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Blue Angels F/A-18 gear doors


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Well, after scouring through a bunch of pics, i see some that look like clean cuts and some that are torn looking. so i guess they are just ripping apart and they fix them by cutting them smooth. i still don't get why it's always the right door. crazy.

Bill

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Lets see if I can toss a bit o' confusion into the mix…

Not always the left door. Looking through my pics I found some on the right, some on the left, some with none, and I can't be totally sure, but this one looks like both doors might have the cutout.

IMG_2075.jpg

Also, here's a detail shot of an A model reserve bird on display. On the port door there seems to be a cutout in the framing which might create a weak spot, prone to damage. More interestingly, the starboard door looks to be dented in that same area, with some interesting wear markings on the outer surface. This leaves me wondering if something during normal ground maintenance tends to damage this part of the door; maybe placement of a jackstand during landing gear work. If this is so, it doesn't seem far-fetched that the Blue Angels would simply remove the section to give clearance and avoid marring the paint job.

IMG_0985.jpg

Or maybe I've meen watching too many reruns of Monk :D

:)

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I never saw that in the 8 years I worked CF-18As ans B. If we found a delamination on a door we changed it, the same goes for damage. We didn't mess much with honeycomb structures and that far exceeds what I recall as acceptable damage. Obviously the Angels have permission to fly with that damage and they do dress the damaged areas.

The tire striking the inside of the door was fairly common but not desired.

Edited by Scooby
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another thing that has become more apparent looking at some of these pics. the blues are clean but definately not free from weathering. i see more chips and stains than i thought would be there. i wonder how a contest judge would handle it if you properly weathered a blue angel plane...hmmm.

Bill

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It's not unusual to see a simple fix of a problem. The early F-14 boat tail was prone to cracking, so Grumman and/or the Navy just cut away the part that was prone to do so. The first F-111As (and all the Bs) had an aft main gear door that opened with a parallelogram mechanism so the door was parallel to the bottom of the fuselage. This was changed in production to a hinged door that would have fouled on the bottom of the fuselage when open, except the aft edge was cut off, exposing the gear well when the door was closed. See http://www.f-111.net/models/landing-gear/index.htm

In this case, there is a recess in the door in this area that must be prone to something like "oil canning" and subsequent cracking, if not break out. The doubtlessly well analyzed and formally approved fix was obviously to cut it away when cracks appeared and continue to use the door until it was convenient to replace it. (It may be that the first cracks were stop drilled until they exceeded some conservative limit and then the recessed section was removed.)

Edited by Tailspin Turtle
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wow, well thanks guys. who woulda thunk a simple door crack would lead to such mystery and intrique? i think i may add this cut out on my no. 7 blues model just to see if anyone even notices it. you know, one of those weird modeler's debate starters. sometimes it's fun to just screw around with contest judges just to see what they do. i know, i'm slightly twisted that way.

Bill

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wow, well thanks guys. who woulda thunk a simple door crack would lead to such mystery and intrique? i think i may add this cut out on my no. 7 blues model just to see if anyone even notices it. you know, one of those weird modeler's debate starters. sometimes it's fun to just screw around with contest judges just to see what they do. i know, i'm slightly twisted that way.

Bill

Puts a whole different spin to "Reeeady - hit it!"

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It's not unusual to see a simple fix of a problem. The early F-14 boat tail was prone to cracking, so Grumman and/or the Navy just cut away the part that was prone to do so. The first F-111As (and all the Bs) had an aft main gear door that opened with a parallelogram mechanism so the door was parallel to the bottom of the fuselage. This was changed in production to a hinged door that would have fouled on the bottom of the fuselage when open, except the aft edge was cut off, exposing the gear well when the door was closed. See http://www.f-111.net/models/landing-gear/index.htm

In this case, there is a recess in the door in this area that must be prone to something like "oil canning" and subsequent cracking, if not break out. The doubtlessly well analyzed and formally approved fix was obviously to cut it away when cracks appeared and continue to use the door until it was convenient to replace it. (It may be that the first cracks were stop drilled until they exceeded some conservative limit and then the recessed section was removed.)

Exactly! Well said!

Curt

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I don't know for sure, but I understand the Blue Angels do some flying with gear down at speeds higher than normally authorized for other Hornets. I think the damage is due to higher than normal speeds with gear down (airloads).

The landing gear doors are made of composite material (thus the 'delamination' problem that was mentioned by Scooby). As a pilot, I often heard about aircraft being grounded because of a delamination, but I never really saw a good example of what it looks like (for sure, CF Hornet techs didn't screw around when they found one - the a/c was grounded until fixed). A tribute to our techs; they rarely let things get to the point where they were obviously broken.

The normal maximum speed for Hornet gear operation is 250 knots calibrated airspeed (KCAS). I think (not sure) I have heard that the Blues sometimes can fly with gear down at speeds up to 300 KCAS or so; this would definitely make it possible to have bits and pieces come off the doors. It makes sense to me that a field repair might be to chop off the part of the door that has delaminated, to stop the rest from coming apart.

On the Tutor, the gear speed was 175 KIAS. One of the students dropped the gear accidentally at 350 KIAS; this caused all of the gear doors to rip off, leaving the gear legs OK and fine for landing. Landing gear doors are the most fragile part of landing gear, and the speed limits are designed to ensure they don't get damaged when cycling open/closed or simply flying while locked down.

On the CF-5, one guy managed to drop the gear at 500 KIAS; he was using his left hand on the glare shield to help crank his body around to look behind him when the hand slipped under 5 G and smacked the gear handle down. Not only did the doors rip off, but the gear legs as well. He had to eject from the aircraft, which landed (pilotless) on its belly on the frozen surface of Cold Lake, with a barely visible broken spine but looking otherwise normal! My father (the base flight safety officer at the time) walked right by it as it sat on jacks in the hangar, and asked where 'the wreckage' was being stored. He was informed it was right behind him; definitely did a double take!

ALF

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i don't know what the top speed is when the 6 plane does his low take-off high speed departure, but i know the gear doors stay open for quite a while when he's screaming down the runway, that is one area where i know they probably exceed the doors limits. Most of the other door open maneuvers are fairly slow but i suppose could be above it as well.

Bill

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Hi All,

I have a question for all you Hornet fans out there. I was searching for Blue Angels pics on the web and discovered an interesting anomaly. It would appear that the R/H forward MLG door has a cut-out on the lower edge on some of the jets. This can be seen on the following images.

us-navy-blue-angels.jpeg

blue-angels-pilots-cockpit.jpeg

Just wondering if anyone knows the reason behind this modification to the gear door?

Cheers,

John

There must be a difference in models, or they just upgraded. Did anyone notice the different antenna's on the back spine. I was really surprised and never noticed that before

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I'm 98% sure NAVAIR has quit buying the UHF-only (square ones) models. The swept back ones are VHF/UHF capable and are fully interchangeable for high-speed applications.

HTH

Spongebob

Spongebob

The square antennae are actually V/UHF, but for the older radios (F/A-18A and early C models). The swept ones are normally indicative that the aircraft has been outfitted with the ARC 210, which include the high-speed data transmissions such as Digital CAS, Have Quick, and encryption (without the KY 58).

The easy way to tell (on a Canadian, Australian, or early USN Hornet) if ECP 583 has been accomplished is to look for the antenna shape (both upper and lower ones).

I may be wrong though - it is possible that the USN has mated the new-style antennae with the older radios on these aircraft, but I don't know if they are compatible.

ALF

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