hercmech14 Posted April 21, 2010 Share Posted April 21, 2010 Can anyone tell me the difference between the 74 Dyess Hercs and the ones the Reserves started getting in 78? Externally they look the same. Thanks in advance........Dave in western PA Quote Link to comment Share on other sites More sharing options...
AMPTestFE Posted April 21, 2010 Share Posted April 21, 2010 Here's one difference: They got rid of the wing isolation valves for the H2. They didn't get the high pressure brakes until tail number 85-0035. Same with oil cooler augmentation, unless someone spend the cash on the TCTO. Digital fuel gages didn't come until 84-0206, unless someone spent the cash. Since active duty didn't/doesn't own any H2s (slicks), there's a chance someone actually did spend money to upgrade these. Quote Link to comment Share on other sites More sharing options...
DC10FE Posted April 21, 2010 Share Posted April 21, 2010 Hercmech14, Check your PM's. I sent you a message. Don R. Quote Link to comment Share on other sites More sharing options...
RZHill Posted April 21, 2010 Share Posted April 21, 2010 The seats man the seats, pitot system Rosemont in 86 I believe. Rz Quote Link to comment Share on other sites More sharing options...
Dan Wilson Posted April 21, 2010 Share Posted April 21, 2010 The Dyess H models were not hugely different than the E models except: (H1 vs E) APU vs GTC/ATM -15 Engines vs -7 Engines Structural wing differences INITIALLY: E models eventually all got the H model wings. 30/60 PPM flight deck AC pak vs 30 PPM Pak Wing Divider Valve vs Isolation Valves Bleed Air Regulators vs Bleed Air Valves There we other minor differences I think like with the aux hyd pump cooler and a few other things but I think most were put into the E model system over the years. Dan Quote Link to comment Share on other sites More sharing options...
SEFEGeorge Posted April 21, 2010 Share Posted April 21, 2010 Here's one difference: They got rid of the wing isolation valves for the H2. I didn't know that they got rid of the wing isolation valves. How did they configure the bleed air system then? Quote Link to comment Share on other sites More sharing options...
Dan Wilson Posted April 21, 2010 Share Posted April 21, 2010 George, they put a single valve in the center of the manifold and called it the wing divider valve. If it was a valve like the isolation valve or some totally different method of operation I couldn't say though. Dan Quote Link to comment Share on other sites More sharing options...
polcat Posted April 22, 2010 Share Posted April 22, 2010 H2s have the better radar (AN/APN-241) and got rid of the old PPI. Instead, they have the Radar Display unit which can display your flightplan (inputted via SCNS) with weather and TCAS overlays. Really nice, just not good for being SKe wingman, but who ever really uses the PPI? Also, they have the funky ADI and HSI, where you have to set the course and HDG bug down by the autopilot. Also, flushable toilet with urinals on the aft side of 245 (think plastic containers, don't drain outside). The H2s also have the emergency exits located in front of the prop arcs instead of behind. Also, yes, the wing isolation valves are gone with only the bleed air divider valve. If you don't know, the nice thing about the divider valve is that it allows the FE isolate part of the bleed air system while allowing pressurization with one unit unlike the E, H, H1 where you lose both packs if both isolation valves had to be closed. Quote Link to comment Share on other sites More sharing options...
