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Discrepancies between DCS and AAF Manual 51-127-5


XAiracobraX

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I have a copy of the pilot training manual TECHNICAL ORDER NO. 1F-51D-1 (AAF MANUAL 51-127-5) for the P-51 Mustang dated 15 August 1945, I also have the equivalent for the p-47b/c/d/g TECHNICAL ORDER NO. 01-65BC-1 dated 20 January 1943. Trying to use the former for the P-51 in DCS has resulted in two specific discrepancies that I would like better understanding on.

 

First is use of war emergency power on page 14. Here it states "This throttle reserve is called war emergency power, and should be used only in extreme situations. If you use it for more than 5 minutes at a time you'll risk damaging vital parts of the engine. In training therefore, the throttle must never be moved beyond the gate stop. Whenever you do use war emergency power, be sure to note the length of time on Form 1A, and also report it to the crew chief or engineering officer so that record can be kept and the engine inspected before the airplane is flown again. The engine must be removed for a complete knock-down inspection after 5 hours." The way I understood that is you can use WEP for 5 min at a time, cumulative time must be tracked, with full engine inspection/rebuild at cumulative 5 hrs. Time between would have perhaps depended on when engine cooled down some. I have not been able to have even one 5 min WEP use without blowing the engine. Has anyone gotten WEP in DCS figured out? :helpsmilie:

 

Second is on page 40 regarding gun harmonization. Note, I am not an advocate for everyone having ability to adjust convergence by preference. During the war pilots didn't fly the same plane each mission, even flying different aircraft same day. The manual states on page 40, "The guns are adjustable on the ground, so they can be harmonized to different patterns for various tactical situations. Usually they are aligned to converge at a range of from 250 to 300 yards." In feet this is 750 ft to 900 ft. The P47 manual has similar but on page 41 of its manual lists "250 or 350 yards" and provides both in the convergence diagram on page 42. "Tactical situations" is mission specific but revolves on the simplest level between air superiority or close air support i.e. aircraft on air superiority mission may have a different convergence than those on CAS mission. My question is why is 1100 ft the convergence in DCS? Would it be possible to have two set harmonizations, one for air superiority and another for ground attack? If not would it be possible to change the 1100 ft down to something within the range listed in manual?


Edited by XAiracobraX

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About the WEP, check that thread if you have enough time to waste :D

https://forums.eagle.ru/showthread.php?t=247436

People have been discussing it numerous times in that one, and in multiple others as well.

 

About convergence, it's a bit of a dead horse too. Currently DCS supports one predefined setting and I've never read devs stating they would want to change it anytime soon. Custom convergence changing is a no-no for sure, but two sets to choose from? Who knows? They seem to be investing more time in WWII lately, so I guess we'll wait and see.

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I have a copy of the pilot training manual TECHNICAL ORDER NO. 1F-51D-1 (AAF MANUAL 51-127-5) for the P-51 Mustang dated 15 August 1945, I also have the equivalent for the p-47b/c/d/g TECHNICAL ORDER NO. 01-65BC-1 dated 20 January 1943. Trying to use the former for the P-51 in DCS has resulted in two specific discrepancies that I would like better understanding on.

 

First is use of war emergency power on page 14. Here it states "This throttle reserve is called war emergency power, and should be used only in extreme situations. If you use it for more than 5 minutes at a time you'll risk damaging vital parts of the engine. In training therefore, the throttle must never be moved beyond the gate stop. Whenever you do use war emergency power, be sure to note the length of time on Form 1A, and also report it to the crew chief or engineering officer so that record can be kept and the engine inspected before the airplane is flown again. The engine must be removed for a complete knock-down inspection after 5 hours." The way I understood that is you can use WEP for 5 min at a time, cumulative time must be tracked, with full engine inspection/rebuild at cumulative 5 hrs. Time between would have perhaps depended on when engine cooled down some. I have not been able to have even one 5 min WEP use without blowing the engine. Has anyone gotten WEP in DCS figured out? :helpsmilie:

 

Second is on page 40 regarding gun harmonization. Note, I am not an advocate for everyone having ability to adjust convergence by preference. During the war pilots didn't fly the same plane each mission, even flying different aircraft same day. The manual states on page 40, "The guns are adjustable on the ground, so they can be harmonized to different patterns for various tactical situations. Usually they are aligned to converge at a range of from 250 to 300 yards." In feet this is 750 ft to 900 ft. The P47 manual has similar but on page 41 of its manual lists "250 or 350 yards" and provides both in the convergence diagram on page 42. "Tactical situations" is mission specific but revolves on the simplest level between air superiority or close air support i.e. aircraft on air superiority mission may have a different convergence than those on CAS mission. My question is why is 1100 ft the convergence in DCS? Would it be possible to have two set harmonizations, one for air superiority and another for ground attack? If not would it be possible to change the 1100 ft down to something within the range listed in manual?

