Da `jednom za svagda` sto kazu resimo tu enigmu zvanu `smanjili potisak` ili `motori smanjenog potiska` bilo kod Svaba ,Poljaka ili nekih drugih i nebitno je li to bio 9-12A ili 9-12B itd ...
Kako ne bi ispalo da ovo dolazi iz moje glave prenecu komentar naseg kolege doslovce kako je napisano a bilo na temi ranije u komentarima i pojasnjenjima vezanim za `Borbenu upotrebu MiG-29`,`Proracun potrosnje goriva kod MiG-29` ,`Opis lovca MiG-29` itd ...
Citat:Сви мотори РД 33 имају режим повишене температуре или такозвани РПТ режим.
Када се укључи тај режим мотор има потисак већи за око 10%
Тај режим се укључује на земљи, прекидачем који се налази у десној гондоли основне ноге стајног трапа.
Дакле ако је нормална температура на максималу пред турбином око 1680 степени целзијуса, повећањем температуре (више горива у основној комори сагоревања) до 1700 степени целзијуса, добијамо већи потисак.Исти је масени проток ваздуха, но већи је степен ширења јер смо повећали температуру пред турбином.
Овај режим се укључује само кад се авион испраћа на борбену мисију.А после борбене мисије се тај решим искључује.
Па стога сви мотори РД 33 се користе у нормалном пројектованом режиму, нема смањења потиска. Већ само по потреби повећања, укључењем РПТ режима.
Dakle za onaj svima nama poznati potisak na Maksimalu od 50kN / nekih 5000kgs / u rezimu RPT imamo povecanje za 10% isto tako i za `Forsaz` ,od 83kN /8300kgs / i povecanje za 10% u ovom rezimu .E sad mi vidimo koliko je recimo brojcana vrednost forsaznog potiska( Puni Forsaz) pri ukljucenju RPT a da ponovim da je potisak na 1000m visine pri pocetnoj brzini penjanja od 330m/s vrednosti 11500kgs ( oko 110kN ).
Evo nam i slikovitog pojasnjenja ,tacnije jedan dijagram koji pokazuje upravo taj rezim RPT,pogledajmo gore u uglu... imamo radne rezime Maks-Maksimal ,F-Forsaz i onda PF -Polni/ puni/ Forsaz sa RPT ...
komentar
Citat:дијаграм по коме ради електронски регулатор рада мотора БПР 88 и то кад је укључен режим РПТ. Т4 је температура иза турбине и она износи кад је РПТ укључен 900 степени.
Не заборавите да врели гасови пролазе и шире се кроз две турбине (турбину ниског и турбину високог притиска). Друга величина је зауставна температура ваздуха пред вентилатором тј. компресором ниског притиска.
i jedan dokument( o RPT oznaceno crvenom bojom )
БЛОК ПРЕДЕЛЬНЫХ РЕГУЛЯТОРОВ БПР-88 СЕРИИ 4 ОПИСАНИЕ И РАБОТА
Znaci da ponovimo ...nema tu nikakvog smanjenja potiska ,cak sta vise on moze da se poveca za tih 10% u RPT ( na RUD to je onaj PF ) .Jos nesto da je sve ovo relativno govori i to da potisak nije konstantan da on npr. zavisi od spoljne temperature sto nam je opste poznato .Tako npr onaj `turisticki` da kazem UB Bort 005 u zimskom periodu se sa lakocom penje na 23 km visine dok u ovom periodu npr to je vec dosta teze izvodljivo ...Tako da i to moramo imati na umu ... Dakle ne uzimajmo onaj podatak o 83kN potiska na forsazu kao `zdravo za gotovo` jer time nije sve receno tj u praksi se desavaju drugacije stvari nego sto mi mozemo procitati na netu , u casopisima itd ..
Nadam se da je sad svima nama jasnije ovo i da su price o nekakvom smanjenju potiska kod RD-33 ustvari samo novinarske price ...
Mislim da je neko ovde pobrkao stvari.
Interesantno i nisam znao za ovo da u borbenom rezimu (znaci samo u borbenoj misiji) motor moze dobiti dodatnih 10% potiska.