jbob Posted April 22, 2010 Share Posted April 22, 2010 H2s have the better radar (AN/APN-241) and got rid of the old PPI. Instead, they have the Radar Display unit which can display your flightplan (inputted via SCNS) with weather and TCAS overlays. Really nice, just not good for being SKe wingman, but who ever really uses the PPI? Also, they have the funky ADI and HSI, where you have to set the course and HDG bug down by the autopilot. Also, flushable toilet with urinals on the aft side of 245 (think plastic containers, don't drain outside). The H2s also have the emergency exits located in front of the prop arcs instead of behind. Also, yes, the wing isolation valves are gone with only the bleed air divider valve. If you don't know, the nice thing about the divider valve is that it allows the FE isolate part of the bleed air system while allowing pressurization with one unit unlike the E, H, H1 where you lose both packs if both isolation valves had to be closed. Funky ADI and HSI! That's the FCS-105 flight director. ;-) And dude the 241 radar didn't come out until WAY after the H2s were delivered. What you're seeing are modded H2s with the 241. You must be young. :-) Main differences are: H2s had the Bleed Air Divider Valve, FCS-105 Flight Director. There may have been some minor differences but those two were perhaps the main ones. I'm not sure about the flush toilets. They slowly made gradual changes to the H2 line all the way until the H3s were delivered. When did the old dual INS first start showing up? Now I forget when the 3000 psi brake pressures came about. Edit: I will say I'm talking about H2's as delivered from Lockheed. Trying to compare differences now would be fruitless due to all the post delivery mods. Quote Link to comment Share on other sites More sharing options...
agarrett Posted April 22, 2010 Share Posted April 22, 2010 Some of the H2s came with Thermal off-stroke. Quote Link to comment Share on other sites More sharing options...
Dave in WV Posted April 23, 2010 Share Posted April 23, 2010 H1s had the same avionics as an E model. The First H2's had the older type pitot system. It seemed every couple of years the H2s had something different. The 88's were contracted without SKE. It was added later. I didn't miss SKE for those few years without it. Quote Link to comment Share on other sites More sharing options...
RZHill Posted April 23, 2010 Share Posted April 23, 2010 Another difference is the Hf Antenna's The long wire are gone , replaced by the antenna at the base of the tail. RZ Quote Link to comment Share on other sites More sharing options...
meh130 Posted April 23, 2010 Share Posted April 23, 2010 The seats man the seats, pitot system Rosemont in 86 I believe. Rz Rosemount started with tail 85-0035. Quote Link to comment Share on other sites More sharing options...
jimsmith130 Posted April 23, 2010 Share Posted April 23, 2010 The AF didn't have a lot of configuration control with the H2 line. They had good intentions though. Their plan was to get the best new options available on new aircraft and then retrofit the older aircraft. They were able to get new equipment, but the retrofit plan just didn't happen. The H3 came along not on purpose, but because there were just so many differences at that point they just couldn't call it an H2 anymore. Quote Link to comment Share on other sites More sharing options...
meh130 Posted April 23, 2010 Share Posted April 23, 2010 Can anyone tell me the difference between the 74 Dyess Hercs and the ones the Reserves started getting in 78? Externally they look the same. Thanks in advance........Dave in western PA I'll leave it to the engineers for the specifics, but they are very, very similar. I think the flight directors on the 78s may be different than the 74s. I really think they should be considered H1s and not H2s. It would be trivial for a Dyess crew to fly a Pittsburgh (former OK ANG) plane, but it takes a couple of hours of differences academics for an 85 or later H2 engineer to do it if they are unfamiliar. Quote Link to comment Share on other sites More sharing options...
bobdaley Posted April 23, 2010 Share Posted April 23, 2010 How many H2.5's were built? I had a list once upon a time but I can't find it. I thought I remembered there were only 20. 12 originally at Louisville 91-1231 to 39 91-1651 to 53 8 at Mansfield 90-1791 to 1798 Maybe some at Youngstown? Thanks Bob Quote Link to comment Share on other sites More sharing options...
tinyclark Posted April 23, 2010 Share Posted April 23, 2010 Avionics wise: H2 has FD-109 flight director, FCS-105 Autopilot, APN59 unless modified, they did have GPWS but those were all modified to GCAS, and they still have long wire HF antennas. Quote Link to comment Share on other sites More sharing options...
Dave in WV Posted April 23, 2010 Share Posted April 23, 2010 Tiny, some H2s have the long wire HF antennas and some don't. The '88s didn't have them. Delawares H2s have the luggage rack HF antennas. The '88s have them in the base of the vertical stabilizer. Quote Link to comment Share on other sites More sharing options...
