After more than 10 years research on the AQM-34, I realised that I had only the vaguest idea of what an actual mission looked like. Together with Craig Kaston I started looking into the available data, in order to produce some first estimates. I chose the AQM-34L (Model 147SC) and its missions as the first subject of the studies. 'Lightning Bugs and other reconnaissance drones' by William Wagner contained some snippets on missions, that are listed below. The performance data of the BQM-34A target drone was analysed and roughly recalculated for the heavier AQM-34. All in all it is a lot of guessing, but maybe this page triggers the memories of those involved, or better ideas how to approach the subject. See also the Blue Springs missions page.
|Guestimated flight track 1: U-Tapao take-off, via Thailand and Laos to South-Vietnam, crossing south of DMZ to South China Sea / Gulf of Tonkin. Holding pattern and launch off the coast of Haiphong, turning north for a short 150 nm low-level leg, then 350 nm climb-cruise. Flame-out before reaching Da Nang, MARS recovery|
|Guestimated flight track 2: Haiphong launch, turning south for a slightly longer 200 nm low-level leg, then 250 nm climb-cruise. Flame-out before reaching Da Nang, MARS recovery|
|Guestimated flight track 3: U-Tapao take-off, via Thailand and Laos to North Vietnam. Holding pattern and launch just outside North Vietnam, west of Hanoi. To Hanoi, then turning south for 200 nm low-level leg, then 250 nm climb-cruise. Flame-out before reaching Da Nang, MARS recovery|
no information, randomly picked waypoints
altitude 3000 ft
DC-130 speed unknown
500 knots assumed
Range estimates for different flight profiles:
lo-lo: 375 nm
lo-hi: 200 nm + 250 nm, 450 nm total
lo-hi: 150 nm + 350 nm, 500 nm total
hi-hi: 750 nm (source ?) (1160 nm is calculated below from BQM-34A 'Standard Aircraft Characteristics' (PDF) Mission A)
no idea of the actual number. Three or four assumed
possibly the tracks were more detailed
no idea of the actual number. Three or four assumed
random areas and lengths picked
55,000 ft flame-out guessed. Might be too high, service ceiling of the BQM-34A is 53,500 ft
glide ratio 8 (which might be optimistic)
15,000 ft chutes open
53 nm glide range calculated
p92: "At around 4:00 a.m. one programmer went up in smoke while it was being stepped through and checked. A malfunction caused the programmer to stop operation at pulse 70 or 80"
p108: "The basic principle is to deploy chutes at medium altitude - somewhere around 15,00 feet. The retrieval helicopter is some 3,000 feet lower."
p191: "Flying at 1000 to 1200 feet altitude in a very hostile atmosphere the drones were taking unacceptable losses. To counter the concentrated firepower, mission profiles were changed so that after launch at 3000 feet the S birds were flown down to 500 feet above enemy terrain at 500 knots."
p192: "A check of flight records for the recce drones during November operations reportedly shows 19 sorties flown, and all birds recovered. None appear to have been scheduled for flights as far north as Hanoi. Two missions on the 20th and 21st were cancelled because of weather. Whether or not they were scheduled to have been routed over Son Tay is not clear. On other occasions, however, the drones did bring back good photos of the downtown 'Hanoi Hilton.' "
p194: "The drones have been operating in areas that are normally denied to manned reconnaissance airplanes because of the high threat environment. Routes typically covered are Haiphong and Hanoi; in fact all of North Vietnam and even some flights over South Vietnam in areas that are now occupied by the North Vietnamese Army."
p194: "The drone flights are usually launched over the Gulf of Tonkin and occasionally from Northern Laos, but I'd say at least 90% are from the Gulf of Tonkin."
p194: "These low altitude Buffalo Hunter missions are usually flown between 500 and 800 feet. This is where the drone brings back the best technical intelligence. The SC doesn't have the added navigational capability that the SD does. It has to be updated by remote control on occasions to be sure that the targets are covered. But with the deployment of the SD sometime in June they will have a system that will be much more accurate; not only the basic nav system in the SD but there will be a Loran capability also that will provide accuracies up to ± 200-250 feet."
p195: "There have been many missions flown over Haiphong. I don't know if they were specifically to count the number of ships in the harbor or to survey bomb damage in the Haiphong area."
p195: "The low-level 147SCs, he reported, frequently went in far deeper northwest of Hanoi than ever before, requiring terminating the flights much farther north in the Gulf of Tonkin. On those occasions, the Air Force arranged to have the Navy pick up the birds; then the Air Force would pick up the birds; then the Air Force would immediately fly the intelligence 'take' back for processing and interpretation."
p195: "Also, the SCs were capable of being routed so as to obtain information on a number of targets, reducing the requirement for going after just a single target."
p195: "Monitoring shipping activities, or rather the lack of activity, in Haiphong Harbor was a special concern of the 100th Strategic Reconnaissance Wing's 'Buffalo Hunter' missions during May."