Ipak ovde se govori o redovnoj eksploataciji i smanjenjom potisku motora (znaci neki radovi su uradjeni na motorima, dodatno) kako bi im se produzio resurs (znaci nevezano za ovo dodatno opterecenje motora namenjeno borbenim misijama)
Dosta detaljno (skoro do najsitnijih detalja) o Mig-u 29 i o RD-33 u Indisjkom RV u prvih par godina sluzbe...
Citat:The Indian Air Force (InAF) MiG-29 Experience:
The Comptroller and Auditor General of India published on 31March1993 the results of an in depth study on the operational performance and reliability of the MiG-29 aircraft. This study was first reported in Aviation Week & Space Technology during 25July1994 (pg.49), and has been obtained by author from Mr. Pushpindar Singh, of the Society of Aerospace Studies, New Delhi.
65 x MiG-29 single-seat and 5 x dual-seat trainers with 48 x spare engines (sparing factor of 0.7/aircraft) were delivered between 1986 and 1990 at a total program cost of approximately $600 million that included initial spares and support. These aircraft were the first MiG-29's to ever leave the Soviet Union and were not up to the weapons system standard of those that went later to the Warsaw Pact allies. The aircraft were sent disassembled by sea, and re-assembled, and test flown in India. By 1990 three squadrons were operational. Two Flight Data Ground Processing Units were included to help pilots debrief their utilization of flight controls and systems. Expectations were that single-seat aircraft would fly 15 hours per month (180 hrs/yr) and dual-seat aircraft 20 hours per month (240 hrs/yr).
There were extensive problems encountered in operational and maintenance due to the large number of pre-mature failures of engines, components, and systems. Of the total of 189 engines in service, 139 engines (74%) failed pre-maturely and had been withdraw from service by July 1992, thus effectively shutting down operations. 62 of these engines had not even accomplished 50% of their 300 hours first overhaul point. Thus the desired serviceability showed a steadily decreasing trend.
Engineering reports mainly attribute RD-33 failures to design/material deficiencies causing discolored engine oil ( , clefts in the nozzle guide vanes (31), and surprisingly, foreign object damage (FOD). The eight material deficient engines (discolored oil) were repaired by the contractor under warrantee provisions, but the engines had to be recycled to the manufacturer. The thirty-one engines with clefts in their nozzle guide vanes were fixed in the field by contractor teams and adjustments were made to the entire engine fleet. But even though the incidents reduced the occurrences of the clefts, they continued. But the FOD situation is the most interesting, especially after the inlet FOD doors received world press coverage, but there were other concerns about production quality control that led to problems.
Since the Indian Air Force received early model Fulcrum A's, some just after the 200th production article, there were quality control deficiencies that resulted in numerous pieces of FOD (foreign object damage) and tools being left behind after final construction inside of the aircraft. Remember that the Fulcrum skeleton is made first and then the skin is riveted over top, in the way aircraft were made in the fifties and sixties in the West. Nuts, bolts, tools, etc. all made their way to the engine bays and inlet ducts and when they were loosened up after accelerations they damaged engines and equipment.
On top of all this, it was discovered that the unique FOD doors on the MiG-29's inlets were not stopping material from getting into the engine ducts. Since the doors retracted "up" into the inlet, debris that was kicked up by the nose wheel lodged on or at the bottom of the door seal and then was ingested into the engine when the door opened during the nose gear lifted off the ground during takeoff.
This problem was known from the earliest days. After the first four MiG-29 prototypes were evaluated, the nose gear was moved further back, but nose wheel "mud-flaps" or guards were still required to protect the engine from flying debris. It took until 1988 before all delivered aircraft were so equipped, therefore the initial batch of InAF aircraft had to be locally retro-fitted with mud guards and that activity was not completed until June 1992. All costs were supposed to be re-imbursed by the contractor but Mikoyan reneged and left the InAF with $300,000 in liabilities. In subsequent MiG-29K/M models the FOD doors were replaced by screens that closed "down", forcing any debris out of the louvers repositioned to the lower side of the inlet duct..
The Indian Air Force procurement contract was concluded in September 1986, and the first engine was expected to go into overhaul in 1989. However, four engines prematurely came up for overhaul and no repair facility had been prepared. As time went on, 115 of the 122 engines (94%) prematurely failed and had to be re-cycled through engine depots in Russia at great cost. Backlogs were created and only 79 (65%) engines returned on schedule. Even when a regional Indian repair facility was completed in August 1994, the high failure rates continued and the majority of broken engines had to be sent back to Russian depots. Self-sufficiency was achieved in 1994, only after the operations tempo was significantly reduced on a permanent basis. In the process of refurbishing failed engines, the total technical life of most of the engine fleet was effectively reduced from 800 hours / 8 years to 400 hours / 4 years, at a minimum.