RZHill Posted April 24, 2010 Share Posted April 24, 2010 From Deleware on up the Hf antenna is in the base of the vertical stab. RZ Quote Link to comment Share on other sites More sharing options...
tinyclark Posted April 24, 2010 Share Posted April 24, 2010 (edited) Aren't those H2-1/2's? I don't know, I never got to work on anything new... The flush mount was installed on 84s and up, except 87-00157, #5121, whatever that bastardized thing is. Edited April 24, 2010 by tinyclark Quote Link to comment Share on other sites More sharing options...
Dave in WV Posted April 24, 2010 Share Posted April 24, 2010 H-2 1/2 have a glass or semi glass cockpit. I never did get that straight. We couldn't fly on them as we couldn't H-3s. We had Jackson,MS H-2s ('79s IIRc) and then got new '88 H-2s. The newer H-2s we got had the newer seats, a flush toilet, HF antennas in the tail base, AC bus tie switch, laser ring gyro INS, and QD torq tube connects on the main gear (started with acft 88-1301). About every two years some things were different on the H-2s. The unit I was in has H-3s they got from Martinsbug,WV when they transitioned to C-5s. Quote Link to comment Share on other sites More sharing options...
Spectre623 Posted April 24, 2010 Share Posted April 24, 2010 We had 84-204 and 205 at Dobbins and they had all the trick stuff such as the flush toilet, no long lines HF, 2 big side escape hatches and dual INS and batteries from the factory. I worked at Lockheed when the first ship with all the mods came down final assy....what a nightmare. I installed the first large set of side hatches as per the prod. engs written instructions. They didn't work. He told me to figure out how to rig them and he would put that in writing. It took me a day or two but I finally got it. Go figure ha ha. I think all the big -2 mods mentioned above started on ship serial 5000 in 1983 or 84. Can you confirm that With your trick book Bob? We had 6 ,81-2"s and 2, 84-2's at the DARB, a real can of worms sometimes... I loved it...but I don't miss it ! Bill Quote Link to comment Share on other sites More sharing options...
CTII Raven Posted April 25, 2010 Share Posted April 25, 2010 How many H2.5's were built? I had a list once upon a time but I can't find it. I thought I remembered there were only 20. 12 originally at Louisville 91-1231 to 39 91-1651 to 53 8 at Mansfield 90-1791 to 1798 Maybe some at Youngstown? Thanks BobBob, 92-3021-3024 at Youngstown are 2.5s Quote Link to comment Share on other sites More sharing options...
larry myers Posted April 28, 2010 Share Posted April 28, 2010 Dan, you have one heck of a memory. I had a minor part in the delivery of the Dyess Hs. The command tried to get several subsystems improved or replaced. The only reason the acft. got -15 engines was there were no more -7 engines. Among other things, we wanted to replace the APN 59 the autopilot and move the top anti-collision lite to the backbone. ASD was the roadblock to the improvements sought. And in the middle of the run two acft. were diverted to the RCAF. Quote Link to comment Share on other sites More sharing options...
SEFEGeorge Posted April 28, 2010 Share Posted April 28, 2010 Dan, you have one heck of a memory. I had a minor part in the delivery of the Dyess Hs. The command tried to get several subsystems improved or replaced. The only reason the acft. got -15 engines was there were no more -7 engines. Among other things, we wanted to replace the APN 59 the autopilot and move the top anti-collision lite to the backbone. ASD was the roadblock to the improvements sought. And in the middle of the run two acft. were diverted to the RCAF. I was LRF starting in 1975 and we had the 73 Hs, basically pretty much E models with -15s; E model ACs, bleed system. The only other difference that I recall was the water removal system in the fuel tanks. I thought that the Dyess H models, 74s, were the 1st true H models, namely the ACs packs. It would appear that from the 73s on that the engines were all going to be -15s. Quote Link to comment Share on other sites More sharing options...
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