Craig Kaston reports:
As I minimally understand it, the early 1960-vintage patchboard programmer had about 40 commands including turns. Dual commands could be enabled by using a 'Y' jumper (two commands at the same pulse). There were no waypoints in the modern sense. It was all dead reckoning based on the mission planning, weather (winds aloft), plus distance flown and crosstrack correction generated by the Model 523 Doppler Radar Navigator. The 523 would issue one pulse to the programmer for every seven miles traveled. Egress commands could notionally look like:
pulse 27 scorer off (27 * 7 is about 189 nautical miles downrange in our hypothetical flight)
pulse 28 turn to 160 degrees
pulse 28 increase thrust
pulse 29 climb
pulse 35 straight and level
pulse 35 decrease thrust
pulse 50 MCGS to 'ON' (RPV can now receive external commands, is remotely controllable and is off the internal programmer) (50 * 7 is about 350 miles flown from launch point)
Crosstrack correction was probably fed directly to the flight control box. By the time you got into the 147SDL with the solid state computer and LORAN, things changed greatly for now you now had closed loop guidance with correction (to the limits of LORAN).
As a side note, in one photo made at the People's Air Force Museum & Air Defense Museum, Hanoi, the remains of a mechanical programmer can be seen.
max launch weight 3065 lbs
100 gallons in BQM-34A + 68 gallons in rear fuselage extension (Wagner p26), total 168 gallons
JP-4 density 750-802 kg/m3 or 6.5 lb/gallon
JP-5 density 788-845 kg/m3
max rating 1700 lbf static (30 min), SFC 1.10 (Jane's)
normal rating 1375 lbf static (30 min), SFC 1.085 (Jane's)
BQM-34A 'Standard Aircraft Characteristics' (PDF), analysis of 'Mission F' which is 610 knots at low level and hence most like that of the AQM-34L.
engine at max rating = mil rating: 1700 lbf static (30 min), SFC 1.10 (Jane's), fuel consumption 1870 lbs/hr or 288 gallons/hr or 4.80 gallons/min
engine at normal rating: 1375 lbf static (30 min), SFC 1.085 (Jane's), fuel consumption 1492 lbs/hr or 230 gallons/hr or 3.83 gallons/min
Mission F includes 4 minutes of mil power on the pylon (warm up and range free wait). 4 minutes consumes 19.2 gallons. 100-19.2 = 80.8 gallons left. Usable fuel could be even less?
Since the fuel left is 80.8 gallons, 0.281 hrs = 16.8 min running time at mil rating remains. Theoretically, for full fuel, 0.347 hours = 20.8 minutes
Two ranges are quoted for Mission F, 137 and 156 nm. The average is 147 nm, and this gives a flight time of 147/610 = 0.241 hours = 14.5 minutes. 2.3 minutes less than calculated above, unexplained
BQM-34A at 500 knots at low level
If speed is reduced from 610 to 500 knots, a drag reduction is expected in the order of (500/610)^2 = 0.67, ignoring Mach effects, which would make the reduction greater. If drag is 67%, required thrust is also 67%, and fuel consumption also 67% if constant SFC is assumed, therefore 1253 lbs/hr or 193 gallons/hr or 3.21 gallons/min
For full fuel, this would give 100/193 = 0.516 hr = 31.0 min, giving a range of 0.516 * 500 = 258 nm
AQM-34L at 500 knots at low level
If it is assume that the 147SC has 1.68 times the fuel, that it is topped off completely before launch, and assuming the BQM-34A drag model, the range becomes 1.68*258 = 433 nm. Since the AQM-34L is heavier thus will have extra induced drag, plus a bit more skin drag, so actual range is likely be below 400 nm. The 375 nm figure quoted above for a lo-lo mission seems reasonable.
AQM-34L at 500 knots at high level
If the BQM-34A range for 'Mission A' from the BQM-34A 'Standard Aircraft Characteristics' (PDF) is simply multiplied by 1.68 as above, and then reduced by a guesstimated 15% for the higher mass, 1160 nm is calculated.
The BQM-34A polar (including Mach effects) could be derived from data and graphs in the Standard Aircraft Characteristic sheet. The polar could then be modified for the AQM-34. A J69 thrust model is also required, including density and speed effects. See for example: 'Theory and Practice of Aircraft Performance' by Ajoy Kumar Kundu, Mark A. Price, David Riordan. Or seach on "polar high subsonic aircraft"