Non-availability of radar and weapon system components also resulted in the grounding of seven aircraft for a period of six to twenty months. Two may have been damaged for life due to cannibalization. Besides this, a large number of subsystems and computers experienced unpredicted failures in the last four years which adversely effected the operational readiness of the squadrons. Some of the computers were field-repaired by specialists from the manufacturers, others were replaced. These repair costs were all in excess to the initial contract costs. It was noted that the 10 additional computers, which were imported, cost the InAF around $806,000. Two Flight Data Ground Processing Units quickly became unserviceable during their warranty period and have been lying un-utilized and un-repaired for over two years.
The InAF Headquarters also noted in March 1991 report that a severe shortage of product support equipment had resulted in the decline of fleet availability by 15-20%, which in turn, took negative effect on operational readiness and mission requirements.
So in general, lessons learned from this first out-of-country operation of a Russian front line fighter were:
1. The MiG-29 had intensive problems in operation and maintenance since its induction due to premature failure of engines, components, and systems. 74% of the engines failed within five years, were out of supply pipeline for three years, and reduced aircraft availability by 15, to 20%. This led to a decision to restrict flying efforts and therefore compromised operational and training commitments.
2. There were significant shortfalls in the performance of the MiG-29 fleet resulting in operational and training inadequacies. The shortfall ranged from 20 to 65% in respect to combat aircraft availability and 58 to 84% in trainers between 1987 - 1991.
3. There was a mismatch between induction of the aircraft (1987) and the establishment of its repair facilities (end of 1994). Until that time engines had to be continually sent to manufacturers abroad at great monetary cost, reduction of one-half total life, and a significant stretch of schedule.
4. Non-availability of critical radar components and spares resulted in the grounding of significant numbers of aircraft. Five aircraft were out of action for over six months while two were in the hanger for over two years. Unserviceability of computers and the inability to fix them cost excessive amounts of money to rectify.
5. The pilot debrief Ground Data Processing Unit, imported at high cost, was left lying around unserviceable and unused since its reception in August 1990.
6. The lack of nose wheel mud guards had to be solved by importing upgrade kits and expensive local re-design after material deficiencies could not be overcome.
With a regional support capability in place (regardless of how tenuous it was) and having one of the few respectable MiG-29 operating legacies, the Indian aerospace companies, especially Hindistan Aeronautical Ltd. (HAL), and the InAF became natural partners for MAPO in consummating the sale of MiG-29's to Malaysia. They were offered the opportunity to get involved with providing training and logistics support for the new Malaysian MiG-29 program. India, of course, gives greater credibility to MAPO in convincing customers that the MiG-29 is a viable fighter candidate for Pacific Rim nations. It remains to be seen, however, what solutions the new joint venture brings to the Indian Air Force problems.
Mercury ::Mislim da je neko ovde pobrkao stvari.
Interesantno i nisam znao za ovo da u borbenom rezimu (znaci samo u borbenoj misiji) motor moze dobiti dodatnih 10% potiska.
Ipak ovde se govori o redovnoj eksploataciji i smanjenjom potisku motora (znaci neki radovi su uradjeni na motorima, dodatno) kako bi im se produzio resurs (znaci nevezano za ovo dodatno opterecenje motora namenjeno borbenim misijama)
Mozda je moguce taj rezim ( RPT ) iskoristiti i na aeromitinzima ,tj letnim pikazima pred javnoscu ili samo za neke VIP recimo ???
To za smanjenje potiska pa kako to izvesti u praksi ? Sta Svabama prodali motore koji na forsazu ne postizu 83kN ( 8300kgs ) potiska ??? Ili jos veci na Punom forsazu tj u RPT ??? ,Kako se postiglo to ... smanjenjem radne temperature u turbini,dotoka vazduha ... ,mislim da su to bile samo price .Isto kao i ona prica od Svaba kako su im Ruje uklonile data- link sistem `Laslo` i ostalo iz aviona 9-12A a toga i nije bilo u njima ...Uredjaj za identifikaciju su svakako imali
Citat:
"I should stress that I’m talking about our Luftwaffe MiG-29s, which are early aircraft. They also removed the Laszlo data link and the SRO IFF before the aircraft were handed over to us, so in some respects we’re less capable than other contemporary MiG-29s.
