8 & 9
480 g fuel tank on station 6 (17.7K total fuel)
2 AIM9M (stations 1 & 11)
Targeting FLIR on station 5
plus the flexibility of adding:
Choice of AIM7M, AIM120C, or AGM88 on stations 2 & 10
Choice of AIM7M, AIM120C, or NAVFLIR on station 7
63 to 65K launch weight
Fuel:
A6 max fuel is 26K (5 300 g tanks). No weapons! At 24K fuel one weapons
station is available.
F/A18E max fuel is 24.3K (3 480 g tanks). 8 weapons stations available!
The wing is structurally provisioned to accommodate 2 additional 480 g
tanks (bringing total fuel to 30.8K with 6 stations still available for
weapons), but we are not testing this configuration in the first flight
test program.
The A6 could carry the larger fuel tanks, but there are no plans to
invest in an integration and flight test program for them.
Now both jets have similar fuel flows at cruise. The Hornet's optimum
altitude is 510K higher, and speed is .11.13 Mach faster. In most
scenarios this means the F/A18E will go farther.
Reliability:
Mean Flight Hours between Failure (MFHBF), a measure of the average number
of hours the airplane will fly before something breaks.
A6E: 0.5 Hrs
F/A18C: 1.5 Hrs
The F/A18E will have even better performance because several of the new
subsystems have demonstrated improved MTBF. Very likely the new Hornet
will be in the 2.6 Hrs range.
Direct Maintenance ManHours per Flight Hour (DMMH/FH), a measure of how
many man hours of scheduled and unscheduled maintenance are required for
each hour the jet flies.
A6E: 51.9 Man hours
F/A18C 19.1 Man hours
A lot of the A6 maintenance is scheduled, which means compliance with
airframe and powerplant bulletins where mechanics have to conduct
recurring fatigue inspections...very indicative of an older aircraft. The
F/A18E will see reduced maintenance time because we have better access to
systems, better diagnostics and fault isolation. We can also change an
engine in 30 minutes. Ask an Intruder Mech how many hours it takes to
change out a J52!
Safety:
Class A mishap rate (Flight Mishaps per 100,000 flight hours)
Cum Hours Rate
A6 3,401,461 7.53
F/A18 1,037,496 4.03
Data through 28 February 1995
Survivability:
The new Hornet goes faster, is less detectable, has better ECM & more
expendables, has better sensor integration, and a formidable air to air
capability. I put out a detailed post on this and won't waste bandwidth
by repeating it here. Email me if want the data.
The Intruder has served the navy well. It's an ugly, noisy bomb truck. I
loved flying it for 20 years. I used to bash Hornets all the time. I
know better now. Now you do too.

Bill DuBois {wdubois@opnavemh.navy.mil} ) )
CAPT, U.S. Navy {HORNET265@aol.com} )) ))\
Deputy Program Manager )) ) ))))\__
for F/A18E/F \=*=*=*=*=*=/
Naval Air Systems Team "Anyone can hold the helm
Washington DC when the sea is calm."

 