 

Regarding to WEP use, that issue was brought numerous times here on this forum.

Regarding gun settings i think we have standard set up which should looks like that

250-300 yards is for difrent gun sight

1200-1500ft converge this is setting for K-14 gun sight only

P9DzthF.jpg


Edited by grafspee

System specs: I7 14700KF, Gigabyte Z690 Aorus Elite, 64GB DDR4 3600MHz, Gigabyte RTX 4090,Win 11, 48" OLED LG TV + 42" LG LED monitor

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The report that picture is from is a North American Corporation publication, not a USAAF manual. AAF Regulation 50-17 called for using AAF Manuals of which manual 51-127-5 dated 15 Aug 1945 superseded those previous. I have found AAF manual 200-1 dated January 30 1945 which focused on gun harmonization of the USAAF fighters that has some at 1100 ft. But it specifically states:

"The harmonization patterns were compiled at the proving ground command to facilitate the conduct of service tests on aircraft weapons. ...The patterns for harmoniza-tion contained herein are indorsed by Army Air Forces but may be amended by each individual station in accordance with local conditions to obtain effective fire power. "

Just because they researched and used it to test service life for guns doesn't mean that was what they used in combat. Seems like AAF pilot manuals were what was provided to prepare pilots for combat. The Manual 51-127-5 I cited is later than both the NA report that picture was from as well as AAF manual 200-1, it covered the K14 gun sight so it was not for another gunsight. It would be nice if we knew what individual fighter groups used.


Edited by XAiracobraX

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You are right, I do concede that I don't actually have problems with convergence set in this game, at least in the sense that I can consistently take out both me109 in the instant dogfight over Normandy. Multiplayer is a different story. I guess I just need to be more flexible. I do still wish WEP and the automatic coolant / radiator were improved to be more reliable.

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I can say that WEP engine fial is not related to temps,

I overheated coolant in flight when i was dog fighting bf109 and then i burst good 20 minutes on WEP chased by 3 Doras (2 Ai and one player dora) and managed to land safely, but next time my engine went off much quicker even when i was super careful about temps that time heh.

Temp has nothing to do it with it or very little.

System specs: I7 14700KF, Gigabyte Z690 Aorus Elite, 64GB DDR4 3600MHz, Gigabyte RTX 4090,Win 11, 48" OLED LG TV + 42" LG LED monitor

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  • 3 weeks later...

The 5 min value is to cool down the aftercooler. It PROBABLY isn't modeled in DCS at all, or if so, isn't accurate. The RL aircraft doesn't report (or even measure) the aftercooler temp, which might be why ED doesn't model it.

 

Like Graf said, manifold and oil temps aren't going to inform you as to the timing of WEP. When I use it I leave it on and bounce between the low and high blower. That is a really good altitude to boom and zoom and I've never had an engine blow up doing that. Although I'm never using more than 60MP for more than a minute at a time, and I'm cooling it off with very high speeds and a MP of less than 50.

 

I don't think it was designed to go from FT 3000 RPM, to WEP 3000 RPM for 5 mins, and then back down to FT 3000RPM. But maybe it was, I don't know. I've always been in the habit of flying at max continuous and have never had a problem with WEP using how I want (which is probably "sparingly" by most people's standards).

 

And for all we know the damage after 5 mins could be to engine longevity rather than an actual failure.

 

ED said they're updating the engine heating and cooling dynamics so I'm going to wait until that drops before taking criticism too seriously.

 

As far as convergence, maybe I'm the only one, but wouldn't it be cool to be able to set up the Mustang with 4 MGs and extra ammo? What was that? "No."??? Are six guns REALLY better than four? REALLY?

 

Ya, they are. But if they're gonna mess with convergence it would be a cool feature IMO. Just not one that everyone else would be into.

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