9-12A je imao N019EA ,9-12B N019EB i to je poznato ,ostale uredjaje, taj `Laslo` ,zatim instalacije i SUV koji podrzava upotrebu one `mini- atomke` RN-40 su imali samo 9-12/9-13.
Da se malo prisetimo gradiva ... pitanje ,sta se od opreme nalazi na onoj `dvokolici` pored aviona
Citat:MiG-29 at Preschen (East Germany) in 1990
Sto se Indusa tice treba znati da su oni dobili prve uopste izvozne ( 9-12B ) ,dakle i motore iz prvih serija za izvoz .Ovome treba dodati specificne klimatske uslove indijskog podkontinenta ,mozda i neodgovornost sa obe strane po pitanju VTS itd ...
Kako takvih problema nije bilo u Evropi ( 9-12A i 9-12B ) ? Valjalo bi naci podatke ,mada je to tesko kakvo je stanje bilo kod Iracana i Sirijica recimo koji su od 1986/87 dobijali 9-12B pa da se to poredi ( podrucja sa izuzetno visokim spoljnim temperaturama u kojima potisak motora bas i ne dolazi do izrazaja ,stanje VTS itd ...sve to treba imati u vidu ...)
Ray volim ja MiG-29, nemoj imati sumnje u to, ali ako se u ovom izvestaju kaze (samo cu o motorima, a gde su drugi sklopovi koji su zadavali probleme):
- kod 8 motora se desila pojava da se usled materijalne greske na motoru, ulje zamutilo tj. menjalo boju
(i Rusi su morali te motore potpuno da prerade i vrate Indijcima posto su jos bili u garanciji)...
- u 31 slucaju se desila naprslina na mlaznicam kod lopatica (dakle ne na jednom ili 2 pa da kazemo slucajnost).Uostalom pise da su se cak i nakon ruskih modifikacija na tim motorima sa pukotinama, iste nastavile pojavljivati (verovatno u manjem obimu)....
-da ona vratanca nisu uopste (ili bar ne dovoljno efikasno) sprecavala uvlacenje tj. usisavanje stranih tela (o cemu su i Rusi bili svesni) itd....
E sada tesko ce me neko ubediti da su za tolike naprsline i defekte krivi mehanicari (uostalom imali su Indusi i ruske kolege kao ispomoc u garantnom roku)...
Ako je do klime, kako ti klimatski uslovi nisu pravili probleme nekim ranijim verzijama Migova u Indiji ili Mirazima, Jaguaru isl???Ako je to tacno, onda otpada fama o tome, kako je MiG-29 vrlo pouzdan i lak za upotrebu u svim vremenskim uslovima.Tesko.Pre ce biti da je Rusima trebao izgovor da pokriju te probleme koje su Indusi imali tih godina....
Kod Indijaca bar pare nisu bile problem, a tada im je to bio najmocniji lovacki avion, i kao takav u centru paznje, sto se tice odrzavanja (verujem da su za njega birani najbolji piloti, mehanicari) isl...
Tvoje pitanje kako ostali nisu imali toliko problema je logicno a po meni logicni odgovori su:
-Niko u Evropi niju ikupio ni blizu toliko aviona kao Indija
-Niko od saveznika (pa ni Istocni Nemci do ujedinjena) nije leteo toliko 29-ku kao Indijci (mislim na prosecan godisnji nalet)....
-Iako su ostali imali probleme, nisu o tome pricali (sto je bilo standardna praksa za vreme Varsavskog ugovora)
Cesi tj. Cehoslovaci su prekinuli sa Rusima garantni rok 1990. godine tj. poslali ruske mehanicare kuci godinu dana pre isteka ugovora, malo zbog para (stednje) ali malo i zbog toga sto su oni (Rusi) kada bi trebali nesto da poprave u garantnom roku otezali do zla boga (na deo iz Rusije bi se cekalo po par meseci)....
