In the years after Yeager broke Mach 1 in the X-1, the plane and its growing band of pilots were frequent visitors to the front pages of newspapers and magazines around the world; Life, Time, and probably even Pony Weekly featured articles. This set the publics perception of the X-planes: they were fantastic machines made to break records and piloted by the bravest and best, a sentiment that is true, and a vital part of the story (as we’ll see), but only part of the story. The X-plane story generated a tremendous reputation, but their story is really about research.
When the X-1 was conceived it was sized to not only carry the pilot, the rocket and its fuel, it was sized to carry sensors, probes, telemetry and recording equipment.
Its goal wasn’t only to go supersonic, it was to understand how best to reach those speeds. The same can be said of many of the X-planes that followed.
Flights of the X-1 were planned in detail by the engineers and pilots. They had to be. Even firing only one of the rockets four chambers would used the entire fuel supply in 10 minutes. Firing 3 chambers would reduce that time to 4 minutes. Pilot Bob Champine, for example, logged 13 flights in the X-1, for a grand total of just 1.2 hours! So, testing was a very focused business.
Test flights were designed to explore the aircraft’s envelope. Typical points of interest were where vibration and turbulence occurred, where a wing would droop, or induce rocking. Especially interesting were points where the control surface’s effect was diminished (only around Mach 1 apparently).
One of the standard tests for a control system is the step input. In these tests the step input was typically joystick deflection, the stick is moved as rapidly as possible from the center to a fixed position. It sounds easy (even if no pilot would actually want to fly like that) but in reality the motion created by moving the stick jostles the pilot, making bringing the stick to the correct position (without overshoot etc) very difficult.
In a move typical of the down to earth (sorry) thinking of the X-plane teams, they created a series of different length chains. The pilot would attach one end of the chain to the cockpit wall and the other to the joystick. He would then perform the step input by shoving the stick over as far as it would go until the chain restrained it. Voila, one perfect step input of the correct size. The pilot would then replace the chain with a different size and repeat the process for a different step size. Bear in mind, this is akin to driving down the freeway and twisting the wheel violently just to see what happens.
Compared to the glory of “breaking the sound barrier” and setting altitude records, the bulk of the work done by the X-planes and their pilots was more routine stuff than right stuff, but their patience paid off with a greater understanding of how to design safer, improved handling, supersonic aircraft. And that’s what every fighter pilot wants, to fly faster and higher with the greatest degree of control. Why? Because to a fighter pilot being higher and faster means having the advantage over an enemy, and having the advantage means their round will hit it’s mark.
Such a reputation (and being able to follow through) does a lot to shape an adversary’s opinion. For example, it wasn’t heavily reported in the press, but when just two F-22’s were deployed to Osan, on the Korean peninsula, the North Korean dictator, Kim Jong-il, immediately went into a bunker for 8 days straight.
That’s a deterrent that helps keep the peace based on reputation, a reputation that can be traced straight back to the aircraft and pilots that graced the covers of those magazines in the 1940s.
What do you think about research into flight? Has enough been done? Should America use the money for something else? Or are there wonders out there waiting to be discovered and if we don’t look for them, someone else will?
Cheers!
(Images courtesy of NASA and Lockheed Martin)
Hi Nigel. Thanks for another nice article. I can’t see myself attempting the “chain” routine except perhaps while motionless on the tarmac.
In general I prefer rigorous and more costly up front testing and a better first production model.with less expensive operations and mistakes and fewer in service upgrades required.
Two pieces of military hardware stand as great examples for the value of rigorous pre-deployment testing.
The p-38 Lightning: Before the manufacture was done with basic tests the US Army decided to use the test model in a cross country race. The pilot won the race and crashed the Lightning. This outrageous behaviour delayed the development of the P-38 by many months and when the P-38 went to war It still lacked a solution for the
“compressability” issue encountered in high speed dives and had supercharger and air intake systems that required refinement. Those problems caused the loss of hundreds of extra lives in the form of fighter pilots and inadequately escoreted bomber pilots. All that for a damned race trophy and some Air Corps prestige.
If the P-38 had undergone the testing and early development that Lokheed had planned for the war in Europe might have ended several weeks sooner. Given the civilian casualties that were occuring every day in NAZI Germany what would ending the war a few weeks sooner have been worth in human lives and in cash?
The second example is the US Navy Torpedo during WW-2: To save money congress rejected budget requests for torpedo testing. When the US Navy took the MK XIV torpedo and the MK VI magnetic exploder to war they rarely worked. Submarine crews risked their lives to maeuver into shooting range of Japanese war ships and merchant ships. The torpedos failed to run at selected depth. The contact exploder guide rods were too narrow and collapsed on impact. The magnet exploders caused premature explosions or failed to detonmate the torpedo. the three problems were all easily detected and two of them esaily resolved once testing was conducted by Admiral Lockwood’s staff in Pearl Harbor but the submarine force had already spent over a year of combat with very defective torpedoes. The magnetic exploders were not quite resolved during the war.
A million tons or more of Japanese shipping escaped attacks during 1942 and early 1943 due to bad torpedoes. An unknown number of submarines were sunk when their torpedoes failed to explode against attacking destroyers. If those ships had been sunk the war in Japan might not have ended sooner but the costly battles of Okinawa and Iwo Jima might have been conducted sooner allowing for shorter bomber routes and fewer losses to the Air Corps. The Phillipines might also have been recaptured sooner and with fewer naval losses.
The costs of building enough test P-38s and testing torpedoes would have been inconsequential compared to the monumental costs of not adequately testing these and other important weapons.
Hi Holmes. Interesting stories about the Lightning and the torpedo, you might just find me quoting those back to you in a blog to come.
Testing is frequently the first thing to be cut in the development of expensive systems. The continual argument is – why pay for testing after paying so much for a development process that is supposed to minimize errors? But as any squaddie knows, shit happens. Both your examples are classics of that thinking and the consequences.
Cheers!
You guys knock me out. Great article, Nigel. Great comment, Holmes.