Given that many club members are interested in aircraft as well as radio and electronics, there may be interest in this book that describes the conception, design, and commissioning of the Oxcart aka SR71 Blackbird as a system.
The book describes what it is like to be a system engineer and test pilot on an ultra secret project. It talks about the challenges in designing and commissioning the airframe and propulsion, but then does on to describe the issues of getting the sideways looking radar to work with this optical correlator which required a wet film processing unit flying along in a near vacuum at over Mk3. The infra-red sensors (which only partially worked) required an onboard liquid helium system. A fascinating book well worth reading, which I found difficult to put down.
To give an insight into the book I include a short section to whet your appetite:
Mercury vapor lamps overhead cast harsh shadows on the ramp below, isolating individuals and pieces of equipment in the predawn chill. Little of this light reflects off of the dusky black fuselage and wings of an SR-71, Blackbird number 955, as she undergoes her final grooming for the day's flight. The smell of jet fuel floats in the still desert air and clings to our clothes.
Start-cart exhausts pop and grumble as the matched pair of V-8s in each cart warm up. The clink of exhaust flappers provides an irregular punctuation to the activities taking place below the wings where ground crew members wait for a signal to pour the power to the Buicks. Not just converted auto engines, these machines were Buick Wildcat engines fresh from the southern California shop of racing legend Mickey Thompson. Each cart's engine pair drives a single transmission which, in turn, through an hydraulically extended shaft, reaches up inside the Blackbird's massive J-58 engines and spins them to starting rpm.
Perched on a maintenance stand ten feet above the ground I sit cross-legged level with the aircrew's shoulders. Seated in the pilot's cockpit is Bill Skliar and in the Reconnaissance Systems Officer's (RSO) cockpit is Noel Warner. I see each crew member's lips move as they talk behind the sealed faceplates of their helmets. Their voices crackle through my headset. I speak to them and members of the ground crew through an intercom system where the microphones are strapped over our mouths to keep out the surrounding noise. It's not too hard to hear right now, but once the engines start, no conversation is possible without the intercom. Anticipation is strong as all of us work our way through the preflight preparations.
Open in my lap is the all-important checklist. Every single step and action needed to prepare, start, and launch this aircraft are written in this book. These pages also contain special instructions for engineering changes, changes which will be tested on this flight. Everyone on the intercom circuit, air crew, ground crew, including myself is going through the checklist item by item. I read, they respond. I am the flight test engineer for Number Six. Her tail number is 955, but we all call her by the production sequence number. Standing on the ground near the front of the aircraft is Earl, my crew chief, an Air Force tech sergeant. At just five feet nine inches, he was full of guts, determination, and ingenuity, an aircraft mechanical genius. We were both there when this elegant creature was born, and we have been her constant companions ever since. At 6 a.m. the desert is showing only the very first signs of morning light. I am still reading the checklist by overhead light. Earl and I have been here since 3 a.m. patting and smoothing the feathers on this bird. The ground support guys came in at four.
She is full of fuel, liquid oxygen is on board for the aircrew, and fifty gallons of liquid nitrogen for fuel tank explosion suppression is loaded. All the other fluids and parts are ready. The complex and picky cameras are filled with film and installed. Even the infrared system detector has cooled down nicely in its own supply of liquid helium. In each engine nacelle the TEB tanks have been filled with triethylene borate, a hypergolic chemical used to ignite the SK-1 fuel when the engines start. Just one shot for each engine is all it takes. TEB replaces the usual jet engine igniter plugs because the Blackbird's special fuel is much more difficult to light than standard JP-4.
Number Six left the hanger for her outside prelaunch parking space at 4:15 a.m.
The personal equipment technicians and aircrew got here by 4:30 a.m. Now we are working our way through the checklist to the engine start sequence.
Many aircraft maintenance and operations people treat the ground support troops like dirt, but not Earl and me, not in the Blackbird game. We do everything but send these guys flowers. How else could you get four master sergeants to roll out of bed and arrive at work by 4 a.m. when they could have sent us a couple of three stripers? How else could you get a start-cart and crew for each engine at this hour of the morning? Today is a big day for Earl and me, for Number Six, and for Bill and Noel, who are doing the flying. Today is the day we fly the route called Hester.
Hester is an awful name, and this flight route is equally terrible. Four hot legs of nearly eighteen hundred miles each, three refuelings, and about eight hours of flying time. This flight profile consumes everything the bird and crew have. They will return with roughly four thousand feet of exposed film of various widths, empty liquid nitrogen containers, the infrared detector's liquid helium almost gone, the tape recorders out of tape, and the crew exhausted. Because cruising above Mach 3 heats the airframe to very high temperatures, even the inside surface of the pilot's windscreen reaches 275°F. When Number Six parks after the last leg, parts of her will be too hot to touch. This mission was designed to simulate the toughest operational mission we could imagine. If Number Six makes the whole trip successfully today, she will get another red silhouette of a blackbird painted beneath the canopy rails, with a white H, for Hester, stenciled on the silhouette. Earl and I are hopeful, but the batting average for this mission profile is not very high.
Still seated on the maintenance stand, I turn to Bill in the front cockpit and ask, ";Ready for engine start?";
His helmet turns to face my way and nods affirmatively.
I look to Noel in the back seat. He nods and I hear, ";Ready for engine number one.";
Earl does a careful review of the people under the wing and the area behind the engines. ";Okay Major, we're ready down here.";
I start my chant. ";Let's crank number one. Pilot call ten percent. Ground confirm the TEB shot. Call when you see fire in the tailpipe. Pilot confirm rise in exhaust gas temperature.";
This is a great job! Where else could a scrawny kid from Texas sit beside the world's fastest aircraft and tell everybody what to do?
- Copyright ©1999, Sage Mesa Publications. All rights reserved.Stewart/G3YSX
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