U redu recimo da i jeste bilo tih nekih fabrickih gresaka na RD-33 koje su posebno dolazile do izrazaja kod indijskih 9-12B ( dakle izvozne serije ) ,nediscipline i tokom fabricke izrade tako i u VTS pa su rezultati bili takvi kakvi su bili .A to o vratancima uvodnika vazduha ( Panel-Klin ) zar moze nesto da prodje kroz ovo ? Kroz vrata sigurno ne cak i kroz ove perforirane `mrezaste` otvore ...
Mislim da su to rekoh samo price kao i one o nekakvom smanjenju potiska za 10% ili 20% itd ..Ako bi tako bilo pa kako su onda 29-ke ( one u Luftwaffe ) mogle sa lakocom da izmanevrisu F-16 i F/A-18 u BVB cak i M-2000 koji je a malo je to poznato najbolje se pokazale protiv 29ki u sim. BVB .
Sigurno da su u tim uslovima upotrebljavali onaj RPT tj dodatni /puni forsazni rezim rada ( kao borbeni u tom slucaju ) pa su postizali onu ugaonu brzinu od 28°/s ustaljenog zaokreta sto je bilo nedostizno za nabrojane rivale ..Takodje i vertikalnu brzinu tj penjanje u kojem mu nije bilo premca pa se cesto desavalo da F-16 ili F/A-18 jednostavno odustanu od `trke u vertikali` ,padnu u kovit ili slicno ...
Dakle bilo je tu gresaka nema sta, zato bi bilo dobro doci do nekih pouzdanih podataka o njegovoj upotrebi u sirijskim i irackim VS-ma krajem 80-tih i pocetkom 90-tih posto su oni odmah nakon Indije dobijali te 9-12B ,naravno i mi od dec. 87me ..
To o Siriji i Iraku ces tesko iskopati
Sadamovi, sto su leteli do "Pustinjske oluje" leteli, posle toga pomalo, a 1995. garazirani
Inace kod tih vratanca problem je (koliko sam ja razumeo) bio sto bi nesto uletelo (bilo ubaceno pomocu prednjeg tocka ST) pre nego sto bi se ona zatvorila, kvaka je bila da su se vrata zatvarala "na gore" sto je omugavalo, da se nesto zadrzi na samom ulazu i kasnije prilikom otvaranja-zatvaranja bude usisano....Na novim verzijama poput K/KUB isl. se vratanca zatvaraju "na dole"...
Rusi su taj problem resili do 1988. godine uvodjenjem blatobrana na prednjem tocku stajnog trapa, a u Indiji su svi avioni takodje modifikovani tj. dobili taj deo na predjem tocku, ali je to dosta dugo trajalo (poslednji je zavrsen tek 1992.)
U pravu si ,tesko ce se doci do tih informacija ... a za ostale podatke vezane za indijske i ove u Luftwaffe ajmo sad da se uozbiljimo ,ispada kao da nista nismo naucili nakon skoro 1900 str
Pazimo ovaj komentar
Citat:Since the Indian Air Force received early model Fulcrum A's, some just after the 200th production article, there were quality control deficiencies that resulted in numerous pieces of FOD (foreign object damage) and tools being left behind after final construction inside of the aircraft. Remember that the Fulcrum skeleton is made first and then the skin is riveted over top, in the way aircraft were made in the fifties and sixties in the West. Nuts, bolts, tools, etc. all made their way to the engine bays and inlet ducts and when they were loosened up after accelerations they damaged engines and equipment.
On top of all this, it was discovered that the unique FOD doors on the MiG-29's inlets were not stopping material from getting into the engine ducts. Since the doors retracted "up" into the inlet, debris that was kicked up by the nose wheel lodged on or at the bottom of the door seal and then was ingested into the engine when the door opened during the nose gear lifted off the ground during takeoff.
Na ovoj slici se vidi da tockovi prednje noge ST zaista nisu imali onaj blatobran koji je stavljen kasnije ,moguce nakon jednog ili dva incidenta ,pa nisu valjda dozvolili da im se svako malo desava upad raznih objekata u uvodnik na PSS ???
Drugo, kako to moze da se desi prilikom pokretanja motora kad se to radi na stajanci i po pokretanju se odmah spustaju vrata uvodnika vazduha ..nema sansi .. takodje prilikom rulanja i onda u zaletu na PPS se podizu kad se dostigne 200km/h i odmah potom sledi odvajanje od PSS tj poletanje ,jedino tad da nesto uleti u uvodnik sa PSS sto je jako mala verovatnoca mada ne i nemoguce ...
Vrata kod 9-12B se spustaju na dole i deo su sklopa zvanog `Klin-Panel` ( ima na prednjoj instrument tabli jedan pokazivac sa nazivom KLIN ) .Novi K/KUB uopste nemaju ta vrata vec posebnu titanijumsku resetku kao kod Su-27 .Vidi se na ovoj slici tj slikovitom prikazu ,resetka koja se podize u radni polozaj, uvodnik ima na donjoj ivici onaj spusajuci panel (klapnu ) a vrata vise nema ,ostao je Klin zbog regulisanja kompresije vazdusne struje u uvodniku ...
Meni su ovakvi komentari vise neke price ,dezinformacije ili slicno ..Svabe su pominjale kako im NSC `Schelj-3UM` ima ugaono ogranicenje zahvata svega 45°,kako kad je kod nasih 9-12B to ogranicenje bilo 60° sto se jasno da procitati u VTUP
Kako kod 9-12B je to 60° a kod 9-12A je svega 45° ,ne ide zar ne ? Pa to smanjivanje potiska i ostalo ...nista od toga nema u praksi ,rekla -kazala cini mi se ..
Poljski na probnom stolu ,kako vibrira u jednom momentu soplo na forsazu ,mozemo to da uocimo na ...
Nisam bio tamo pa da znam kako su im se desavla ta uletanja u uvodnike, ali ako su resili da odrade tu modifikaciju (blatobran na prednjem tocku) sa Rusima, sigurno da je bilo nekih problema...
Ovo za Schelj-3UM nisam cuo do sada...
Cak i da je "samo" 45 stepeni i dalje je bolje od onoga sto je imala konkurencija u to vreme (oko toga nema spora)!
Da se nasalim malo ,mora da su Indusi imali farme peradi pored stajanki i PSS ... ,sad salu na stranu ..bio je neki problem moguce ..E sad jel se to dovodi u vezu sa ugradnjom onog blatobrana posto koliko vidim na slikama njih nije bilo na avionima iz prvih serija ( od 1983 AB Kubinka pa dalje ) .To su oni sto su imali one uzduzne stabilizatore ispod vertikalaca ..To se sigurno radilo kasnije ...Da taj `Schelj-3UM` je bila jako opasna stvarcica cak i da je bilo ogranicenje 45°..
Pored svih ovih tehnickih aspekata ,problema i svega drugog meni je recimo interesantan podatak a koji se tice obuke tj preobuke u IAF kod 29 ki
Citat:65 x MiG-29 single-seat and 5 x dual-seat trainers were delivered between 1986 and 1990
Na 70 aviona ukupno imali su samo ali samo 5 `sparki` sto je po meni jako malo ( Madjari su sredinom 90-tih dobili 28 aviona od cega je cak 6 bilo UB ).Mi smo na 16 aviona ukupno imali 2 sparke sto bi moglo znaciti da bi na 32 aviona imali 4 9-51B/ UB,Svabe na 24 ukupno su imali 4 UB itd ...
, clefts in the nozzle guide vanes (31), and surprisingly, foreign object damage (FOD). The eight material deficient engines (discolored oil) were repaired by the contractor under warrantee provisions, but the engines had to be recycled to the manufacturer. The thirty-one engines with clefts in their nozzle guide vanes were fixed in the field by contractor teams and adjustments were made to the entire engine fleet. But even though the incidents reduced the occurrences of the clefts, they continued. But the FOD situation is the most interesting, especially after the inlet FOD doors received world press coverage, but there were other concerns about production quality control that led to problems.
,sad salu na stranu ..bio je neki problem moguce ..E sad jel se to dovodi u vezu sa ugradnjom onog blatobrana posto koliko vidim na slikama njih nije bilo na avionima iz prvih serija ( od 1983 AB Kubinka pa dalje ) .To su oni sto su imali one uzduzne stabilizatore ispod vertikalaca ..To se sigurno radilo kasnije ...Da taj `Schelj-3UM` je bila jako opasna stvarcica cak i da je bilo ogranicenje 45°..
